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Gasification of sawdust in a fluidized bed Shake, Fon-Yun 1982

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GASIFICATION OF SAWDUST IN A FLUIDIZED BED by FON-YUN ^ H A K E B . E . ( H o n s . ) U n i v e r s i t y o f C a n t e r b u r y , N . Z . 1979 A THESIS SUBMITTED IN PARTIAL FULLFILMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF APPLIED SCIENCE in / THE FACULTY/OF GRADUATE STUDIES Depar tmen t o f C h e m i c a l E n g i n e e r i n g We a c c e p t t h i s t h e s i s as c o n f o r m i n g to the r e q u i r e d s t a n d a r d THE UNIVERSITY OF BRIT ISH COLUMBIA F e b r u a r y , 1982 ( C ) Fon -Yun Shake In p r e s e n t i n g t h i s t h e s i s i n p a r t i a l f u l f i l m e n t o f the requirements f o r an advanced degree a t the U n i v e r s i t y of B r i t i s h Columbia, I agree t h a t the L i b r a r y s h a l l make i t f r e e l y a v a i l a b l e f o r r e f e r e n c e and study. I f u r t h e r agree t h a t p e r m i s s i o n f o r e x t e n s i v e copying of t h i s t h e s i s f o r s c h o l a r l y purposes may be granted by the head of my department or by h i s or her r e p r e s e n t a t i v e s . I t i s understood t h a t copying or p u b l i c a t i o n o f t h i s t h e s i s f o r f i n a n c i a l g a i n s h a l l not be allowed without my w r i t t e n p e r m i s s i o n . Department of C / ^ / < ^ £ / > f f v ^ A c j The U n i v e r s i t y of B r i t i s h Columbia 2075 Wesbrook P l a c e Vancouver, Canada V6T 1W5 Date n F - f i (2/79) i i ABSTRACT Hemlock sawdust with an average s i z e of 0.67 mm and moisture content 5% was g a s i f i e d in a 7.6 cm diameter f l u i d i z e d bed with four d i f f e r e n t f l u i d i z i n g media, namely, n i t r o g e n , carbon d i o x i d e , a i r and a mixture of steam and n i t rogen . The s t a t i c bed height was 20 cm and the bed mater ia l was 0.55mm diameter Ottawa sand. The bed was operated at 1 - 1.5 times the minimum f l u i d i z a t i o n v e l o c i t y . The major ob jec t ive of the present study was to examine the q u a l i t y of the gas produced with the d i f f e r e n t g a s i f y i n g media as a funct ion of the reactor temperature. Due to the d i f f i c u l t y in c o n t r o l l i n g the s o l i d f eedra te , i t was not p o s s i b l e to maintain the gas /dry s o l i d r a t i o (w/w) constant fo r runs using a p a r t i c u l a r f l u i d i z i n g medium. The dry s o l i d feedrate var ied from 0.03 to 0.24 g / s , and f o r most runs , i t was in the v i c i n i t y of 0.1 g / s . Both production rate and q u a l i t y of the gas genera l ly increased with temperature and were very s e n s i t i v e to the type of f l u i d i z i n g medium used. For ni t rogen p y r o l y s i s , the net gas heating value increases from 3 11.7 to 13.7 MJ/std.m when the temperature i s increased from 410 to 690°C. Add i t ion of steam to ni trogen produced gases of heating values 3 6.5 to 14.6 MJ/std.m on a ni trogen f ree b a s i s , as temperature increased from 420 to 600°C. Carbon d iox ide p y r o l y s i s produces a gas with heating value-3 .68-12.78 M J / s t d . m 3 between the temperature range 4 2 0 - 5 1 7 ° C . In cont ras t to the above systems, only low-Btu gas i s produced with a i r g a s i f i c a t i o n between 440 and 670°C . The c a l o r i f i c value of o 3 the raw gas produced at 670°C i s 1.35 MJ/std.m . TABLE OF CONTENTS PAGE ABSTRACT • ^ ACKNOWLEDGEMENTS ^ I. INTRODUCTION ( 1 ) General (2) Background ( i ) S o l i d Wastes as Energy Sources 2 ( i i ) A v a i l a b i l i t y o f Wood Wastes in B r i t i s h Columbia 4 ( i i i ) D i rec t Combustion versus G a s i f i c a t i o n 7 ( iv ) Fixed Bed versus F ludized Bed Operation 9 (3) G a s i f i c a t i o n Theory 1 3 II. SUMMARY OF PREVIOUS WORK 2 0 I I I . OBJECTIVES OF PRESENT STUDY 2 7 IV. APPARATUS 2 8 V. EXPERIMENTAL METHODS 3 9 ( 1 ) Experimental Procedure ^0 (2) Experiments Carr ied Out 4 * (3) Sand Preparat ion • ^ t A\ 45 (4) Sawdust Preparat ion and Ana lys is (5) Sawdust Feedrate 4 7 (6) F l u i d Flow Measurements 4 7 (7) Temperature Measurements 4 8 (8) S o l i d E l u t r i a t i o n Rate 4 8 (9) Bed S o l i d Ana lys is 4 9 ( 1 0 ) Tar Ana lys is 4 9 i v V / c o n t ' d PAGE (11) Gas Analys is 50 (12) Gas C a l o r i f i c Value 50 VI . RESULTS AND DISCUSSION - 51 (1) General 51 (2) P y r o l y s i s in Nitrogen 54 (3) G a s i f i c a t i o n with Steam-Nitrogen Mixture 66 (4) P y r o l y s i s in Carbon Dioxide 72 (5) G a s i f i c a t i o n with A i r 76 (6) Comparison of Results with D i f f e r e n t F l u i d i z i n g Media 83 (7) Mass Balances 93 ( i ) Overal l Mass Balance 93 ( i i ) Component Balances 98 (a) Hydrogen Balance 98 (b) Oxygen Balance 101 (c) Water Balance '. 103 (d) Nitrogen Balance 105 (e) Carbon Balance 106 (f) Ash Balance 108 (8) Energy Balance 109 (9) Thermal E f f i c i e n c i e s 113 VII . CONCLUSIONS AND RECOMMENDATIONS 115 VI I I . REFERENCES H 8 IX. APPENDICES !23 (1) Appendix 1: Mechanical De ta i l s 123 (2) Appendix 2: Rotameter C a l i b r a t i o n s I 2 8 (3) Appendix 3: O r i f i c e Plate C a l i b r a t i o n I 4 4 IX /cont 'd PAGE (4) Appendix 4: Minimum F l u i d i z a t i o n V e l o c i t y Measure-m e n t s . . . 150 (5) Appendix 5: Typica l Gas A n a l y s i s 159 (6) Appendix 6: G a s i f i c a t i o n Results 161 (7) Appendix 7: L i t e r a t u r e Review 176 (8) Appendix 8: Mass Balances 206 (9) Appendix 9: Energy Balance 218 (10) Appendix 10: Computer Program and Pr intout 233 vi LIST OF TABLES PAGE TABLE I - l Gasification Reactions 15 TABLE 11 -1 Pyrolysis of Wood in Nitrogen 23 TABLE 11-2 Gasification of Wood with Air in a Fluidized Bed . . 24 TABLE 11-3 Gasification of Wood with Air in a Fixed Bed 25 TABLE 11-4 Gasification of Wood with Steam or Steam-Air Mixture 26 TABLE IV-1 Particulars of Major Equipment 34 TABLE V-l Operating Conditions 42 TABLE V-2 Minimum Gas Required for Fluidization 44 TABLE VI-1 Experimental Results from All Runs 52 TABLE IV-2 Characteristics of Net Gas Produced for All Runs . . 53 TABLE VI-3 Experiments Performed in N,, Atmosphere 60 TABLE VI-4 Experiments Performed with Steam-N^ 69 TABLE VI-5 Experiments Performed in CO,, Atmosphere 74 TABLE VI-6 Experiments Performed with Air 79 TABLE VI-7 Summary of Mass and Energy Balances 96 TABLE VI-8 Overall Mass Balance 97 TABLE VI-9 Hydrogen and Oxygen Balances 100 TABLE VI-10 Water & Oxygen & Overall Mass Balance after Hydrogen is Balanced 102 TABLE VI-11 Nitrogen and Water Balances 103 TABLE VI-12 Carbon and Ash Balances 107 TABLE VI-13 Energy Balance 112 TABLE VI-14 Thermal Efficiencies 114 v i i LIST OF FIGURES PAGE FIGURE 1-1 FIGURE IV-1 FIGURE IV -2 FIGURE IV-3 FIGURE IV-4 FIGURE VI-1 FIGURE VI-2 FIGURE VI-3 FIGURE VI-4 FIGURE VI-5 FIGURE VI-6 FIGURE' VI-7 FIGURE VI-8 FIGURE VI-9 FIGURE V I - 1 0 FIGURE VI-11 Schematic of a Countercurreht G a s i f i e r Showing the Zones of Operations and Var ia t ion of Gases and S o l i d temperatures ( C o u s i n s ^ ) Schematic Arrangement of Experimental Equipment for Sawdust G a s i f i c a t i o n 35 Sawdust Feeding System 36 Grid Plate Assembly 37 Arrangement of Thermocouples on the Reactor 38 Gas Produced (Net Gas) vs Temperature for P y r o l y s i s in N^ 61 Comparison o f Y ie ld of Residue for P y r o l y s i s in N 2 62 Gas Composition (Net Gas) v s . Bed Temperature for P y r o l y s i s in N£ 63 Major Gases from P y r o l y s i s of Wood (Br ink , M a s s o u d i ) 1 2 64 Comparison of Gas Composition (Net Gas) fo r P y r o l y s i s in 65 Gas Composition (Net Gas) v s . Bed Temperature for G a s i f i c a t i o n with S t e a m ^ 70 Comparison of Gas Produced ( C H 4 , C 0 , H 2 ) fo r G a s i f i c a t i o n with Steam or Steam-Air 71 Gas Composition (Net Gas) v s . Bed Temperature for P y r o l y s i s in CO2 75 Gas Composition (Net Gas) v s . Bed Temperature fo r G a s i f i c a t i o n with A i r 80 Comparison of Gas Composition (Net Gas) fo r G a s i f i c a t i o n with A i r 81 Comparison o f Gas Composition (Raw Gas) for G a s i f i c a t i o n with A i r 82 vi i i PAGE FIGURE VI-12 Net Gas Produced v s . Bed Temperature 85 FIGURE VI-13 Gas (Net Gas) Heating Value v s . Bed Temperature . . 86 FIGURE VI-14 H 2 and CH^ Production v s . Bed Temperature 87 FIGURE 'VI-.15 CO Production v s . Bed Temperature 88 FIGURE VI-16 C0 2 Production v s . Bed Temperature 89 FIGURE VI-17 H 2 and CH^ Content in Net Gas v s . Bed Temperature . go FIGURE VI-18 CO Content in Net Gas v s . Bed Temperature 91 FIGURE VI-19 C0 9 Content in Net Gas v s . Bed Temperature 92 ix ACKNOWLEDGEMENTS The author wishes to acknowledge Dr. A . P . Watkinson, the pro jec t s u p e r v i s o r , f o r h is inva luable advice o f fered throughout the course of t h i s p r o j e c t . Contr ibut ion from the s t a f f members of the Chemical Engineering store and workshop in the const ruc t ion of the experimental apparatus i s a lso acknowledged. Thanks to G. Cheng, research a s s i s t a n t , a lso f o r h is ass is tance in the gas a n a l y s i s . L a s t l y , to Mrs. C. Lee fo r her pat ient and capable serv ice in typing t h i s manuscript . I. INTRODUCTION (1 ) GENERAL The impending shortage of conventional f o s s i l f u e l s and the unre-l i a b i l i t y of t h e i r continuous supply coupled with a rapid r i s e in p r ices has resu l ted in a world-wide search fo r a l t e r n a t i v e fuel sources. U t i l i z a t i o n of wastes such as municipal s o l i d wastes, a g r i c u l t u r a l and animal wastes, f o r e s t product residues and processing wastes represent a s i g n i f i c a n t potent ia l in cont r ibu t ing toward independence from expensive f o s s i l fue l energy. Due to a wider range of potent ia l a p p l i c a t i o n s , production of a fuel gas by g a s i f i c a t i o n i s a more a t t r a c t i v e method of u t i l i z a t i o n wood wastes than d i r e c t combustion. Various g a s i f y i n g media such as a i r , a i r -s team mixture , oxygen-steam mixture or pure oxygen may be used; depending on the type of resu l tan t fuel gas that i s d e s i r e d . G a s i f i c a t i o n may be c a r r i e d out in a v a r i e t y of reactors inc lud ing f ixed bed, entrained or f l u i d i z e d bed r e a c t o r s . Various contact ing schemes of upflow and downflow, co -cur rent and countercurrent operat ion are p o s s i b l e . Whereas coal g a s i f i c a t i o n i s an es tab l ished i n d u s t r i a l p rocess , g a s i f i c a t i o n of s o l i d wastes from the f o r e s t products industry and from m u n i c i p a l i t i e s i s not yet proven on the commercial s c a l e . 2 (2) BACKGROUND ( i ) S o l i d Wastes as Energy Sources The high energy consumption of i n d u s t r i a l i z e d soc ie ty has resu l ted in dep le t ion of the wor ld 's f o s s i l fuel resources . In 1974, t y p i c a l 35 estimates ind ica ted that the world suppl ies of natural gas would l a s t only 11 more y e a r s , while o i l reserves would l a s t 25-30 years and the present coal suppl ies would l a s t for another 500 y e a r s . Coal use presents problems of environmental impact, inc lud ing e f f e c t s on both land and water at the s i t e of min ing , and the removal of oxides of sulphur from combustion products. The developing energy shortage, which i s character ized by dwindling suppl ies of a v a i l a b l e f o s s i l f u e l s and esca la t ing costs of these premium f u e l s , together with environmental cons idera t ions has prompted a massive research e f f o r t in developing new technology f o r the u t i l i z a t i o n of a l t e r n a t i v e energy sources. Nuclear energy, although i t has the potent ia l of leading to energy independence, presents h ighly undesirable side e f f e c t s ; namely the unsolved and p o t e n t i a l l y ca tast rophic problem of rad ioac t ive waste d i s p o s a l . A f i n a l so lu t ion to the energy c r i s i s w i l l require renewable energy sources. Plant matter provides such an a l t e r n a t i v e , f o r as the product of photosynthes is , i t i s a renewable source. Energy from refuse should be considered as part of a complete economic system. On a mass b a s i s , refuse conta ins about ha l f of the heating value of l i g n i t e coal (17300 KJ /Kg) . The use of the organic mater ia ls in refuse as fuel represents a source of present ly wasted energy. In add i t ion to the r e s u l t i n g economic gains in u t i l i z i n g refuse as f u e l , extensive envirnomental benef i ts are a lso acqui red . D i rec t burning 3 or g a s i f i c a t i o n processes reduces the s o l i d wastes in to s t e r i l i z e d a s h , much reduced in volume and mass which would a l l e v i a t e the growing problem of decreasing a v a i l a b i l i t y of l a n d f i l l s f o r s o l i d waste d i s p o s a l . The to ta l s o l i d waste generated in the United States in 1974 was I R Q Q estimated to be 122 x 10 Kg of f o r e s t product r e s i d u a l s , 15.2 x 10 Kg q of m i l l r e s i d u a l s , 254 x 10 Kg of household, municipal and commercial g wastes, 559 x 10 Kg of a g r i c u l t u r a l wastes and crop res idua ls and 9 1524 x 10 Kg of animal manures. Each kilogram of dry wood waste was estimated to have an energy content of 21000 KJ. Assuming a conversion e f f i c i e n c y of 80%, f o r e s t product res idua ls and mi l l wastes could be 10 3 converted to an equivalent of 5.7 x 10 m of natural gas or 10% of the present U.S. gas demand. It has been estimated that the to ta l U.S. present day gas demand could be suppl ied by convert ing a l l carbonaceous sol id wastes to gas. Thus, wood r e s i d u a l s have the potent ia l of being a future source of fuel gas. This i s p a r t i c u l a r l y true s i n c e : (a) wood r e s i d u a l s represent an annual crop which has increased in quant i ty by 3-6%/year in the past and i s expected to do so in the foreseeable f u t u r e , (b) t h e i r ash and sulphur content are low (ash + sulphur < 2% weight ) , (c) l e s s p o l l u t i o n i s generated through t h e i r use and r e f i n i n g than c o a l , (d) they are an energy source that i s l o c a l l y a v a i l a b l e ( in many places in North America) and (e) hydrocarbons, p a r t i c u l a r l y low-sulphur natural gas sources , are being depleted r a p i d l y . 4 To the chemfst, wood i s a mixture of c e l l u l o s e , hemicel lu lose and l i g n i n together with gums, r e s i n s , s t a r c h e s , t a n i n , co lour ing matter , 30 v o l a t i l e o i l s , mineral matter and varying amounts of water . The l i g n i n i s in terspersed between the c e l l u l o s e c e l l s and acts as cementing agent. Wood may be considered to be a natural p l a s t i c product with c e l l u l o s e as the natural re inforcement. The components of wood d i f f e r in composi t ion , but i t s elementary composition var ies l i t t l e . For dr ied wood, a t y p i c a l composition by weight i s 50.0% carbon, 6.0% hydrogen, 0.5% n i t r o g e n , 42.5% oxygen and 1.0% ash. Factors of importance when consider ing wood as fuel are moisture content , d e n s i t y , s p e c i e s , age and the part of the tree from which i t i s cu t . These f a c t o r s are re la ted to the most important property of a fuel i . e . i t s heating va lue . On a moisture and r e s i n f ree b a s i s , however, 30 most wood species e x h i b i t the same heating value of about 19300 KJ/Kg ( i i ) A v a i l a b i l i t y of Wood Wastes in B r i t i s h Columbia Consider ing the complete tree as the s t a r t i n g material f o r pulp and paper product ion , the paper i n d u s t r y ' s u t i l i z a t i o n of i t s basic raw mater ia l i s excep t iona l l y low. The d i s t r i b u t i o n (percent by weight) of 13 sa lab le products v s . residues as estimated fo r three t y p i c a l end products i s given below: Marketable Organic Bark Slash Stump Pulp or Residue (Branches and Newsprint in Spent and Tops) Roots Liquors Kraf t Pulp 22% 24% 10% 17% 27% Newsprint 37% 9% 10% 17% • 27% D i s s o l v i n g Pulp 16% 30% 10% 17% 27% 5 The most s i g n i f i c a n t quant i ty of r e s i d u e , as i n d i c a t e d , i s the stump and r o o t s . The i r u t i l i z a t i o n f o r any purpose, at l e a s t in the near f u t u r e , appears t e c h n i c a l l y d i f f i c u l t due to the problem of removal. The residues of more immediate potent ia l f o r u t i l i z a t i o n are barks , and, to a l e s s e r extent , the s l a s h . The u t i l i z a t i o n of wood residues fo r fuel or other a p p l i c a t i o n s requi res that they f i r s t be reduced to an e a s i l y handled s i z e . A "hog" machine can e f f e c t a s i z e reduct ion of large volumes of wood and bark residues producing p a r t i c l e s commonly re fer red to as hogged fuel or hog f u e l . Hogged fuel inc ludes any wood or bark residues in a reduced p a r t i c l e s i z e . It i s def ined as a waste material u n f i t f o r use in pulp manufacture. It i s of va r iab le consis tency and contains bark as woodwastes. It c o n s i s t s of d i f f e r e n t aggregates of some or a l l of sawdust, bark, planes shavings, ch ip f i n e s , sander d u s t , plywood t r im and in some c a s e s , waste wood such as tr im ends, s labs and edgings which have not been used f o r the production of pulp c h i p s . The product i s not homogeneous. Various un i ts of measure and terminology are in use throughout the indust ry . Some of these a r e ^ : (a) Grav i ty Packed Unit (G.P .U. ) 3 One G . P . U . contains 200 f t . of mater ial compacted by g rav i ty on ly . The terms g rav i ty packed uni t and volumetric un i t (V.M.U.) are synonymous. (b) Cunits 3 One cuni t of wood contains 100 f t . of s o l i d wood. This measure excludes decay, voids and bark. (c) Bone Dry Unit (B.D.U. ) One B.D.U. weighs 2400 l b s . when oven dry . (d) Foot Board Measure (fbm) One fbm i s a volume of s o l i d wood, one square foot in area by one inch t h i c k , or 0.0833 f t . 3 R e i d , C o l l i n s and Assoc ia tes Limited of Vancouver recorded the fo l lowing estimates of the hog fuel a v a i l a b i l i t y in B r i t i s h Columbia: (a) For the South Coastal Region of B r i t i s h Columbia^ in 1977 4,980,000 G . P . U . s of hog fuel were produced and of those, 75% came from sawmills a lone . 3,670,000 G . P . U . s were used to ra ise steam f o r energy requirements in the m i l l s which resu l ted in a surplus of 1,310,000 G . P . U . s of hog f u e l . (b) For Central and Lower Vancouver in 1977 1.33 x 10 6 Oven Dried Ton (O.D.T . ) of bark, 6 x 10 5 O .D.T . 5 of sawdust and 3 x 10 O.D.T . of shavings were estimated to have been produced in 1977. (c) For the province of B r i t i s h C o l u m b i a ^ B a s i s : G . P . U . of hog f u e l / y e a r Year Total Produced Usage Surplus 1976 10,920,000 5,156,000 5,764,000 1980 11,586,000 7,108,000 4,478,000 2000 13,148,000 9,598,000 3,550,000 •I C A t y p i c a l plywood m i l l which processes 150 x 10 of 3/8" equivalent per year w i l l generate 5.3 x 10 6 Kg per year of dry waste. I ts energy g requirement w i l l be 402 x 10 KJ/year while the a v a i l a b l e energy in the g waste i s 548 x 10 KJ /year . 7 ( i i i ) D i rec t Combustion vs G a s t i f i c a t i o n One problem with s o l i d wastes i s that they are seldom in a form that can be r e a d i l y u t i l i z e d . A number of processing methods have been proposed whereby p lant matter may be converted to energy or f u e l s having higher u t i l i t y . Woodwaste i s used as fue l in hog fuel b o i l e r s to generate steam fo r process uses. The i n i t i a l c a p i t a l and maintenance costs of hog fuel b o i l e r s are high and moreover, even a wel l -designed hog fuel b o i l e r can not meet s t r ingent a n t i - p o l l u t i o n regula t ions without add i t ion of expensive p o l l u t i o n abatement dev ices . In s p i t e of these drawbacks, with increas ing fuel c o s t s , hog fuel b o i l e r s are being widely adopted in the pulp and paper indust ry . G a s i f i c a t i o n or l i q u e f a c t i o n of the s o l i d wastes before combustion allows more e f f i c i e n t cleanup of p a r t i c u l a t e s and other ob ject ionable emissions than stack gas cleanup a f t e r s o l i d fuel combustion. Gas i fy ing the s o l i d wastes to fue l gas can permit s o l i d fuel u t i l i z a t i o n s in o i l and gas f i r e d boilers and furnaces and p o t e n t i a l l y to gas turbines and fuel c e l l s with minimal process m o d i f i c a t i o n s . The fue l gas can a l s o be upgraded before f i r i n g . The most useful and b e n e f i c i a l a p p l i c a t i o n fo r g a s i f i c a t i o n is f o r the small user who does not have the large energy demand that j u s t i f i e s the l a r g e r , though genera l ly a f f o r d a b l e , cap i ta l investment f o r a d i r e c t combustion u n i t . In a comparison of the process e f f i c i e n c i e s of d i r e c t combustion and g a s i f i c a t i o n , b o i l e r e f f i c i e n c y e x c l u s i v e l y i s evaluated in the case of d i r e c t combustion, while the to ta l combined e f f i c i e n c y of the g a s i f i e r and the b o i l e r must be considered in g a s i f i c a t i o n . Wood fuel f i r e d b o i l e r s can operate at 75-80% thermal e f f i c i e n c y . With higher moisture 8 content f u e l s , t h i s value may drop to 65%. A well designed f i x e d bed g a s i f i e r can operate at an e f f i c i e n c y of 90% or higher and assuming the e f f i c i e n c y of burning t h i s fuel gas in the b o i l e r i s on the order of 75 to 80%, the to ta l process e f f i c i e n c y i s estimated to be 67.5 to 72%. In an environmental comparison of d i r e c t combustion versus g a s i f i -c a t i o n , there i s a decided advantage toward g a s i f i c a t i o n . The g a s i f i e r product burns more c l e a n l y than s o l i d fuel in a d i r e c t combustion u n i t . There i s some p a r t i c u l a t e ca r ryover , depending on the v e l o c i t y through the g a s i f i e r and the p a r t i c l e s i ze of the s o l i d fuel that i s being g a s i f i e d . For d i r e c t combustion in a spreader-stoker f i r e d b o i l e r , the dust loadings genera l ly require a mul t ip le tube cyclone e f f i c i e n c y of 80% to 90% to 22 meet acceptable l e v e l s . The advantages of producing fuel gas and the f l e x i b i l i t y in i t s u t i l i z a t i o n over that of d i r e c t s o l i d fuel combustion l i e in the f a c t that fuel gas can be: (a) combusted more e f f i c i e n t l y than a s o l i d f u e l , (b) separated from ash before combustion, (c) processed before combustion fo r maximum heat recovery by car ry ing out i n d i r e c t heat t rans fe r to below the dew p o i n t , (d) separated from p a r t i c u l a t e s by e f f i c i e n t scrubbing techniques handling several f o l d l ess volume of gases than a f t e r complete combustion, (e) used fo r d i r e c t heating in cont ras t to i n d i r e c t heating by steam which i s ra ised in the d i r e c t combustion b o i l e r , ( f ) t ransported more simply than steam within a plant s i t e , (g) processed to a form that may be transported more cheaply than s o l i d fue l or e l e c t r i c i t y and (h) processed to form chemicals e . g . methanol and ammonia. 9 Thus, in view of the u t i l i z a t i o n of s o l i d waste in the most e f f i c i e n t and c leanest poss ib le way, g a s i f i c a t i o n i s super ior to the d i r e c t combus-t ion technique. The fuel gas produced v i a g a s i f i c a t i o n can be used e f f i c i e n t l y and economical ly by i n d u s t r y , u t i l i t i e s and m u n i c i p a l i t i e s . ( iv ) Fixed Bed Versus F l u i d i z e d Bed Operation In a s o l i d waste f i x e d bed g a s i f i e r , the s o l i d enters the top of the v e r t i c a l shaf t and moves very slowly downward as mass i s removed from the lower zones. The fuel gas produced at r e l a t i v e l y high temperatures in the lower zones flows upward through the s o l i d bed. The waste f i r s t warms and drys and the water vapour evolved from the material s t i l l drying protects the a l ready dr ied mater ia l s u f f i c i e n t l y so that r e l a t i v e l y l i t t l e fu r ther processing occurs u n t i l most of the fuel i s d r i e d . Once the waste reaches the end of t h i s dry ing zone and enters the p y r o l y s i s zone, decom-p o s i t i o n occurs and considerable physica l changes take p lace . A f t e r completion of p y r o l y s i s , the s o l i d residue enters the f i n a l zone as char and inorganic res idue . Here, the temperatures are s u f f i c i e n t l y high to al low gas reac t ions to o c c u r , the s o l i d i s ox id ized by the gas phase e i t h e r exothermical ly by 0 2 or endothermical ly by HgO or C 0 2 . In a f i x e d bed g a s i f i e r , the s o l i d consumption rate i s the dependent v a r i a b l e . The basic process control i s oxidant f lowrate and temperature (and composition f o r cases where steam/air or steam/02 1 S u s e £ * ) - ^ condensable organic r e c y c l i n g i s used, i t s f low can a lso be used fo r process c o n t r o l . The potent ia l advantages of a f ixed-bed g a s i f i e r a re : low gas f low which reduces the amount of p a r t i c u l a t e s and f l y a s h in the product gas; the f i x e d bed which i s above the ash zone acts as a f i l t e r to remove entrained par t icu la tes from the gas stream; the f ixed bed reactor conserves 18 heatj and the energy conversion e f f i c iency i s very high (about 80%) ; the system can be used to process wastes with a high water content such as sewage sludge; the system has the capab i l i t y of conversion of a l l combustible wastes to a low Btu gas; and the f ixed-bed gas i f i ca t i on reactor i s the simplest of the a l te rnat ive gas i f i ca t i on processes. However, the countercurrent mode of the f ixed bed g a s i f i e r maximises 3 the content of tars in the gas , thus requir ing an elaborate cleaning f a c i l i t y . It i s subject to channell ing of the charges and the high combustion zone temperatures at the grate f a c i l i t a t e the formation of c l inkers and renders ash removal d i f f i c u l t . A l so , so l i d motion can be a problem with non-uniform feed s ize and shape. A typ ica l f l u i d i zed bed reactor consists of a ver t i ca l cy l inder in which the lower end i s f i t t e d with a gr id to support the bed of iner t pa r t i c les (e .g . sand) and f a c i l i t a t e even d i s t r i bu t ion of the upflowing f l u i d i z i n g gas. Increasing the gas flowrate causes a proportional increase in the bed pressure drop with the sand remaining in the packed state un t i l i t equals the pressure exerted by the sand on the gas d i s t r i bu t ion p la te . At higher gas f low, the sand bed expands in height and the indiv idual sand par t i c les are no longer touching. This i s the point of inc ip ien t f l u i d i -za t ion . Continuing to increase the gas flowrate expands the bed of sand pa r t i c l es in the gas stream and allows for less r e s t r i c t i v e movement of the ind iv idual sand p a r t i c l e s . The sand bed i s said to be f l u i d i z e d . In the f l u i d i zed s ta te , the sand has many charac te r i s t i cs of a f l u i d . Further increase in the gas flow w i l l produce gas bubbles in the bed which resu l t in vigorous and v io lent ag i ta t ion of the sand p a r t i c l e s . This region of violent s o l i d p a r t i c l e a g i t a t i o n holds the key to the e f f i c i e n t f l u i d i z e d bed g a s i f i c a t i o n and i n c i n e r a t i o n of s o l i d waste m a t e r i a l . There i s no s i g n i f i c a n t temperature gradient across the bed. The pressure drop across the bed w i l l begin to f a l l o f f at s t i l l higher gas f lowra te . At t h i s s t a t e , the gas f lowrate has reached the terminal v e l o c i t y of some of the sand p a r t i c l e s and the sand i s c a r r i e d out of the bed with the f l u i d i z i n g gas. The chemical industry has found that the f l u i d i z e d bed o f f e r s economic and operat ional advantages f o r many chemical react ions of the type: aA(so l id ) + bB (gas) rR(gas) + s S ( s o l i d ) + heat where i t i s important to obtain good contact between a react ing gas and s o l i d reactant . This i s the general type of react ion that takes place in s o l i d waste g a s i f i c a t i o n . In order to i n i t i a t e the r e a c t i o n , i t i s necessary to heat the s o l i d A up to an i g n i t i o n temperature. Once i g n i t e d , the react ion gives o f f energy that must be removed. The f l u i d i z e d bed acts as a thermal flywheel which gives up and rece ives energy from the combustible s o l i d s due to the v i o l e n t a g i t a t i o n of the bed p a r t i c l e s . No hot zone w i l l develop in the bed. The uniform temperature and composition of the f l u i d i z e d bed provide good c o n t r o l . Depending on the fue l c h a r a c t e r i s t i c s , the bed temperature can be kept normally in the range of 550°C to 1 1 0 0 ° C 3 ' 4 in cont ras t to the temperature in the combustion zone of a f i x e d bed reactor which i s in the range of 1300 -2000°C . This r e l a t i v e l y low temperature prevents s i n t e r i n g and agglomeration of ash and thus f a c i l i t a t e s ash removal. In a d d i t i o n , i t a l s o extends reactor l i f e and i s l ess demanding on the mater ia l of c o n s t r u c t i o n . Formation of nitrogen o x i d e s , which pose environmental problems i s reduced at t h i s lower temperature. It a lso sharply reduces the vapor i za t ion of s a l t which i s a major problem inherent in burning wood waste conta in ing s a l t accumulated in the wood by f l o a t i n g the logs on sea water. Because of the exce l l en t mass and heat t rans fe r rates experienced in the bed, the throughput of the f l u i d i z e d bed reactor i s l a rger than that 3 4 of a f i xed bed reactor of the same s i z e ' . Tar formation can a lso be minimised by in t roducing the fuel in to the zone of highest temperature in the r e a c t o r . The f l u i d i z e d bed has c e r t a i n cons t ra in ts that l i m i t i t s range of opera t ion . If the i n e r t bed material i s sand, the temperature of the bed cannot exceed 1 1 0 0 ° C so as not to approach i t s sof tening po in t . In the usual design of f l u i d i z e d beds, the gas f lowrate at operat ing cond i t ions cannot exceed the terminal v e l o c i t y nor can i t be l e s s than the minimum f l u i d i z a t i o n v e l o c i t y of the sand/or s o l i d f u e l . These v e l o c i t i e s depend upon the p a r t i c l e s i z e , thus , some form of s i ze reduct ion before the s o l i d fuel may be fed to the bed i s requ i red . Feed must be d i s t r i b u t e d over the bed c r o s s - s e c t i o n fo r e f f i c i e n t operat ion and th is i s a major problem with h ighly reac t ive s o l i d m a t e r i a l s . The high pressure drop across the reactor requi res higher blower capac i ty than f o r f i xed bed opera t ions . Because the f i l t e r i n g e f f e c t of the f i xed bed fo r the gas leav ing the reac tor i s absent in the f l u i d i z e d bed, s o l i d carryover from the bed may be s i g n i f i c a n t . 13 (3) GASIFICATION THEORY G a s i f i c a t i o n i s the chemical process of convert ing energy in a s o l i d form to energy in a gaseous form. This can be achieved by incomplete combustion of any s o l i d carbonaceous mater ia l to produce CO, C 0 2 , N 2 , CH^, H 2 and gaseous hydrocarbons using a g a s i f y i n g medium such as a i r , oxygen, steam or C 0 2 . The process can be descr ibed by three p r i n c i p a l s tages; d r y i n g , p y r o l y s i s and char r e a c t i o n . The f i r s t two stages are e s s e n t i a l l y 36 determined by the rate of heating . There i s no s i g n i f i c a n t react ion between the s o l i d and the gas phase surrounding i t . P y r o l y s i s can be simply descr ibed as the thermal decomposition of carbonaceous mater ia l in the absence of oxygen. The process can be represented by: C e l l u l o s i c Heat „ Gases L iqu ids , So l id Mater ia l (H 2 ,C0,C0 2 ,H 2 0,CnHm) ( tar + l i g h t o i l ) (char + ash) The y i e l d of each of these products i s re la ted to the chemical s t r u c t u r e , s i z e and shape of the mater ia l to be pyro lyzed , the temperature and pressure of the decomposit ion, and the heating ra te . The p y r o l y s i s products can be burned in the presence of oxygen to form combustion products . Rapidly heating a c e l l u l o s e molecule to a high temperature in the 35 36 absence of oxygen causes the molecule to a c t u a l l y explode . This f i r s t stage decomposition g ives r i s e to H 2 0 , CO and C 0 2 molecules where r e l a t i v e l y l o o s e l y bonded const i tuents are dr iven o f f . This i s fol lowed by more extensive decomposition with ta rs being the major product . Further fragmentation r e s u l t s i n s impler products ( e . g . H 2 , CH^, C 2Hg) being 14 dr iven o f f leav ing only char as the s o l i d res idue . The energy required 14 to pyrolyze any c e l l u l o s i c mater ial depends upon the r a t i o of the products formed which in turn depend upon the heating r a t e , the temperature and sample s i z e . Low temperature-low heating rate environments favour increas ing s o l i d product format ion, while high temperature-high heating rate env i ron -ments favour increas ing gaseous product format ion. If a g a s i f y i n g medium of a i r or oxygen i s used, then the p y r o l y s i s products can react with oxygen to produce combustion products of C 0 2 and H 20 with the accompanying heat evolved. The char residue i s ox id ized by the gas phase e i t h e r exo-thermica l l y by 0 2 (combustion react ions) or endothermical ly by H 20 or C 0 2 ( g a s i f i c a t i o n r e a c t i o n s ) . Gas phase react ions between the var ious gaseous products a lso occur . (Refer Table 1-1 f o r d e t a i l s of r e a c t i o n s ) . It i s with the react ions of the p y r o l y s i s products that a great d i v e r s i t y of processes can occur . The oxidant may be a i r , preheated a i r or oxygen - with or without steam. Scrubbed condensables or other f u e l s may be added. The obvious d i f fe rence between the oxygen and a i r oxidant i s the ni trogen d i l u t i o n with a i r . A theore t ica l model which considers the countercurrent g a s i f i e r to be d iv ided in to four zones was developed by C o u s i n s ^ (Figure 1-1). In the lowest zone, the ox idat ion zone, carbon reacts with oxygen to re lease the heat that d r ives a l l ' of the remaining g a s i f i c a t i o n r e a c t i o n s . Temperatures of gases and s o l i d s reach t h e i r maximum va lues . Because of the high temperatures, the rate of chemical reac t ion i s extremely h igh , and so the o v e r a l l rate of react ion in the zone i s governed by slower physica l processes such as gas t ransport and mix ing. Above t h i s zone i s the much th icker reduct ion zone. Since there i s no longer any f ree oxygen present , the dominant processes in t h i s region are the h ighly endothermic g a s i f i c a t i o n react ions between C , C0 ? and H ? 0. Consequently, TABLE 1-1: GASIFICATION REACTIONS Number P a r t i c u l a r s Reaction H (KJ/mol) Equ i l ib r ium Constant 1100 K 1300 K 1100 K 1300 K 1 Combustion react ion C + J s 0 2 - ^ C 0 -112.614 -113.882 8.80 x 109 1.31 x 10 9 2 Combustion react ion CO + y)2—»-co2 -282.295 -281.416 7.21 x 108 6.29 x 10 6 3 Combustion react ion | c + o2 -*-co2 -394.913 -395.298 6.35 x 1 0 1 8 8.25 x 1 0 1 5 4 Combustion react ion H 2 + %0 2 —*-H 2 0 -248.422 -249.685 7.60 x 108 1.15 x 10 7 5 High pressure j C + 2H 2 *—- CH^ - 90.605 - 91.735 3.68 x I O - 2 7.93 x IO" 3 6 G a s i f i c a t i o n react ion i C + H 20 ^ C O + H 2 i 135.807 135.636 2.62 1.14 x 10 2 7 G a s i f i c a t i o n react ion C + 2H 20 ^ C0 2 + 2H 2 -146.492 -145.780 1.11 x 101 6.24 x 10 1 8 G a s i f i c a t i o n react ion Boudouard react ion C + C0 2 ^ 2C0 169.685 167.534 1.22 x 101 2.08 x 10 2 9 Gas phase react ion Water-gas s h i f t CO + H 20 ^ C 0 2 + H 2 - 33.878 - 31.898 1.10 x 1 01 0 0.55 10 High pressure CO + 3H 2 ^ CH 4 + H 20 11 High pressure C0 2 + 4 H 2 ^ C H 4 + 2H 20 16 heat i s absorbed and temperatures decrease. The overal l rate of reaction i s lower than that in the oxidation zone. At a certa in l e v e l , temperatures and reaction rates become so low that the gas composition i s e f f ec t i ve l y frozen. This defines the upper boundary of the reduction zone, and the boundary temperature i s ca l led the reaction temperature of the g a s i f i e r . Temperatures in the region immediately above the reduction zone are s t i l l high enough, however, to cause pyrolys is of the incoming feed. The breakdown products are charcoal , which enters the reaction zone, and l i qu ids and gases. A l l of the breakdown gases and the more v o l a t i l e l i qu ids mix with the gases leaving the reduction zone and so become part of the ex i t ing gas stream. The less v o l a t i l e l i qu ids condense on the cool incoming feed and are retained in the pyrolys is zone unt i l they too are cracked into more highly v o l a t i l e 34 compounds. According to Roberts , the pyro ly t i c breakdown i s s l i g h t l y exothermic, and so very l i t t l e or no heat i s absorbed in the pyrolys is zone. Above the pyrolys is zone, the incoming feed i s dried by the ex i t ing hot gas stream. In a typical mixed flow f l u i d i zed bed g a s i f i e r , feed and blast both enter at the bottom of the reactor vessel and ash and gases leave at the top. A f l u i d i zed bed i s . well mixed, and so the processes of ox idat ion , reduction, pyrolys is and drying can a l l combine in one reaction zone. (Some f l u i d i zed gas i f i e r models s t i l l consider 2 zones; the combustion zone near gr id and the gas i f i c a t i on zone above). The feed to the reaction zone contains C, H and 0 from the feed,feed moisture and 0 2 (and sometimes N2) of the b las t . In contrast , only part of the C and none of the H, 0 and moisture from the feed enter the reaction zone of a countercurrent plug flow reactor. wet r a w f u e l f e e d g a s Figure 1 - 1 : Schematic of a Countercurrent G a s i f i e r Showing the Zones of Operation and Var ia t ion of Gases and So l id Temperatures ( C o u s i n s ^ ) . 18 If the temperature of the f l u i d i z e d bed i s s u f f i c i e n t l y h i g h , chemical equ i l ib r ium may be reached in the e x i t i n g gas phase. When t h i s happens, a l l the l i q u i d s r e s u l t i n g from the p y r o l y s i s of the feed are cracked into s table gases. It i s not c l e a r which process i s super ior as each has advantages and disadvantages. The countercurrent i s super ior to the f l u i d i z e d process in terms of ( i ) decreased oxygen consumption, ( i i ) automatic predrying of the feedstock (and hence the a b i l i t y to g a s i f y a wet feedstock) and ( i i i ) the gases produced with an a i r b l a s t give higher a t ta inab le flame temperatures. Whereas the f l u i d i z e d bed process i s super ior in terms of ( i ) reduced p o l l u t i o n ( less tar format ion) , ( i i ) higher g a s i f i c a t i o n e f f i c i e n c y , and ( i i i ) the product gas i s more s u i t a b l e f o r chemical s y n t h e s i s . Low-Btu gas i s produced by the g a s i f i c a t i o n of c o a l , char , wood or even refuse with steam and a i r , genera l ly at atmospheric pressure . The r e s u l t i n g gas i s d i l u t e d with the ni trogen of the a i r which comprises 45-60% by volume of the dry gas , with the r e s t of the components being 5 CO, H 2 , C 0 2 and small amount of CH^. Its gross c a l o r i f i c value i s in the range of 3.73-6.52 M J / s t d . m 3 (100-175 B t u / s c f . ) . Medium-Btu gas i s produced by g a s i f i c a t i o n of carbonaceous material with steam or oxygen at atmospheric or higher pressure , and temperatures of 5 0 0 - 1 5 0 0 ° C . The produced gas has l i t t l e ni trogen (2%), CO and C 0 2 concentrat ions of 30-40%, up to 4% CH^, and gross c a l o r i f i c value of 9.31-20.49 M J / s t d . m 3 (250-550 B t u / s c f . ) . High-Btu gas or synthet ic natural gas i s e s s e n t i a l l y methane and has a gross heating v a l u e 5 of 35.40-37.26 M J / s t d . m 3 (950-1000 B t u / s c f ) . High-Btu gas can be produced v ia two routes . The f i r s t employs the medium-Btu gas as the s t a r t i n g m a t e r i a l , with the s h i f t conversion of H 20 to H 2 by CO fol lowed by methanation. The s h i f t conversion i s genera l ly done at 300-450°C and 2750 KPa (27 atm.) in the presence of a c a t a l y s t in such a way that the C 0 : H 2 r a t i o i s adjusted to 1:3 p r i o r to the c a t a l y t i c methanation s tep . Nickel i s the c a t a l y s t used. Cardon d iox ide i s removed by chemical absorpt ion . The second route to synthet ic natural gas i s the d i r e c t hydrogenation of coal or h y d r o g a s i f i c a t i o n at pressures in excess of 3435 KPa (34 atm.) . From the thermodynamic data l i s t e d in Table 1-1 fo r the g a s i f i c a t i o n r e a c t i o n s , i t can be seen that the most favourable react ion i s react ion (3) , whereas the l e a s t favourable i s react ion (5). Increasing temperature w i l l favour react ions (6) and (8) , thereby increas ing the amount of combustible gases. In comparing the rates of r e a c t i o n s , only four are l i s t e d : Reaction Re la t ive Rate ( 8 0 0 ° C , 1 atm) (4) 10 5 (6) 3 (8) 1 (5) 3 x 10" 3 Thus, both thermodynamic and k i n e t i c cons idera t ions ind ica te that in a g a s i f i c a t i o n system at atmospheric pressure , as long as any oxygen i s present , the combustion reac t ions are favoured over the g a s i f i c a t i o n reac t ions of C-H 2 0 and C - C 0 2 while the d i r e c t hydrogenation of carbon i s the l e a s t favourab le . II. SUMMARY OF PREVIOUS WORK The work on p y r o l y s i s and g a s i f i c a t i o n in the l a s t four decades has been concentrated l a r g e l y on the use of f o s s i l f u e l s as feedstocks . The technology f o r the conversion of p lant matter as well as f o s s i l f u e l s was being developed r a p i d l y through the t h i r d decade of t h i s century . Then, with the burgeoning developments of petroleum and natural gas that were taking p l a c e , the economics of g a s i f i c a t i o n simply became untenable. Interest in the technica l development of g a s i f i c a t i o n became r e l a t i v e l y dormant u n t i l very recent ly when i t was genera l ly recognized that the era of energy economy dominated by cheap natural gas and petroleum was drawing to an end. With t h i s awareness, a strong i n t e r e s t has been rek indled in the potent ia l of g a s i f i c a t i o n along with other a l t e r n a t i v e s in u t i l i z i n g n o n - f o s s i l fuel as a source of supplementary energy. This has resu l ted in an exponential growth in the amount of research performed on the p y r o l y s i s and g a s i f i c a t i o n of woodwaste and refuse during the previous and present decades. The var ious experimental systems employed to car ry out the p y r o l y s i s and g a s i f i c a t i o n processes by d i f f e r e n t inves t iga to rs are as shown below: Year Invest igators System Feed used 1944 30 Reviewer: Jones Fixed Bed Sawdust, Shavings, ba 1963 Ki lburn & Level t o n 8 F l u i d i z e d Bed Wood waste 1972 B a i l i e & I s h i d a 6 F l u i d i z e d Bed Municipal refuse 1973 B a i l i e 2 0 F l u i d i z e d Bed Sawdust & coal 1974 B a i l i e & B u r t o n 3 5 F l u i d i z e d Bed Refuse 1974 Hammond^8 Fixed Bed S o l i d waste Feed used Shredded municipal s o l i d waste Wood & municipal s o l i d waste Sawdust & coal Wood Ca t t l e feed lo t manure, sawdust & corn stover De ta i l s of t h e i r work can be found in Appendix 7, and a summary of the experimental f i n d i n g s from p y r o l y s i s and g a s i f i c a t i o n of wood e x c l u s i v e l y i s presented in Tables II—"!, 11-2, 11-3 and 11 -4 . The k i n e t i c study of the p y r o l y s i s of c e l l u l o s i c mater ia ls has been undertaken by var ious inves t iga to rs using many d i f f e r e n t techniques. The 14 two commonly used methods in thermal ana lys is are thermogravimetric Ana lys is (TG) and D i f f e r e n t i a l Thermal Ana lys is (DTA). Flow techniques are a lso used widely . Many d i f f e r e n t types of reactors such as f l u i d i z e d bed, entrained f low, f ree f a l l , and s l u r r y reactor have been used. It i s understood that the a p p l i c a t i o n of thermal a n a l y s i s techniques does not provide accurate i d e n t i f i c a t i o n and d e f i n i t i o n of the ind iv idua l r e a c t i o n . Most i n v e s t i g a t o r s propose k i n e t i c models based on the weight of residue and many have shown that the p y r o l y s i s step fo l lows the k i n e t i c s of a f i r s t order or pseudo f i r s t order react ion although some have d iv ided the step in to two d i f f e r e n t stages. Since these k i n e t i c s tudies have been conducted under varying experimental c o n d i t i o n s , c o n f l i c t i n g data with a wide range of k i n e t i c parameters are repor ted . The observed a c t i v a t i o n energy v a r i e s ^ 4 from 14.65 to 227.3 KJ/mol and Year Invest igators System 1975 T o l m a r 3 1 F l u i d i z e d Bed 1 2 1976 Brink Flow Reactor 2 1977 L i u , Serenius & F l u i d i z e d Bed Martinez3 25 1978 Brink & Massoudi Flow Reactor 1979 Beck, Wang & F l u i d i z e d Bed Hightower^l the reac t ion rate constant va r ies from 0.053 to 2.7 x 10 s . The value 34 of the heat of reac t ion per un i t mass of v o l a t i l e products formed was found to be varying from -136 to -1600 J / g . The wide spread of experimental data impl ies that the p y r o l y s i s and g a s i f i c a t i o n react ions are very s e n s i t i v e to the experimental c o n d i t i o n s , which renders q u a l i t a t i v e and quant i ta t i ve comparison between works performed by d i f f e r e n t inves t iga to rs a h ighly d i f f i c u l t task. Any meaning-fu l comparative study would have to be that between r e s u l t s obtained under a s p e c i f i c set of experimental c o n d i t i o n s . TABLE II-l: PYROLYSIS OF WOOD IN NITROGEN ATMOSPHERES Brink & Massoudi25 (1976) Tran & Ra114 (1979) Barooah & Long19 (1976) System A flow reactor where particles are suspended in nitrogen is used. The reactor is heated electrically by furnace elements surrounding it . Operating pressure is atmospheric and the residence time is 3.02-5.32 sec. DuPont 951 Thermogravimetric Analyzer The reactor used is a fluidized sand bed in an atmosphere of nitrogen at tempera-tures up to 400°C. The reactor is 7.6 cm in diameter in the middle of a 15.2 cm vertical mild steel pipe 61 cm long and 1s surrounded by electrical heating element. Feed Air dried white Fir wood particles Particle size 4-8.4 mm Powdered Douglas Fir bark {8.8% wet) Ultimate Analysis (%W): C 53.05 H 6.12 N 0.15 0 40.62 S 0.06 Heating Value (KJ/g): 22.12 Catalyzed bark was made by impreg-nated with K2C03. Beech sawdust (B.S.-18+25) dried at 102°C which contains 48.6% carbon on a dry-basis. 40 g of sawdust and 800 g sand are Intro-duced to the reactor simultaneously. Results (1) C-H2O and C-CO2 reaction rates are greatly increased as temperature increases above 500°C. (2) The mechanisms of pyrolysis-gasification have been divided into two kinetic regimes, below and above 647°C. (3) The effects of temperature on the characteristics of the gas produced and residues are presented in Table IX-7-1, Figures IX-7-2 and IX-7-3. (Appendix 7). (1) A kinetic.model in which acti-vation energy is assumed to be a linear function of the extent of reaction was used to describe the pyrolysis of bark. (2) The order of reaction was found to be 1 and 2 for the non-catalyzed and the catalyzed bark, respectively. Two stages of decomposition were found. The kinetics of weight loss In the first stage were approximately first order with respect to residual weight of organic matter, while the second stage approxi-mated to a second-order process with respect to the weight loss to be completed in reaching equilibrium. In both stages, there was a marked change In the tempera-ture dependence of the rate of decomposi-tion of wood in the region 300-350°C. ro co TABLE 11-2: GASIFICATION OF WOOD WITH AIR IN A FLUIDIZED BED System Feed Results Kilburn & Levelton8 (1963) A fluidized bed of charcoal with no grid plate is used. Both feed and air entered the bed together. Millwaste (-4 mesh U.S.) was flash dried and preheated to decomposi-tion temperature. 11.23 x 10"4 std.m3 of 9.32-10.43 MJ/std.m3 gas was produced from 1 g of dry wood. Wen, Lin, O'Brien, Bail ie 2 0 & Burton35 (1973) Liu, Serenius2 & Martinez3 (1976) A 38 cm diameter fluidized bed, 3.6 m in height is heated by the combustion gases as natural gas is burned in the bottom chamber. The initial bed height is 76.2 cm while the sand particle diameter is 0.603 mm. The superficial velocity is 0.46 m/s. Gas feed (%V): H2 0.11 C02 10.17 O2 1-18 CH4 0.07 N2 88.47 "Sawdust (0.603 mm) with moisture 2.62% (wet basis) Ultimate analysis (%W) : C 47 2 H 6 49 N 0 0 0 45 34 s 0 0 ash 0 97 Heating values (KJ/g): 20.50 The reactor is 0.6 m in diameter and is 3 m high with a fluidized bed that is made up of the solid feed material itself. Air and fuel are introduced concurrently into the reactor bottom. Hemlock sawdust Particle size: 2.6 mm Moisture content wet): 41.2-53.9 Ultimate analysis : 52.5 6.1 41.4 Heating value (KJ/g): 19.77 The gas product is considered to be the net gas flow, after subtracting the flow of gases prior to solid feeding from the flow of gases leaving the reactor during the pyrolysis reaction. The solid feedrate was varied from 0.9 to 5.2 g/s. 11.4 x 10-4 std.m3 of 10.7-15.4 MJ/std.m3 gas was produced from 1 g of dry feed. Refer to Table IX-7-2 in Appendix 7 for details. Low-Btu gas with heating value of 3.6-5.8 MJ/std.m3 was produced. The sawdust feedrate varied between 11 and 2 4 g/s while the weight ratio of air/solid varied from 2 to 3. Figure IX-7-7 in Appendix 7 shows the gas composi-tion at various heights above the grate. ro TABLE 11-3: GASIFICATION OF WOOD WITH AIR IN A FIXED BED V 0 s s 2 2 (1977) 30 Reviewer: Jones (1944) System The temperature maintained in the bed is approximately 900°C Feed Woodchips Sawdust, shav ings , bark Results Gas Heating Value (MJ/std.m 3 ) = 7.5 Gas Heating Value (MJ/std.m3) = 5.5 TABLE 11-4: GASIFICATION OF HOOD WITH STEAM OR STEAM-AIR MIXTURES Hammond, Mudge, Allen & Schiefelbein l u (1974) Beck, Wang & Hightower41 (1979) Tran & R a i 1 5 (1976) System A 0.9-m diameter fixed bed reactor in the countercurrent mode is used. Solid waste is transferred into the top of the reactor while the air-steam mixture and product gases pass up through the reactor. Reactor tempera-ture varied from 1000°C near the grate to 100°C on top. The process is based on a countercurrent fluidized bed reactor in which the feed enters the top of the reactor and is gasified by an upward flowing stream of air and steam. Solid feed is charged into the 2.5 cm o.d. flow reactor and 1s brought to the desired operating conditions before steam injection Is started. Feed Woodenips (1) Dry oak sawdust (4% moisture, wet) (2) Green oak sawdust (40% moisture, wet) Gas feed: steam/air Powdered Douglas Fir bark Results Gas Heating value (MJ/std.m 3): 7.0 Total gas yield = 17 x 10"4 std. m3/g daf / feed 3 Gas heating value > 9.5 MJ/std.m Refer Figure IX-7-9 for the variation of gas composition with temperature. (1) Gas produced. 3 " 0.79 x 10 std. m /g carbon = 1.50 x 10"4 std. m3/g dry feed. (2) In the presence of K2CO3, this increased to 4.88 x 10-4 s td.m J /g dry feed with a gas heating value of 17.00 MJ/std.m3. (3) In the presence of K0CO3 and nickel , the gas heating value is 29.5 MJ/std.m 3. ro CTi III. OBJECTIVES OF PRESENT STUDY The l i t e r a t u r e survey has shown a range of gas product compositions and k i n e t i c parameters depending on the type of woodwaste, the contact ing cond i t ions and the temperature of opera t ion . The ob jec t ive of the present work was to study the gas composit ion evolved from a l o c a l woodwaste as a funct ion of temperature in d i f f e r e n t atmospheres. The atmosphere chosen were those of primary reactants and products in an a i r b las t g a s i f i e r i . e . 0 2, N 2, H 20 and C 0 2 -A f l u i d i z e d bed was se lected as the preferred reactor because of known advantages on the la rger s c a l e . In order to e l iminate long heat-up times during which react ion would take p lace ,a continuous system was dev ised . IV. APPARATUS The g a s i f i c a t i o n of sawdust i s c a r r i e d out in a small p i l o t p lant designed with the f l e x i b i l i t y to provide d i f f e r e n t gases as the f l u i d i z i n g medium. In t h i s c a s e , the gases are carbon d i o x i d e , n i t r o g e n , steam, a i r or any combination among them. A schematic f lowsheet i s shown in Figure IV-1 and the p a r t i c u l a r s of the major items of equipment are l i s t e d in Table IV-1. The carbon dioxide or ni t rogen feed i s suppl ied from a gas c y l i n d e r . The f lowrate can be regulated using a valve before entrance into the rotameter. The condi t ions of the gas p r i o r to passage through the valve are made known by means of a pressure gauge and a chrome!-alumel thermo-couple . The a i r mains in the bu i ld ing suppl ies a i r which i s then regulated to a pressure varying between 101.3 and 204.8 KPa. The a i r i s d r ied by passage through a dry ing column 5 cm in diameter and 0.609 m in length conta in ing s i l i c a g e l . The humidity of the dr ied a i r i s measured with the wet and dry bulb thermometers before passing through the f lowrate regu la t ing v a l v e . The a i r then flows through a rotameter on i t s way to the gas preheater . Steam can be introduced into the reactor v ia two routes . A water rotameter i s used to monitor the amount of water from the water mains to be admitted in to the preheater , where water i s t r ans -formed into steam. The second route i s the d i r e c t in t roduct ion of the steam from the steam mains in to the r e a c t o r , which by-passes the preheater. Th is steamline i s insu la ted with asbestos tape. The preheater c o n s i s t s of seven 6.4 mm S . S . tubes, 0.69 m in length which are mounted in p a r a l l e l and connected at both ends to a 5 cm S . S . 29 tube, 5 cm long . On these two end pieces are attached two 1.3 cm S . S . pipes as the i n l e t and o u t l e t to the preheater . The middle 0.46 m of the preheater i s enclosed in an e l e c t r i c a l furnace capable of d e l i v e r i n g 3.6 kw. The furnace i s c o n t r o l l e d by a temperature c o n t r o l l e r in the 0-1000°C range with the preheater she l l temperature as the c o n t r o l l e d v a r i a b l e . The e x i t gas from the preheater i s fed into the bottom of the r e a c t o r . The upward f low of gas passes through the g r i d plate supporting the sand bed to f l u i d i z e the bed. The g r i d plate cons is ts of three p a r t s ; a bottom plate to provide equal d i s t r i b u t i o n of the upflowing gas , a U.S. 100 mesh screen and a top p late to hold the screen. The nominal s i z e of the Ottawa sand used i s 0.55 mm (-30 + 35 U . S . ) . The gas d i s t r i b u t i o n p late (bottom plate) i s 4.76 mm th ick and made of type 316 s t a i n l e s s s t e e l . There are 16 holes and each i s 1.5 mm in diameter (Figure IX-1-2) . Upon enter ing the reactor bottom, the steam experiences a drop in v e l o c i t y and some condensed steam drople ts w i l l s e t t l e out of the vapour. This condensate together with that condensed in the l i n e can be c o l l e c t e d in a water r e s e r v o i r attached to the reac to r . The d r i e d , prescreened sawdust i s stored in a storage bin maintained under a s l i g h t ni t rogen pressure . The storage capac i ty i s about 5 Kg of bone-dry sawdust. A magnetic v i b r a t i o n a l feeder conveys the sawdust from the bin to a 1.3 cm tube, which i s l a t e r reduced to a 0.95 cm tube. Figure IV-2 shows the d e t a i l s of the s o l i d feed system. The t ransport n i t rogen i s introduced at the ou t l e t of the feeder to t ranspor t the sawdust p a r t i c l e s pneumatical ly into the sand bed in the reac to r . To ensure uniform feed of sawdust through the feeder , a small stream of ni t rogen introduced at the base of the feeder i n l e t to create a continuous m o t i o n o f t he s o l i d p a r t i c l e s i s n e c e s s a r y . The f l o w r a t e o f the sawdus t c a n be m o n i t o r e d by a d j u s t i n g t h e s e t t i n g o f t he v i b r a t o r . The r e a c t o r i s a 1 .45 m l o n g c y l i n d e r , 7 . 6 cm i n o u t e r d i a m e t e r and 7 . 2 cm i n i n n e r d i a m e t e r . I t i s c o n s t r u c t e d o f Type 316 s t a i n l e s s s t e e l . The t o p 0 . 3 m and t h e bo t tom 0 . 1 6 m s e c t i o n s a r e i n s u l a t e d w i t h a s b e s t o s . 2 . 5 mm i n t h i c k n e s s w h i l e t he m i d d l e 0 . 9 9 m i s e n c l o s e d i n a 7 .2 kw e l e c t r i c a l f u r n a c e . The bo t tom h a l f o f t h e f u r n a c e i s c o n t r o l l e d w i t h t he sand bed t e m p e r a t u r e w h i l e t h e t o p h a l f i s c o n t r o l l e d by t he r e a c t o r gas t e m p e r a t u r e . A f t e r l e a v i n g t he r e a c t o r , the e f f l u e n t gas i s s t r i p p e d o f t he e n t r a i n e d s o l i d p a r t i c l e s ( c h a r and a s h ) i n a 3.8 cm d i a m e t e r c y c l o n e , 15 cm i n l e n g t h , w h i c h opens i n t o a c o l l e c t i n g b i n . B o t h the c y c l o n e and t he b i n a r e made o f Type 316 s t a i n l e s s s t e e l . The gas l e a v i n g the c y c l o n e i s t h e n p a s s e d t h r o u g h a c o p p e r d o u b l e p i p e h e a t e x c h a n g e r t o c o n d e n s e t a r . The gas i s f u r t h e r c o o l e d i n an i m p i n g e r l o c a t e d i n a box f i l l e d w i t h i c e t o c o l l e c t , t a r and condense w a t e r v a p o u r a f t e r h a v i n g p a s s e d t h r o u g h an o r i f i c e p l a t e f o r f l o w r a t e m e a s u r e m e n t s . The o r i f i c e p l a t e i s made o f 316 s t a i n l e s s s t e e l t o m i n i m i s e c o r r o s i o n w h i l e t he f l a n g e s a r e made o f l e s s r e s i s t a n t b r a s s . The gas i s f i l t e r e d t h r o u g h a g l a s s - w o o l co lumn a f t e r coming ou t o f the i m p i n g e r t o remove t h e l a s t t r a c e o f t a r and w a t e r v a p o u r . The c l e a n e d p r o d u c t gas i s v e n t e d t o t he b u i l d i n g e x h a u s t s y s t e m and a s m a l l amount i s pumped t h r o u g h a 3 . 2 mm c o p p e r t u b i n g t o a s a m p l i n g p o r t where samp les o f r e a c t o r gas c a n be w i t h d r a w n . A f t e r t he i n i t i a l c o m m i s s i o n i n g o f t he e x p e r i m e n t a l a p p a r a t u s (Run 1 ) , i t became a p p a r e n t t h a t m i n o r m o d i f i c a t i o n s s h o u l d be i m p l e m e n t e d . D u r i n g t h i s i n i t i a l r u n , a i r was used as t h e f l u i d i z i n g medium. The i n i t i a l 31 height of the sand bed was 20 cm (8") and the sawdust was being introduced 25 cm (10") above the g r i d p l a t e . The minimum amount of a i r necessary .to f l u i d i z e d the bed at a bed temperature of 500°C was found to be 5 x 10"^ s t d . m / s , i . e . 0.6 g /s (Figure IX-4-2) . However, the amount of t ranspor t n i t rogen required f o r the successful conveying of the sawdust through the 0.95 cm (3/8") polyethyelene tubing to the reactor i s of the same magnitude as that of the f l u i d i z i n g medium, 7-9 x 10~ 4 s t d . m 3 / s or 0.8 g / s . If the reactor was to be operated at twice the minimum f l u i d i z i n g v e l o c i t y , the amount of t ranspor t ni t rogen would s t i l l c o n s t i t u t e about 40% of the to ta l mass input of gas in to the r e a c t o r . The s o l i d feed system has a very narrow range of workable feedrate due to the c logging tendency of the sawdust in the 0.95 cm conveying tube. Larger tubing i n i t i a l l y reduces the tendency to c log but g rav i t y eventua l ly leads to c l o g g i n g . To minimize th is e f f e c t , a greater amount of t ransport medium i s r e q u i r e d . This together with the l imi ted space a v a i l a b l e on the reactor g r id p late f o r the feed l i n e passage renders the i n s t a l l a t i o n of a l a r g e r feed l i n e h ighly undes i rab le . The sawdust feedrate ranges from 0.03 to 0.24 g /s depending on the s o l i d moisture . Feedrate i s maintained in the v i c i n i t y of 0.1 g /s f o r most of the runs. The weight r a t i o of the to ta l gas intake ( t ransport gas and f l u i d i z i n g gas) to the s o l i d feed i s about 21. Due to the nitrogen d i l u t i o n e f f e c t , reac t ions between the react ing elements; carbon (0.05 g /s ) and hydrogen (0.006 g /s ) in the sawdust and the oxygen (0.2 g /s ) in the a i r would r e s u l t in very minute concentrat ions of gases CO, C0 2 » CH^, H 2 being formed, which renders accurate gas detect ion d i f f i c u l t . To reduce the intake of gas in to the r e a c t o r , p a r t i c u l a r l y that of the t ranspor t medium, the sawdust was transported by the f l u i d i z i n g gas. As originally designed, the solids are fed 25.4 cm above the grid plate. For the sand bed to be fluidized by the transport gas, either the feed line had to be shortened or the sand bed raised so that the transport gas, together with the sawdust, would be introduced near the bottom of the bed. Thus for Run 2, a fixed bed of coarse gravel 23 cm deep was placed on the grid, and the 20 cm sand bed poured on top. Data of transport nitro-gen flowrates and pressure drops across the bed at room temperature indicate' -4 the onset of fluidization of the sand at a flowrate of 7.5 x 10 std. 3 m / s ; which implied that the system can be fluidized with the transport gas (Figure IX-4-4). For all subsequent experiments, the feed line was therefore shortened so that i t opened at 5 cm above the grid plate to achieve the same effect, and the coarse bed of gravel was dispensed with. With this method of fluidization with the transport gas being made feasible, the CO2, CO, air rotameters and the preheater became redundant as the gases can be fed through the rotameter'calibrated for transport nitrogen. Compressed air from the cylinder instead of that supplied from the air-mains, had to be used in this case to provide the necessary pressure drop for sawdust transportation. Thus, for all following experi-ments performed (except for the runs involving steam), the transport medium which also acts as the fluidizing medium was introduced above the grid plate. In order to delay the water condensation process so as to prevent i t from interfering with the orifice meter reading, no exchanger cooling water was to be used, in which case, the exit gas temperature of the heat exchanger was in the vicinity of 110-120°C. Any amount of cooling water used would lower the temperature to below that of the dew point of water and facilitates water condensing in the heat exchanger. In other words, 33 the heat exchanger was not used at a l l . Besides the sampling p o r t , three other sampling l o c a t i o n s are prov ided; the i n l e t and ou t l e t of the glass-wool column and the o u t l e t of the reac to r . For gas sampling at the reactor o u t l e t , the gas i s cooled along a length (1.5 m) of 0.95 cm Tygon tubing which has i t s end submerged in a w a t e r - f i l l e d con ica l f l a s k . Samples can be withdrawn anywhere along the Tygon tubing. 34 TABLE IV-1 : PARTICULARS OF MAJOR EQUIPMENT ITEMS DESCRIPTIONS MATERIAL OF CONSTRUCTION Storage Bin Capacity = 35 l i t r e s 316 S . S . Preheater 7 x 6.4 mm 0 x 0.69 m Furnance = 3 . 6 KW 316 S . S . Reactor Diameter = outer 7.6 cm, inner 7.2 cm Length = 1.45 m 316 S . S . Grid Plate Figure IX-1-2 316 S . S . Cyclone Diameter = 3.8 cm Length = 15 cm Figure IX-1-3 316 S . S . Heat Exchanger Double-pipe Heat Exchanger Diameter = outer 5 cm, inner 1 .3 cm copper O r i f i c e Plate Diameter = 3.6 mm Figure IX-1-4 316 S . S . Rotameters: Gas i fy ing C0£ Gas i fy ing N2 Gasi fy ing A i r Reactor Water Steam Transport N2 Heat Exchanger Water Brooks - Tube Size R-7M-25-1 Brooks - Tube Size R-8M-25-2 Brooks - Tube Size R-7S-25-1 Brooks - Tube Size R-2-15-D Brooks - Tube Size 65F-SR-50 Brooks - Tube Size R-6-15-A Brooks - Tube Size R-8M-25-2 Float = S . S . Float = S . S . Float = S . S . Float = carboloy Float = S . S . F loat = S . S . F loat = S . S . Temperature C o n t r o l l e r s : Reactor Top Reactor Bottom Preheater Controls reactor gas tempera-ture Controls bed temperature Controls preheater s h e l l temperature Thermoelectr i c 0 -1000°C Omega Model 49 . 0 -1350°C Thermoelectr ic 0 -1000°C Thermocoupl es 22 Chromel-Alumel Figure IV-1: Schematic Arrangement of Experimental Equipment f o r Sawdust G a s i f i c a t i o n . CO c n 36 T r a n s p o r t N i t r o g e n 2 2 8 6 2 7 9 4 8 89 17-78 0-32 S . S . T u b i n g 0 40-64 0 35-56 2^54 Copper Tee Tygon Tubing Plexiglass Reducer ( 2 5 4 to 0-95) J»J—0-95Polyethylene Tubing To Reactor A l l Dimensions In centimeters Figure IV-2: Sawdust Feeding System. r- 2 5 4 4 i i 572 20 32 U.S.100Mesh Wire 4 Rodsj0O64 Evenly Spaced On P.C.D.635 I ^ - 6 Holes 0 0 79 Evenly i V/i Spaced On P.C.D. 10-32 — 0 9 5 S.S. 316 Tube A l l Dimensions In centimeters Figure IV-3: Grid Plates Assembly 145-42 10017 < O r-O 4> Abeslos Insulation 55-88 20-32 cm Sond Bed 3429 W F U R N A C E SHELL 15/ F U R N A C E S H E L L REACTOR OUTER SHELL REACTOR OUTER SHELL <3> B E D REACTOR GAS TOP F L A N G E BOTTOM FLANGE R E A C T O R O U T E R f H E L l REACTOR OUTER SHELL All Dimensions In centimeters igure IV-4: Arrangement of Thermocouples on the Reacto V. EXPERIMENTAL METHODS G a s i f i c a t i o n / p y r o l y s i s of sawdust was c a r r i e d out in four media: ni t rogen , carbon d i o x i d e , a steam and ni trogen mixture and in a i r . For a l l systems, the minimum f l u i d i z a t i o n v e l o c i t y of the bed was f i r s t es tab l ished before any g a s i f i c a t i o n experiment was performed (Appendix 4 ) . For each g a s i f y i n g atmosphere, i nves t iga t ions were c a r r i e d out on the e f f e c t of bed temperature on gas composi t ion. Bed depth, p a r t i c l e s i z e of sand and sawdust were maintained at 20 cm, 0.55 mm and 0.67 mm r e s p e c t i v e l y f o r most runs. Moisture content of the Hemlock sawdust var ied between 1 to 6% by weight (wet b a s i s ) . Gas f lowrate was kept in the -4 3 v i c i n i t y o f 6 x 10 s t d . m / s . Due to the complexity of the s o l i d feed system, the s o l i d feedrate presented the most d i f f i c u l t to control parameter. Factors which a f f e c t the s o l i d f low are the s o l i d moisture content , the magnitude of the v i b r a t i o n of the feeder , the pressure in the storage b i n , the motion of sawdust p a r t i c l e s at the feeder i n l e t , the reactor p ressure , the amount of t ransport medium introduced and the amount of e l e c t r o s t a t i c charge encountered by the sawdust p a r t i c l e s along the polyethyelene conveying tube. The f lowrate var ied from 0.03 to 0.24 g /s f o r the 16 experiments performed; however, f o r most runs , i t was maintained at a t y p i c a l value of 0.1 g / s . 40 (1) EXPERIMENTAL PROCEDURE A known quant i ty of dr ied sawdust with a p a r t i c l e s i z e range of -20 +35 mesh i s loaded into the storage b i n . Next, 1405 g of -30 +35 mesh Ottawa sand i s poured from the top of the reactor onto the g r i d p late to give an i n i t i a l bed height of 20 cm. The reactor top bed and bottom bed temperature c o n t r o l l e r s are turned on to commence heating of the reac to r . Once the des i red bed and reactor gas temperatures have been reached, the t ransport medium i s introduced to the storage bin and the conveying tube, and eventua l ly enters in to the reac to r . The s o l i d feed i s the next item to be admitted to the reac to r . For experiments invo lv ing steam, the steam i s withdrawn from the steam mains and i s regulated by a globe v a l v e . Smaller f lowrate adjustments can be monitored on the rotameter. Since the rotameter i s used only as an i n d i c a t o r and not f o r accurate measurement, the mass f lowrate of the steam i s obtained by measuring the amount of condensate c o l l e c t e d at the e x i t of a cool ing c o i l over a c e r t a i n time i n t e r v a l . At l e a s t two measurements are taken to check f o r steady s t a t e . Once the system has at ta ined steady s t a t e , the magnetic feeder i s switched on, the magnitude of the v i b r a t i o n and thus the feedrate of the s o l i d i s gradua l ly increased to the desi red f low. V isual judgment of the f low through the polyethylene tubing i s required to determine whether the s o l i d f low i s too high or low. Care must be taken not to have too high a f low or the feed l i n e would c log and the run has to be abandoned. Steam, i f used, can be introduced into the reactor next. The time at which both of these are admitted in to the reactor i s recorded. The bed temperature drops s l i g h t l y when the s o l i d i s fed in to the r e a c t o r ; however, due to the e x c e l l e n t heat t rans fe r between the bed and the heated reactor s h e l l , the bed only takes another 10 minutes or so to resume i t s o r i g i n a l temperature. Gas samples can be withdrawn from the four sampling loca t ions (Figure IV-1) but the reactor e x i t gas g ives the most cons is ten t gas composi t ion. Sampling i s done every 5 to 8 minutes and a l l f l o w r a t e s , pressures and temperatures of the system are recorded soon a f t e r the sample i s taken. The temperatures can be read d i r e c t l y from a d i g i t a l readout using the mu l t ip le switch or be recorded on a 24-pen recorder . Gas samples are analyzed by gas chromatography. The t y p i c a l durat ion of the experiment i s about 60 minutes. For some runs , longer durat ion i s necessary fo r the reactor gas to reach a s tab le gas composi t ion. For shut-down, the s o l i d feeder is- f i r s t switched o f f , temperature c o n t r o l l e r s turned o f f and the steam ( i f used) i s bypassed into a cool ing c o i l . The t ransport gas can be l e f t on to quench the bed. The condensate f lowrate i s measured aga in . Mass of sawdust remained in the storage b i n , amount of char in bed, amount of cyclone c a t c h , water c o l l e c t e d from r e a c t o r , water c o l l e c t e d in impinger, f i n e s in impinger and amount of tar deposited along the heat exchanger pipe are other measurements c a r r i e d out a f t e r each run. (2) EXPERIMENTS CARRIED OUT Condit ions under which the 16 runs were performed are summarized in the fo l lowing t a b l e : TABLE V- l : OPERATING CONDITIONS Run Transport Medium F l u i d i z i n g Medium Bed Temp ( ° C ) Sampling Posi t ion Other P a r t i c u l a r s S o l i d Moisture (XW.wet) Wet S o l i d Feedrate (g /s) Total Gas Input (g /s ) .1 N 2 A i r 512.0 Port,SI ,S2 S o l i d fed at 25 cm above g r i d . A i r fed from below gr id p l a t e . 6.31 0.0776 1.7070 2 N 2 N 2 513.3 SI ,S2 S o l i d fed at 25 cm above grave l -sand. 6.75 0.0983 0.8641 3 N 2 N 2 688.8 SI ,S2 S o l i d fed at 5 cm above g r i d . 6.12 0.0731 0.9035 4 N 2 N 2 556.5 S1,S2 As for Run 3. 5.86 0.0530 0.8687 5 co2 co2 500.2 SI ,S2 As for Run 3. 6.70 0.0648 0.7533 6 co2 co2 517.0 SI ,S2 As for Run 3. 8.02 0.1019 1 .0934 7 co2 co2 420.3 S3 *As for Run 3. 1 .14 0.1123 1 .0000 8 N 2 N 2 410.3 S3 As for Run 3. 2.80 0.2356 0.8250 9 A i r A i r 436.7 S3 As for Run 3. 5.62 0.0908 0.5244 10 A i r A i r 595.7 S3 As for Run 3. 5.62 0.1526 0.7017 11 A i r A i r 472.9 S3 As for Run 3. 1 .50 0.11 83 0.7150 12 A i r A i r 669.9 S3 As for Run 3. 5.21 0.0929 0.6463 13 N 2 N 2 /steam 421 .0 S3 S o l i d fed at 5 cm above g r i d . Steam fed from below g r i d . 3.51 0.0493 1 .1801 14 N 2 N 2 /steam 597.0 S3 As for Run 13. 2.41 0.0974 0.6651 15 N 2 N 2 /steam 501.0 S3 As for Run 13. 4.40 0.0308 0.6416 16 N 2 N 2 /steam 415.6 S3 As for Run 13. 3.14 0.0729 0.6783 ( i ) I n i t i a l bed height for a l l runs = 20 cm (8"). ( i i ) Sawdust A was used for Runs 1-7, Sawdust B for Runs 8-16 (Refer to Sect ion 4) . ( i i i ) *Sawdust s i ze 0.67 mm except for Run 7 i . e . 0.46 mm. Mater ia l measurements obtained f o r Run 1 were d iscarded as they are u n r e l i a b l e simply because i t was the f i r s t attempt and a lso because o f the d i l u t i o n e f f e c t of the t ransport n i t r o g e n , which r e s u l t s in inaccurate gas d e t e c t i o n . By comparing the gas samples obtained at the p o r t , SI and S2; samples withdrawn from the port were found to be the only ones that contain oxygen. Thus, a i r leakage must have occurred at some points along the sampling l i n e . To avoid t h i s problem, samples were l a t e r taken only at the p l a s t i c tubings before and a f t e r the glass-wool column i . e . SI and S2 r e s p e c t i v e l y . Before s t a r t i n g Run 2, as descr ibed p r e v i o u s l y , a f i x e d bed of gravel was poured onto the reactor g r i d p l a t e . The s o l i d feed was l a t e r i n t r o -duced in to the bed i t s e l f 25 cm above the f i xed bed grave l /sand l e v e l . Th is Run was therefore somewhat d i f f e r e n t than the o thers . For a l l subsequent runs , the reactor was operated t y p i c a l l y at 1.2 times the minimum f l u i d i z a t i o n v e l o c i t y (conservat ive estimate) (Table V-2 ) . The s o l i d feed l i n e was shortened so that the s o l i d was fed only 5 cm above the g r id p late which e l iminated the usage of the grave l /sand mixture. During the tes t run f o r the s t e a m - ^ system; Run 13, the steam i n j e c t o r rate was too high f o r a l l the steam to be reacted with the s o l i d f eed . Steam was c a r r i e d over and was c o l l e c t e d in the impinger and eventua l ly f looded the impinger and the o r i f i c e p l a t e . The run had to be abandoned and the measurements gathered fo r the run were thereby d iscarded . TABLE V - ? : MINIMUM GAS REQUIRED FOR FLUIDIZATION Run Gas Used Bed Arrangement Bed Temp. co Minimum Gas Required For Fluidization (std.m3/s) Actual amount of Gas Used (std.m 3 /s) MF1 Air A1r fed from below grid 25 7.0 x 10"4 -MF2 Air Air fed from below grid 501.7 5.0 x 10"' -1 A1r/Tran.N 2 Air fed from below grid 512 5.0 x 10"4 (MF2) 6.0 x 10"4 (A1r) MF3 A1r Air fed through feed l ine , 5 cm above grid 25.0 3.5 x IO"4 A 9 Air As for MF3 436.7 3.5 x 10"4 (MF3) 44 x 10"* 10 Air As for MF3 595.7 3.5 x IO"4 (HF3) 5.9 x 10"4 11 Air As for MF3 472.9 3.5 x 10"4 (MF3) 6.0 x 10* 4 12 Air As for MF3 669.9 3.5 x 10"4 (MF3) 5.2 x 10"4 MF4 N 2 N2 fed through feed l ine, 25 cm above grid 25 7.4 x 10"4 MF5 N 2 N 2 fed through feed l ine , 5 cm above grid 25 5.4 x 10"4 -A 2 3 N 2 N 2 As for MF4 As for MF5 513.3 688.8 7.4 x 10"4 5.4 x 10"4 (MF4) (MF5) 7.4 x 10 * 7.8 x 10"4 4 N 2 As for MF5 556.6 5.4 x 10"4 (MF5) 7.5 x 10"4 8 N2 co2 As for MF5 410.3 5.4 x 10"4 (MF5) 7.1 x 10"4 MF6 C02 fed through feed l ine , above grid 25 3.7 x 10"4 MF7 co2 As for MF6 585.4 3.2 x 10"4 5 . co2 co2 As for MF6 500.2 3.7 x 10"4 (MF6) 4.1 x 10"4 6 As for MF6 517.0 3.7 x 10"4 (MF6) 6.0 x 10"4 7 co2 As for MF6 420.3 3.7 x 10"4 (MF6) 5.5 x 10"4 A 13 N2/steam As for MF5 with steam from below 421.0 5.4 x 10"4 (MF5) 5.8 x IO"* (N2) A 14 Nj/steam As for MF5 with steam from below 597.0 5.4 x 10"4 (MF5) 5.7 x IO"* (N2) * 15 N2/steam As for MF5 with steam from below 501.0 5.4 x 10"4 (MF5) 5.3 X 10"* (N2) A 16 N2/steam As for MF5 with steam from below 416.6 5.4 x 10"4 (MF5) 5.5 x 10"* (N2) * MF= Minimum Fluidization Measurements (3) SAND PREPARATION Ottawa sand was segregated in to d i f f e r e n t p a r t i c l e s i ze ranges in a "Ro-Tap" tes t ing s ieve shaker on a se r ies of s i e v e s . The p a r t i c l e s wi thin the range of U.S. -30 +35 mesh were used as the f l u i d i z e d bed m a t e r i a l . The average nominal s i z e i s 0.55 mm. To determine the amount of sand needed to bu i ld up a 20 cm s t a t i c bed, the bulk densi ty was found 3 to be 1700 Kg/m . With the inner c r o s s - s e c t i o n a l area of the reactor being 0.00407 m , a 20 cm deep s t a t i c bed would have a mass of 1405 g. (4) SAWDUST PREPARATION AND ANALYSIS Hemlock sawdust was obtained from the MacMillan Bloedel sawmill s i tuated near Boundary Road and Marine D r i v e , Vancouver. Two batches of the sawdust were obta ined. The f i r s t batch, sawdust A , as received from the K3 plant contained 45% moisture by weight on a wet b a s i s . This mater ial was used for Runs 1-7. The sawdust was dr ied in the oven at about 80°C to a moisture content in the v i c i n i t y of 6% (wet b a s i s ) , and then c l a s s i f i e d in the "Ro-Tap" tes t ing sieve shaker. The mass f r a c t i o n s of the d i f f e r e n t sizes- of the sawdust p a r t i c l e s are as shown below: U.S. Sieve Nominal Size Mass Frac t ion  (microns) +10 > 2000 0.12 -10 +16 1190-2000 0.27 -16 +20 841-1190 0.21 -20 +35 500-841 0.22 -35 +40 420-500 0.05 -40 +50 297-420 0.07 -50 < 297 0.06 The s o l i d feed system was t r i e d with the d i f f e r e n t s i z e f r a c t i o n s and i t was found that p a r t i c l e s i z e s coarser than 841 y presented problems as the feed l i n e f requent ly clogged up. Successful feeding was achieved f o r the s i z e range -20 +35 U.S. Eas ier operat ion and contro l of the feed rate was experienced with s t i l l smal ler s i z e s . Higher s o l i d feedrate can be a t ta ined with smal ler p a r t i c l e s s ince the number of p a r t i c l e s per un i t volume of the t ransport gas i s grea ter . However, due to the small amount of the smal ler s i z e p a r t i c l e s (-35 U .S . ) present i n the sample r e c e i v e d , the -20 +35 f r a c t i o n which comprises about 22% by weight of the bulk was chosen as the feed fo r the g a s i f i c a t i o n process. The ul t imate a n a l y s i s of the sawdust was undertaken by a commercial l abora to ry , Canadian M ic roana ly t i ca l Serv ice L t d . of Vancouver. For C, H, N percentage composition e v a l u a t i o n , the sawdust i s weighed in a t i n conta iner loaded in to the sampler and in jec ted i n t o a combustion reactor at 1010°C. The combustion gases are then c a r r i e d by a constant f low of helium through to the c a t a l y t i c sect ion of the reactor f o r a complete ox idat ion to CO2, H^O, N 2 and N x 0^. This mixture flows into a second reactor at 6 4 5 ° C , which i s f i l l e d with copper, f o r the reduct ion of N O and removal of excess oxygen. A chromatographic column separates x y the components, N^, C 0 2 and H 20 and each concentrat ion can be detected by the thermal c o n d u c t i v i t y de tec tor . The sulphur content i s determined by oxygen f l a s k combustion fol lowed by barium perchlorate t i t r a t i o n using screened thor in as the i n d i c a t o r . Determination of the ash content i s achieved by heating the sawdust to constant weight in a s i l i c a c r u c i b l e at 750°C in a i r . Oxygen content i s obtained by d i f f e r e n c e . The u l t imate a n a l y s i s (mass percentage) and the heating value of the bone-dry sawdust are as shown: Heating C ' H N 0 Ash S Value (KJ/g) Sawdust A 4 8 . 9 7 6 . 0 9 1 . 1 6 4 2 . 8 1 0 . 8 9 0 . 0 8 1 9 . 8 8 Sawdust B 4 9 . 4 4 6 . 2 1 0 . 0 7 4 3 . 2 9 0 . 7 0 0 . 2 2 1 8 . 9 4 The heating value i s determined by using a Pa i r Calor imeter and the procedure out l ined in A S T M - D 2 0 1 5 i s fo l lowed. For Runs 1 - 7 i n c l u s i v e , Sawdust A was used whereas Sawdust B was used fo r Runs 8 - 1 6 i n c l u s i v e . P r i o r to any experiment, the moisture of the sawdust to be loaded into the storage bin i s determined by heating i t to a constant weight. The value i s checked again a f t e r the experiment has been ca r r i ed out. (5) SAWDUST FEEDRATE A known mass of sawdust i s introduced into the storage bin p r i o r to the experiment. The sawdust remaining in the bin i s weighed a f t e r a run has been completed. The sawdust feedrate i s taken as the d i f fe rence d iv ided by the time elapsed during which the sawdust i s fed into the r e a c t o r . ( 6 ) FLUID FLOW MEASUREMENTS For a l l runs (excluding Run 1 ) except fo r those invo lv ing steam, only the t ranspor t gas i s introduced into the reactor besides the s o l i d f e e d , thus only the rotameter c a l i b r a t e d f o r t ranspor t ni t rogen was used (Appendix 2 ) . For runs where the t ransport gas employed i s C 0 n or a i r , the f lowrate can be corrected using the same c a l i b r a t i o n curve fo r t ranspor t n i t rogen . The volumetr ic f lowrate i s reported at the North American Standard cond i t ions f o r gases, i . e . 294.11 K (70 F) and 101.3 KPa (30" Hg, d r y ) . The steam mass f lowrate i s measured by weighing the condensate c o l l e c t e d from a coo l ing c o i l , during an in te rva l of t ime. This measure-ment i s performed both before and a f t e r the experiment. An average value i s used. However, the actual amount of steam that has s u c c e s s f u l l y made i t s entrance in to the react ing sect ion should be th is amount minus the amount of condensate c o l l e c t e d from the reactor over the durat ion of the experiment. Since the reactor bed i s operated well above the dew point of water, any water formed by react ions would be c a r r i e d over as steam and condenses eventua l ly in the impinger. An o r i f i c e p la te s i tuated at the ex i t of the heat exchanger i s used to determine the f lowrate of wet gas evolv ing out of the reac to r . The pressure drop across the o r i f i c e i s read from the mercury manometer. The appropr iate value of the discharge c o e f f i c i e n t can be obtained from the c a l i b r a t e d curve p lo t ted in Figure IX-3-1. (7) TEMPERATURE MEASUREMENTS A to ta l of 22 thermocouples are i n s t a l l e d at var ious parts of the apparatus to ind ica te the temperature v a r i a t i o n s . Only chromel-alumel thermocouples are used and they are connected to a mul t ip le channel switch and can be read on a d i g i t a l d i s p l a y . The p o s i t i o n of the thermocouples i s c l e a r l y marked in Figure IV-1. (8) SOLID ELUTRIATION RATE Entrained s o l i d p a r t i c l e s in the reactor e f f l u e n t s gas are c o l l e c t e d in the cyclone b i n . The s o l i d e l u t r i a t i o n rate i s taken as the average s o l i d c o l l e c t i o n rate in the bin throughout the course of the experiment. The carbon content of t h i s cyclone catch was analysed by the Canadian M i c r o a n a l y t i c a l Serv ice L t d . , the remainder was assumed to be ash. (9) BED SOLID ANALYSIS ' A f te r each run, the reactor bottom i s opened so that the sand and any unburnt sawdust p a r t i c l e s present c o l l e c t e d in a b i n . A sample of the mater ial i s taken and weighed. The char p a r t i c l e s are removed by submerging the sample in water and d iscard ing the material which f l o a t s on top. The remaining wet sand mixture i s then dr ied in an oven to constant weight. The amount of char p a r t i c l e s in the bed per uni t mass of sand can thus be obtained and hence the to ta l amount of char accumulated in the reactor bed during the experiment i s est imated. The unburnt char i s assumed to be 100% carbon in the mass balances as d iscussed in Chapter VI . (10) TAR ANALYSIS Tar deposited along the pipes in the e x i t of the r e a c t o r , p a r t i c u l a r -l y that along the heat exchanger, i s c o l l e c t e d by d i s s o l v i n g in acetone. The acetone i s then evaporated o f f under vacuum created by a water j e t . The tar l e f t i s then weighed and averaged over the durat ion of the run. The heating value of the tar was determined by Canadian M ic roana ly t i ca l Serv ice L t d . and i s reported to have a value of 29.99 K J / g . (11) GAS ANALYSIS 3 At s u i t a b l e i n t e r v a l s , 5 cm sample of the reactor gas i s in jec ted in to a Hewlett Packard gas chromatograph model 5710 A which c o n s i s t s of a 2.1 m molecular 5A sieve column, a 4 m Porapak Q column and a thermal conduc t i v i t y de tec tor . Argon i s used as the c a r r i e r gas . The detector temperature i s adjusted to 200°C. Gases resolved are H2> C 0 2 , N 2 , 0 2 , CH 4 and CO. The gas chromatograph i s connected to a Hewlett Packard 3388 in tegra tor which can be programmed f o r automatic valve switching f o r the gas chromatograph column. Nitrogen gas i s used to f a c i l i t a t e the switching mechanism. The c a l i b r a t i o n data input to the 3388 in tegra tor are obtained from the G .C . a n a l y s i s of a standard gas sample which contains a s i g n i f i c a n t amount of each of the gas components mentioned above. The 3388 Integrator analyses the var ious peaks numerical ly and the concen-t r a t i o n s of the gases are reported on a dry b a s i s . (12) GAS CALORIFIC VALUE The gross heating value of the reactor gas i s ca lcu la ted from the three combustible gases present in the gas i . e . H 2 , CO and CH^. According to the North American Standards fo r Combustion processes , where the reference condi t ions are 288.6 K ( 6 0 ° F ) and 101.3 KPa (30" Hg, d r y ) , the gross heating value Hcv, i s given by: HCv(MJ/m 3) = {[(%V H 2 ) * 12.109] + [(%V CO)* 11.997] + [ ( ° / V C H 4 ) * 37.743]}/100 VI . RESULTS AND DISCUSSION (1) GENERAL Experiments have been performed to inves t iga te the e f f e c t of reactor bed temperature over the range 400-700°C upon the gas composition (and hence heating value) fo r four d i f f e r e n t systems: ( i ) P y r o l y s i s in Nitrogen ( i i ) G a s i f i c a t i o n with a Steam-Nitrogen mixture ( i i i ) P y r o l y s i s in Carbon Dioxide ( iv ) Pa r t i a l ox idat ion with A i r During each run, an average of ten gas samples were withdrawn and analyzed by gas chromatography. Since the instantaneous s o l i d feedrate could not be maintained abso lu te ly constant , the resu l tan t gas composi-t ion var ied with t ime. Typical gas composition f o r each run were s e l e c t e d , based on the frequency of the same gas composition being reproduced. Operating condi t ions and the experimental r e s u l t s fo r the e x p e r i -ments performed are l i s t e d in Tables VI-1 and VI-2 and in Appendix 6. The amount of dry 'Net Gas' produced by the process i s c a l c u l a t e d by subt ract ing the input gas from the dry raw gas produced. TABLE VI-1: EXPERIMENTAL RESULTS FROM ALL RUNS N2 C02 Air Steam-N2 Run Number 8 4 3 7 5 6 9 11 10 12 16 15 14 Bed Temperature (°C) 410 557 689 420 500 517 437 473 596 670 416 501 597 Dry Solid Feedrate (g/s) Gas Feedrate (g/s) Gas/Dry Solid (w/w) Molar 0/C 0.229 0.825 3.6 0.35 0.050 0.869 17.4 0.37 0.069 0.904 13.2 0.37 0.111 1.000 9.0 5.35 0.060 0.753 12.5 7.32 0.094 1.093 11.7 6.89 0.086 .0.524 6.1 1.50 0.117 0.715 6.1 1.48 0.144 0.702 4.9 1.27 0.088 0.646 7.34 1.73 0.071 0.078 9.6 0.11 0.030 0.642 21.4 0.89 0.093 0.665 7.1 0.43 Net Dry Gas Produced (std.m3/g dry solid)xl0"4 (g/g dry solid) 1.53 2.00 4.52 8.1 i i 10.4 j 7.0 19.08 6.81 5.72 15.50 0.99 6.66 10.85 0.174 0.461 0.487 1.328 1.462 j 0.789 2.66 1.17 1.01 2.19 0.139 0.69 0.90 Gas Heating Value (MJ/std.m3) 11.73 13.50 13.70 3.68 i 7.04 j 12.78 i 5.71 1.35 0.82 5.55 6.49 16.06 14.63 Cyclone Catch (g/g dry solid) Tar (g/g dry solid) Char (g/g dry solid) 0.091 0.098 0.0 0.039 0.061 0.059 0.041 0.022 0.0 0.123 0.063 0.022 0.025 0.038 0.003 0.069 0.055 0.126 0.017 0.010 0.0 0.007 0.027 0.0 0.007 0.004 0.0 0.003 0.007 0.0 0.093 0.137 0.097 0.033 0.078 0.0 0.009 0.108 0.0 Total Residues (g/g dry solid) 0.189 0.159 0.063 0.208 0.066 0.250 0.027 0.034 0.011 0.010 0.329 0.111 0.117 Water*Produced (g/g dry solid) 0.51 0.39 0.39 0.49 0.36 0.32 0.29 0.52 0.55 0.33 0.55 0.28 0.08 Moisture* Content of Net Gas {% w) 74.6 45.8 44.5 27.0 19.8 28.9 9.8 30.8 40.1 13.1 79.8 28.9 8.2 * Amount of water computed after correcting for hydrogen balance (Refer Table VI-10). TABLE VI-2: CHARACTERISTICS OF NET GAS PRODUCED FOR ALL RUNS N2 co2 Air Steam-N2 Run Number 8 4 3 7 5 6 9 11 10 12 16 15 14 . Bed Temperature (°C) 410 557 689 420 500 517 437 473 596 670 416 501 597 Net Gas Produced (std.m3/g dry solid) x IO"4 H2 0.2295 0.4234 0.6360 0.0786 1.0598 0.9128 2.5396 0.2629 0.0669 1.9654 0.0849 0.6591 2.1026 CO 0.6645 1.1186 2.2310 1.3738 2.5792 3.4167 4.7280 0.2302 0.2528 3.5185 0.1959 2.5685 2.6094 CH4 0.1905 0.2238 0.7277 0.3280 0.7800 0.9912 0.5705 0.0858 0.0223 0.5317 0.0809 0.9666 1.0776 CO, 0.4395 0.1934 0.8272 6.3196 5.9810 1.6793 11.2419 6.2311 5.3780 9.4844 1 0.6229 0.0050 0.8671 C N2 0.0060 0.0408 0.0981 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0061 0.0 0.0040 Total 1.53 2.00 4.52 8.1 10.4 7.0 19.08 6.81 5.72 15.50 0.99 6.66 10.85 Heating Value (MJ/std.m3) 11.73 13.50 13.70 3.68 7.04 12.78 5.71 1.35 0.82 5.55 6.49 16.06 14.63 co (2) PYROLYSIS IN NITROGEN Four experiments were performed using pure nitrogen as the f l u i d i z i n g as well as the t ransport medium fo r the sawdust feed . Results obtained f o r Run 2, where the s o l i d was fed 2.5cm above a packed bed of a gravel and sand mixture , were not cons is ten t with the other three runs and were consequently ignored. The sample syr inge used fo r t h i s run was d iscovered to be leaking and was l a t e r rep laced . Sawdust B was used in Run 8 and the r e s u l t s fo l low the trend of the other two v a l i d runs. Table V1-3 summarizes the experimental f i n d i n g s . Runs were c a r r i e d out at temperatures from 410°C to 689°C . The gas feedrate was maintained between 0.83-0.98 g / s . The s o l i d feedrate could not be c o n t r o l l e d and var ied from 0.05 to 0.23 g / s . The higher f lowrate co inc ided with lower moisture content of the sawdust which reduces the tendency of the s o l i d p a r t i c l e s to s t i c k to the conveying tube. The gas /dry s o l i d (w/w) r a t i o thus ranged from 3.6 to 17.4. Since no f ree oxygen or any gaseous form of oxygen entered the r e a c t o r , the only oxygen atoms a v a i l a b l e were those contained in the dry sawdust and the assoc ia ted moisture . The molar 0/C r a t i o i s constant at 0.37 (0.35 fo r sawdust B) . In a p y r o l y s i s process , p a r t i c u l a r l y where the heat i s suppl ied by an external source , the to ta l volumetr ic gas y i e l d and y i e l d of var ious species would be expected to increase as the throughput of s o l i d inc reases . Thus r e s u l t s are presented in terms of s p e c i f i c 3 y i e l d s i . e . m gas/g sawdust. In Figure V I -1 , the s p e c i f i c gas y i e l d i s p lo t ted versus reactor temperature. The gas y i e l d increases s t rongly with temperature, and the r e s u l t s l i e somewhat below those of Brink and 25 Massoudi . They used the f low reactor technique where a i r - d r i e d White F i r wood p a r t i c l e s (4-8.4 mm) were suspended in a stream of ni trogen Upon enter ing the r e a c t o r , the p a r t i c l e s were heated up and underwent chemical r e a c t i o n s . Results are shown f o r p a r t i c l e s of 6.5% moisture which i s about the same moisture l eve l of the sawdust feed used in the present work. The temperature e f f e c t can be a t t r ibu ted to the greater rates at which the gaseous p y r o l y s i s products react with the char at higher temperatures. This i s in accordance with the genera l ly accepted f a c t that low temperature-low heating rate environments favor increas ing s o l i d product format ion, while high temperature and high heating rates create environments which favor increas ing gaseous product format ion. Gas production per un i t mass in Brink and Massoudi 's case i s higher than that in the present study at any temperature. Comparison in Figure VI-2 of the amounts of condensables and carbonaceous residues ( i . e . cyclone catch + char + tar ) between the two studies shows an agreement as they both decrease with increas ing temperature. The amount of res idues obtained from the present study i s h igher , as expected from the gas y i e l d data . As no f ree oxygen i s admitted in to the r e a c t o r , the combustion react ions are i n s i g n i f i c a n t . At atmospheric c o n d i t i o n s , the important react ions which fo l low the i n i t i a l breakdown of the wood into carbon and gaseous species are C •+ 2H 2 ^ " CH 4 (1) C + H 20 CO + H 2 (2) C + C 0 2 2C0 (3) C + 2H 20 C 0 2 + 2H 2 (4) CO + H 20 v C 0 2 + H 2 (5) From Figure V I -3 (B) , i t can be seen that the increas ing gas y i e l d with temperature i s p r i m a r i l y due to increased product ion of CO. However, the concentrat ions of CO and H 2 appear to go through a maximum around 550°C f o r the range of temperature invest igated ( 4 0 0 - 7 0 0 ° C ) . The minima of C 0 2 and CH^ content occur at the same temperature while the content va r ies p r o p o r t i o n a l l y with the bed temperature. Rapid r i s i n g CO, CH^ composit ions and the f a l l i n g of the C 0 2 content between 400 and 500°C seem to suggest that react ions C-H 2 0 and C - C 0 2 ( react ions 2 and 3) are prominant at t h i s low temperature range. With the higher bed temperatures, reac t ions 1, 4 and 5 appear to outweigh react ions 2 and 3 as suggested by the ascending CH^ and C0 2 content . H 2 produced v ia react ions 4 and 5 i s being used f o r the d i r e c t hydrogenation react ion and the overa l l H 2 content drops over the 550-700°C range. Water production decreases with increas ing temperature (Refer Table V I -1 ) . This suggests react ions 2, 4 and 5 are proceeding to the r i g h t at higher temperatures. The i r respect ive equ i l ib r ium constants at 800°C (Table 1-1 in Sect ion 3, Chapter I) of 2 .62, 1.11 x 10 and 1.10 x 10^° ind ica te that react ion 5 i s most favored thermodynamically around 800 tj . Experimental evidence appears to substant ia te th is suggestion that C O ^ O i s by f a r the most important react ion between 550 and 700°C by the downward trend of CO and the corresponding upward trend of C 0 2 concent ra t ion . A comparison of y i e l d s of d i f f e r e n t gaseous species in th is work with those of Brink and Massoudi can be made with Figure VI-3 and Figure VI-4. S imi la r trends are noted with temperature except f o r the C 0 2 y i e l d ; which r i s e s a f t e r 560°C in the present work and continues to f a l l in that of Brink and Massoudi. The rapid r i s e of CO and H 2 from 500°C onwards as they have observed i s a t t r ibu ted d i r e c t l y to g a s i f i c a t i o n react ions of C with H 20 and CO,,. The rates of these are asserted to be g rea t ly increased as temperature increases above 500°C. The sharp drop of C 0 2 content above 500°C shown by Brink and Massoudi does not f i n d support in the thermodynamic ev idence, as the water-gas s h i f t reac t ion (CO-r^O) w i l l d r ive toward formation of C 0 2 and H 2 at higher temperatures (un t i l % 1 0 0 0 ° C ) . Gas composit ion data (Figure V I - 5 ) , agreed in r e l a t i v e ranking with Brink and Massoudi only at temperatures around 600°C. The magnitude of experimental e r ro rs in Brink and Massoudi 's r e s u l t i s not known. The i r gas composi t ion , as tabulated i n Table IX-7-1 appears to be f l u c t u a t i n g g rea t ly between 600 and 8 0 0 ° C , whereas that as presented in Figure VI-4 i s not f l u c t u a t i n g . Although there i s no a f f i rmat ion that both the tabulated and the graphical r e s u l t s are from the same system (s ince the s o l i d moisture content i s not s p e c i f i e d f o r the tabulated r e s u l t s ) , i t would appear to be so s ince the general trend of each component i s the same and i s wi thin the same l i m i t s . Although many inves t iga to rs have studied the k i n e t i c s of p y r o l y s i s of wood and var ious types of c e l l u l o s e , i t i s genera l ly agreed that i t i s almost impossible to study each p y r o l y s i s react ion separa te ly . Many k i n e t i c models have been proposed based on the weight of residue and the weight loss a f t e r an i n f i n i t e t ime. Some inves t iga to rs d iv ided the p y r o l y s i s step in to two d i f f e r e n t stages in order to f i t t h e i r data but i t has been shown by many that i t resembles the k i n e t i c s of a f i r s t order or pseudo f i r s t - o r d e r r e a c t i o n . Brink and Massoudi de l ineated two k i n e t i c regimes. The a c t i v a t i o n energy and frequency f a c t o r f o r the lower-temperature regime (below 647°C) are 58.62 K J / m o l , 3 x 1 0 3 S _ 1 r e s p e c t i v e l y and are 104.67 KJ /mol , 2.64 x 10 S" f o r the higher temperature regime. Using the assumption of f i r s t order k i n e t i c s , the rate constant was def ined as the r a t i o of the converted f r a c t i o n over the unconverted f r a c t i o n of the s o l i d feed over the reactor residence t ime. Experimental operat ion v a r i a b l e s such as gas phase residence time and s o l i d feedrate are s i m i l a r to those in the present work i . e . 2 .4 -5 .3 S and 0.6 g /s r e s p e c t i v e l y . The s o l i d residence time in the reactor f o r Brink and Massoudi was c a l c u l a t e d as the r a t i o of the reactor volume over the to ta l f lowrate of gas i . e . t = 7^ - . Qt This would only be true i f the s o l i d pneumatical ly conveyed system experiences no s l i p v e l o c i t y between the p a r t i c l e s and the gas. For the present study, the lack of knowledge of the weight of the s o l i d feed in the bed prevents the c a l c u l a t i o n of a mean residence time of 49 s o l i d s in the f l u i d i z e d bed (residence time a bed w e i g h t / s o l i d f lowrate) A temperature c o e f f i c i e n t of r e a c t i o n , estimated as shown in Appendix 6, was found to be 33.8 KJ/mol which i s cons iderab ly below e i t h e r stage reported by Brink and Massoudi. 19 Barooah and Long used the same k i n e t i c model to descr ibe the primary stage of decomposition and the secondary stage was approximated to a second order process with respect to the weight l o s s to be completed in reaching e q u i l i b r i u m . They ind icated that the primary stage gives about 85% of the to ta l weight change and that the secondary stage occurs at the l a s t 15% of the to ta l weight change. Beechwood sawdust, s i z e 18 to 25 mesh BS sieve was decomposed in a f l u i d i z e d bed of sand in an atmosphere of n i t rogen at temperatures up to 400°C . Further s i m i l a r i -t i e s in the apparatus used compared to that of the present study are that the reactor was a lso 7.6 cm in diameter and was heated e l e c t r i c a l l y by surrounding heating elements. A marked change in the temperature dependence of the rate of wood p y r o l y s i s in the region 300-350°C was observed. For temperatures higher than 330°C , the k i n e t i c s parameters 4 -1 f o r the primary stage are 84 KJ /mol , 2.3 x 10 S and 115 KJ/mol , 9 -1 4 x 10 S f o r the secondary stage. A n a l y s i s of data by Tran and R a i ^ of experiments on the p y r o l y s i s of powdered Douglas F i r bark (8.8% wet) with a DuPont 951 Thermogravi-metr ic Analyzer used a k i n e t i c s model in which the a c t i v a t i o n energy i s assumed to be l i n e a r funct ion of the extent of r e a c t i o n . The i r s o l i d feed was of s l i g h t l y higher heating value but i t s ul t imate ana lys is i s s i m i l a r to that of the sawdust used in t h i s study. The a c t i v a t i o n energy was found to vary from 101.7 to 201.8 KJ/mol as non-catalyzed bark conversion increases from 10% to 70%. The temperature c o e f f i c i e n t of react ion or a c t i v a t i o n energy fo r Hemlock sawdust decomposition in the present study i s lower than r e s u l t s obtained by Brink and Massoudi , Barooah and Long and Tran and R a i . The best comparison i s found with that of the lower-temperature regime observed by Brink and Massoudi. For more d e t a i l e d k i n e t i c s t u d i e s , a more accurate technique in analysing the s o l i d residues i s mandatory and prec ise amounts of carbon, a s h , tar and other residues would have to be determined. Since chemical c o n d i t i o n s , such as composition of feedstocks , ambient atmosphere, and c a t a l y s t a f f e c t the nature , the extent , and the sequence of var ious p y r o l y s i s r e a c t i o n s ; and a lso the physica l condi t ions of the feedstock and the environmental condi t ions of the process a f f e c t the d i s p e r s i o n of heat in the s o l i d feedstock and the d i f f u s i o n of v o l a t i l e products from the feedstock , the only meaningful comparisons are those between experiments performed under a s p e c i f i c c o n d i t i o n . 60 TABLE V I - 3 : EXPERIMENTS PERFORMED IN No ATMOSPHERE Run Number 8 4 3 Bed Temperature ( ° C ) 410 557 689 S o l i d moisture content (% w, wet bas is ) 2.80 5.86 6.12 Dry s o l i d feedrate (g /s ) 0.229 0.050 0.069 Wet s o l i d feedrate (g /s ) 0.236 0.053 0.073 Gas feedrate (g /s) 0.825 0.869 0.904 Gas/Dry s o l i d (w/w) 3.6 17.4 13.2 0/C (moi/moi) 0.35 0.37 0.37 Raw Gas Produced Gas Composition (%V, dry) H 2 0.71 0.69 0.55 CO 2.06 1.80 1.92 CH 4 0.59 0.36 0.63 co2 1.36 0.31 0.71 N 2 95.28 98.84 96.19 Heat Value of gas (MJ/std.m3) 0.56 0.44 0.53 Dry gas produced ( s t d . m 3 / g dry s o l i d ) 32.6x10" 4 151.9x10~ 4 1 1 8 . 0 x l 0 - 4 (g/g dry s o l i d ) 3.778 17.869 13.650 Tar (g/std.m dry gas produced) 30.03 4.00 1.88 Net Gas Produced Gas Composition (% V, dry) H 2 15.00 21.17 14.07 CO 43.43 55.93 49.36 CH 4 .12.45 11.19 16.10 co2 18.73 9.67 18.30 0.39 2.04 2.17 Heating Value of gas (MJ/std.m 3 ) 11.73 13.50 13.70 Dry gas produced ( s t d . m 3 / g dry s o l i d ) 1 .53xl0" 4 2 .00x10 - 4 4.52x10" 4 (g/g dry s o l i d ) 0.174 0.461 0.487 Tar (g/g dry s o l i d ) 0.098 0.061 0.022 Cyclone catch (g/g dry s o l i d ) 0.091 0.039 0.041 Char (g/g dry s o l i d ) 0.0 0.059 0.0 S u p e r f i c i a l v e l o c i t y (m/s) 0.28 0.56 0.50 Comments: Sawdust B Sawdust A Sawdust A 29 Figure VI-3: Gas Composition (Net Gas) vs . Bed Temperature fo r P y r o l y s i s in N CTl CO 4 4* L e g e n d E x p e r i m e n t a l B r i n k & M a s s o u d i w o o d p a r t i c l e : 6 - 5 % w e t 4 - 0 — 8 - 4 m m f l o w r e a c t o r BED TEMPERATURE ( C ) Figure VI-5: Comparison of Gas Composition (Net Gas) f o r P y r o l y s i s in N 2 (3) GASIFICATION WITH STEAM-NITROGEN MIXTURES Three runs were c a r r i e d out with a ni trogen f lowrate of 0.62 - 0 . 6 6 g / s The weight percent of the steam introduced in the input gas mixture var ied from 1.5 to 6 .5 . Dry s o l i d feedrate var ied from 0.03 to 0.09 g /s and the molar r a t i o of H2O/C ranged from 0.2 to 0.89. The temperature range var ied from 416 to 597°C. The s p e c i f i c net gas y i e l d increased with temperature as can be seen from Table VI -4. The extremely rapid increase which occurs between 400 and 500°C does not appear to be re la ted to increas ing steam/wood r a t i o which only increased by 25%. Production of CO, H 2 and CH^ are increas ing with temperature although the rapid ascent of CO and CH^ i s somewhat deminished above 5 0 0 ° C , p o s s i b l y due to the lower steam con-c e n t r a t i o n . The production of C0 2 reaches a minimum at 500°C (Figure V1-6(B) ) . Moisture content o f the met gas produced decreases r a p i d l y with increas ing temperature (Table V I -1 ) . From Figure V I -6 (A) , i t i s shown that the rapid r i s i n g of CO, CH^ and H 2 content i s accompanied by a f a l l i n g of the C 0 2 content between 400 and 500°C. Reactions C - 2 H 2 , C-H 2 0 and C - C 0 2 would account f o r th is phenomenon. With temperature increased beyond 5 0 0 ° C , the CO and CH^ content begins to f a l l while the H 2 content continues to increase r a p i d l y and the descent of the C0 2 content decreases. This can be a t t r i b u t e d to the water-gas s h i f t react ion which gains importance at higher temperatures with the production of C 0 2 and H 2 - A small c o n t r i -bution of these two gas species could have been the products of C-2H 2 0 r e a c t i o n . The methanation r e a c t i o n , which i s sa id to be s i g n i f i c a n t in the higher temperature region when there i s no steam i n j e c t i o n , i s outweighed by the r i v a l water-gas s h i f t reac t ion in the presence of a steam atmosphere. Thus, the production of H 2 continues to cl imb and the product ion i s resumed at temperatures above 500°C. With the assumption of a p s e u d o - f i r s t order k i n e t i c s , the r e a c t i v i t y of sawdust in the steam-N 2 atmosphere i s found to have an a c t i v a t i o n •3 _ i energy of 64.44 KJ/mol and a pre-exponent ia l f a c t o r of 4.7 x 10 s . More t e s t s are needed f o r a better estimate of the k i n e t i c parameters s ince the three exper imental ly obtained points don ' t f a l l exac t ly in a s t r a i g h t l i n e in the Arrhenius p lo t (Appendix 6 ) . 15 In Tran and R a i ' s experiments , the powdered Douglas F i r bark was charged in to"a 2.5 cm flow reactor which was brought to the des i red operat ing condi t ions before steam i n j e c t i o n was s t a r t e d . Steam rate -4 was var ied from 0 to 0.0056 g / s . In the presence of K 2 C 0 3 , 4.88 x 10 3 3 std.m of 17 MJ/std.m gas i s sa id to be produced from 1 gram of dry feed around the 600 TJ reg ion . Production rate dropped to 1.5 x I O - 4 3 std.m when no c a t a l y s t was used and the heating value of the gas was somewhat lower. The present study shows that at 5 9 7 ° C , gas produced 3 provides a heating value of 14.63 MJ/std.m . This i s in good agreement with Tran and R a i ' s r e s u l t s ; the higher conversion rate (10.85 x 10 4 3 std.m / g dry s o l i d ) i s probably due to the higher steam i n j e c t i o n rate (0.01 g / s ) . When operat ing the f l u i d i z e d bed in a countercurrent mode with an 41 upward stream of a i r and steam, Beck, Wang and Hightower obtained a -4 3 gas y i e l d as high as 17 x 10 std.m / g dry feed . The heating value 3 of the raw gas exceeds 9.5 MJ/std.m f o r both dry and green oak sawdust. In the a i r -s team atmosphere, the f i x e d bed reactor g ives r i s e to a lower q u a l i t y gas ( i . e . 7 MJ/std.m ) as found by Hammond, Mudge, A l l e n and S c h i e f e l b e i n on the g a s i f i c a t i o n of wood c h i p s . D i rec t comparison between these two studies and the present study i s not poss ib le because of the change in react ion processes due to the in t roduct ion of f ree oxygen in the a i r f eed . Figure VI-7 attempts to compare the CO, and CH^ production rates in the f l u i d i z e d bed process f o r the two c a s e s ; i . e . steam or steam a i r as gas feed . When the data obtained f o r the steam case i s extrapolated in to the higher temperature regions as invest igated by Beck et a l . , i t can be seen that and CH^ production are both much lowered v ia the in t roduct ion of a i r . The CO production rate i s not s i g n i f i c a n t l y a f f e c t e d . Since the combustion react ions are favoured over the g a s i f i c a t i o n react ions of C-h^O and C-CO2, s i g n i f i c a n t amounts of CO and produced v ia these two react ions are reacted with oxygen to form CO2 and water. The reduct ion in H2 content a lso serves to reduce the extent of d i r e c t hydrogenation of carbon. T A B L E V I - 4 : E X P E R I M E N T S P E R F O R M E D W I T H S T E A M - N o Run Number 16 15 14 Bed Temperature ( ° C ) 416 501 597 S o l i d moisture*content (%w, wet bas is ) 3.15 2f41 4.41 Dry s o l i d feedrate (g /s) 0.071 0.030 0.093 Wet s o l i d feedrate (g /s) 0.073 0.031 0.097 Steam feedrate (g /s) 0.044 0.024 0.010 Gas feedrate (g /s ) (steam & t ransport No, 0.678 0.642 0.665 % steam in input gas (weight) 6.5 3.7 1.5 Gas/Dry sol id (w/w) 9.6 21.4 7.1 H 2 0/C (mol/mol) 0.89 1.11 0.20 0/C (mol/mol) 0.77 0.89 0.43 Raw Gas Produced Gas Composition (%V, dry) H2 0.11 0.44 4.82 CO 0.24 1.70 5.98 CH 4 0.10 0.88 2.47 C 0 2 0.78 0.64 1.99 N 2 98.77 96.34 84.75 Heating value of gas (MJ/std.m 3 ) 0.08 0.59 2.23 Dry gas produced ( s t d . m 3 / g dry s o l i d ) 7 8 . 3 x l 0 - 4 183.8x l0" 4 71.5x10" 4 (g/g dry s o l i d ) 9.150 21.560 8.108 Tar (g /std.m dry gas produced) 17.44 4.23 1.51 Net Gas Produced Gas Composition (%V, dry) Hp 8.57 11.94 31.57 CO 19.77 46.53 39.18 CH 4 8.16 24.02 16.18 C O o 62.87 17.51 13.02 0.62 0.0 0.06 Heating Value of gas (MJ/std.m 3 ) 6.49 16.06 14.63 Dry Gas produced ( s t d . m 3 / g dry s o l i d ) 0 .99x l0" 4 6 .66x10 - 4 10.85x10" 4 (g/g dry s o l i d ) 0.139 0.69 0.90 Tar (g/g dry s o l i d ) 0.137 0.078 O.On Cyclone catch (g/g dry s o l i d ) 0.093 0.033 0.009 Char (g/g dry s o l i d ) 0.097 0.0 0.0 S u p e r f i c i a l v e l o c i t y (m/s) 0.34 0.36 0.40 Comments: 20 cm sand bed, Sawdust B oz 500 600 700 B E D T E M P E R A T U R E ( ° C ) Figure VI-7: Comparison of Gas Produced (CH^, CO, h^) fo r G a s i f i c a t i with Steam or Steam-Air (4) PYROLYSIS IN CARBON DIOXIDE Resul ts obtained from runs performed in pure C 0 2 atmosphere are summarized in Table VI -5 . V a r i a t i o n in dry s o l i d feedrate i s cons iderab ly smal ler than that encountered f o r runs performed in n i t rogen . These runs were c a r r i e d out at a sawdust feedrates of 0.06-0.11 g /s and a g a s / s o l i d r a t i o of 9-12.5. No f ree oxygen was admitted in to the reactor and the oxygen atoms entered predominantly as C 0 2 . Molar 0/C r a t i o ranged from 5.35 to 7.32. The temperature was var ied over the range 420 to 517°C. -4 -4 3 The s p e c i f i c net gas y i e l d ranged from 7 x 10 to 10 x 10 std.m / g sawdust as shown in Table VI -5 . The gas heating value (Table VI-5) r i s e s sharply with temperature p a r t i c u l a r l y at temperatures higher than 500°C. In Figures VI-8(B),the production of d i f f e r e n t gas species i s shown as -4 a funct ion of temperature. Production of CO experiences a 0.9 x 10 3 -4 -4 std.m jump while the C 0 2 produced drops from 6 . O x 10 to 1.7 x 10 3 std.m per gram of input dry s o l i d feed during a s l i g h t r i s e in the bed temperature, from 500 to 517°C. Three react ions appear to be of s i g n i f i c a n c e ; the C - H 2 0 , C - C 0 2 and the water-gas s h i f t r e a c t i o n . The carbon-steam react ion accounts f o r the production of H 2 as well as CO although most of the CO comes from C - C 0 2 r e a c t i o n . The s l i g h t drop in the H 2 p roduct ion , the rapid increase in CO product ion and the corresponding sharp drop in C 0 2 production from 500°C onward c l e a r l y ind ica te that the reverse water-gas s h i f t react ion 45 has become compet i t ive at higher temperatures . When the r e a c t i v i t y of sawdust in a carbon d iox ide atmosphere i s f i t t e d to a pseudo f i r s t - o r d e r k i n e t i c s (Appendix 6 ) , the parameters obtained are K , n = 2.2 x 10 S and E, = 92.59 KJ/mol . No comparable data are a v a i l a b l e f o r wood g a s i f i c a t i o n , however, Eklund and Svensson invest iga ted the g a s i f i c a t i o n of Ranstad o i l shale in a f l u i d i z e d bed and found that the r e a c t i v i t y i s lower. Thei r reported a c t i v a t i o n energy i s 171 KJ/mol and the pre-exponential f a c t o r being 8780 S - 1 . 74 T A B L E V I - 5 : E X P E R I M E N T S P E R F O R M E D I N C O o A T M O S P H E R E Run Number 7 5 6 Bed Temperature ( ° C ) 420 500 517 S o l i d moisture content (%w, wet bas is ) 1.14 6.70 8.02 Dry s o l i d feedrate (g /s ) 0.111 0.060 0.094 Wet s o l i d feedrate (g /s) 0.112 0.065 0.102 Gas feedrate (g /s) 1.000 0.753 1.093 Gas/Dry sol id'(w/w) 9.0 12.5 11.7 0/C (moi/moi) 5.35 7.32 6.89 Raw Gas Produced Gas Composition (%V, dry) H 2 0.14 1.36 1.31 CO 2.38 3.30 4.88 CH 4 0.57 1.00 1.42 co2 96.92 94.34 92.40 N 2 0.0 0.0 0.0 Heating Value of gas (MJ/std.m ) 0.52 0.94 1.28 Dry gas produced (std.m / g dry s o l i d ) 57 .5x l0" 4 78 .8x l0" 4 7 1 . l x l O " 4 (g/g dry s o l i d ) 10.337 13.928 12.460 Tar (g/std.m dry gas produced) 11 .02 4.68 7.76 Net Gas Produced Gas Composition (%V, dry) H 2 0.97 10.19 13.04 CO 16.96 24.80 48.81 CH 4 4.05 7.50 14.16 co2 78.02 57.51 23.99 N 2 , 0.0 0.0 0.0 Heating Value of gas (MJ/std.m ) 3.68 7.04 12.78 Dry Gas produced (std.m / g dry s o l i d ) 8 . 1 x l 0 " 4 10 .4x l0" 4 7 . 0 x l 0 " 4 (g/g dry s o l i d ) 1.328 1 .462 0.789 Tar (g/g dry s o l i d ) 0.063 0.038 0.055 Cyclone catch (g/g dry s o l i d ) 0.123 0.025 0.069 Char (g/g dry s o l i d ) 0.022 0.003 0.126 S u p e r f i c i a l V e l o c i t y (m/s) 0.28 0.29 0.41 Comments: 0.46 mm 0.6705 mm 0.6705 mm sawdust sawdust sawdust X 10 400 500 600 BED TEMPERATURE (°C ) (A) 700 400 500 600 700 BED TEMPERATURE C°C) (B) Figure VI-8: Gas Composition (Net Gas) vs Bed Temperature f o r P y r o l y s i s in CC^ 76 (5) GASIFICATION WITH AIR Molar O/C r a t i o f o r the system was maintained around 1.5 f o r the four runs conducted with a i r which i s 75% of that required f o r complete combustion. Table VI-6 l i s t s the experimental c o n d i t i o n s . The s o l i d feedrate var ied over the range 0.09 to 0.15 g / s . In three of the runs the raw gas produced contained t races of unreacted oxygen. The net gas production rate went through a minimum as reactor temperature was inc reased , as i s evident from Table VI -6 . In Figure V I -9 , production rate of var ious gas species and the gas composition are shown as funct ions of temperature. In the temperature range invest iga ted ( 4 6 0 - 6 7 0 ° C ) , the react ion rate drops to a minimum around 550°C and only s t a r t s to resume a f t e r 600°C. This phenomenon i s not reported by previous inves t iga to rs s ince t h e i r working range of temperature i s genera l ly h igher . Corresponding to t h i s drop in C02» CO, H 2 and CH^ production r a t e s , there i s an increase in the water formation (Table V I - 1 ) . This serves to suggest that the combustion of hydrogen predominates wi thin the 500-600°C range. This rapid consumption of hydrogen reduces the hydrogen a v a i l a b l e f o r d i r e c t hydrogenation of carbon, thus a drop in CH^ production f o l l o w s . The r i s e in CO2 and the f a l l of CO content can be a t t r ibu ted to the CO-O2 react ion which ox id i zes CO to CO2. 20 35 Wen, L i n , O ' b r i e n , B a i l i e and Burton used a l a r g e r f l u i d i z e d bed. Natural gas was burned and the combustion gases were mixed with a i r before passing through the g r i d p l a t e . Typical gas composition would comprise 88.5% N 2 , 10.2% C 0 2 , and 1.2% 0 2 - Apart from t h i s minor d i f f e r e n c e in gas feed and a lower gas /dry s o l i d r a t i o (0.13 compared to 6 ) , operat ion v a r i a b l e s such as s u p e r f i c i a l v e l o c i t y , sawdust s i z e , heating value and moisture content of s o l i d feed were within the range used in t h i s study. F igures VI-10 and VI-11 show that i f the trends of the v a r i a t i o n of each gas concentrat ion with temperature obtained in t h i s study are extended in to the temperature range invest iga ted by Wen et a l r e a s o n a b l e agree-ment f o r each gas component concentrat ion i s found. The net gas production -4 3 rate of 15.5 x 10 std.m / g dry s o l i d fo r Run 12 (670°C) i s somewhat higher than that reported by Wen et a l . between 780 and 8 2 0 ° C , i . e . % 11.4 x 10" 4 s t d . m 3 / g dry s o l i d . Other i n v e s t i g a t o r s who have g a s i f i e d wood with a i r in a f l u i d i z e d 8 2 3 bed are Ki lburn and Level ton and L i u , Serenius and Martinez ' . K i lburn and Level ton claimed that 11.2 x 10" 4 s t d . m 3 of 9.32-10.43 M J / s t d . m 3 was produced from 1 g of dry wood. This r e s u l t c l o s e l y resembles the data obtained by Wen et a l . , although the gas /dry s o l i d r a t i o was much h igher , i . e . at 9 (Appendix 7 ) . Liu et a l . operated at an intermediate gas /dry s o l i d r a t i o range of 2 to 3. The raw gas produced exh ib i t s a much higher heating value than that observed from the present works. However, they were operat ing at much higher temperatures and the Hemlock sawdust used was 35.0-52.5% wet. The moisture introduced with the wood dr ives the C ^ O to the formation of CO and and consequently CH^ v ia the d i r e c t hydrogenation r e a c t i o n . Hence, CH^, CO and concentrat ions are higher than would have been predic ted assuming the same trend obtained from the present study to be app l i cab le at higher temperatures (Figure VI -11) . 22 30 For f i x e d bed o p e r a t i o n , both Voss and Jones reported a raw gas with H 2 and CO content as high as 10% and 30% r e s p e c t i v e l y . The 3 corresponding heating value i s around 5 MJ/std.m . When the bed temperature 7.6 cm above the grate was about 1093°C , Liu et a l . manufactured a s i m i l a r raw gas to that obtained from f ixed bed opera t ion . This together with the large temperature gradient experienced across the bed, suggests that they did not have a t r u l y 4 f l u i d i z e d bed. Other evidence that leads to such a conc lus ion are the low p a r t i c u l a t e emiss ion , the low volumetric heat re lease in the fuel bed, low fuel throughput and the gas ana lys is r e l a t i o n s h i p with bed height . 79 ) TABLE VI-6: EXPERIMENTS PERFORMED WITH AIR Run Number 9 11 10 12 Bed Temperature ( ° C ) S o l i d moisture content (%w, wet bas is ) Dry s o l i d feedrate (g /s ) Wet s o l i d feedrate (g /s ) Gas feedrate (g /s ) Gas/Dry s o l i d (w/w) 0/C (moi/moi) 437 5.62 0.086 0.091 0.524 6.1 1.50 473 1.50 0.117 0.118 0.715 6.1 1.48 596 5.62 0.144 0.153 0.702 4.9 1.27 670 5.21 0.088 0.093 0.646 7.34 1.73 Raw Gas Produced Gas Composition (%V, dry) H 2 CO CH 4 C0 2 N 2 0 2 4.31 8.03 0.97 19.09 67.60 0.0 0.55 0.48 0.18 13.06 83.51 2.23 0.18 0.68 0.06 14.50 83.42 1.16 3.07 5.50 0.83 14.85 74.69 1.06 Heating value of gas (MJ/std.m 3 ) 1.85 0.19 0.13 1.35 Dry Gas produced ( s t d . m 3 / g dry sol id) 58.9x10" 4 47.8x10' •4 37 .2x l0" 4 6 4 . 0 x l 0 " 4 (g/g dry s o l i d ) 7.280 5.950 4.780 7.830 Tar ( g / s t d . m 3 dry gas produced) 1.717 5.39 1.12 1.13 Net Gas Produced Gas Composition (%V, dry) H 2 CO CH 4 CO2 N 2 o2 13.31 24.78 2.99 58.92 0.0 0.0 3.86 3.58 1.26 91.50 0.0 0.0 1.17 4.42 0.39 94.02 0.0 0.0 12.68 22.70 3.43 61 .19 0.0 0.0 Heating value of gas (MJ/std.m 3 ) 5.71 1.35 0.82 5.55 Dry Gas produced ( s t d . m 3 / g dry sol id) 19 .08xl0" 4 6.81x10" •4 5 .72x l0" 4 15.50x10" 4 (g/g dry s o l i d ) 2.66 1.17 1 .01 2.19 Tar (g/g dry s o l i d ' Cyclone catch (g/g dry s o l i d ' Char (g/g dry s o l i d ) S u p e r f i c i a l V e l o c i t y (m/s) 0.010 0.017 0.0 0.22 0.027 0.007 0.0 0.40 0.004 0.007 0.0 0.40 0.007 0.003 0.0 0.40 Comments 20 cm sand bed Sawdust B i Figure VI-9: Gas Composition (Net Gas) vs . Bed Temperature f o r G a s i f i c a t i o n with A i r 1 0 0 4 0 0 5 0 0 6 0 0 7 0 0 8 0 0 B E D T E M P E R A T U R E ( °C ) Figure VI-10: Comparision of Gas Composition (Net Gas) f o r G a s i f i c a t i o n with A i r 100r 60h 40h z o o o < 300 Exper imental 400 500 -A co 2 - • o 2 Wen, Lin.O Brien, Bailie & Burton ^ Liu, Serenius & Mart inez • ~ "~ ~ - ^ A*A A 1 A C 0 2 • • • B H 0 2 H2 O / / / / / A A O O o • a o o- • 600 700 800 BED TEMPERATURE C C ) 900 -fjCH, 1 1000 1100 Figure VI-11: Comparison of Gas Composition (Raw Gas) f o r G a s i f i c a t i o n with A i r CO ro (6) COMPARISON OF RESULTS WITH DIFFERENT FLUIDIZING MEDIA S p e c i f i c net gas production rates versus reactor temperature are compared in Figure VI-12 for the d i f f e r e n t f l u i d i z i n g media used. The r e l a t i v e pos i t ions of the curves fo r the d i f f e r e n t f l u i d i z i n g gases appear reasonable . P y r o l y s i s in ni t rogen i s expected to produce the smal lest amount of gas at a given temperature s ince there would be l i t t l e attack on the carbon, except from the p y r o l y s i s products themselves which would be r a p i d l y swept out of the reactor zone. Introduct ion of steam, C 0 2 or a i r in to the system enhances the react ion rate and more gas is produced. The gas production with C0 2 p y r o l y s i s experiences a drop at 500°C which i s bel ieved to have caused by the increased rate of the reverse water-gas s h i f t r e a c t i o n , reducing the volumetric amount of gas with the formation of water (Refer Section 4 ) . For a i r g a s i f i c a t i o n , the drop in gas production between 500°C and 600°C is thought to be caused by water formation a l s o , but v ia a d i f f e r e n t react ion - in t h i s c a s e , the combustion of hydrogen with free oxygen (Sect ion 5) . With increas ing bed temperature, the heating value of the gas produced from ni trogen p y r o l y s i s increases (Figure VI -13) . When steam i s added to the system, the resu l tan t gas i s super ior in heating value to that from pure ni trogen p y r o l y s i s at temperatures above 450°C . The heating value begins to drop, however at 500°C due to the production of C 0 2 being resumed. For runs c a r r i e d out with C 0 o , the heating value o f the r e s u l t i n g gas increases with increas ing temperature, while no apparent r e l a t i o n s h i p can be deduced fo r the a i r runs. A comparison o f the d e t a i l e d gas composition production from the d i f f e r e n t f l u i d i z i n g media i s shown in Figures VI-14 to 16. Gas volumetr ic compositions are p lo t ted in Figures VI-17 to 19. In comparison with n i t r o g e n - p y r o l y s i s , when steam i s introduced into the system, a d r a s t i c increase in CO, and CH^ production rate i s observed while the increase in CO2 production i s not as marked. Although the gas produced i s higher in CH^ and H2 content (at higher temperatures) , the CO content i s comparatively lower than the gas produced from n i t rogen-p y r o l y s i s . P y r o l y s i s of sawdust in the presence of CO2 produces more h^, CH^, CO and CO2 than when c a r r i e d out in an atmosphere of ni trogen for the temperature range i n v e s t i g a t e d . The to ta l amount of net gas produced per gram of dry s o l i d feed i s thus h igher . However, because of the smal ler amount o f CO2 produced in the ni trogen p y r o l y s i s , the resu l tant gas turns out to be a bet ter q u a l i t y gas, r i c h e r in CO and H 2 (a lso CH^ for the lower temperature range) between 400 and 530°C . For temperatures above 530°C , the reverse is expected to be true i f the trend of the va r ia t ions o f CO2, CO, H 2 and CH^ production rate with temperature is fol lowed into the higher temperature reg ion . Gas produced with a i r used as the f l u i d i z i n g medium is a lso of i n f e r i o r nature compared to the ni trogen p y r o l y s i s gas wi th in the range of temperature i n v e s t i g a t e d . With the resumption of the production of CH^, CO, H2 and CO2 from 600°C onwards, gases produced v ia a i r g a s i f i c a -t ion at higher temperatures are expected to be super ior to those obtained v ia n i t rogen p y r o l y s i s . 20 Gasification With S t e a m / N 2 300 4 0 0 500 600 700 B E D T E M P E RATU RE (°C ) Figure VI-13: Gas (Net Gas) Heating Value vs Bed Temperature ex. M E T H A N E X 10 ^ 2 E u 3 Q O X o G a s i f i c a t i o n W i t h S t e a m / N . P y r o l y s i s In N 2 G a s i f i c a t i o n W i t h A i r J I 400 700 B E D T E M P E R A T U R E (°C) Figure VI-14: H2 and CH^ Production vs Bed Temperature 88 Figure VI-15: CO Production vs Bed Temperature C A R B O N D I O X I D E 12h Gasi f icat ion With Air Pyrolysis In C 0 2 Gasi f icat ion With S t e a m / N , _L Pyrolysis In N 2 400 500 600 B E D T E M P E R A T U R E ( °C ) 700 F i g u r e V I - 1 6 : P r o d u c t i o n vs Bed Tempera tu re 90 HYDROGEN CONTENT >• k. -o > 30 • < o r— UJ z 20 z P y r o l y S i s In N 2 / G a s i f i c a t i o n W i t h S t e a m / N 2 CONTENT o • O • / A • o CVJ I P y r o l y s i s In / C ° 2 A / - . ^ / G a s i f i c a t i o n / W i t h A i r i 400 500 600 700 B E D T E M P E R A T U R E (°C) Figure VI~i7 : H? and CH. Content in Net Gas vs Bed Temperature C A R B O N M O N O X I D E C O N T E N T ' 60 B E D T E M P E R A T U R E (°C ) Figure VI-18: CO Content in Net Gas vs Bed Temperature 400 500 600 ^ BED TEMPERATURE (°C) 700 gure V I -19: C0 ? Content in Met Gas vs Bed Temperature (7) MASS BALANCES Overa l l and ind iv idua l elemental mass balances were c a r r i e d out for the 13 successfu l runs fo r the v a l i d a t i o n of the experimental data . A de ta i l ed sample c a l c u l a t i o n performed on Run 10 can be found in Appendix 8. Calcu la ted r e s u l t s for a l l runs on mass balances are l i s t e d inTab les VI-8 to VI-12 and are summarized in Table VI -7 . ( i ) Overal l Mass Balance Table VI-7 shows that in general the outputs are short of the inputs by 2-15%. In some c a s e s , however, the outputs are higher and the d iscrepancies are around 3-4%. On the whole, the average discrepancy in the overa l l mass balance i s 7.1% which is within experimental e r r o r s . Inaccuracies introduced in the mass balance which contr ibuted to the imbalance between outputs and inputs are d iscussed below. (a) Since a l l mass balancesuse average operat ing c o n d i t i o n s , instantaneous v a r i a t i o n s in operat ing parameters such as s o l i d feedra te , t a r formation r a t e , char accumulation rate and s o l i d e l u t r i a t i o n rate are not accounted f o r . As the experimental condi t ions (temperature, pressures and a l l flowmeter readings) could not be recorded simultaneously when the sample was taken, use of these values in the c a l c u l a t i o n const i tu tes another source of e r r o r s . (b) The water output of the reactor is measured i n d i r e c t l y by d i f fe rence between the measured wet gas flow using the mercury manometer and the ca lcu la ted dry gas flow using nitrogen or carbon as the t i e substance (Appendix 8). Some degree of inaccuracy is introduced here s ince the ag i ta ted bed causes considerable o s c i l l a t i o n in the mercury manometer measuring the pressure drop across the o r i f i c e plate used to determine the wet gas f low. Further er rors are introduced when the o r i f i c e upstream pressure deviates s i g n i f i c a n t l y from atmos-pher ic pressure at which the o r i f i c e plate was c a l i b r a t e d . The discharge c o e f f i c i e n t used can be erronous and may r e s u l t in non-convergence o f the i t e r a t i v e approach in c a l c u l a t i n g the water in the output reactor gas. For such c a s e s , the water c o l l e c t e d in the impinger i s used to c a l c u l a t e the average water f lowrate associa ted with the reactor ex i t gas. The s o l i d e l u t r i a t i o n rate is reported as the average rate o f s o l i d s c o l l e c t e d in the cyclone throughout the course of the experiment. Although some inaccuracy i s introduced by t h i s procedure, the cont r ibut ion of the e l u t r i a t e d s o l i d s to the to ta l output mass i s below 2.5%. The tar condensed along the pipework i s d isso lved in acetone and i n v a r i a b l y the amount c o l l e c t e d i s short of that a c t u a l l y produced. However, s ince the amount c o l l e c t e d const i tu tes less than 0.5% (average) of the to ta l output mass, er rors introduced with the c o l l e c t i o n technique are therefore o f l i t t l e consequence to the overa l l mass balance. S o l i d p a r t i c l e s which remained in the bed at the end of the experiment are determined by weight loss in a se lec ted bed sample. Water was added to the sample, s ince the s o l i d p a r t i c l e s w i l l f l o a t in the water while the sand remains 95 i n the bottom, they were removed when the water was decanted. Experimental e r rors r e s u l t when the sand p a r t i c l e s are removed together with the s o l i d p a r t i c l e s and causes an overest imation of the accumulation of char in the bed. Further er rors are introduced as these unburnt char p a r t i c l e s are assumed to be 100% carbon; any ash l e f t in the bed i s not measured. Here a g a i n , the e r rors associa ted are less than 1% of the output mass and thus the e f f e c t on the o v e r a l l mass balance i s i nsi gni f i cant . TABLE VI-7: SUMMARY OF MASS AND ENERGY BALANCES Air | N2 I' C02 Steam-N2 Run Number 9 ! 11 10 12 1 i 8 j 4 i 3 7 ] 5 j 6' | 16 15 14 Overall Mass Balance -4.48 14.82 | 12.41 4.51 13.30 ! 2.33 3.65 -5.61 | -3.44 0.12 11.02 4.45 2.0 Hydrogen Balance 24.0 75.16 32.19 33.64 83.68 71.80 74.40 83.51 66.44 60.22 96.79 77.44 18.92 Oxygen Balance 0.32 44.45 30.28 23.51 67.89 49.68 71.58 -7.69 -5.14 0.2 88.87 66.67 7.61 Nitrogen Balance Balanced Balanced Output not detected Balanced Carbon Balance -68.68 33.27 41.08 -36.46 73.46 40.95 53.65 Balanced 57.88 34.90 1.1 Ash Balance 40.17 59.56 54.76 81.17 -259.00 17.57 40.75 -284.00 53.16 1-27.80 -260.00 -5.71 71.67 Energy Balance 42.30 14.08 80.69 76.21 74.50 67.69 55.26 70.58 66.26 51.05 79.74 80.27 50.25 After hydrogen is balan ced (Refer Tables VI-10, VI-13) Overall Mass Balance -6.6 9.0 9.0 2.0 2.7 -0.04 0.4 -10.3 j -6.6 ' -2.9 -0.5 9.5 0.4 Oxygen Balance -6.6 24.8 19.5 15.3 -27.0 -30.6 -12.3 -13.6 -5.1 -3.6 -8.7 -15.4 -12.7 Energy Balance 41.18 71.00 80.16 75.03 70.53 65.84 51.75 67.36 63.93 48.95 77.32 79.67 49.22 Values are expressed as ( Input-Output } x m i TABLE VI-8: OVERALL MASS BALANCE Basis = g/s System Air N2 i'| C02 Steam-N,, Run Number 9 11 10 12 8 4 3 i 7 : 5 6 16 15 14 Bed Temperature (°C) 437 473 i 596 j 670 410 557 689 420 • 500 517 416 501 597 Wet solid 0.0908 0.1183 0.1526 0.0929 0.2356 0.0530 0.0731 0.1123 0.0648 | 0.1019 0.0729 0.0308 r 0.0974 Transport N2 0.0 | 0.0 0.0 0.0 0.8250 0.8687 ; 0.9037 0.0 ! 0.0 i 0.0 0.6341 0.6175 i 0.6555 Gasifying medium 0.5244 | 0.7150 1 0.7017 i 0.6464 0.0 0.0 | 0.0 | 1.0000 0.7533 1.0934 0.0442 0.0241 0.0096 Total In i j j 0.6152 j 0.8333 , 0.8542 : 0.7393 1.0606 0.9217 1 0.9768 ; 1.1123 | 0.8181 1.1953 0.7512 0.6724 0.7625 Dry Gas 0.6240 j 0.6933 j 0.6879 0.6892 0.8649 0.8917 i 0.9369 i 1 .1474 ; 0.8416 I 1.1674 • 0.6439 0.6383 0.7396 Water in gas 0.0165 j 0.0127 | 0.0588 i 0.0158 0.0113 I 0.0006 ; 0.0 0.0042 •: 0.0006 0.0030 0.0015 0.0009 0.0059 Tar 0.0009 | 0.0030 \ 0.0006 j 0.0006 0.0224 i 0.0030 i 0.0015 i 0.0070 j 0.0023 0.0052 0.0096 0.0023 0.0010 Cyclone catch 0.0014 0.0008 0.0010 | 0.0003 0.0209 0.0019 0.0028 i 0.0136 J 0.0015 0.0065 0.0066 0.0010 0.0008 Char 0.0 0.0 0.0 1 0.0 0.0 0.0030 0.0 0.0025 0.0002 0.0118 0.0068 0.0 0.0 Total Out 0.6428 0.7098 0.7483 0.7059 0.9195 0.9002 0.9412 1.1747 0.8462 1.1939 0.6684 0.6425 0.7473 I n - ° u t x 100 (%) In -4.48 14.8 12.4 4.51 13.3 2.33 3.65 -5.61 -3.44 0.12 11.02 4.45 2.0 98 ( ( i i ) Component Balances Since the gas/sawdust mass r a t i o i s large (Table V I -1 ) , small e r rors i n gas a n a l y s i s , gas f lowrate or sawdust feedrate r e s u l t i n poor c losure o f the component ba lances . This i s p a r t i c u l a r l y true for hydrogen which amounts to about 6% of the sawdust feed , (a) Hydrogen Balance The to ta l input hydrogen comprises about 1% of the input mass. Balances are therefore subject to la rge percentage e r r o r s . A s i g n i f i c a n t part o f the hydrogen enter ing and leav ing the reactor i s waterbound and therefore the to ta l hydrogen mass balance is very s e n s i t i v e to the inaccurac ies in the deter -mination of the water vapour in the reactor e x i t gas. A c c o r d i n g l y , an imbalance between the to ta l hydrogen input and output of up to 100% i n v a r i a b l y r e s u l t s (Table VI-9) with the output being short o f the input . The impact of the hydrogen imbalance on the overa l l mass balance i s minor, however. Amounts o f hydrogen enter ing with the s o l i d feed can be accura te ly determined through the s o l i d ul t imate a n a l y s i s and moisture content . On the other hand, the quant i ty o f hydrogen leav ing the reactor with the dry gas i s subject to a greater e r r o r because o f the d i l u t i o n e f f e c t of the t ransport medium ( p a r t i c u l a r l y ni t rogen s ince i t i s ine r t ) which renders the detect ion of hydrogen by gas chromatography d i f f i c u l t y . The to ta l dry gas f low, which i s ca lcu la ted from the concentrat ion o f the most predominant gas component i s l e s s subject to e r r o r . From Table VI-9, i t can be seen that hydrogen in the dry gas i s lower than the hydrogen present in the dry sawdust. I f the remaining hydrogen required fo r the c losure o f the hydrogen balance i s assumed to be waterbound, then the r e s u l t i n g oxygen balance i s found to have improved (Table VI-Both o f these pieces o f evidence show that water has been produced by the react ion process . TABLE VI-9: HYDROGEN AND OXYGEN BALANCES Basis » g/s System . n Air N 2 co2 Steam-Nj Run Number 9 11 10 12 8 4 j 3 7 5 6 16 15 14 Bed Temperature (*C) 437 473 596 670 410 557 689 420 500 517 416 501 597 HYDROGEN BALANCE Hater-bound In Inlet gas 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0049 0.0027 0.0011 Water-bound In wet sol id 0.0006 0.0002 0.0010 0.0005 0.0007 0.0004 0.0005 0.0001 0.0005 0.0009 0.0003 0.0001 0.0005 In dry solid 0.0053 0.0072 0.0089 0.0055 0.0142 0.0030 0.0042 0.0068 0.0037 0.0057 0.0044 0.0019 0.0058 Total In 0.0059 0.0074 0.0099 0.0060 0.0149 0.0034 0.0047 0.0069 0.0042 0.0066 0.0096 0.0047 0.0074 Water-bound in outlet gas 0.0019 0.0014 0.0066 0.0018 0.0013 0.0001 0.0 0.0005 0.0001 0.0003 0.0002 0.0001 0.0007 In dry gas 0.0026 0.0004 0.0001 0.0022 0.0012 0.0009 0.0012 0.0007 0.0013 0.0023 0.0001 0.0000 0.0053 Total Out 0.0045 0.0018 0.0067 0.0040 0.0025 0.0010 0.0012 0.0012 0.0014 0.0026 0.003 0.0011 0.0060 !2 jM x 1 0 0 (X) 24.0 '5.16 32.19 33.64 83.68 7.8 J74.04 83.51 66.44 60.22 96.79 77.44 18.92 OXYGEN BALANCE Water-bound 1n Inlet gas 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0393 0.0214 0.0085 As 0 2 In Inlet gas 0.1214 0.1655 0.1624 0.1496 0.0 0.0 j 0.0 0.0 0.0 0.0 | 0.0 0.0 0.0 Water-bound 1n wet solid 0.0045 0.0016 0.0076 0.0043 0.0059 0.0028 i 0.0040 0.0011 0.0039 0.0073 II 0.0020 0.0007 0.0038 As C0 2 In Inlet gas 0.0002 0.0003 0.0003 0.0002 0.0 0.0 | 0.0 0.7271 0.5477 0.7950 1 0.0 0.0 0.0 As CO 1n Inlet gas 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 As argon In Inlet gas 0.0067 0.0092 0.0090 0.0083 0.0 0.0 j 0.0 0.0 0.0 0.0 0.0 0.0 0.0 In dry solid | 0.0371 0.0504 0.0623 0.0381 0.0991 0.0214 0.0294 0.0475 0.0259 0.0401 0.0306 0.0130 0.0403 Total In j 0.1699 0.2270 0.2416 0.2005 0.1050 0.0242 0.0334 0.7757 0.5775 0.8424 0.0719 0.0351 0.0526 Water-bound (n outlet gas 0.0146 0.0113 0.0522 0.0140 0.0101 0.0005 0.0 0.0037 0.0006 0.0027 0.0014 0.0008 0.0053 In dry gas 0.1547 0.1147 0.1162 0.1394 0.0237 0.0116 0.0095 0.8317 0.6066 0.8380 0.0066 0.0100 0.0433 Total Out I 0.1693 0.1260 0.1684 0.1534 | 0.0338 0.01211 0.0095 0.8354 0.6072 0.8407 0.0080 0.0117 0.0486 l n - ° u t x 100 (X) In 0.32 44.45 30.28 23.51 67.89 49.68 71.58 -7.69 -5.14 0.2 88.87 66.67 7.61 101 (b) Oxygen Balance A tota l oxygen balance i s also very sens i t ive to the water output determination (Table V I - 9 ) . When the amount of water present with the reactor ex i t gas which would y i e l d the exact amount of hydrogen for the hydrogen balance i s used, s i g n i -f i cant improvement in the oxygen balance i s found (except for 4 runs). This suggests that the wet gas moisture thus determined may be more accurate. The "corrected" oxygen and water balances are presented in Table V I - 1 0 . No free oxygen enters the reactor except for the four a i r-gas i f i ca t ion runs. For pyrolys is conducted in carbon dioxide atmosphere, the oxygen enters as C 0 2 - Oxygen i s waterbound for the steam-No runs and during runs when only nitrogen i s being used, the only oxygen admitted i s associated with the so l i d feed. TABLE VI-10: MATER & OXYGEN & OVERALL MASS BAALNCES AFTER HYDROGEN IS BALANCED Basis= g/s System Air N2 co2 Steam-N2 Run Number 9 11 10 14 8 4 3 7 5 6 16 15 14 Bed Temperature (°C) 437 473 596 670 410 557 689 420 500 517 146 501 597 WATER BALANCE In 0.0051 0.0018 0.0086 0.0048 0.0066 0.0031 0.0045 0.0013 0.0043 0.0482 0.0465 0.0248 0.0139 Out 0.0297 0.0630 0.0882 0.0342 0.1233 0.0225 0.0315 0.0558 0.0261 0.0387 0.0855 0.0333 0.018 Water Produced 0.0246 0.0612 0.0796 0.0294 0.1167 0.0194 0.027 0.0545 0.0218 0.0305 0.0390 0.0085 0.0041 OXYGEN BALANCE Total In 0.1699 0.2270 0.2416 0.2005 0.1050 0.0242 0.0334 0.7757 0.5775 0.8424 0.0719 0.0351 0.0526 Water-bound in outlet gas 0.0264 0.0560 0.0784 0.0304 0.1096 0.020 0.0280 0.0496 0.0047 0.0344 0.0760 0.0296 0.016 In dry gas 0.1547 0.1147 0.1162 0.1394 0.0237 0.0116 0.0095 0.8317 0.6066 0.8380 0.0066 0.0109 0.0433 Total Out 0.1811 0.1707 0.1946 0.1698 0.1333 .0.0316 0.0375 0.8813 0.6073 0.8724 0.0826 0.0405 0.0593 I n : 0 u t x 100 (%) In 4 -6.6 24.8 19.5 15.3 j-27.0 || -30.6 -12.3 -13.6 -5.1 -3.6 -8.7 -15.4 -12.7 OVERALL MASS BALANCE Total In 0.6152 0.8333 0.8542 0.7393 1.0606 0.9217 0.9768 1.1123 0.8181 1.1953 0.7512 0.6724 0.7625 Total Out 0.6560 0.7583 0.7777 0.7243 1.0315 0.9221 0.9727 1.2263 0.8717 1.2296 0.7547 0.7363 0.7594 I n j 0 u t x 100 {%) -6.6 9.0 9.0 2.0 2.7 -0.04 0.4 -10.3 -6.6 -2.9 -0.5 1 9.5 0.4 1 0 3 (c) Mater Balance The "corrected" water balance i s presented in Table VI-10 while the "uncorrected" balance i s in Table VI -11. According to both t a b l e s , water has been produced in the r e a c t o r . The "corrected" amount i s greater than that c a l c u l a t e d using wet gas f low, and s ince a bet ter c losure o f the oxygen balance i s resul ted using these "corrected" v a l u e s , they appear to be more accurate estimates o f the amount of water formed by the react ion process . The corresponding overa l l mass balance (Table VI-10) shows that 8 runs have been improved whereas the discrepancy between input and output for the other 5 runs are inc reased . The range o f d iscrepancy , however, has been narrowed from 0.12-15% to 0.04-10%. TABLE VI-11: NITROGEN AND WATER BALANCES Bas1s= g/s System Air N2 co 2 Steam-N 2 Run NUmber 9 11 10 12 8 4 3 7 5 6 16 15 14 Bed Temperature (°C) 437 473 596 670 410 557 689 420 500 517 416 501 597 NITROGEN BALANCE In solid In total gas input 0.0001 0.3961 0.0001 0.5400 0.0001 0.5300 0.0001 0.4882 0.0002 0.8250 0.0006 0.8687 0.0008 0.9037 0.0013 0.0 0.0007 0.0 0.0011 0.0 0.00005 0.6341 0.00002 0.6175 0.0001 0.6555 Total in 0.3962 0.5401 0.5301 0.4883 0.8252 0.8693 0.9045 0.0013 0.0007 o.oon 0.6341 0.6175 0.6556 Out in outlet gas - balanced - - balanced - 0.0 0.0 0.0 - balanced -WATER BALANCE In gas Input 0.0 0.0 0.0 0.0 0.0 j 0.0 0.0 0.0 0.0 0.0 0.0442 0.0241 0.0097 In solid 0.0051 0.0018 0.0086 0.0048 0.0066 0.0031 0.0045 0.0013 0.0043 0.0082 0.0023 0.0007 0.0043 Total In 0.0051 0.0018 0.0086 0.0048 0.0066 0.0031 0.0045 0.0013 0.0043 0.0082 0.0415 0.0248 0.0139 Out in outlet gas 0.0165 0.0127 0.0588 0.0158 0.0113 0.0006 0.0 0.0042 0.006 0.0030 0.0015 0.0009 0.0059 105 (d) Nitrogen Balance Total input ni trogen i s a sum o f the ni trogen present in the s o l i d feed and in the t ransport and/or f l u i d i z i n g medium. The output n i t r o g e n , on the other hand, e x i s t s only as ni t rogen gas assuming that no ni t rogen oxides are formed by the react ion process (Table VI -11) . For a l l experiments except those where CO2 i s the t ranspor t and f l u i d i z i n g medium, the predominant gas component i s n i t r o g e n . Thus, for such runs, ni t rogen i s taken as the reference gas to obtain the f lowrate o f the dry gas evolved from the reac to r . For the CO2 runs , only very minute amounts of nitrogen are admitted in to the system s ince the ni trogen content in the s o l i d feed i s l ess than 1.5%. It i s genera l ly below 0.1% of the to ta l input mass. The nitrogen gas present in the r e s u l t i n g gas is non-detectable in the gas chromatograph. 1 106 (e) Carbon Balance Carbon i s the t i e substance for the CO2 p y r o l y s i s runs to determine the f lowrate of the dry gas produced in the r e a c t o r . For a l l other runs where ni trogen i s used as the reference substance f o r such c a l c u l a t i o n s , the amount o f carbon i n the output stream i s genera l ly lower than that enter ing the reactor (Table VI -12) . Major source of e r ro r is that assoc ia ted with the determination of the carbon e l u t r i a t i o n r a t e . Since not a l l of the s o l i d s e l u t r i a t e d from the reactor are c o l l e c t e d in the c y c l o n e , the carbon e l u t r i a t i o n rate is underestimated. Although the bed ana lys is technique and the assumption that the char p a r t i c l e s remain in the bed are pure carbon tend to overestimate the output , s ince output char c o n s t i t u t e s to 0.2% of the output mass, the e f f e c t of the er ror associa ted with the carbon e l u t r i a t i o n rate pre-dominates (about 0.5% of the output mass). TABLE VI-12: CARBON AND ASH BALANCES o 108 ( f ) Ash Balance Amounts o f ash measured are d i r e c t l y re la ted to the carbon measurements. Thus, an ash imbalance can be a t t r i b u t e d to the e r rors that cause the carbon imbalance. Since the output ash i s genera l ly lower than the inpu t , a poss ib le explanat ion could be that the amount of ash accumulated in the bed has been neglected (Table VI-12). 109 (8) ENERGY BALANCE A d e t a i l e d energy balance in the f l u i d i z e d bed would require a knowledge o f the amounts o f gas produced by each of the p y r o l y s i s , combustion and g a s i f i c a t i o n react ions and considerat ions of the d i f f e r e n t heats o f reac t ion at the p r e v a i l i n g operat ing c o n d i t i o n s . Since much of th is data is not a v a i l a b l e and in order to s i m p l i f y the a n a l y s i s , a s i m p l i f i e d energy balance is adopted. The energy balance i s not c o n s i -dered to be as c r u c i a l as the mass balance and serves only as a rough guide as to the d i f f e r e n t forms o f energy enter ing and leaving the system. The s i m p l i f i e d model considers the reactor as a "black box" or a system which i s encompassed by a boundary l i n e . The e l e c t r i c a l furnace is p ictured as part of the outside environment and i s therefore outside "the boundary l i n e . Energy balance i s performed between the energy inputs ,which a re ; the heat contents o f the s o l i d , steam, t ransport ni t rogen and f l u i d i z i n g medium and e l e c t r i c a l i n p u t , and the energy outputs which inc lude the heating value of the produced dry gas , heat contents of steam, e l u t r i a t e d carbon, tar and char , sens ib le heat of the dry gas and heat losses through the end f langes and i n s u l a t i o n . Sensib le heats o f t a r , e l u t r i a t e d carbon, tar and char are not accounted f o r . A d e t a i l e d sample c a l c u l a t i o n performed on Run 10 can be found in Appendix 9. A major source of e r ror introduced in the ana lys is is the e s t i -mation of heat t rans fe r c o e f f i c i e n t s used in the determination of the inward heat t rans fe r from the furnace in to the reactor and the outward heat loss from the reactor to the surroundings through the i n s u l a t i o n 110 and the f langes at the reactor ends. Various empir ica l c o r r e l a t i o n s are a v a i l a b l e in the l i t e r a t u r e fo r the evaluat ion o f such heat t r a n s f e r c o e f f i c i e n t s but most o f them are subject to some e r r o r s . A d e t a i l e d sample c a l c u l a t i o n on t h e i r est imat ions i s l i s t e d in Appendix 9. From the r e s u l t s tabulated in Table VI -13, the input energy always exceeds that of the output and the average discrepancy i s in the order of 67%. For most runs , the heat content of the incoming s o l i d feed alone i s greater than the t o t a l output energy. Since the e r r o r in determining the s o l i d heating value i s r e l a t i v e l y s m a l l , the large discrepancy in the energy input and output energy can be a t t r i b u t e d mainly to the errors assoc ia ted i n determining the output energy. As part of the experimental measurement e r r o r s , not a l l of the char , ta r and e l u t r i a t e d carbon generated from the process were c o l l e c t e d . As a r e s u l t of these l o s t mass, the tota l output mass i s genera l ly short o f the incoming mass (Table V I -7 ) . The amount of water vapour ca lcu la ted v ia the i t e r a t i v e approach as d iscussed in Sect ion 9 i s a lso subject to e r r o r . The amount of water vapour in wet gas evaluated using hydrogen as the t i e substance gives a bet ter c losure o f the oxygen balance and i t s value i s always greater than that ca lcu la ted using the above technique Consequently, t h i s estimate a l s o r e s u l t s in an improvement in the energy ba lance. The heat contents o f these unaccounted char , t a r , e l u t r i a t e d carbon and water vapour together with the ignored sens ib le heats of c h a r , ta r and e l u t r i a t e d carbon could cont r ibute s i g n i f i c a n t l y to the lack o f c l o s u r e . Apart from the heat content of the s o l i d f e e d , another major con t r ibu to r in the input energy i s in the form of e l e c t r i c a l heat. Est imat ion o f t h i s heat input i s d i f f i c u l t s ince the heat t rans fe r Ill c o e f f i c i e n t s fo r the heated wall to bed, and for the heated wall to reactor gas t rans fers could not be accura te ly determined. I f lower values o f these c o e f f i c i e n t s were used, the c a l c u l a t e d e l e c t r i c a l heat input would be reduced considerably which in turns r e s u l t s in a bet ter c losure of the energy ba lance. TABLE VI-13: ENERGY BALANCE Basis • KJ/S System Air | N 2 co 2 Steam-N2 Run Number 9 11 10 12 | 8 4 3 7 5 6 I 16 i 15 14 Bed Temperature (°C) 437 473 596 670 1 410 557 689 420 500 517 | 416 501 597 Dry Solid 1.7033 2.3156 2.8615 1.7495 1 4.5503 0.9452 1.3001 2.1024 1.445 1 .7745 j 1.4041 0.5970 1.8503 Inlet gas (Exclude transport Nitrogen t steam) 0.0043 0.0030 0.0052 0.0033 1 0.0 0.0 0.0 0.0013 0.0022 0.0 0.0 0.0 0.0 Steam 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.1168 0.0644 0.0255 Solid Moisture 0.0002 0.00004 0.0002 0.0001 0.0002 0.0001 0.0002 0.00006 0.0002 0.005 0.00006 0.00002 0.0001 Transport Nitrogen 0.0 0.0 0.0 0.0 0.0045 0.0030 0.0031 0.0 0.0 0.0 0.0048 0.00281 0.0023 Electr ical Input 0.7263 2.9820 1.0942 4.1405 3.5804 2.7679 1.6865 3.0683 2.0334 3.2136 3.6530 3.5222 2.4059 Total In 2.4341 5.3006 3.9611 5.8934 8.1354 3.7171 2.9899 5.17206 3.1803 4.9886 5.1788 4.1863 4.2841 Dry Gas Produced 0.9348 0.1064 0.0687 0.7579 0.4145 0.3299 0.4324 0.3294 0.4460 0.8516 0.0443 0.3245 1.4874 Sensible Heat of Dry Gas 0.3073 0.2814 0.3877 0.4887 0.4029 0.5673 0.7028 0.5131 0.4501 0.7782 0.2864 0.3363 0.5812 Steam In Wet Gas 0.0554 0.0413 0.2088 0.0598 0.0377 0.0022 0.0 0.0139 0.0021 0.0114 0.0050 0.0030 0.0216 Elutriated Carbon 0.0346 0.0165 0.0164 0.0061 0.4963 0.0507 0.0909 0.0794 0.0457 0.3218 0.2108 0.0404 0.0683 0.1779 0.1563 0.0255 0.0207 Tar 0.026B 0.0900 0.0184 0.0191 0.6720 0.1549 0.2892 0.0700 0.0301 Char 0.0 0.0 0.0 0.0 0.0 0.0964 0.0 0.0803 0.0063 0.3864 0.2236 0.0 0.0 Heat Loss through Insulation 0.0282 0.0200 0.0367 0.0410 0.0301 0.0324 0.0398 0.0312 0.0340 0.0435 0.0280 0.0362 0.0419 Heat Loss through Flanges 0.0174 0.0082 0.0284 0.0296 0.0209 0.0311 0.0376 0.0212 0.0258 0.0382 0.0169 0.0305 0.0283 Total Out 1.4045 1.3738 0.7651 1.4022 2.0744 1.2009 1 .3377 |] 1.5217 1.0730 2.4421 1.0495 0.8259 2.1313 •"-Out x 1 0 0 (j) In 42.30 74.08 80.69 76.21 74.50 67.69 55.26 ! 70.58 1 66.26 51.05 79.74 80.27 50.25 With "corrected" water f lc M 1n wet ga s Steam In Net Gas 0.0826 0.2049 0.0208 0.1294 0.3611 0.0711 0.1049 i| 0.1804 0.0763 0.1159 0.1300 0.0283 0.0659 Total Out 1.4317 1.5374 0.7859 1.4718 2.3978 1.2698 1.4426 j] 1.6882 1.1472 2.5466 1.1745 0.8512 2.1755 I n : 0 u t x 100 {%) I n 41.18 71.00 80.16 75.03 70.53 65.84 51.75 67.36 63.93 48.95 77.32 79.67 49.22 113 (9) THERMAL EFFICIENCIES The thermal e f f i c i ency of a gas i f i ca t ion system is a measure of the e f f i c i ency with which the energy contained in the so l i d feed i s transformed into a gaseous f u e l . Two kinds of thermal e f f i c i enc i es can be defined. The f i r s t i s the raw gas thermal e f f i c i enc y , which i s defined as the ra t io between the tota l heating value of the gas (combustion heat + sensible heat + sensible heat of steam) and the tota l energy input to the system. Heat Content of the Hot Wet Gas „ l n n o / M - =—-—=—n—r—T 1 X IUU/O raw Total Heat Input The other i s the cold clean gas thermal e f f i c i ency , which i s the ra t io between the combustion heat of the gas at 288 .6 K of the clean (no so l ids or tars) gas produced by a unit mass of s o l i d fed and the heating value of that unit mass of s o l i d , i . e . n = Combustion Heat of Clean Gas Produced x - J Q Q ^ c .q . Combustion Heat of Sawdust Fed Only the clean gas thermal e f f i c i ency i s calculated in this the values are tabulated in Table VI-14. TABLE VI-14 : THERMAL EFFICIENCIES System A i r N 2 co2 Steam-N^ I Run Number 9 11 10 12 8 4 3 7 ! 5 6 16 15 14 A (KJ/S) 0 .94 0.11 0.07 0.76 0.42 0.33 0.43 0.33 0.45 0.85 0.04 0.33 1 .49 B (KJ/S) 1 .70 2.32 2.86 1.75 4.55 0.95 1 .30 2.10 1 .14 1 .78 1 .40 0.60 1 .85 n (%) e . g . 55 .3 4.74 2.45 43.4 9.20 34.7 33.1 15.7 39.5 47.8 2.90 55.0 80.54 A = Combustion Heat of Clean Gas B = Combustion Heat of Sawdust VII . CONCLUSIONS AND RECOMMENDATIONS Hemlock sawdust was pyrolyzed or g a s i f i e d in a f l u i d i z e d bed reactor operated at a s o l i d feedrate o f about 0.1 g / s . The bed material used was 0.55 mm diameter Ottawa sand with an i n i t i a l bed height of 20 cm. The enter ing gases and the f l u i d i z e d bed were heated e l e c t r i c a l l y . The major operat ing va r iab le invest igated in t h i s study was the reactor temperature. Due to operat ional problems, the s o l i d feedrate was a lso v a r i a b l e . Thus r e s u l t s are presented in terms of s p e c i f i c 3 y i e l d s i . e . _ m _ gas/g s o l i d e t c . Four d i f f e r e n t f l u i d i z i n g media were s t u d i e d . The gas q u a l i t y and gas production rate were found to vary both with the reactor temperature and the type of f l u i d i z i n g medium used. Feed rate e f f e c t s may in f luence reported r e s u l t s . Reaction rates were observed to be great ly increased compared to the nitrogen p y r o l y s i s process when e i t h e r steam, CO2 or a i r was i n t r o -duced into the reac to r . As a r e s u l t , the net gas production rate/gram of sawdust inc reased . Apart from the runs conducted with s t e a m ^ mixture at temperatures above 450°C,gas produced from nitrogen p y r o l y s i s was super ior in heating va lue . The heating value of the gas from s t e a m ^ runs , however, reaches a maximum at 500°C and the gas deter iora tes in q u a l i t y due to the resumption of CO2 production when temperature i s fur ther increased beyond 500°C. I f the trend of the production of the component gases i s projected above 520°C fo r the CO2 p y r o l y s i s process , gas heating value would be higher than found with ni trogen p y r o l y s i s . T h i s , however, would require v e r i f i c a t i o n with fur ther inves t iga t ions s ince runs with 116 C O o p y r o l y s i s were conducted below 520°C . The water-gas s h i f t react ion appeared to be important at temperatures higher than 500°C during nitrogen p y r o l y s i s and a lso during steam-nitrogen g a s i f i c a t i o n . This was marked by the f a l l i n g o f CO content and the corresponding increase or the much leve led descend o f the C0 2 content in the gas produced temperature. The reverse observat ion was obtained with C 0 2 p y r o l y s i s , s ince the C O o in excess would react with H 2 in the reverse w a t e r - s h i f t react ion g i v i n g r i s e to CO and H 2 0 . This react ion increases r a p i d l y in rate at temperatures above 500°C. Except for the a i r - g a s i f i c a t i o n runs , water production for the other three systems decreases with increas ing temperature. This seems to confirm the increase in react ion rate o f the water-gas s h i f t react ion with temperature encountered in nitrogen p y r o l y s i s and steam-nitrogen g a s i f i c a t i o n . For C0 2 p y r o l y s i s , however, the rapid f a l l i n g of C0 2 content with increas ing temperature impl ies the appreciable rate at which the reverse water gas s h i f t react ion i s proceeding at higher temperatures. The la rger amount of water produced w i l l react with carbon to give r i s e to a greater amount of CO and w i l l supply the H o required for the reverse water-gas s h i f t r e a c t i o n . Thus, the net production o f water at higher temperatures i s lower. In a i r g a s i f i c a -t ion with the presence of free oxygen, the increase of water production wi th in the 500-600°C range suggests that the rap id ox idat ion o f hydrogen i s the dominant r e a c t i o n . Composition of resu l tan t gas from a i r g a s i f i c a t i o n i s in good agreement with that reported by Wen et a l . who used a leaner f l u i d i z i n g medium. Oxygen break-through as observed by L iu et a l . f o r a i r / f u e l r a t i o greater than 3 was not encountered i n the present study. 117 The % e r r o r on the o v e r a l l mass balance (ca lcu la ted as the d i f fe rence between input and output over the input) i s genera l ly p o s i t i v e , , but the average discrepancy is an acceptable 7.1%. The poor c losure o f the component balances i s a t t r i b u t e d to the large g a s / s o l i d mass r a t i o which renders the balances to be very s e n s i t i v e to the gas ana lys is and f lowrate measurements. The overwhelming p o s i t i v e % er rors are caused by the e r rors assoc ia ted with the reactor gas flow measurement and the neglect o f some minor mass flows o f ta r and e l u t r i a t e d carbon. These same fac tors are a lso responsib le f o r the energy imbalance around the reactor with the r e s u l t o f the output energy being short o f the input . Other sources o f e r rors are introduced in—the est imat ion o f the var ious heat t r a n s f e r c o e f f i c i e n t s . Improvements in both oxygen and energy balances are resu l ted when the amount o f water vapour present in the reactor gas i s estimated using hydrogen as the t i e substance instead o f that c a l c u l a t e d v ia the o r i f i c e p la te o f wet gas f lowrate . Recommendations fo r future inc lude : (1) A s e r i e s o f experiments should be c a r r i e d out at constant temperature to determine the e f f e c t , i f any, o f sawdust feedrate on the r e s u l t s . (2) A number o f r e p l i c a t e s should be run to determine the magni-tude o f experimental e r r o r in the r e s u l t s . (3) An i n v e s t i g a t i o n o f temperature e f f e c t s in the region o f 500°C should be c a r r i e d out to v e r i f y the observat ion o f the change of react ion pattern as reported in th is study. 118 VII I . REFERENCES 1. B .H. 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Cousins "A Theoret ica l Study of Wood G a s i f i c a t i o n Processes" New Zealand Journal of S c i e n c e , V o l . 21, 1978, pp. 175-183. 17. F.R. Nocasek and D.R. Moody "The S o l i d - F u e l Turbine for Indust r ia l Energy Product ion" In te rsoc ie ty Energy Conversion Engineering Conference Proceedings 12th, 1977, pp. 718-724. 18. V . L . Hammond, L .K . Mudge, C H . A l l e n and G . F . S c h i e f e l b e i n "Energy from Forest Residuals by G a s i f i c a t i o n of Wood Wastes" Pulp and Paper, V o l . 48, Jan. -June 1974, pp. 54-57. 19. J . N . Barooah and V .D . Long "Rates of Thermal Decomposition of some Carbonaceous Mater ia ls in A F l u i d i z e d Bed" F u e l , V o l . 55, A p r i l 1976, pp. 116-120. 20. C .Y . Wen, R.C. B a i l i e , C.Y. L in and W.S. O'br ien "Production o f Low-Btu-Gas Involving Coal P y r o l y s i s and G a s i f i c a t i o n " Advances in Chemistry S e r i e s , V o l . 131, p. 1973, pp. 9-28. 21. D.L. B r i n k , J . F . Thomas and G.W. F a l t i c o "The P y r o l y s i s - G a s i f i c a t i o n - C o m b u s t i o n Process . Energy E f fec t iveness using Oxygen v s . A i r with Wood-fueled System" Fuels Energy Renewable Resources Symposium 1977, pp. 141-168. 22. G.D. Voss " Indust r ia l Wood Energy Conversion" Fuels Energy Renewable Resources Symposium, 1977, pp. 125-140. 23. W.G. Wi11 son , L . J . Sea lock , F . C . Hoodmaker, R.W. Hoffman, D.L. St inson and J . L . Cox " A l k a l i Carbonate and Nickel C a t a l y s i s o f Coal-Steam G a s i f i c a t i o n " Advances in Chemistry S e r i e s , V o l . 131, 1973, pp. 203-216. 24. . R .C. B a i l i e " S o l i d Waste Inc inera t ion in F l u i d i z e d Beds" Indust r ia l Water Eng ineer ing , V o l . 7, 1970, pp. 22-25. 120 25. D.L. Brink and M.S. Massoudi "A Flow Reactor Technique for the Study of Wood P y r o l y s i s " Journal of F i r e and F lammabi l i ty , V o l . 9 , A p r i l 1978, pp. 176-188. 26. J . A . Havens, H.T. Hashemi, L . E . Brown and J . R . Welker "A Mathematical Model of the Thermal Decomposition of Wood" Combustion Science and Technology, V o l . 5, 1972, pp. 91-98. 27. A . F . Roberts "Problems Associa ted with the Theore t ica l Ana lys is of the Burning of Wood" Thi r teenth Symposium ( Int . ) on Combustion, 1970, pp. 893-903. 28. A .M. Kanury "Rate of Burning o f Wood" Combustion Science and Technology, V o l . 5, 1972, pp. 135-146. 29. H.W. Eickner "Basic Research on the P y r o l y s i s and Combustion of Wood" Journal o f Forest Products , V o l . 12, No. 4, 1962, pp. 194-199. 30. N.C. Jones "Forest ry and the U t i l i z a t i o n of Waste Wood and i t s Products as Fuel Soc. Chem. Ind. Chem. Eng. Group & Trans. Inst . Chem. E n g r s . , 1944, pp. 120-134. 31 . R. Tolman " S o l i d Waste G a s i f i c a t i o n " Conv. Refuse Energy Int . Conferences Tech. E x h i b i t i o n ( F i r s t ) , 1975, pp. 337-342. 32. H.C. Kung and A . S . Ka le lkar "On the Heat of Reaction in Wood P y r o l y s i s " Combustion and Flame, V o l . 20, 1973, pp. 91-103. 33. A.M. Kanury "Thermal Decomposition K ine t i cs of Wood P y r o l y s i s " Combustion and Flame, V o l . 18, 1972, pp. 75-83. 34. A . F . Roberts "The Heat of Reaction During the P y r o l y s i s o f Wood" Combustion and Flame, V o l . 17, 1972, pp. 79-86. 35. R.C. B a i l i e and R.S . Burton III " F l u i d Bed P y r o l y s i s of S o l i d Waste Mater ia ls" Combustion, V o l . 45, No. 8, 1974, pp. 13-19. 36. A.C.W. Eggen and R. Kraatz " G a s i f i c a t i o n of S o l i d Wastes in Fixed Beds" Mechanical Eng ineer ing , V o l . 24, J u l y 1976, pp. 13-19. 121 37. P . F . MarchenkO "Use of an A luminosol ica te Ca ta lys t During Wood G a s i f i c a t i o n " Izv. Vyssh. Ucheb. Zaved. Les . Zh. 12, 1969, pp. 62-65. 38. S . F . Colovkov a n d . I . F . Koperin " G a s i f i c a t i o n of Chips from Clear ing Wastes" Izv. Uyssh. Ucheb. Zaved. Les . Zh. 12, 1971, pp. 166-168. 39. G. Simmons and M. Sanchez "High Temperature G a s i f i c a t i o n K ine t ics of Biomass P y r o l y s i s " A . I . C h . E . 72nd Annual Meet ing, San F r a n c i s c o , Nov. 1979. 40. R . J . Robertus, L .K . Mudge, D.H. M i t c h e l l , R .L . Cox, L . J . Sealock and S . L . Weber " Invest igat ion o f the G a s i f i c a t i o n of Wood in the Presence of Mixed Ca ta lys ts" A . I . C h . E . 72nd Annual Meet ing, San F r a n c i s c o , Nov. 1979. 41. S .R. Beck, M . J . Wang and J . A . Hightower " P y r o l y s i s of Biomass in SGFM (Synthesis Gas from Manure) Process" A . I . C h . E . 72nd Annual Meet ing, San F r a n c i s c o , Nov. 1979. 42. C H . Chung and A . N . Hixson " C a t a l y t i c Pyro lys is o f C e l l u l o s e " A . I . C h . E . 72nd Annual Meeting, San F r a n c i s c o , Nov. 1979. 43. M. Boyd, C. Anderson, A . DeVera and M. Hawley " P y r o l y s i s and G a s i f i c a t i o n of Hybrid Poplar SPP" A . I . C h . E . 72nd Annual Meet ing, San F r a n c i s c o , Nov. 1979. 44. Walter Gregson Voux " C a l c u l a t i n g Flow through Gas Rotameters" Chemical Engineer ing , V o l . 87, Dec. 1980. 45. I. B j e r l e , H. Eklund and 0. Svensson " G a s i f i c a t i o n of Swedish Black Shale in the F l u i d i z e d Bed. R e a c t i v i t y in Steam and CO2 Atmosphere" Ind. Eng. Chem. Process Des. Dev . , V o l . 19, 1980, pp. 345-351. 46. R.H. Perry and C H . Ch i l ton "Chemical Engineer 's Handbook" McGraw H i l l Book Company, 5th E d i t i o n , 1973, Chapters 10-11. 47. W.L. McCabe and J . C Smith "Unit Operations of Chemical Engineering" McGraw H i l l Book Company, 3rd E d i t i o n , 19, pp. 341. 48. G. Hetsroni "Handbook of Mult iphase Systems" McGraw H i l l Book Company, 1981, Chapter 8. 122 49. D. Kunii and 6. Levenspiel " F l u i d i z a t i o n Engineering" John Wiley & Sons, I n c . , 1969, Chapter 11. 50. R.L. P ig ford "Nonisothermal Flow and Heat Transfer Inside V e r t i c a l Tubes" A . I . C h . E . Chem. Eng. Progress Symposium S e r i e s , V o l . 17, No. 51, 1955, pp. 79-89. f 4 IX. APPENDICES APPENDIX 1 . MECHANICAL DETAILS ( i ) In te r io r of F l u i d i z e d Bed Reactor, ( i i ) Top and Bottom Gr id P l a t e s , ( i i i ) Cyclone, ( iv ) O r i f i c e P la te . 124 Material af Construction: S.S. 316 Reactor Outer Diameter: 7-62CITI Reactor Inner Diameter: 7-20 cm UH76_ i r i 55-88 14541 20-32 Fluidised Med iuT» In I I I J ir ' 33-34 0-476 : 0-476 Transported • Sawdust In • Condensed Steam Out 0'32 Chromel -Alumel Thermocouple All Dimensions In centimeters Figure IX-1-1: In te r io r Arrangement of the Reactor Bottom Grid Plate $ 4 76 Hole for Screen With Top Grid. Al l Dimensions In millimeters igure IX-1-2: D e t a i l s of Top and Bottom Gr id Plates 126 Length 1 2 - 7 External Thread At End. J Material of Construction:S.S. 0 095 length 7 6 2 External Thread At End. A l l Dimensions In centimeters Figure IX-1-3: Detai led Features of the Cyclone Orifice Plate Flange (Motenoi of Cowtruttton: Brw) Orifice Plate (Moter ia l o( Contlructlon; S.S. 316) Figure IX-1-4: O r i f i c e Plate and F.langes (2) APPENDIX 2. CALIBRATION OF ROTAMETERS A rotameter i s a flowmeter c o n s i s t i n g of a metering f l o a t in a tapered g lass tube. When used in measuring the gas f low, the upwardly f lowing gas suspends the f l o a t in the tube. When the gas f lowrate i n c r e a s e s , the f l o a t r i s e s in the tapered tube to provide a l a rger flow area around the f l o a t . The annular space between the f l o a t and rotameter 44 tube can be t reated as an o r i f i c e and the o r i f i c e equation f o r gases can be a p p l i e d : Q-i /pf = CYS r& AP 1 - 6 4 For a given value of the f l o a t p o s i t i o n Z , the discharge c o e f f i c i e n t C, the expansion f a c t o r Y, o r i f i c e area S, Newton's law f a c t o r g , c r o s s -sect ion r a t i o $, and gas pressure drop AP, across the f l o a t are a l l constant , and . . = constant z=constant For a given rotameter f l o a t s e t t i n g , the value of — p ^ i s D f y m f g p ( l - p / p f ) near ly constant , where Q = volumetr ic f lowrate of gas Df = f l o a t diameter rrif = f l o a t mass g = g r a v i t y a c c e l e r a t i o n p = gas dens i ty Pf = f l o a t dens i ty u = gas v i s c o s i t y 129 For a given rotameter f l o a t , m^ and are constant . The gas dens i ty i s much l e s s than the f l o a t dens i ty so that (1-p/p.f) % 1, whereby: „+. = constant z=constant The mass f lowrate of gas , pQ, i s constant through a system (Figure IX-2-1) , so that f o r two points in a system: By the per fec t -gas law: p = PM/RT where P = gas pressure M = gas molecular weight R = gas constant T = absolute temperature Combining l a s t three equations give the working r e l a t i o n s h i p s : -^2 / P P H Q 9 = Q p - / o 1 o f o r f ind ing the gas f lowrate in the process • 2 / T T,M from the rotameter scale read ing , Q Q P 2 / T o T l M and = ^2 T ~ / P P M ^ o r s e t t l n 9 t n e 9 a s f lowrate at the rotameter 2 / o 1 o to give a des i red gas f lowrate in the process. In c a l i b r a t i n g the g a s i f y i n g a i r , g a s i f y i n g n i t rogen , g a s i f y i n g carbon d iox ide and t ransport ni trogen rotameters, the reference condi t ions P , T Q are taken as those at the standard c o n d i t i o n s , i . e . 70°F (294.11 K) and 1 atmosphere (101.325 KPa). The gas f lowrates at d i f f e r e n t f l o a t se t t ings are measured using a wet gas meter and a stop watch. The temperature of gas in the wet gas meter i s taken as that at the e x i t and i s measured by a mercury glass-thermometer. This i s T^ and i s the atmospheric pressure . Intermediate Process (heaters,valves etc.) Process Actual Conditions P2 T2 e2 M 2 Q 2 Flow F l o w Q , Q, Rotameter Actual Conditions P, T, e, M, Q, Rotameter Reference Conditions P0 T0 P 0 M 0 Qo Z Figure IX-2-1: Descr ip t ion of Var iab les f o r a Gas Flow System C O 132 ( i ) Gas i fy ing A i r Rotameter (Ch .E . No. 2703, Brooks R-7S-25-1) A i r i s suppl ied from the a i r mains in the Chemical Engineering bu i ld ing and the pressure can be regulated to a maximum of 15 psig by means of a pressure regu la to r . The a i r i s then passed through a drying column of s i l i c a gel to get r i d of the extra moisture. Just before entrance into the rotameter, the wet-bulb and dry -bu lb temperatures of the a i r are recorded and i t s pressure i s measured with a 0-15 ps ig pressure gauge. TABLE IX-2-1: . GASIFYING AIR ROTAMETER CALIBRATION DATA Rotameter Condi t ions Wet Gas Meter Condit ions Standard Cond i t ions* Reading P n(KPa) T 2 (K ) P 2 (KPa) Q 2 ( m 3 / s ) Q 0 ( m 3 / s ) 10 20 40 70 100 130 160 190 210 230 250 299.22 299.22 299.22 299.22 299.22 299.22 299.22 299.22 299.22 299.22 299.22 109.60 109.60 110.29 111.67 113.05 114.42 116.49 120.63 122.01 123.39 125.46 297.5 297.5 297.5 297.5 297.5 297.5 297.5 297.5 297.5 297.5 297.5 101.325 101.325 101.325 101.325 101.325 101.325 101.325 101.325 101.325 101.325 101.325 2.4992 x l O " 4 2.9013 3.8369 5.1298 6.1827 7.2607 8.3777 9.3764 10.1131 10.9755 11.6052 2.3924x10" 4 2.7772 3.6614 4.8648 5.8273 6.8023 7.7787 8.5553 9.1752 9.9017 10.3831 * Pn = 101.325 KPa, ln = 294.11 K 0 0 133 ( i i ) Gas i fy ing Nitrogen Rotameter (Ch.E . No. 2228, Brooks R-8M-25-2) Compressed ni trogen from a c y l i n d e r i s used. A Chrome!-Alumel thermo-couple i s used to measure the gas temperature j u s t before i t enters the rotameter whereas the gas pressure i s obtained v ia a pressure gauge (0-60 p s i g ) . TABLE IX-2-2: GASIFYING NITROGEN ROTAMETER CALIBRATION DATA Rotameter Condi t ions Wet Gas Meter Condit ions Standard Condit ions Reading T-| (K) ^ ( K P a ) T 2 (K ) P 2(KPa) Q 2 ( m3 / s ) Q 0 ( m 3 / s ) 5 294 108.25 297 101.325 1.2698 x l O "4 1.2144x10" 4 10 294 108.25 297 101.325 1.6349 1.5636 20 294 109.63 297 101.325 2.3715 2.2538 30 294 109.63 297 101.325 2.9374 2.7915 50 294 110.32 297 101.325 4.1765 3.9566 70 294 111.00 297 101.325 5.4143 5.1135 100 292 114.45 297 101.325 7.2981 6.7648 115 291 116.52 297 101.325 8.3284 7.6379 129 290 118.59 297 101 .325 9.4389 8.5656 151 289 123.42 297 101.325 11.1046 9.8610 183.5 288 131.00 297 101.325 13.5487 11.6579 195 288 135.83 297 101.325 14.5214 12.2707 207 288 142.72 297 101.325 15.6446 12.8967 233 288 153.04 297 101.325 17.3191 13.7873 203 288 133.94 297 101 .325 15.1265 12.8718 184 288 133.04 297 101.325 13.5812 11.5959 137 288 120.63 297 : 101.325 10.4143 9.3381 98 290 113.74 297 101 .325 7.1870 6.6596 58 290 110.98 297 101.325 4.6727 4 3834 37 290 110.29 * 297 101.325 3.3710 3.1722 15 292 109.6 297 101.325 2.0851 1.9751 8 292 109.6 297 101.325 1.4887 1.4102 P 2 * P = 101.325 KPa T = 294.11 K Q = Qo r " o o o c. 12 ( i i i ) G a s i f y i n g Carbon Dioxide Rotameter (Ch.E . No. 2489A; Brooks R-7M-25-1) Comparessed carbon dioxide from c y l i n d e r i s being employed. The gas pressure j u s t p r i o r to enter ing the rotameter i s measured by a 0-60 ps ig pressure gauge and the corresponding temperature i s obtained by a Chromel-Alumel thermocouple. TABLE IX-2-3: GASIFYING CARBON DIOXIDE ROTAMETER CALIBRATION DATA Rotameter Condi t ions Wet Gas Meter Condit ions Standard Condit ions Reading T i (K) P^KPa) T 2 (K ) P 2(KPa) Q 2 ( m3 / s ) Q 0 (m/s) 10 298 103.05 297.5 101.325 1.0193 x l O "4 1.0141x10" 4 20 298 103.91 297.5 101.325 1.7720 1.7385 30 298 104.77 297.5 101.325 2.5170 2.4593 40 298 105.63 297.5 101.325 3.2032 3.1170 50 297 105.63 297.5 101.325 3.8214 3.7123 60 297 108.22 297.5 101 .325 4.5162 4.3344 70 296 110.81 297.5 101.325 5.4039 5.1168 80 294 113.39 297.5 101 .325 5.7205 5.3365 90 293 115.11 297.5 101.325 6.4356 5.9484 100 288 118.56 297.5 101.325 7.0352 6.3524 * P Q = 101.325 KPa, T Q = 294.11 K 135 ( iv ) Transport Nitrogen Rotameter (Ch .E . No. 2763; Brooks R-6-15-A) The t ranspor t ni trogen which i s used to convey the sawdust to the reactor i s suppl ied from the compressed gas c y l i n d e r . Unl ike the res t of the gas rotameters used, the gas valve which regulates the f lowrate i s located a f t e r the rotameter. This r e s u l t s in higher gas pressure experienced in the rotameter. The pressure gauge used i s of the 0-200 psig range. The temperature of the gas j u s t before entrance in to the rotameter i s measured by means of a Chromel-Alumel thermocouple. TABLE IX-2-4: TRANSPORT NITROGEN ROTAMETER CALIBRATION DATA Rotameter Condit ions Wet Gas Meter Condit ions Standard ^ Condi t ions Reading T-| (K) P-,'(KPa) T 2 (K) P 2 (KPa) Q 2 ( m3 / s ) Q 0 ( m 3 / s ) 1 291 804.59 296.5 101.325 0.7630 x l O- 4 0.26675xl0" 4 2 291 701.67 296.5 101.325 1.3338 0.4993 3 292 652.9 296.5 101.325 1.9913 0.7741 4 292 673.59 296.5 101.325 2.6267 1.0053 5 292 646.0 296.5 101.325 3.2105 1.2547 7 292 632.22 296.5 101.325 4.4383 1.7534 9 292 625.32 296.5 101.325 5.5741 2.2142 11 292 618.43 296.5 101.325 6.6785 2.6676 13 292 611.54 295.5 101.325 7.6808 3.0956 13.75 292 604.64 295.5 101.325 8.0751 3.2730 * p i 0 = 101.32. 5 KPa, T Q = 294.11 K V / V , ! P P, 0 1 136 (v) Heat Exchanger Water Rotameter (Ch.E . No. 2706; Brooks R-8M-25-2) The 'Bucket and Stopwatch' technique i s used to measure the water f lowrate at var ious f l o a t p o s i t i o n s . The water temperature i s read from the mercury g lass thermometer. . TABLE IX-2-5: HEAT EXCHANGER WATER ROTAMETER CALIBRATION DATA Reading Volume Co l lec ted (ml) Duration (sec) Flowrate (ml/s) 0 1840 49 37.55 10 1870 44 42.50 20 1900 40.2 47.26 40 1900 34.0 55.88 60 1880 28.8 65.28 80 1920 25.5 75.29 110 1880 21.3 88.26 120 1890 19.5 96.92 140 1950 18.8 103.72 158 1940 17.4 111.49 Water temperature taken = 10.5 C (v i ) Reactor Water Rotameter (Ch.E . No. 2715; Brooks R-2-15-D) The 'Bucket and Stopwatch' technique i s employed to c a l i b r a t e the water rotameter. Temperature of the water i s measured with a mercury glass-thermometer. TABLE IX-2-6: REACTOR WATER ROTAMETER CALIBRATION DATA Reading Volume Co l l ec ted Duration Flowrate Observations (ml) (min-sec) (ml/min) 2 9.85 7 min 37s 1.2932 22 .22°C 9.80 6 59.2 1.4030 4 9.62 2 29.6 3.8583 34.5 9 1 3.8263 Bubbles In Rotameter 6 46.0 6 16.4 7.3326 19 .4 °C 40.7 5 29.8 7.4045 8 113.0 9 59.7 11.3056 19 .4 °C 94.8 8 51.8 10.6960 19 .4 °C 10 215.0 13 20 16.1250 18 .89°C 221.0 13 219 16.5360 12 182.0 8 15.4 21.9984 17 .5 °C 152.0 6 33.2 23.1940 F loa t Not Stable 14 220.0 7 53.2 27.8950 17 .5 °C 234.0 8 24.2 27.8460 17°C 40 80 120 160 200 240 R O T A M E T E R R E A D I N G Figure IX-2-2: Calibration of Gasifying Air Rotameter 40 80 120 160 200 R O T A M E T E R R E A D I N G Figure IX-2-3: C a l i b r a t i o n of Gas i fy ing Nitrogen Rotameter <o 20 R O T A M E T E R 60 80 R E A D I N G Figure IX-2-4: C a l i b r a t i o n of Gas i fy ing Carbon Dioxide Rotameter 12 20 40 60 80 ROTAMETER 100 R E A D I N G 120 140 160 Figure IX-2-6: C a l i b r a t i o n of Heat Exchanger Water Rotameter 4> ro 144 (3) APPENDIX 3. ORIFICE PLATE CALIBRATION The to ta l wet gas flow out of the reactor is measured by the pressure drop across an o r i f i c e plate with the o r i f i c e opening being 3.58 mm in diameter. The o r i f i c e plate is located a f t e r the heat exchanger but before the impinger. Readings of pressure and temperature upstream (about 0.46 m) of the o r i f i c e plate are made poss ib le by a pressure gauge (0-15 psig) and a Chromel-Alumel thermocouple r e s p e c t i v e l y . The pressure drop across the o r i f i c e i s measured by a mercury manometer. -The gas passes through a Schedule 40 S t a i n l e s s Steel pipe with a 21.34 mm outer diameter and a 15.80 mm inner diameter. The o r i f i c e plate i s c a l i b r a t e d with a i r and carbon dioxide so as to obtain the discharge c o e f f i c i e n t at d i f f e r e n t gas Reynolds numbers. For various f lows , the pressure drop across the plate as well as the upstream pressure and temperature are recorded. The gas flow i s then measured by a wet gas meter fa r ther downstream with pressure and tempera-ture condi t ions noted. The volumetr ic flow through an o r i f i c e plate i s given by : -where AP S pressure drop across o r i f i c e plate pipe c r o s s - s e c t i o n a l area 1.96037 x I O - 4 m 2 S '2 H o r i f i c e area = 1.00738 x 10 m' height of metering f l u i d (mercury) (m Hg) p densi ty o f metering f l u i d (mercury) (Kg/m3) 3 densi ty o f gas (Kg/m ) 9 acce le ra t ion due to grav i ty 9.81 m / s 2 C discharge c o e f f i c i e n t gas flow at o r i f i c e condi t ions (m3/s) By apply ing per fec t -gas law, the dens i ty of the gas at the o r i f i c e plate cond i t ions can be wr i t ten as : P M W 3 273 3 p = 22 4 x T~ x io] 325 (Kg/m ) where M . W . = gram-molecular weight of gas P o = o r i f i c e p late upstream pressure 6 (KPa) T o = o r i f i c e p la te upstream tempera-J ture (K) By s u b s t i t u t i n g the numerical values of , S 2 , g , the above expression in to the equation fo r C^, and s ince » p, ( p ^ - p) p^ , Q 3 i s reduced to : -2 x 9.81 x h x p. Q 3 = 0.000196037 C J • pr 100 x 377.648917 x ( ~j x y 3 - x ^ \ 2 b ) where h = height of mercury (cm Hg) r ; h p. T~ 1.2883 x 10 x C / T j O T j f Thus, the d ischarge , C, can be obtained by 77621.497 Cu C = h p h T 3 ( M . W . ) P Q 3 3 / h T-If P h i s taken as 13.53 x l t r Kg/m", then Q 3 = 0.0015011 x C / ( M - M > ) p The gas Reynolds Number at the o r i f i c e p la te condi t ions can be c a l c u l a t e d v i a the equation : y 0.141 x 0.0254 x ^ x xZi x _17J_ 1.00738 x 10" 5 22.4 T 3 101.325 42.762 Q 3 P 3 (M.W.) y T 3 o r i f i c e opening = 0.141 x 0.0254 m gas v e l o c i t y through o r i f i c e (m/s) gas v i s c o s i t y at o r i f i c e condi t ions (Kg/s m) TABLE IX-3-1: ORIFICE PLATE CALIBRATION USING DRY AIR Wet Gas Meter Condit ions O r i f i c e Plate Condi t ions T 2 (K ) P 2(KPa) Q 2 (m 3 / s ) h (cm Hg) T 3 (K) P 3 (KPa) Q 3 ( m3 / s ) C Re 297.5 101.325 2.49928x10" 4 1.0 297 112.36 2 .250xl0" 4 0.612 5716 297.5 101.325 2.901316 0.8 297 102.91 2.8518 0.674 7285 297.5 101.325 3.836971 1.5 297 103.74 3.7414 0.648 8509 297.5 101.325 5.129863 2.7 297 105.46 4.9204 0.641 2880 297.5 101.325 6.185717 4.2 297 107.43 5.7063 0.601 15809 297.5 101.325 7.260729 5.7 297 109.6 6.7013 0.612 18231 297.5 101.325 8.377765 7.5 297 112.36 7.5423 0.608 '21037 297.5 101.325 9.376439 9.6 297 115.11 8.2397 0.595 23544 297.5 101.325 10.113159 11.0 297 117.18 8.7301 0.594 25394 297.5 101.325 10.975521 12.7 297 119.6 9.2828 0.599 27499 297.5 101.325 11.605265 14.2 297 121.32 9.6763 0.589 29141 * * M.W. = 28.964 * Since Q2P2 = Q3P3 •k-k TABLE IX-3-2: ORIFICE PLATE CALIBRATION USING CARBON DIOXIDE Wet Gas Meter Condit ions O r i f i c e Plate Condi t ions T 2 (K ) P 2(KPa) Q 2 (m 3 / s ) h (cm Hg) T 3 (K) P 3 (KPa) Q 3 ( m3 / s ) * C Re 297.5 101.325 1.019324x10" 4 0.2 298 101.74 1.01687 0.588 4876 . 297.5 101.325 1.772017 0.5 298 102.15 1.7607 0.645 8476 297.5 101.325 2.517053 1.0 298 102.84 2.4841 0.646 12040 297.5 101.325 3.203263 1.7 298 103.74 3.134 0.610 14943 297.5 101.325 3.821436 2.4 298 104.77 3.702 0.606 17640 297.5 101.325 4.516243 3.4 298 106.43 4.3068 0.587 20531 297.5 101.325 5.403978 4.3 298 107.53 5.1007 0.615 24320 297.5 101.325 5.720575 5.4 298 109.05 5.3243 0.569 25386 297.5 101.325 6.435646 6.7 298 111.25 5.8714 0.558 27995 297.5 101.325 7.035241 8.2 298 113.05 6.3162 0.538 i 30116 * * M.W. = 44.00995 * Since Q 2 P 2 = Q 3 P 3 P o T 0-8 Legend C a l i b r a t i o n U s i n g o dry air 0-7 - • carbon dioxide icient gO-6 u - O ° \ * N ^ ^ ^ ^ - A o» O) ra "S 0-5 </> -Q i 1 i i i i , I 1 1 I I J 1— 5000 10 000 50 000 G a s Reynolds Number At Orif ice Condi t ions Figure IX-3-1: Discharge C o e f f i c i e n t v s . Gas Reynolds Number at O r i f i c e Condit ions 100 000 C O (4) APPENDIX 4. MINIMUM FLUIDIZING VELOCITY FOR VARIOUS SYSTEMS ( i ) Table IX-4-1: Pressure Drop across Grid Plate ( A i r , room temperature) ( i i ) Table IX-4-2: Pressure Drop across Grid Plate and 20 cm * bed ( A i r , room temperature) ( i i i ) Table IX-4-3: Pressure Drop across Grid Plate and 20 cm bed* ( A i r , 501 .9 °C) ( iv ) Figure IX-4-1: Pressure Drop across Grid and/or Bed v s . Gas Flow* ( A i r , room temperature) (v) Figure IX-4-2: Pressure Drop across Grid and Bed v s . Gas FI ( A i r , 501 .9 °C ) (v i ) Figure IX-4-3: Pressure Drop across Bed v s . Gas Flow** ( A i r , room temperature) ( v i i ) Figure IX-4-4: Pressure Drop across Bed v s . Gas Flow** ( N 2 , room temperature) ( v i i i ) Figure IX-4-5: Pressure Drop across Bed v s . Gas Flow** (CO2, room temperature) * Gas fed from below gr id plate * Gas is fed through the sawdust l i n e , above the gr id plate TABLE IX-4-1: PRESSURE DROP ACROSS GRID PLATE (AIR: REACTOR AT ROOM TEMPERATURE) A i r Rotameter Condit ions Preheater Outlet pressure (psig) Reactor pressure (psig) From A i r C a l i b r a t i o n Curve Q 0 ( m 3 / s ) * Actual Flow at Reference Condit ions Q r e f (m3/s)** A P * * * (psig) Reading P l (ps i ) T l CK) 20 15.026 295.22 0.33 0.20 2.78 x 10" 4 2.7785 x IO" 4 0.13 40 15.056 295.22 0.36 0.22 3.63 3.62685 0.14 60 15.296 295.22 0.45 0.43 4.45 4.41672 0.02 80 15.996 295.22 0.95 0.60 5.20 5.3252 0.35 100 16.446 295.22 1.15 0.82 5.82 5.8424 0.33 120 16.946 295.22 1.40 1.02 6.42 6.4587 0.38 140 17.416 295.22 1 .70 1 .30 7.04 7.16082 0.40 160 17.946 295.22 2.05 1 .55 7.65 7.66155 0.50 180 18.846 295.22 2.45 1 .80 8.27 8.2698 0.65 200 19.096 295.22 2.80 2.15 8.88 8.84718 0.65 220 19.696 295.22 3.15 2.50 9.50 9.41679 0.65 240 20.296 295.22 3.65 2.80 10.10 10.2429 0.85 250 20.496 295.22 3.85 2.95 10.45 10.2973 0.90 * At standard condi t ions P 0 = 101.325 KPa (14.696 p s i ) , T 0 = 294.11 K * * At reference cond i t ions . Using rotameter cor rec t ion Q r e f = Q 0 p r e f o r l Since t h i s reference condit ions is that of the standard; P T rrrr 0 / 0 1 r e f r e f P. and T T T, o 1 r e f = V * * * Pressure Drop across gr id i s taken as the d i f fe rence between preheater ou t l e t pressure and reactor pressure . Note: Gas is fed below the gr id p l a t e . See Figure IX-4-1. TABLE IX-4-2: PRESSURE DROP ACROSS GRID PLATE AND 20 cm SAND BED (AIR, REACTOR AT ROOM TEMPERATURE) A i r Rotameter Conditions Preheater Out let Pressure (Psig) Reactor Pressure (psig) From A i r C a l i b r a t i o n Curve Q 0 ( m 3 / s ) * Actual Flow at Reference Condit ions Q r e f (m3/s)** *** AP Reading P l (Psi ) T l (K) (psig) 20 15.396 259.44 1.65 0.20 2.78 x 10" 4 2.8294 x 1 0 ' 4 1 .45 40 15.696 297.44 1.90 0.30 3.63 3.7304 1.60 60 16.596 297.44 1 .95 0.45 4.45 4.7024 1.50 83 16.596 297.44 1.45 0.65 5.28 5.5795 0.80 99 16.896 297.44 1.70 0.80 5.80 6.1841 0.90 120 17.396 297.44 1.95 1 .10 6.42 6.9457 0.85 140 17.896 299.11 2.20 1.35 7.04 7.7035 0.85 160 18.446 299.11 2.60 1.60 7.65 8.4987 1 .00 180 18.996 299.11 2.90 1 .85 8.27 9.3234 1 .05 200 19.696 299.11 3.40 2.20 8.88 10.1939 1 .20 220 20.196 299.11 3.80 2.60 9.50 11 .0432 1 .20 242 20.896 299.11 4.20 2.85 10.1 11 .9424 1 .35 250 21 .196 299.11 ! 4.35 3.00 10.45 12.4447 1 .35 j * At standard condi t ions P 0 = 101.325 KPa (14.696 p s i ) , T n = 294.1 1 (K) T r e f HV} * * At reference cond i t ions . Using rotameter c o r r e c t i o n , Q . = Q „ / T T . r e T 0 V e f / V l Since t h i s reference condi t ion is that of the standard; P f = P , T , = T , thUS Q LfrX . o y 0 1 * * * Pressure drop across g r i d and bed i s taken as the d i f f e r e n t between preheater o u t l e t pressure reactor pressure. Note: Gas i s fed below the gr id p la te . See Figure IX-4-1. and TABLE XI-4-3: PRESSURE DROP ACROSS GRID PLATE AND 20 cm SAND BED (AIR: REACTOR AT 5 0 1 . 9 ° C ) A i r Rotameter Condit ions Preheater Outlet Pressure (psig) Reactor Condit ions From A i r C a l i b r a t i o n Curve Q 0 ( m 3 / s ) * Actual Flow at Reference Q r e f ( m 3 / s ) * * ** AP (psig) Reading P l (ps i ) T l (K) P 2 (psig) T 2 (K) 112 17.696 354.0 2.10 1.20 778 6.20 x 10" 4 6.093 x 10" 4 0.90 150 19.000 355.0 2.80 1.65 773 7.35 7.48 1 .15 198 21 .096 355.3 4.10 2.70 773 8.83 9.48 1.40 236 22.496 356.0 5.20 3.50 773 10.00 11 .08 1.70 180 20.596 356.0 3.65 2.30 773 8.27 8.74 1.35 142 19.096 355.5 2.75 1.60 775.5 7.10 7.20 1.15 100 17.696 355.5 1 .95 1 .00 775.5 5.82 5.685 0.95 80 17.096 355.0 1.55 0.80 775.5 5.20 4.959 0.75 60 16.696 353.5 1.35 0.55 775.5 4.45 4.236 0.80 52 16.496 353.5 1 .22 0.45 775.5 4.10 3.685 0.77 39 16.096 353.5 1 .05 0.35 775.5 3.60 2.839 0.70 20 15.596 353.5 0.85 0.20 776 2.78 1.583 0.65 ** * At standard condit ions P n = 101.345 KPa (14.696 p s i ) , T = 294.11 (K) T / p P re f / n 1 At reference cond i t ions . Using rotameter cor rec t ion Q f = Q • p J — - J re f o 1 Since t h i s reference condi t ion i s that of the standard; P f = P , T f = T , T / D D 0 0 - ' 0 1 thus Q r e f = p~ j JJ o l * * * Pressure drop a c r o s s . g r i d & bed i s taken as the d i f fe rence between preheater ou t l e t pressure and reactor pressure. Note: Gas is fed below gr id p l a t e . See Figure IX-4-2. 20-3-cm sand bed. Reactor is at room temperature. Gas is fed below the grid plate. grid Abed grid bed 10 AIR FLOWRATE ( std. m/s) 12 14 X10' Pressure Drop Across Grid and/or Bed vs . Gas Flow ( A i r ; Reactor at Room Temperature) 2 4 6 8 10 „ - 4 X 10 AIR FLOWRATE (std.m3/s) jure IX-4-2: Pressure Drop Across Gr id and Bed Vs . Gas Flow ( A i r ; Reactor at 500°C) t-(/) Q < i n w 0 . o or Q o r (/) </> ui Q. 20 '35 a S 16 O t-U < UJ a. I 12 0-8 0-4 bed Run 9 20-3-cm sand bed. Reactor is at room temperature. Gas is fed through the sawdust line, 5 cmabove grid X 10 AIR FLOWRATE (std. m3/s) Figure IX-4-3: Pressure Drop Across Bed Vs. Gas Flow ( A i r ; Reactor at Room Temperature) c n •2 frtU bed bed Reactor is ot room temperature. A Run 3 Gas it (ed through sawdust line,at K m above grid. 20-Jcmjand bed. • Run 2 Gas is led through sawdust line ,at»S«cm above grid 20-3<mlond bed (above j j c m gravel-sand mixture). 10 12 NITROGEN FLOWRATE (std.m3/s) X10 fgure IX-4-4: Pressure Drop Across Bed Vs. Gas Flow (N^; Reactor at Room Temperature) 20-3-cm sand bed. Gas is ted through sawdust line,at scm above grid. A Run 5 Reactor is at room temperature. • Run 6 Reactor is at 585-4 "C. 4 6 8 10 4 12 CARBON DIOXIDE FLOWRATE (std.m3/s) X 1 0 Figure IX-4-5: Pressure Drop Across Bed Vs. Gas Flow (CCL; Reactor at Room Temperature) (5) APPENDIX 5. TYPICAL GAS ANALYSIS The gas sample i s sample 1 fo r Run 11 where the f l u i d i z i n g medium used i s a i r . The sample i s withdrawn from sampling p o s i t i o n S3 and i s in jec ted manually into' the gas chromatograph. The var ious peaks are recorded by the Hewlett Packard 3388 Integrator and the concentrat ion fo r each gas component i s pr in ted as shown. 160 6.41 RT'. STOP RUN E h p ] 3388A M A N U A L INJECTION 1251 SEP 20,1981 GAS CALIBRATION STANDARD, SEP 11,1981 NORM % RT HEIGHT TYPE CAL A M O U N T N A M E 2.35 127.97 BB 1 0. 553 H 2 4. 90 131.21 BV 2 13. 59 co 2 5.64 4 .15 VV 3 2- 228 o 2 6. 41 437. 60 + VB 4 83.508 N 2 8. 31 0.63 VB 5 0. 179 C H 4 11.72 0.95 BB 6 0. 474 C O Figure IX-5-1: Typ ica l Gas A n a l y s i s (Run 11, Sample 1) APPENDIX 6. GASIFICATION RESULTS ( i ) Table IX -6 -1 : Experiments Performed with Nitrogen ( i i ) Table IX-6-2: Experiments Performed with Carbon Dioxide ( i i i ) Table IX-6-3: Experiments Performed with A i r ( iv ) Table IX-6-4: Experiments Performed with Steam-N2 Mixture (v) Determination of the K ine t i cs Parameters fo r P y r o l y s i s in Nitrogen Atmosphere (v i ) Determination of the K ine t ics Parameters f o r P y r o l y s i s in Carbon Dioxide Atmosphere ( v i i ) Determination of the K ine t ics Parameters f o r P y r o l y s i s in Steam-No Atmosphere 162 (1) TABLE IX-6-1: EXPERIMENTS PERFORMED WITH NITROGEN (sawdust size 0.67 mm)  Run Number 8 4 3 Experimental Conditions: Bed Temp. CC) Sampling position 410 S3 557 SI 689 S2 Sample Number 3 1 1 Observations : sawdust B 20 cm bed sawdust A 20 cm bed sawdust A 20 cm bed Balances: Overall Mass (in=M x 100X) 13.30 2.33 3.65 H ( " ) 83.68 71.80 74.04 0 ( " ) 67.89 49.68 71 .58 CO ( " ) 73.46 40.95 53.65 Ash ( " ) -259.00 17.57 40.75 Energy ( " ) 74.50 67.69 55.26 H20 In (g/s) 0.0066 0.0031 0.0045 Out (g/s) 0.011 0.0006 0.0 N In (g/s) 0.825 0.869 0.905 Solid Feed [Wet] (g/s) 0.236 0.053 0.073 [Dry] (g/s) 0.229 0.050 0.069 Moisture content of solid (X) 2.8 5.9 6.1 Gas Feed - Transport Nj (g/s) 0.825 0.869 0.903 " (std.m 3 /s) 0.000711 0.000748 0.000779 Molar 0/C [as 0P in gas feed/C 1n sBlid] 0 0 0 [total 0 in /C 1n solid] 0.35 0.37 0.37 Dry gas produced (std.m 3 /s) 0.000746 0.000758 0.000810 Dry gas produced (g/s) 0.865 0.892 0.937 Wet gas produced (g/s) 0.876 0.892 0.937 Moisture content of gas produced 1 .29 0.0 0.0 Gas Composition: (With Transport N2) H 2 (%V, dry) 0.71 0.68 0.55 CO ( - ) 2.06 1.80 1 .92 CH4( " ) 0.59 0.36 0.63 co2( " ) 1 .36 0.31 0.71 N 2 ( " ) 95.28 98.84 96.19 Heating Value (MJ/m3) 0.5 6 .0.44 0.53 Gas Composition: (without transport N?) H 2 (XV, dry) 15.00 21 .17 14.07 CO ( " ) 43.43 55.93 49.36 CH4 ( " ) 12.45 11 .19 16.10 co2 ( " ) 28.73 9.67 18.30 N 2 ( " ) 0.39 2.04 2.17 Heating Value (MJ/m3) 11.73 13.50 13.70 Char (g/s) 0.0 0.0030 0.0 Cyclone catch - (g/g dry solid) 0.091 0.038 0.040 (g/s) 0.0209 0.0019 0.0028 (X C) 72.48 80.88 87.00 Dry Raw Gas - (std.m 3/g dry solid) 0.003258 0.015189 0.011801 (g/g dry solid) 3.778 17.869 13.650 Tar - (g/g dry solid) 0.098 0.061 0.022 (g/s) 0.0224 0.0030 0.0015 (g/dry std.m gas) 30.03 4.00 1.88 Superficial Velocity In Reactor (m/s) 0.4.1 0.56 0.60 IN: Wet Solid (g/g wet solid) 1.000 1.000 1 .000 Gas In ( " ) 3.503 16.387 12.357 Total ( " ) 4.503 17.387 13.357 OUT: Cyclone catch ( " ) 0.089 0.036 0.038 Char ( " ) 0.0 0.056 0.0 Wet Gas ( " ) 3.720 16.833 12.815 Tar ( " ) 0.095 0.057 0.021 Total ( " ) 3.904 16.982 12.874 (11) Table IX-6-2: EXPERIMENTS PERFORMED WITH CARBON DIOXIDE (20 cm sand bed; sawdust A)  163 Run Number Experimental Conditions: Bed Temp. (°C) Sampling position Sample Number Observations : In-Out In HjO n2 CO ) CH4 ( CO, ( n 2 CO ( CH4( co2( N2 ( ) Heating Value (MJ/m ) Char (g/s) Cyclone Catch (g/g dry solid) (g/s) («C) Dry Raw Gas - (std.m /g dry solid) (g/g dry solid) Tar (g/g dry sol id) (g/s) (g/dry std.m3 gas) Superficial velocity in reactor (m/s) IN: West Solid (g/g wet solid) Gas In ( Total ( OUT: Cyclone Catch ( " Char ( Wet Gas ( Tar ( Total ( 7 420 S3 1 5 500 S2 1 Tar collected is lower 0.46mm sawdust 0.67mm Balances: Overall Mass ("';"•"• x 100* H ( 0 ( Ash ( Energy ( N In (g/s) Out (g/s) In (g/s) Out (g/s) C In (g/s) Solid Feed [wet] (g/s) [dry] (g/s) Moisture content of solid (S) Gas Feed - Transport C02 (g/s) - " " (std.m3/s) Molar 0/C [as 0 2 in gas feed/C in solid] [total 0 In/C in solid] Dry Gas Produced (std.m3/s) (g/s) Wet gas produced (g/s) Moisture content of gas produced (%w) Gas Composition: (with Transport C02) H, (IV, dry) 6 517.1 SI 5 0.67mm "2 v Heating value (MJ/m3) Gas Composition: (without Transport C02) H, (%V, dry) -5.61 -3.44 0.1196 83.51 66.44 60.22 -7.69 -5.14 0.2 -284.00 53.16 -27.8 70.58 66.26 24.02 0.0013 0.0007 0.0011 0.000 0.000 0.00 0.0013 0.0043 0.0082 0.0042 0.0006 0.0030 0.327 0.235 0.3443 0.112 0.065 0.102 0.111 0.060 0.094 1.1 6.7 8.0 1.000 0.753 1.093 0.00055 0.00041 0.0006 0 0 0 5.35 7.32 6.89 0.000638 0.000476 0.000666 1.147 0.842 1.167 1 .152 0.842 1.170 0.36 0.07 0.26 0.14 1.36 1 .30 2.38 3.30 4.88 0.57 1 .00 1.42 96.92 94.35 92.40 0.0 0.0 0.0 0.52 0.94 1.28 0.97 10.19 13.04 16.96 24.80 48.81 4.06 7.50 14.16 78.01 57.51 24.00 0.0 0.0 0.0 3.68 7.04 12.78 0.0025 0.0002 0.0118 0.1228 0.0246 0.0694 0.0136 0.0015 0.0065 72.14 83.07 83.00 0.005748 0.007872 0.007109 10.337 13.928 12.460 0.0633 0.0377 0.0551 0.0070 0.0023 0.0052 11.02 4.68 7.76 0.28 0.29 0.41 1.000 1.000 1 .000 8.907 11.631 10.735 9.907 12.631 11.735 0.121 0.023 0.064 0.022 0.003 0.116 10.257 13.004 11.491 0.063 0.035 0.051 10.462 13.065 11.722 (111) TABLE IX-6-3: EXPERIMENTS PERFORMED WITH AIR (20cm sand bed; sawdust B with 0.67 mm diameter; no char formed)  164 Run Number 9 11 10 12 Experimental Conditions: Bed Temp. CC) 437 473 596 670 Sampling position S3 S3 S3 S3 Sample number 3 1 2 4 Observations : Cyclone catch low Balances: Overall Mass (Il!lM „ 1 0oi) -4.48 14.82 12.41 4. 51 H ( " ) 24.0 75.16 32.19 33. 64 0 ( " ) 0.32 44.45 30.28 23. 51 C ( " ) 68.68 33.27 41.08 -36. 46 Ash ( ) 40.17 59.56 54.76 81 . 17 Energy ( " ) 42.30 53.98 80.69 76. 21 H20 In (g/s) 0.0051 0.0018 0.0086 0. 0048 Out (g/s) 0.0165 0.0127 0.0588 0. 0158 N In (g/s) 0.3961 0.5401 0.5301 0. 4882 Solid Feed [wet] (g/s) 0.091 0.118 0.153 0. 093 [dry] (g/s) 0.086 0.117 0.144 0. 088 Moisture content of solid (t) 5.6 1.5 5.6 5. 2 Gas Feed - AIR (g/s) 0.524 0.715 0.702 0646 (std.m 3 /s) 0.00044 0.00060 0.00059 0 00054 - transport Nj (g/s) - - - -(std.m^/s) - - - -Molar 0/C [as 0 ? in gas feed/C 1n solid] 1.07 1.08 0.84 1 .29 [total 0 in /c in s o l i d ] 1.50 1.48 1.27 1 73 Dry Gas Produced (std.m 3 /s) 0.000505 0.000557 0.000547 0 000563 (g/s) 0.624 0.693 0.688 0 689 Wet Gas Produced (g/s) 0.641 0.706 0.747 0 705 Moisture Content of Wet Gas Produced (%w) 2.57 1.80 7.87 2 24 Gas Composition (with transport air) H 2 (SV, dry) 4.31 0.55 0.18 3 07 CO ( » ) 8.03 0.47 0.69 5 50 CH4 ( " ) 0.97 0.18 0.06 0 83 co2 ( " ) 19.09 13.06 14.50 14.85 N 2 ( " ) 67.60 83.51 83.42 74 .70 Heating value (MJ/m ) air 1.86 0.19 0.13 1 .35 Gas Composition: (Without transport air) H 2 (XV, dry) 13.40 3.86 1.17 12 .68 CO ( •• ) 24.97 3.37 4.42 22 .71 CH4 ( " ) 3.01 1.27 0.39 3 .42 co2 ( " ) 58.54 91.50 94.02 61 .19 N 2 { • ) 0.08 0.0 0.0 0 .0 Heating Value (MJ/m3) 5.75 1.35 0.8 5 .55 Char (g/s) 0.0 0.0 0.0 0 .0 Cyclone catch (g/g dry solid) 0.0165 0.0072 0.0067 0 .0034 (g/s) 0.0014 0.0008 0.0010 0 .0003 ( K ) 74.65 60.45 52.31 61 .39 Dry Raw Gas (std.m 3/g dry solid) 0.005893 0.004781 0.003720 0 .006396 (g/g dry solid) 7.28 5.95 4.78 7 .83 Tar (g/g dry sol1d) 0.0104 0.0268 0.0043 0 .0072 (g/s) 0.00089 0.003 0.0006 0 .0006 (g/dry std.m 3 gas) 1.77 5.39 1 .12 1 .13 Superficial velocity In reactor(m/sl 0.22 0.40 0.40 0.40 IN: Wet Solid (g/g wet solid) 1.000 1.000 1.000 1 .000 Gas In ( ) 5.775 6.045 4.600 6 .960 Total ( " ) 6.775 7.045 5.600 7 .960 OUT: Cyclone Catch ( " ) 0.016 0.007 0.006 0 .003 Char ( • ) 0.0 0.0 0.0 0 .0 Wet Gas ( ) 7.054 5.969 4.895 7 .591 Tar ( " ) 0.010 0.025 0.004 0 .007 Total ( " ) 7.080 6.001 4.905 7 .601 (Iv) TABLE IX-6-4: EXPERIMENTS PERFORMED WITH STEAM-N, MIXTURE (20 cm sand bed; sawdust B with 0.67 mm diameter) Run Number 16 15 14 Experimental Conditions: Bed Temp. (*C) 416 501 597 Sampling position S3 S3 S3 Sample Number 1 3 4 Observations : No char No char Balances: Overall Mass ( l n ' ° u t x 100?) 11.D2 4.45 2 0 H ( ' ) 96.79 77.44 IB 92 0 ( • ) 8S.87 66.67 7 61 C ( " ) 57.88 34.90 1 1 Ash ( " ) -260 -5.71 71 67 Energy ( " ) 79.74 80.27 50 25 H20 In (g/s) 0.0465 0.0248 0 0139 Out (g/s) 0.0855 0.0333 0 .018 N In (g/s) 0.6341 0.6175 0 6556 Solid Feed [wet] (g/s) 0.0729 0.0308 0 0974 [dry] (g/s) 0.0707 0.0300 0 0931 Moisture content of sol id (%) 3.15 2.41 4 41 Gas Feed - steam (g/s) 0.044 0.024 0 010 - transport N 2 (g/s) 0.634 0.616 0 655 (std.m 3 /s) 0.00055 0.00053 0 00057 Molar 0/C [as 0 ? 1n gas feed/C 1n solid) 0 0 0 [total 0 1n/C in sol id] 0.77 0.89 0 43 Dry gas produced (std.m 3 /s) 0.000553 0.000552 0 000666 (g/s) 0.6439 0.6383 0 7 396 Wet Gas Produced (g/s) 0.6454 0.6362 0 7455 Moisture content of wet gas produced (tw) 0.23 0.14 0 79 Gas Composition: (with Transport N )^ H 2 (%V, dry) 0.11 0.44 4 82 CO ( " ) 0.24 1.70 5 98 CH4 ( " ) 0.10 0.88 2 47 co2 ( • ) 0.78 0.64 1 99 K 2 ( " ) 98.77 96.34 84 75 Heating value (MJ/ro3) 0.08 0.59 2 23 6as Composition: (without transport N2) H 2 (XV, dry) 8.57 11 .94 31 57 CO ( " ) 19.77 46.53 39 18 CH4 ( " ) 8.16 17.51 16 18 co2 ( " ) 62.87 0.09 13 02 N 2 ( • ) 0.62 0.0 0 06 Heating Value (MJ/m3) 6.49 16.06 14 63 Char (g/s) 0.0068 0.0 0 0 Cyclone Catch (g/g dry solid) 0.0931 0.0333 0 0088 (g/s) 0.0066 0.001 0 000821 ( K ) 72.62 77.84 77 06 Dry raw gas (std.m 3/g dry solid) 0.007827 0.018376 0 007.154 (g/g dry solid) 9.15 21.56 8 11 Tar (g/g dry solid) 0.137 0.078 0 on (g/s) 0.010 0.002 0 001 (g/g dry std.m 3 gas) 17.44 4.23 1 51 Superficial velocity In reactor (m/s) 0.34 0.36 0 40 IN: Wet Solid (g/g wet solid) 1.000 1.000 1 000 Gas In ( " ) 9.299 20.842 6 829 Total ( " ) 10.299 21.842 7 829 OUT: Cyclone Catch ( " ) 0.09 3 0.033 0 008 Char ( • ) 0.097 0.0 0 0 Wet gas ( ) 9.136 21. 27E 7 655 Tar ( ) 0.137 0.07 8 0 010 Total ( • ) 9.463 21. 389 7 673 166 (v) Determination of the K ine t i cs Parameters f o r P y r o l y s i s in Nitrogen  Atmosphere 25 According to Brink and Massoudi , the exper imental ly determined rate of wood p y r o l y s i s could be expressed using f i r s t order k i n e t i c s : r = K (1 - Xg) where r = rate of p y r o l y s i s Xg = extent of conversion of wood p a r t i c l e in to gaseous products K = react ion rate constant For the theore t i ca l a n a l y s i s of the ideal s t i r r e d - t a n k reactor f low, and noting that the mass of reactant converted in the volume element i s the a lgebra ic sum of the inf low and e f f l u e n t , the above equation i s reduced to l n T J ^ g T t = l n K = l n K o " PT where KQ = pre-exponential f a c t o r E = apparent a c t i v a t i o n energy R = universa l gas constant The average residence time i s determined according to t = J L z Qt and the extent of conversion of wood p a r t i c l e s in to gaseous products i s c a l c u l a t e d by xg - - J T — s where V = reactor volume Q.j. = to ta l f lowrate of gas Ws = weight of s o l i d s fed WR = c o l l e c t e d residues weight TABLE IX-6-5: KINETICS PARAMETERS DETERMINATION FOR N 9 PYROLYSIS Run Number 8 4 ' 3 Bed Temperature (K) 683.25 829.50 961.75 T " 1 (K" 1 ) 14 .64x l0" 4 12.06xl0~ 4 10.40xl0" 4 Ws (g /s) 0.2356 0.0530 0.0731 WR (g /s) 0.0433 0.0050 0.0043 X 9 0.8162 0.9057 0.9412 S u p e r f i c i a l v e l o c i t y (m/s) 0.41 0.56 0.60 t (s) 3.5467 2.5967 2.4236 X q 0 - x g ) t 1 .2522 3.6970 6.6018 X L N TT^XgTt 0.2249 1 .3075 1.8873 Note: Wf. = wet s o l i d feed WR = cyclone catch + char + tar Height o f reactor = 1.45415 m From Figure IX-6-2 ln KQ = 6.2 =* • KQ = 492.75 = 4.9 x 10^ s" E = slope x 8.3144 J/mol = ^ =• x 8.3144 J/mol 0.32 x 10"° = 33.78 KJ/mol 168 169 (v i ) Determination o f the K ine t ics Parameters for P y r o l y s i s in Carbon  Di oxi de Water-gas react ion C + H^O + heat CO + H 2 Water-gas s h i f t react ion CO + H 2o v C 0 2 + H 2 + heat Boudouard react ion C + C0 2 + heat ^ 2C0 For the Boudouard r e a c t i o n , the rate of g a s i f i c a t i o n can be re la ted to the carbon monoxide product ion . The amount of CO detected must in t h i s case be corrected by the cont r ibu t ion of CO by the reverse s h i f t r e a c t i o n . Hydrogen i s produced through the decomposition of the s o l i d s t ructure and the decomposition rate can be estimated as the d i f fe rence between the to ta l H 2 production and theore t ica l H 2 production re la ted to the actual CO and C 0 2 production according to the water gas and s h i f t r e a c t i o n . This p y r o l y t i c hydrogen production has been cor re la ted to a f i r s t - o r d e r with respect to hydrogen content in the char for bituminous-coal feed (Cambell 4 ^) and o i l - s h a l e feed ( B j e r l e , Eklund and Svensson 4 ^) . Due to the large C 0 2 excess in the r e a c t o r , the H 2 w i l l react with C0 2 according to the reverse s h i f t r e a c t i o n . The production o r i g i n a t i n g from the Boudouard react ion could therefore be wri t ten r i l r M I r - i ^ i u i moi. of carbon [ r c J C 0 2 _ 2 L M C 0 • 2 L r H J + M H 2 J Kg of feed ( d r y ) , s where r c = react ion rate in C0 2 atmosphere r L | = p y r o l y t i c decomposition rate of H 2 M C0'^2 = m 0 ^ e s ° ^ ^ o r H 2 P r °duced P e r u n i t m a s s ° f dry feed in uni t time 170 The c o n t r i b u t i o n of the c o r r e c t i o n terms i s qui te large at lower temperatures, but i t does attempt to i s o l a t e the Boudouard react ion and w i l l give a more true p ic ture of the char g a s i f i c a t i o n . However, s ince no a v a i l a b l e data of [r^] can be found, one would have to be prepared to use the uncorrected express ion , based on the to ta l CO production o n l y . ^ C O , - 1 / 2 M C0 Reaction rates of f i r e d carbon with steam and carbon dioxide have been shown by several i n v e s t i g a t i o n s (Gadsby et a l . , 1946; Johnstone et al . 1952; S t r i c k l a n d - C o n s t a b l e , 1947) to fo l low Langmuir-Hinshelwood express ions . At low p a r t i a l pressures of the react ion products , e . g . H 2 and CO, the re tardat ion e f fec ts could be neglected . The react ion rate in C0 2 atmosphere can therefore be expressed according to K 2 P C 0 2 ^c-'co = " K l M l + K P ) with C c being moles of carbon/Kg o f dry feed . The constants and K 2 fo l low an Arrheni us type equation K^ . = K ^ e " ^ 1 ^ ^ . Under condi t ions of very low carbon dioxide conversions at low pressures , the rate expression can be s i m p l i f i e d to p s e u d o - f i r s t - o r d e r k i n e t i c s , ^ C 0 2 = " K l C c Therefore K\ - [ £ = 1 /2 ^ ° = e " E l ' R T TABLE IX-6-6: KINETICS PARAMETERS DETERMINATION FOR COV PYROLYSIS Run Number 7 5 6 Bed Temperature (K) 693.29 773.20 * 790.00 1 T" 1 (K" 1 ) 14.42x10" 4 12.93x l0"4 12.66x l0" 4 CO (std.m / g . d r y feed) 1.37x10" 4 2.58x l0" 4 3 .42x l0"4 M C Q (moles/Kg dry feed) 1.8769 10.6910 1 1 .6964 0.022997 0.13099 ' 0.143309 ln [ rc ] c o 2 -3.772 -2.033 -1 .9428 * C c = 40.8083 moles/Kg of dry feed From Figure I X - 6 - 3 , In K ' = 12.3 = * - K , n = 2.2 x 10 5 s' E ] = slope x 8.3144 J/mol = 4 - ^ =• x 8.3144 J/mol 0.44 x IO" - 3 = 92.59 (KJ/mol) 172 ( v i i ) Determination of the K ine t ics Parameters for G a s i f i c a t i o n in Steam-N 2 Atmosphere S i m i l a r to react ion of f ixed carbon in carbon d i o x i d e , react ion rate in steam atmosphere can a lso be f i t t e d the Langmuir-Hinshelwood expression and be reduced to a p s e u d o - f i r s t order k i n e t i c s at low pressures with very low steam convers ions . The react ion rate of f ixed carbon can be re la ted to the production of CO and CO^ according to water gas and water gas s h i f t r e a c t i o n s . Carbon oxides w i l l a lso be produced during v o l a l t i l e matter p y r o l y s i s and by decomposition of inorganic carbonates in the ash. As these cont r ibut ions are qui te s m a l l , they have not been accounted for and the react ion rate i s given by ( M r n + M r n ) detected in gas moles of C (kg o f char) (s) K 3 M CO + MC02  C c = K 30 e - E 3 / R T 1 7 4 TABLE IX-6-7: KINETICS PARAMETERS DETERMINATION FOR STEAM-N,, GASIFICATION Run Number 16 15 14 Bed Temperature (K) T " 1 (K) 3 CO (std.m / g dry feed) 3 C0 2 (std.m /g dry feed) M C Q (moles/Kg dry feed) M co2 ( m 0 ^ e s / K 9 d r y f e e c | ) 688.58 14.52x10" 4 0 .155x10" 4 0.493xl0" 4 0.6400 2.0429 774.00 12 .92xl0" 4 2.968xl0" 4 1.118xl0" 4 12.2555 4.6328 870.00 11 .49x l0" 4 3.709xl0" 4 1 .233xl0" 4 15.3152 5.1094 r c MCO + M C 0 2 c c 0.0651 0.4099 0.4957 r l n [ C^ ] H 2 0 -2.7315 -0.8918 -0.7017 * C c = 41.2 moles/Kg o f dry feed From Figure IX-6-4, ln K^Q = 8.45 K3Q = 4.7 x 10 3 S " 1 E 3 = slope x 8.3144 J/mol 3.1 0.4 x 10 64.44 KJ/mol 3 x 8.3144 J/mol 10 APPENDIX 7. LITERATURE REVIEW ( i ) System A: P y r o l y s i s in Nitrogen Atmosphere (a) B r i n k 1 2 and M a s s o u d i 2 5 (1976) (b) Tran and R a i 1 4 19 (c) Barooah and Long (1976) ( i i ) System B: G a s i f i c a t i o n with A i r in a F l u i d i z e d Bed (a) Ki lburn and L e v e l t o n 8 (1963) (b) Wen, L i n , O ' b r i e n , B a i l i e 2 0 and B u r t o n 3 5 (1973) 2 3 (c) L i u , Serenius and Martinez (1976) ( i i i ) System C: G a s i f i c a t i o n with A i r in a Fixed Bed (a) V o s s 2 2 (1977) 30 (b) Review: Jones (1944) ( iv ) System D: G a s i f i c a t i o n with Steam and A i r 18 (a) Hammond, Mudge, A l l e n and S c h i e f e l b e i n (1974) (b) Beck, Wang and Hightower 4 1 (1979) (v) System E: G a s i f i c a t i o n with Steam Tran and R a i 1 5 (1976) 177 ( i ) System A: P y r o l y s i s in Nitrogen Atmosphere 12 25 (a) Inves t iga to rs : D.L. Brink and M.S. Massoudi (1975) A flow reactor technique was developed for the study of wood p y r o l y s i s . A schematic diagram of the experimental apparatus is given in Figure IX-7-1 . The major components were: reactor and furnace , s o l i d p a r t i c l e feeding system, c o l l e c t i o n system, a n a l y t i c a l system and flow measuring d e v i c e s . A i r dr ied white f i r wood p a r t i c l e s were c l a s s i f i e d using an 18-inch Sweco Separator f i t t e d with 20 and 40 mesh screens . In preparat ion for an experimental run , the e l e c t r i c heater of the furnace was ac t iva ted and the reactor was heated to the desi red react ion temperature. The feed hopper was f i t t e d with wood p a r t i c l e s of a s p e c i f i e d s i z e , weighed, and then attached to the hor izonta l feed l i n e . When the reactor reached the desi red temperature, ni trogen flow was adjusted through the reactor to y i e l d a s p e c i f i e d residence t ime. Upon enter ing the r e a c t o r , the suspension of wood p a r t i c l e s was rap id ly heated and underwent chemical react ions invo lv ing thermal decomposit ion, i . e . p y r o l y s i s and g a s i f i c a t i o n . P a r t i a l l y reacted wood p a r t i c l e s (char) suspended in ni trogen together with the generated p y r o l y s i s gases were conveyed through the gas t r e a t -ment t r a i n . Gas sampling bot t les were used to c o l l e c t samples o f the gaseous stream as i t issued from gas sampling por t - At the end of an experimental .run, ind iv idua l components were weighed. The overa l l k i n e t i c s were invest iga ted over a temperature range of 3 1 6 - 8 1 7 ° C . The p a r t i c l e diameter ranged from 0.04 to 0.084 cm and the reactor operated at atmospheric pressure . Using nitrogen as a c a r r i e r gas, flow rates were var ied which r e s u l t in residence times ranging from 3.02 to 5.32 second. The mechanism of p y r o l y s i s - g a s i f i c a t i o n of a gas suspension of wood p a r t i c l e s have been d iv ided in to two k i n e t i c regimes. At lower temperatures, below 6 4 7 ° C , thermal decomposition react ions were dominant. The a c t i v a t i o n energy and pre-exponent ia l fac tor were found to be 58.6 KJ/mol and 3 -1 3 x 10 S r e s p e c t i v e l y . At temperatures higher than 6 4 7 ° C , both thermal decomposition react ions and surface react ions between formed gases and charred p a r t i c l e s were i n v o l v e d . In th is temperature reg ions , the a c t i v a t i o n energy and pre-exponent ia l fac tor were to be 104.7 KJ/mol 5 -1 and 2.64 x 10 S r e s p e c t i v e l y . The experimental s tudies showed that the extent of conversion of s o l i d p a r t i c l e s in to gaseous products var ied d i r e c t l y and average molecular weight of the p y r o l y s i s gases produced var ied i n v e r s e l y with temperature and/or residence t ime. The extent of conversion to gaseous products i s a t t r ibu ted d i r e c t l y to g a s i f i c a t i o n react ions o f carbon with steam and carbon d i o x i d e . The rates of these are great ly increased as temperature increases above 500°C. Water i s a c r i t i c a l reactant in the g a s i f i c a t i o n r e a c t i o n . Because of the low moisture content of the feed material the amount of water a v a i l a b l e for g a s i f i c a t i o n should have become n e g l i g i b l e at a temperature in the range of 700°C. The e f f e c t of reducing the water content of the p y r o l y s i s gas to low concentrat ions w i l l dr ive the s h i f t react ion toward formation o f carbon monoxide and water. Results o f several runs were presented in Table IX-7-1 , Figures VI-1 and IV-7-2 . For wood with a moisture content of 6.5%, the c /0 r a t i o was 1.313, H/0 2.345; the resu l tan t v o l a t i l e s 1 C/0 was 1.076, H/0 1.775; whereas the C/0 r a t i o of the v o l t a t i l e s plus residues was found to be 1.137. TABLE IX-7-1 : EXPERIMENTS PERFORMED BY BRINK AND MASSAUDI Reaction Temperature ( ° C ) 316 480 593 j 604 677 704 732 816 843 871 * P y r o l y s i s Gas Produced (a,/100 gts) 31.2 31.0 46.7 51.5 66.5 88.3 68.2 76.0 91.1 90.6 (A/100 g t s / s ) 6.8 8.9 11.4 j 16.5 19.1 17.0 17.4 21.6 30.2 18.7 Gas Composition {% mol) H 2 Trace Trace 35.8 | 0 12.7 34 14.8 0 17 24.1 CO 17.3 24.5 36.3 65.2 54.6 50.4 63.5 74.2 54.6 52.2 c o 2 82.7 75.5 16.1 21.8 17.0 3.3 10.4 3.5 7.6 5.1 CH 4 0 0 11.8 13.0 15.6 10.7 11.3 17.0 16.2 14.6 C 2 H 4 0 0 0 0 0 1.7 Trace 5.0 4.5 3.9 C 2 H 6 0 0 0 0 0 Trace 0 Trace 0 0 Average Molecular Weight 41.2 40.1 19.8 29.9 25.6 18.4 24.5 26.5 22.6 20.8 Heating Value (Kcal/100 gts) 60.7 85.0 1138.8 732.7 975.5 1595.2 942.0 1373.3 1666.3 1662.2 * gts = gram to ta l s o l i d s of feed input * Feed moisture content was not s p e c i f i e d Air Supply To Hood Q-1 GEAR REDUCTION MOTOR TEMPERATURE RECORDER VARIABLE TEMPERATURE C O N T R O L REFRIGERATION UNIT WATER MANOMETER Figure IX-7-1: Schematic of Experimental Apparatus (Br ink , Massoudi) 25 Condensables plus CA R B O N A C E O U S RESIDUE (9 /100gts) ro J> o> 00 I 8 T '(b) I nves t iga to rs : D.Q. Tran and C. Rai (1979) A k i n e t i c study o f ca ta lyzed and noncatalyzed p y r o l y s i s of Douglas f i r bark was conducted using a DuPont 951 Thermogravimetric Analyzer (F igure IX-7-3) with the e l e c t r o n i c programming and recording f a c i l i t i e s o f the DuPont 990 Thermal Analyzer module. It cons is ts of a f ixed h o r i -zontal furnace with a nu l l -ba lance uni t which s l i d e s in to the furnace. The balance operates on a n u l l - b a l a n c i n g p r i n c i p l e employing a taut-band e l e c t r i c meter movement. A sample thermocouple (Chrome!-Alumel) i s placed d i r e c t l y on top of the sample but not touching i t ; the sample capaci ty i s of 500 mg, inc lud ing the sample boat . The 990 Thermal Analyzer i s the control and recording u n i t , with a heating rate of up to 100°C/min obta inab le . The recording uni t p lots both the weight loss and i t s rate as a funct ion of temperature (or t ime) . Powdered Douglas f i r bark, trade name S i lvacon 490, was used. The ult imate ana lys is of the bark with a moisture content of 8.8%, wet b a s i s , showed 53.05% carbon, 6.12% hydrogen, 0.06% sulphur , 0.15% nitrogen and 40.62% oxygen. The bark was sa id to have a heating value of 9510 B t u / l b . Catalyzed bark was made by an impregnation procedure; up to 20 wt % of potassium carbonate was thus impregnated on the bark res idues . In each run , a sample o f approximately 20 mg was used. Several runs were made at heating rates o f 1 0 ° , 2 0 ° , 5 0 ° , 77° and 1 0 0 ° C / m i n ; a nitrogen flow rate of 150 ml /min. was used. Each run was s tar ted at about 22° to 25°C and terminated 5 to 10 min. a f t e r the desired temperature, 8 5 0 ° C , was reached. A k i n e t i c model in which a c t i v a t i o n energy i s assumed to be a l i n e a r funct ion of the extent of react ion was used to descr ibe the p y r o l y s i s of bark. It was found that as conversion increases from 10% to 70%, the a c t i v a t i o n energy increases from 101.7 to 201.8 k j / moi for the noncatalyzed bark and from 102.6 to 162.9 k j / moi fo r the cata lyzed bark. The order of react ion was found to be 1 and 2 for the noncatalyzed and the cata lyzed bark, r e s p e c t i v e l y . gas out gas in Quartz Balance Arc Furnace o o o o o o o o o b o o o o Sample Holder Thermocouple Photocells Counterweight Lamp Shutter Total-Band Meter Suspension Figure IX-7-3: The Dupont 951 TGA Balance Assembly (Tran, Rai) 14 00 (c) I nves t iga to rs ; J . N . Barooah and V.D. Long (1976) Beech sawdust, granular c e l l u l o s e and sucrose-impregnated pumice have been separate ly decomposed in a f l u i d i z e d bed of sand in an atmosphere of ni t rogen at temperatures up to 400°C . Decomposition was c a r r i e d out in a f l u i d i z e d bed to maximise heat t rans fe r to the s o l i d s , separat ing as fa r as poss ib le the chemical and physical aspects of the process . The reactor comprised e s s e n t i a l l y a 76 mm diameter f l u i d i z e d bed held in the middle 150 mm of a v e r t i c a l m i l d - s t e e l pipe 610 mm long surrounded by an e l e c t r i c a l heating element and thermal i n s u l a t i o n . Oxygen-free ni trogen was the f l u i d i z i n g gas during r e a c t i o n . Reaction was s tar ted by in t roducing simultaneously in to the reactor 40 g reactant ( for beech sawdust; s i z e f r a c t i o n 18-25 mesh BS s i e v e , dr ied at 102°C and conta in ing 48.6% carbon) and 800 g ign i ted sand (36-72 mesh BS s i e v e ) , 600 g o f the sand being preheated s u f f i c i e n t l y to ra ise the mixture to the reactor temperature. Runs were ca r r i ed out at a range of reactor temperatures up to a maximum of 400°C . In each run , samples of about 50 g mixed s o l i d s were withdrawn from the bed at preselected times in the range 2-90 min v ia sampling probes connected to massive evacuated r e c e i v e r s . A sample was a lso taken of the charge remaining in the reactor a f te r coo l ing under n i t rogen . In a l l c a s e s , decomposition occurred in two s tages , the primary stage g iv ing about 85% of the to ta l change at any temperature leve l in less than 10 min. The k i n e t i c s of weight loss in the f i r s t stage were approximately f i r s t - o r d e r with respect to res idual weight of organic matter , while the second stage approximated a second-order process with respect to the-weight loss to be completed in reaching e q u i l i b r i u m . In both s tages , there was a marked change in the temperature dependence of 186 the rate of decomposition of wood in the region 3 0 0 - 5 0 0 ° C . The maximum weight loss at any temperature was a funct ion of temperature, showing that react ion path was temperature dependent. The k i n e t i c parameters of beech sawdust for the use in the Arrhenius equation K = KQ exp (-E/RT) were as f o l l o w s : -Primary decomposition Secondary decomposition Below 330°C Above 330°C Below 330°C Above 330°C E (KJ mol" 1 ) 5.3 x 10" 2 2.3 x 10 4 18 84 10.7 4 x 10 9 17 115 ( i i ) System B: G a s i f i c a t i o n with A i r in a F l u i d i z e d Bed (a) I nves t iga to rs : D.G. Ki lburn and B.H. Levelton (1963) Woodwaste was pyrolyzed in a f l u i d i z e d bed to generate gas and manufacture c h a r c o a l . A unique conf igura t ion was used that required no g r id p l a t e , and the feed was d i s t r i b u t e d in the f l u i d i z i n g gas, and both gas and feed entered the bed together . The reactor was 15 cm in diameter and 25 cm l o n g . M i l l waste hogged to -4 mesh was f l a s h dr ied and preheated to decomposition temperature before i t was introduced into the r e a c t o r . Preheated a i r (plus recyc led woodgas) was employed as the f l u i d i z i n g medium. With the dry feed rate maintained at 1.26 g / s , the a i r flow was adjusted to y i e l d a a i r / d r y feed r a t i o (weight) of 9 to 1. The f l u i d bed was made up of incandescent c h a r c o a l . It was found that the amount of endothermic react ions (from crack i of primary products and from water gas react ion) increased with bed 3 temperature. At optimum condi t ion 0.51 m (288.6 K, 760 mm Hg) of 3 9.3-10.4 MJ/std.m was produced from 0.45 Kg of dry wood while the y i e l d o f charcoal was about 5% by weight of the dry feed . Studies a lso ind ica ted that high heating rates and temperature are required for high gas y i e l d s and f l u i d i z a t i o n deter iora tes with increas ing bed hei ght . 188 (b) Inves t iga to rs : C .Y . Wen, C.Y. L i n , W.S. O ' b r i e n , R .C . B a i l i e and R.S. B u r t o n 3 5 (1973) An exper imenta l , 38-cm diameter f l u i d i z e d bed was developed to study the p y r o l y s i s of coal and other carbonaceous compounds. In the bottom chamber of the reactor natural gas was burned, and the hot combustion gases were mixed before passing through the gr id plate to f l u i d i z e the sand bed. The composition of the combustion product gas was ad jus ted , wi th in a l i m i t e d range, with add i t iona l a i r to form s p e c i f i c component ra t ios . A f t e r leaving the r e a c t o r , the e f f l u e n t gases were cooled and then cleaned by passage through e i ther a c a n i s t e r - t y p e nylon-bag f i l t e r or a dry-gas cyclone (25 cm in diameter and 56)cm long),and l a t e r scrubbed in a se r ies of two wet scrubbers: the f i r s t is a t ray - type and the second is packed with 2.5 cm Intalox Saddles. The fuel s o l i d s are fed in to the f l u i d i z e d bed by means of a screw conveyor with a s p e c i a l l y designed feeder v a l v e . The feed port i s located 127 cm above the gas d i s t r i b u t i o n p l a t e . The gases leav ing the f l u i d - b e d reactor are sampled every 5 min. and analyzed by Bendix Chroma-Matic Model 618 Process Gas Chromatograph. This uni t quant i ta -t i v e l y analyzes the gas for H 2 , C 0 2 , CO, CH^ and 0 2 / a r g o n . P e r i o d i c a l l y , grab-samples of the e f f l u e n t gases were withdrawn and analyzed by a Beckman GC-2A gas chromatograph and a F isher S c i e n t i f i c Co. gas chroma-tograph for the gas components l i s t e d above, plus ace ty lene , e thy lene , ethane and n i t r o g e n . A schematic arrangement of the p i l o t plant f l u i d i z e d - b e d reactor and i t s a u x i l i a r y equipment i s shown in Figure IX-7-4. The reactor i s f i l l e d with 0.635 mm diameter sand to a co l lapsed height of 76 cm. The gas v e l o c i t y through the bed is maintained at a level where a good f l u i d i z a t i o n of the sand is assured and the bed is heated to the preselected temperature ( in the range o f 760-1040°C) by the combustion of methane in the bottom sec t ion of the r e a c t o r . The operat ing condi t ions in the reactor are summarized as f o l l o w s : Operating temperature 760-1040°C Operating pressure 0-10 psig Expanded bed height 1-1.2 m Average p a r t i c l e s i z e of sand 0.64 mm Density of s o l i d sand 3 p a r t i c l e 1602 Kg/m S u p e r f i c i a l f l u i d i z i n g gas v e l o c i t y 0.46 m/s The gas produced from the coal or sawdust p y r o l y s i s i s considered to be the net gas flow va lue , a f te r subtract ing the volumetr ic flow rate of the e f f l u e n t gases p r io r to feeding the s o l i d s from the flow rate of gases leav ing the reactor during the s o l i d p y r o l y s i s r e a c t i o n . The operat ing condi t ion values during pyro lys is experiments a r e : 3 In let a i r flow rate 0.017 m / s In let natural gas flow rate 0.002 n?/s I n i t i a l Reactor temperature 1004°C I n i t i a l gas composition e x i t i n g reactor ( p r i o r to s o l i d feeding) (%V,dry)H 2 0.11 C0 2 10.17 0 2 / a rgon 1 .18 CH 4 0.07 N 2 88.47 The type of e f f l u e n t gas resu l ted from the tests under various operat ional condi t ions i s summarized in Table IX-7-2. TABLE IX-7-2: -EFFLUENT GAS COMPOSITION FROM SAWDUST EXPERIMENTS Run A B C D Duration o f test (min) 86 75 70 577 Reactor Temperature ( ° C ) 111 793 788 816 S o l i d feed rate (g /s) 2 . 7 8 0 . 92 5 . 16 2 . 59 Raw Gas Composition (%V, dry) H 2 4 . 5 8 2 . 50 6 . 03 5 . 21 CO 7 .54 2 . 21 11 . 50 7 . 57 CH 4 2 .24 0 . 32 3 . 31 1 . 85 CO 2 1 2 . 1 8 1 2 . 11 1 2 . 24 11 . 47 0 2 / a r g o n 0.81 1 . 07 0 . 83 0 . 93 N 2 7 3 . 5 8 0 . 8 6 6 . 7 7 3 . 5 C2H2 0 . 5 3 0 . 07 0 . 96 0 . 56 C 2 H 4 NM* NN I 0 . 07 0 . 06 C 2 H 6 0.11 0 . 04 0 16 0 . 06 Net Gas Composition (%V, dry) 2 5 . 6 3 7 . 5 2 3 . 6 3 0 . 0 c o 2 \ 1 5 . 0 2 4 . 3 14 1 11 . 1 CH 4 1 2 . 4 3 . 72 11 9 10 5 CO 4 3 . 3 33 8 45 7 4 4 . 5 | C 2 ^ 2 3 . 0 5 1 04 3 82 3 28 C 2 H 4 NM NM 0 29 0 28 ! C 2 H 6 0 . 6 5 0 54 0 63 0 32 Net Gas Production Rate _ 4 (std.m^/g dry s o l i d ) x 1 0 " 11 .4 11 4 10 0 11 6 Net Gas Heating Value (MJ/std.m 3 ) 1 4 . 8 10 7 15 .4 14 9 * NM = not measured NATURAL GAS COMPRESSOR Off Gas To Stack And After-Burner Off Gas To Stack 1-22m 0 056m 122m 0038 m 1 22' 0 0-36m BURNER I M . ^ T — n 1 *0-36« AIR COMPRESSOR NYLON BAG FILTER r—O Water Water Drain Drain Figure IX-7-4: FIuidized-Bed Pyrolysis Reactor System (Wen, Lin, O'brien, Bailie, Burton) 2 0 192 (c) I n v e s t i g a t o r s : M.S. L i u , R. Serenius and 0. Martinez (1976) A p i l o t - s c a l e g a s i f i c a t i o n un i t designed for the g a s i f i c a t i o n of woodwaste has been i n s t a l l e d at B . C . Research. A schematic diagram of the plant i s shown in Figure IX-7-5. The reactor i s c y l i n d r i c a l in shape, has a 0.6 m in terna l diameter and i s 3 m h igh . It i s l i n e d with r e f r a c t o r y mater ia l and equipped with a grate and an overflow p ipe . The height of the overflow pipe is 1.5 m. A i r and fuel are introduced cocurrent ly into the r e a c t o r . Fuel i s fed in to the bottom of the reactor above the grate by the screw feeder , exposing the feed to the zone of highest temperature. Low-Btu gas r e s u l t i n g from the g a s i f i c a t i o n react ion is piped to a ven tur i - t ype burner i n s t a l l e d in the furnace. The gas i s then mixed w i t h - a i r and burned in the furnace. Ash which is cont inuously formed ins ide the reactor is removed through the overflow pipe and the amount is determined by weighing, and the contents are analyzed. Composition and the c a l o r i f i c value of the gas in the reactor was found to change d r a s t i c a l l y at d i f f e r e n t heights in the bed. It i s evident that as the bed height i n c r e a s e s , the concentrat ions of H,,, CH^ and C 2 H^ and the c a l o r i f i c value of the gas a lso i n c r e a s e . The average composition and c a l o r i f i c value at bed heights of 0 .9 , 1.2 and 1.5 m are presented in Figure IX-7-6. It i s suspected that the stack emissions a lso w i l l increase as the bed height i n c r e a s e s . Accumulation of ash may a lso r e s u l t s ince the removal of ash w i l l be more d i f f i c u l t as the bed height i n c r e a s e s . Several tes ts are conducted with hog fuel (5 cm in s ize ) and the r e s u l t s are summarized in Table IX-7-3 . 193 TABLE I X - 7 - 3 : EXPERIMENTAL RESULTS OF GASIFICATION OF HOGFUEL WITH AIR Typica l Hogfuel High Ash Hogfuel A i r (g /s) 4 0 . 9 4 3 . 7 3 3 . 6 2 6 . 5 3 2 . 2 Fuel ( g / s , dry) 1 3 . 2 2 3 . 6 1 4 . 7 * 1 0 . 6 ** 1 1 . 6 A i r / F u e l (w/w) 3.1 1 .9 2 . 3 2 . 5 2 . 8 Fuel Moisture Content (%, wet) 4 6 . 0 3 4 . 7 3 4 . 7 5 2 . 5 5 2 . 5 3 Raw Gas Produced (std.m / g dry fue l ) x IO" 4 2 9 . 4 23.1 2 6 . 0 2 6 . 8 31 .4 Raw Gas Composition (%V, dry) H 2 7 .2 1 4 . 9 1 3 . 8 11 .2 11 .5 ° 2 0 .4 0 . 0 0 . 0 0 . 0 0 . 0 N 2 6 2 . 4 4 7 . 2 52.1 5 5 . 6 57 .7 CO 1 6 . 7 2 6 . 6 2 3 . 7 1 9 . 5 1 6 . 6 CH 4 1 .3 1 .4 1 .4 1 .3 1 .3 c o 2 11 .6 9 . 5 8 . 6 1 2 . 4 1 2 . 5 C 2 H 4 0 . 4 0 . 4 0 . 4 0 . 4 0 . 4 3 Raw Gas Heating Value (MJ/std.m ] 3 . 6 5 .8 5 . 3 4 . 4 4.1 Temperature 7 . 6 cm over grate Cc) 927 1093 760 +NM NM * 0 . 7 6 g /s of sand was added * * 0 . 8 8 g/s of sand was added t NM = not measured STACK CYCLONE GASIFICATION REACTOR Rejects Fuel Steam & Water Air GAS SAMPLING BULB DRY GAS METER ICE BATH Ash Figure IX-7-5: Schematic Flow Diagram of the P i l o t - S c a l e G a s i f i c a t i o n Unit 3 ( L i u , Serentius and Martinez) 1 9 5 2 4 196 ( i i i ) System C: G a s i f i c a t i o n with A i r in a Fixed Bed (a) I n v e s t i g a t o r s : G.D. V a s s 2 2 (1977) Fixed Bed G a s i f i c a t i o n were c a r r i e d out by the American Fyr-Feeder Engineers on a v a r i e t y o f biomass commodities inc lud ing woodchips, p e l l e t i z e d municipal s o l i d waste and corncobs. Approximately 30% of the t o t a l a i r required for combustion of the gas is introduced through the gra te . The remaining 70% i s introduced for combustion at the burner. The temperature maintained in the bed of the g a s i f i e r i s approximately 900°C which i s a cherry red co lor of wood. Approximate const i tuent of wood gas and natural gas are compared as f o l l o w . It a lso i l l u s t r a t e s the r e l a t i v e combustion propert ies of wood gas and natural gas. Wood gas Natural < Flammable l i m i t s in a i r (%V) Lower 12 4.8 Upper 74 13.5 Gas Composition (%V) CH 4 1 96 C 2 H 6 - 3 co2 6 . 0.2 N 2 50 0.8 CO 30 -H 2 10 -Tar & Oi l vapours 3 -Heating Value (MJ/std.m 3 ) 7.45 38.3 Flame temperature ( ° C ) 1760 1927 3 3 m dry a i r /m gas 1.59 9.65 3 MJ/std.m of g a s - a i r mixture 2.9 3.6 3 3 m combustible f lue gas products/m gas 1 .83 10.6 3 B t u / f t combustible f lue gas products 4.1 3.6 197 (b) Reviewer: N.C. J o n e s J U (1944) The gas producer a f fords a simple and inexpensive means of generating power from sawdust, shav ings , bark e t c . S ta t ionary up-drought plants o f 9 to 556 KW are a v a i l a b l e , and veh ic le down-drought plants up to about 56 KW. A s ta t ionary plant comprises a f i r e b r i c k - l i n e d metal c a s i n g , with a f l a t , step or plate gra te , centra l hopper with a i r l o c k , su i tab le doors and ex i t pipes with in terna l s c r a p e r s . Steam i s not employed. The gas passes through: (1) tubular dust c o l l e c t o r with water spray , (2) a s tee l plate coo l ing tower with upper water spray over wooden g r i d s , coke or coo l ing r i n g s , (3) a cent r i fuga l tar e x t r a c t o r , (4) expansion chamber with wood wool or coarse sawdust f i l t e r . Typica l gas composition resu l ted cons is ts o f 9.5% (by volume) of carbon d i o x i d e , 22.8%carbon monoxide, 13.8% hydrogen, 3% methane and 50.9% of n i t rogen . The 3 c a l o r i f i c value of the gas is estimated to be 5.5 MJ/std.m . 198 ( iv ) System D: G a s i f i c a t i o n with Steam and A i r (a) Inves t iga to rs : V . L . Hammond, L .K. Mudge, C H . A l l e n and G . F . S c h i e f l b e i n (1974) P i l o t plant operat ions were conducted using a 3 - f t -d iameter f ixed and reactor in the countercurrent mode. The g a s i f i c a t i o n process i s shown schemat ica l ly in Figure IX-7-7. S o l i d waste i s t rans fer red in to the top o f the reactor through an a i r - l o c k arrangement and passes downward through the reactor while the a i r -s team mixture and product gases pass up through the reac to r . Ash i s discharged from the reactor through an a i r l o c k . The process i s operated at a s l i g h t l y p o s i t i v e pressure of less than 1.0 p s i g . Feed mater ia ls used in these studies were woodchips and shredded municipal s o l i d waste. Typical gas produced are as shown below: 18 Gas Composition (%V) Feed H 2 CO CH 4 C 2 H 6 C 2 H 4 Woodchi ps 20.3 23.7 2.7 0.25 0.31 Munici pal 21 .6 21 .0 1 .8 0.15 0.27 CO, Heati ng Value (MJ/std. m3) Refuse 40.3 12.4 7.04 6.40 199 Drying & Preheat Zone-fyfolysis Zone-Char-gasification Zone-Ash Zone-Rotary Grate Ash Receiver Airlock Ash Discharge Airlock Feeder Product Gases 21% H 2 21% CO 1-896 CK) 43 % N 2 12% CO2 172 Btuyf t 3 p | u s t a r 100 C 200 °C 700 C 800 °C 1000°C -Air- Steam 100-500°C Figure IX-7-7: Schematic (Hammond, of Battelle Gasification Process Mudge, Allen, Schiefelbein) 200 (b) Inves t iga to rs : S .R . Beck, M . J . Wang, J . A . Hightower 4 1 (1979) The Synthesis Gas From Manure (SGFM) process p i l o t plant (450 Kg/day) was constructed to study the production of synthesis gas from biomass feedstocks . The process is based on a countercurrent f l u i d i z e d bed reactor in which the biomass enters the top o f the reactor and i s g a s i f i e d by p a r t i a l o x i d a t i o n - p y r o l y s i s in an upward f lowing stream of a i r and steam. The reactor i s 15.2 cm in the lower 1.5 m and 20.3 cm in the upper 1 m of disengaging zone. The s o l i d s are fed to the top through a screw feeder , which cont ro ls the feedrate and f a l l s by g rav i ty in to the reactor i t s e l f . The a i r -s team mixture which enters the bottom of the reactor is preheated in a 8 m length of tubing that serves as a res is tance heater . The char i s removed from the reactor through a centreport opening in the bottom d i s t r i b u t o r p l a t e . A hydrau l ic ram i s used to prevent any br idg ing of the char in the discharge l i n e . The gases ex i t the top of the reactor and pass in to a cyclone that i s operated at 350°C . The cyclone is heated to prevent condensation of any of the react ion products and adequately removes most of the entrained s o l i d s . The gases leav ing the cyclone then pass through a 3-stage impinger sequence which i s operated at about 1 1 0 - 1 4 0 ° C . This serves to condense the ta r but maintains the water in a vapour s t a t e . Following the impingers, the water i s condensed in a double-pipe heat exchanger and c o l l e c t e d in the downstream impinger s e c t i o n . The product gases are then passed through a turb ine meter fo r flow rate measurements and vented to the atmosphere. G a s i f i c a t i o n o f c a t t l e feed lot manure, oak sawdust and corn stover was c a r r i e d out . The product gas contains up to 10% C^Hg and the to ta l gas y i e l d i s as high as 1.7 l/q dry ash- f ree feed . The higher heating value of the raw gas exceeds 9.5 MJ/m the production of H 2 , CO and C 2 H 4 from dry sawdust in r e l a t i o n to the reactor contains 40% water (wet basis) whereas to 4% moisture . in a l l cases . Figure IX-7-8 shows g a s i f i c a t i o n of both green and temperature. The green oak sawdust the dry sawdust has been a i r - d r i e d 202 Legend dry sawdust green sawdust \ i \ i \ , CH 4 • 600 700 800 900 REACTOR TEMPERATURE (°C ) Figure IX-7-8: Gas Composition vs Reactor Temperature (Beck, Wang and Hightower) System E: G a s i f i c a t i o n with Steam 15 I nves t iga to rs : D.Q. Tran and C. Rai (1976) The g a s i f i c a t i o n of powdered douglas f i r bark and black l i q u o r con-centrate from Kraf t pulping process was studied in a 2.5 cm O.D. f i xed bed flow r e a c t o r . The reactor was constructed from 316 s t a i n l e s s steel with 3 a capac i ty of 300 cm (Figure IX-7-9) . The temperature in the reactor was monitored by thermocouples from ambient to 1000°C. The reactor pressure could be var ied from atmospheric to about 500 p s i . The water i n j e c t i o n rates in to the reactor could be var ied from 0 to 20 niX /hr . The flow reactor experiments were c a r r i e d out by charging the reactor with powdered douglas f i r bark and a l k a l i carbonate or black l iquor concentrate and in some runs with an experimental or a n icke l c a t a l y s t . The reactor was then brought to the des i red operat ing c o n d i t i o n s , which required about 1 h r . The temperature in the react ion zone of the reactor could be c o n t r o l l e d p r e c i s e l y wi thin a few degrees. The product gases were sampled and analyzed every 30 min. during the course of the run. Steam i n j e c t i o n was star ted when the g a s i f i c a t i o n rate of bark-black l i q u o r mixture had dropped to a predetermined l e v e l . The steam addi t ion was continued u n t i l the g a s i f i c a t i o n rate has dropped s u b s t a n t i a l l y . Based on elemental a n a l y s i s , the douglas f i r bark can be represented by the empir ica l formula O - J Q H ^ O ^ gN Q Q 2 . The p y r o l y t i c g a s i f i c a t i o n of bark proceeds rather slowly under the process c o n d i t i o n s , the g a s i f i c a t i o n 8 3 rate being 2.2 x 10" std.m / ( s ) (g of carbon) . However, when the g a s i -f i c a t i o n was conducted in the presence of potassium carbonate, there was a s i g n i f i c a n t improvement in the volume of gas produced and the overa l l -8 3 g a s i f i c a t i o n rate increased to 7.2 x 10" std.m / ( s ) (g of carbon) . The presence of a n icke l c a t a l y s t in add i t ion to potassium carbonate enhanced the g a s i f i c a t i o n rate f u r t h e r . The c a t a l y t i c g a s i f i c a t i o n produces a 3 product gas having a higher c a l o r i f i c v a l u e , 29.5 MJ/std.m compared to 3 17.0 MJ/std.m with potassium carbonate a lone . Water 107 m REACTOR & 0 56 m SUPERHEATER ENCLOSED IN FURNACE ELEMENTS REACTOR SECTIONl Cooling Water CONDENSER 1 o o o o o o BACK-PRESSURE REGULATOR Vent FLOW METER WET-TEST METER SUPERHEATER SECT ION 4 MINI PUMP A \. fa G A S CHROMATO-GRAPH Vent SCRUBBER Figure IX-7-9: 25-mm O.D. Fixed Bed Flow Reactor (Tran, Rai) no o cn 206 (8) APPENDIX 8. MASS BALANCE Of a l l the runs performed (1-16; Runs 1, 2 and 13 d i s c a r d e d ) , the ine r t ni t rogen flow is used as the reference gas to c a l c u l a t e the amount of gases in ex i t of the reactor except for those runs (Runs 5, 6 and 7) where carbon d iox ide is used as the f l u i d i z i n g medium. (Refer part ( v i i ) ) . Thus, the procedure involves c a l c u l a t i n g the dry gas volume at standard condi t ions evolv ing from the reactor through a ni trogen balance s ince the to ta l amount of input nitrogen and the nitrogen content in the out le t gas are known. The water vapour is then taken as the d i f fe rence between the dry gas volume and the wet gas volume measured by the o r i f i c e p l a t e . Overal l mass balances and ind iv idua l elemental mass balances can then be performed. The c a l c u l a t i o n procedure i s i l l u s t r a t e d below for Run 10 (A i r as f l u i d i z i n g medium) for sample 2. A l i s t i n g of the computing program ( in Fortran) and the output (Run 4) can be found in Appendix 9. A i r G a s i f i c a t i o n , Run 10, Sample 2 ( i ) Data Input: Amount of sand in bed (SAND) = 1405 g I n i t i a l bed height (HEIGHT) 20.32 cm Sand bulk dens i ty (DENS) 1700 Kg/m 3 Size of sawdust (SIZE) 0.6705 mm Water ca lcu la ted in impinger (Y) 0.010170 g/s Wet sawdust feed (M44) 0.1526 g/s Moisture content of sawdust (MCS0L) 5.62 % w (wet basis) Dry feed content , carbon (CDSMPC) = 49.44 % w (dry basis) hydrogen (HDSNPC) = 6.21 %w (dry basis) ni t rogen (NDSMPC) = 0.07 %w (dry basis) oxygen (ODSMPC) = 43.29 %w (dry bas is ) ash (ASHDS) = 0.7 %w (dry basis) Tar produced (TARR) = 0.000612 g/s Cyclone catch (CYL) = 0.006647 g/g dry s o l i d Carbon content in cyclone catch (CCATMP) = 52.31 %w Char accumulated in bed (CHARR) = 0.0 g / s Humidity of a i r (HUMID) = 0.0 S p e c i f i c volume of steam at o r i f i c e condi t ions (SV) = 1.572 m" * Discharge c o e f f i c i e n t for o r i f i c e (COEFF) = 0.640 3 Transport ni t rogen in (N2V3) = 0.0 std.m / s F l u i d i z i n g steam in (H20M1) = 0.0 g/s 3 F l u i d i z i n g ni trogen in (N2V1) = 0.0 std.m / s 3 F l u i d i z i n g carbon monoxide in (C0V1) = 0.0 std.m / s F l u i d i z i n g a i r in (AIRV1) = 5.846 x 10" 4 s t d . m 3 / s 3 F l u i d i z i n g carbon dioxide in (C02V1) = 0.0 std.m / s Dry gas composi t ion , H 2 (H2DGVP) = 0.181 %v CO (CODGVP) = 0.6847 %\i CH 4 (CH4DGV) = 0.057 %v C 0 2 (C02DGV) = 14.498 %v N 2 (N2DGVP) = 83.416 %v 0 2 (02DGVP) = 1.163 %v 0 (ODGMPC) 16.891 %w N (NDGMPC) = 77.057 %w H (HDGMPC) = 0.0196 «w C (CDGMPC) = 6.0322 %w Ori f i c e upstream pressure (POP) = 109.6 KPa * Refer part ( v i i i ) 208 O r i f i c e upstream temperature (T17) = 378 K Pressure drop across manometer (PDIFF) = 5.0 cm Hg Other inputs data inc lude a l l pressure and thermocouple readings. 209 ( i i ) C a l c u l a t i o n s  INPUTS (1) Transport Nitrogen (g /s) = 0.0 (2) Gasi fy ing stream Gas i fy ing ni trogen (g/s) = 0 . 0 Gas i fy ing carbon monoxide (g /s) =0 .0 Gas i fy ing carbon dioxide (g/s) = 0.0 Gas i fy ing a i r (g /s ) = 5.846 x 10" 4 ( s t d . m 3 / s ) * 1200.22 (g /s td .m 3 ) = 0.7017 (3) Sub-Ai r Stream Water in a i r (g /s) = 0.0 Dry a i r (g /s) = 0.701652 Oxygen in dry a i r (g /s) = 0.2314 * 0.7017 = 0.1624 Argon in dry a i r (g /s) = 0.0128 * 0.7017 = 0.0090 Carbon dioxide in dry a i r (g/s) = 0.0005 * 0.7017 = 0.00035 Nitrogen in dry a i r (g /s ) = 0.7553 * 0.7017 = 0.5300 (4) Gas i fy ing stream of manifold Nitrogen at manifold (N2M5),(g/s) = Gas i fy ing nitrogen + nitrogen in dry a i r = 0.5300 Water at manifold (H20M5),(g/s) = Gas i fy ing stream + water in a i r = 0.0 Carbon monoxide at manifold (C0M5),(g/s) = Gasi fy ing carbon monoxide = 0 . 0 Carbon dioxide at manifold (C02M5),(g/s) = Gasi fy ing carbon dioxide + carbon dioxide in a i r = 0.00035 Argon at manifold (ARGM5),(g/s) = Argon in dry a i r = 0.0090 Oxygen at manifold (02M5),(g/s) = Oxygen in dry a i r = 0.1624 Total amount o f gas at manifold (g /s ) = 0.7017 (5) S o l i d s Water in wet sawdust (g /s ) = ( Ij^f ) * 0.1526 = 0.0086 210 Total water in (g /s) = water in wet sawdust + water at manifold = 0.0086 Dry sawdust (g /s ) = 0.1526 - 0.0086 = 0.1440 OUTLETS (1) Molecular Weight of Dry gas (MWDRY) = [(H2DGVP * 2.02) + (CODGVP * 28.010) + (CH4DGVP * 16.03) + (N2DGVP * 28.01) + (C02DGV * 44.01) + (02DGVP * 32.00)] / l ( = 30.02 (2) Nitrogen Balance (For Runs 5, 6 & 7, re fe r part ( v i i ) ) Nitrogen in s o l i d (g /s) = ( ^ p O * Mass flow of dry s o l i d = 0.0001 Total ni t rogen in (g /s ) = Transport Nitrogen + Nitrogen at manifold + nitrogen in s o l i d = 0.0 + 0.5300 + 0.0001 =0.5301 3 Volume of ni t rogen ( s t d . m 3 / s ) = 0.5300 (g/s) * 1 1 6 Q Q 2 ( s t d g m ) = 0.000457 (3) Total Dry Gas Flow Based on Volume of Nitrogen Dry gas flow ( s t d . m 3 / s ) = 0.000457 * ( j^f /p) = 0.000547 (4) Wet Gas Flow ( I f temperature at o r i f i c e is less than the condensation temperature for steam, then water in gas i s assumed to be that c o l l e c t e d in the impinger averaged over the durat ion of the run) . Since c a l c u l a t i n g the wet gas flow from the o r i f i c e plate pressure drop requires knowledge o f the molecular weight of the wet gas and th is remains unknown u n t i l the water content of the gas i s known, an i t e r a t i v e method i s necessary. For f i r s t es t ima t ion , the average rate of water c o l l e c t e d in the impinger i s used. 3 Water vapour volume at o r i f i c e condi t ions (H207), (m / s ) = 3 . SV Q * (TQ^j-g-) * Y (g /s ) = 0.000025 211 3 Dry gas volume at o r i f i c e condi t ions (DGAS7), (m / s ) = ( S t d . m 3 } * T17 * 101-325 = \ s ; 294.11 . POP u.uuuto^ Molecular f r a c t i o n of water vapour in wet gas (MF) = H207/(H207 + DGAS7) = 0.0369 Molecular weight of wet gas (MWWG) = [MWDRY * (1-MF)] + [18.015 * MF] = 29.8691 Referr ing to o r i f i c e equation (Appendix 3) Wet gas flow at o r i f i c e condi t ions (WGAS7), (m 3 /s ) = COEFF * 0.0015011 * PDIFF * TI7 V MWWG * POP - — . = 0.000730 WGAS7 ?H207 + DGAS7 = 0.000677 So, l e t the next estimate for the water vapour in wet gas be X = WGAS7 - (H207 + DGAS7) = 0.000053 3 I terate u n t i l | X l i s less than 0.000005 m / s In th is case , WGAST (m 3 /s ) = 0.000743 H207 (m 3 /s ) = WGAS7 - DGAS7 = 0.000091 3 Mass of water vapour in wet gas (g /s ) = H207 (^-) * (^|) * 1000 (^-) = 0.0588 Overal l Mass Balance Total input mass (g /s) = Transport n i t rogen + Gas at manifold + wet s o l i d = 0.854203 Mass of dry gas produced (DGASM7), (g /s ) =[(H2DGVP *83.53) + (C0DGVP * 1160.72) + (CH4DGV * 564.78) + (C02DGV * 1823.71) + (N2DGVP * 1160.82) + (02DGVP * 1326.00)] * ( s t d . dry gas flow/100) = 0.6879 Tar produced (TARR), (g /s ) = 0.000612 212 Total cyclone catch (CATCH), (g /s) = CYL * mass flow of dry s o l i d = 0.000957 Char accumulated in bed (CHARR), (g /s) = 0.0 Total output mass (g /s) = DGASM7 + TARR + CATCH + CHARR = 0.7482 ( i i i ) Hydrogen Balance  INPUTS: Hydrogen in gas input (g /s) = water at manifold (g /s) * ( f^r j f f^ = 0 - 0 Hydrogen in s o l i d moisture (g /s) = water in s o l i d (g /s) * (y^oTB^ = 0.000959 Hydrogen in dry s o l i d in (g /s) = ( H | Q Q P ^ ) * dry s o l i d mass flow = 0.008941 Total hydrogen in (g /s) = 0.009900 OUTPUTS: Hydrogen in water vapour in wet gas (g /s ) = H20M7 * (y^ jy f ) = 0.006578 Hydrogen in dry gas (g/s) = ( H ° Q Q P C ) * dry gas mass flow = 0.000135 Total hydrogen out (g /s) = 0.006713 ( iv) Oxygen and Argon Balance  INPUTS: Oxygen in gas input as moisture (g /s ) = water at manifold (g /s ) * (15.9994 } = M8.015 ' U - U Oxygen in gas (g /s) = oxygen at manifold = 0.1624 15 9994 Oxygen in s o l i d moisture (g /s ) = water in s o l i d (g /s) * (•)8 'o i5 ^ = ° - 0 0 7 5 Oxygen in carbon dioxide in (g /s ) = carbon dioxide at manifold (g /s ) * (15.9994. * 2  K 44.01 1 d = 0.000255 2 1 3 Oxygen in carbon monoxide in (g/s) = carbon monoxide at manifold (g /s ) * ' ,15.9994. l28.011 ; = 0.0 Oxygen in argon in (g /s) = argon at manifold (g /s ) = 0.0090 )SMPC 100 Oxygen in dry s o l i d in (g /s) = (^ fSP-) * dry s o l i d mass flow = 0.0623 Total oxygen in (g /s ) = 0.2415 OUTPUTS: Oxygen in water vapour in wet gas (g/s) = H20M7 * { \ Q ' Q ] 5 ) = 0.0522 Oxygen in dry gas (g /s) = (~D^QQC) * dry gas mass flow = 0.1162 Total oxygen out (g/s) = 0.1684 (v) Carbon Balance INPUTS Carbon in carbon monoxide in (g /s) = carbon monoxide at manifold (g /s) * (12^011, = o 0  L28.011 ; U , U Carbon in carbon dioxide in (g/s) = carbon dioxide at manifold (g/s) * (?OTT) = 0-000096 Carbon in dry s o l i d in (g /s) = (C°QQPC) * dry s o l i d mass flow = 0.0712 Total carbon in (g /s) = 0.0713 OUTPUTS: Carbon in dry gas (g /s) = (C^QQPC) * dry gas mass flow = 0.0415 Carbon in cyclone catch (g /s ) = ( C ^ M P ) * CATCH = 0.0005 Assume char i s 100% carbon Carbon accumulated in bed (g /s) = char accumulated in bed = 0.0 Total carbon out (g /s ) = 0.4200 214 Ash Balance . A c u n c Total ash in (g/s) = ( {^j ) * dry s o l i d mass flow = 0.00101 Total ash out (g /s ) = Ash c o l l e c t e d in cyclone catch = CATCH * [1 - (CCATMP/100)] = 0.00046 ) F l u i d i z i n g Using Carbon Dioxide (Runs 5,6 and 7) Carbon Balance INPUTS: Carbon in carbon monoxide in (g /s ) = carbon monoxide at manifold (g /s) * , 12 .01K  l 2 8 . 0 i r Carbon in carbon dioxide in (g /s) = carbon dioxide at manifold (g /s) * ,12 .01K M 4 . 0 1 V C DSM P C Carbon in dry s o l i d in (g /s) = ( " Q Q ) * dry s o l i d mass flow Total carbon in (g /s) = CINP OUTPUTS: Total cyclone catch (g /s ) = CYL * dry s o l i d mass flow = CATCH Carbon in cyclone catch (g /s) = ( C ^ Q M P ) * CATCH = CCATCH Assume char is 100% carbon Carbon accumulated in bed (g /s ) = char accumulated in bed = CCHAR Carbon in dry gas (g /s ) = CINP-CCATCH-CCHAR = CDGM7 Total dry gas flow based on ca lcu la ted amount of carbon in dry gas Total dry gas mass flow (g /s) = CDGM7 * CCDGMPC^ Density o f dry gas (g /s td .m 3 ) = [H2DGVP * 83.53) + (C0DGVP * 1160.72) + (CH4DGV * 664.78) + (C02DGV * 1823.71) + (N2DGVP * 1160 . 82) + (02DGVP * 1326.00)]/100 Dry gas volumetr ic flow (std.m / s ) = DGASV7 215 (c) Nitrogen Balance INPUTS: Nitrogen in s o l i d (g /s ) = ( N ^ Q P C ) * dry s o l i d mass flow Nitrogen in input gas (g /s) = t ransport nitrogen + nitrogen at manifold OUTPUT: Nitrogen in dry gas (g /s) = ( N ^ Q P C ) * dry s o l i d mass flow The rest of the c a l c u l a t i o n s w i l l be the same as that descr ibed e a r l i e r . ( v i i i ) C a l c u l a t i o n for Discharge C o e f f i c i e n t for O r i f i c e Plate Run 10 During the experiment, a to ta l o f seven samples are withdrawn within the durat ion of 45 min. Since an averaged value of the discharge c o e f f i -c ien t is to be used, the fo l lowing p a r t i c u l a r s of the'system during the operat ion of Run 10 are averaged. O r i f i c e upstream pressure (POP) = 15.910 ps ig O r i f i c e upstream pressure (POP) = 15.910 psig O r i f i c e upstream temperature (T17) = 372.57 K Total input gas ( s t d . m 3 / s ) = 5.8445 x 10" 4 3 Input gas at o r i f i c e condi t ions {j-) = 5.8446 x 10" 4 * x ] t ' l ] 6 = 6.839 x 10" 4 V i s c o s i t y of ni t rogen at o r i f i c e condi t ions (§L) = 2.07 x 10" 5 Of the seven gas samples ana lysed , only three are found to be c o n s i s -tent and the average molecular weight of the dry gas passing through the o r i f i c e for these three samples is 30.3375. The gas cons is ts about 76% ni t rogen and thus the gas v i s c o s i t y i s taken as that of n i t rogen . The flow of the input dry gas to the reactor i s used as an estimate for the flow o f gas through the o r i f i c e . 216 The gas Reynolds Number at the or i f i ce plate conditions is given by (Appendix 6): R e = 42.76195 g ^ P ( M W j w h e r e Q = g a s volumetric flow (m 3/s) = 12619.4 P = pressure (KPa) T = temperature (K) y = gas viscosity (Kg/sm) Referring to Figure IX-3-1 where the relationship between discharge coe f f i -cient and or i f i ce Reynolds Number is plotted, a discharge coeff icient of 0.64 corresponds to the value of Reynolds number estimated above is obtained for the l ine drawn when air is used in the or i f ice plate cal ibrat ion. 2 1 7 (9) APPENDIX 9. ENERGY BALANCES An energy balance i s performed on the f l u i d i z e d - b e d r e a c t o r . The reference temperature i s taken as that for the North American Standard reference temperature fo r combustion processes ( 6 0 ° F or 288.6 K) . ( i ) Add i t iona l Data: Heating value o f dry sawdust (HVDSOL) = 19.8747 KJ/g Enthalpy o f steam at reactor i n l e t (HVSTIN) = 0.0 KJ/g Enthalpy o f steam at reactor ou t le t (HVSTOU) = 3.5959 KJ/g Heating value o f carbon = 32.737 KJ/g Heating value of ta r = 29.993 KJ/g Heat Transfer c o e f f i c i e n t , i n s u l a t i o n - a i r (HTCOI) = 0.00567 KJ/m 2 s K Convective Heat Transfer c o e f f i c i e n t , f l a n g e - a i r (HTCOF) = 0.00353 KJ/m s K Radiat ive Heat Transfer c o e f f i c i e n t , f l a n g e - a i r (HTR) = 0.00959 KJ /m 2 s K Heat Transfer c o e f f i c i e n t , wal l -bed (HTCIR) = 0.30234 KJ/m 2 s K Heat Transfer c o e f f i c i e n t , w a l l - r e a c t o r gas(HTG) = 0.00433 KJ/m s K * For s p e c i f i c heat o f gases, re fe r part ( i i i ) For de ta i l ed c a l c u l a t i o n of the heat t rans fe r c o e f f i c i e n t s , re fe r part ( i v ) . Refer Figure IV-1 for the loca t ion of thermocouples. 218 (i i ) Cal d i l a t i o n s  INPUTS: (a) Heat content o f dry s o l i d (HCDSOL) (KJ /s ) = dry s o l i d mass flow * HVDSOL = 2.8615 (b) Heat content o f i n l e t gas (excluding i n l e t steam and t ransport ni trogen) HCGIN (KJ /s ) ={(N2M5 * CPN25) + (C02M5 * CPC025) + [(ARGM5 + 02M5) *CP025] + (C0M5 * CPC05)} * ( In le t temp. -288.6) = 0.0052 (c) Heat content of steam (enthalpy HVSTIN has to be corrected for the base temp, at 273 K) HCSTIN (KJ /s ) = H20M5 * [HVSTIN - 0.0042 * (288.6 - 273)] = 0.0 (d) Heat content of water in s o l i d HCH20S (KJ/S) = water in s o l i d * Heat capac i ty of water * (Room temp. -288.6) = 0.0002 nitrogen * CPN2T2- * (T5 -288.6) thermoconductivi ty of s tee l 0.016 KJ/s mK 1.0017 m outer reactor diameter = 0.0762 m inner reactor diameter = 0.0720 m outer reactor area = TrLd o inner reactor area = irLd^ A - A . o 1 l n ( A 0 / A . ) (e) Heat content o f t ransport ni t rogen HCTRN2 (KJ/S) = mass mass of t ransport = 0.0 (f) E l e c t r i c a l Input 0.3175m 1.0017m 1 0.1 207m j T13 T12 1 TRW TRS HTG TR00M -HTCIR K l L d wall 219 x, = wall th ickness w TRS = (T10 + T l l ) / 2 TRG = (T12 + T13)/2 HTT = 0.3 * HTCIR + 0.7 * HTG ( re fe r part ( i v ) - ( f ) ) TRW K l -I *A ( _ w a n w T R S + H T T * A * T R G ) xw ] K , , * A ( w a 1 1 w + HTT * A , ) xw 1 (1 .7359 TRS + HTT * 0.2183 * TRG ) ( 1 .7359 + HTT * 0.2183) Assuming an expanded bed height of 0.3 m ( re fe r part ( i v ) - ( f ) ) , HELECT (KJ/S) = HTCIR * (0.3 T F * d ^ (TRW-T12) + HTG * (0.70 rr* dn-) (TRW-T13) = 1 .0942 Total Energy In (KJ/S) = 3.9611 220 OUTPUTS: (a) Heat content o f dry gas. produced C a l o r i f i c value (KJ /s td .n i 3 ) = [(12109 * H2DGVP) + (11997 * CODGVP) + (37743 * CH40GV)]/100 = 125.57 HCGOUT (KJ/S) = dry gas (std .m 3 ) * 125.57 = 0.0687 (b) Sensib le heat of dry gas HGSENS (KJ/S) = dry gas ( s t d . m 3 / s ) * (T13 - 288.6) *[(H2DGVP * CPH27 * 83.53) + (CODGVP * CPC07 * 1160.72) + (CH4DGV * CPCH47 * 664.78) + (C02DGV * CPC027 * 1823.71) + (N2DGVP * CPN27 * 1160.82) + (02DGVP * CP027 * 1326.00)]/100 = 0.3877 (c) Heat content of steam HCSTO (KJ/S) = water in gas * [HVSTOU - 0.0042 * (288.6 -273)] = 0.2088 (d) Heat content o f e l u t r i a t e d carbon in cyc lone . Neglect sens ib le heat . HCCCAT/(KJ/S) = carbon in cylone catch (g /s ) * 32.737 (KJ/g) = 0.0164 (e) Heat content o f . t a r (HCTAR)(KJ/S) = Amount of ta r (g /s ) * 29.993 (KJ/g) = 0.0184 ( f ) Heat content o f char in bed HCCHAR (KJ/S) .= char accumulated in bed (g /s ) * 32.737 (KJ/g) = 0.0 (g) Heat loss (I) Through top and bottom f langes TROOM TFLANG. Flange diameter = 0.127 m Flange area = 0.01267 m 2 221 TFLANG = (T20 + T21)/2 The r a d i a t i v e heat t r a n s f e r c o e f f i c i e n t (HTR) was evaluated for black body; assuming the e m i s s i v i t y of the f lange to be that of ox id ized s tee l ( i . e . 0 .79) , HCENDS (KJ/S) = (HTCOF + HTR * 0.79) * Flange Area * (TFLANG - TROOM) * 2 = 0.0284 (II) Through i n s u l a t i o n TINSO TINSI ASBESTOS ^ INSULATION o o oc K. = thermal conduct iv i ty o f asbestos m s _ 4 = 0.38 x 10 H KJ/s mK L = length of i n s u l a t i o n = 0.43815 m X i n s = i n s u l a t i o n thickness = 0.0254 m d„ = outer diameter of reactor = 0.127 m ^ins = log-mean i n s u l a t i o n surface area A o l - n s = outer i n s u l a t i o n surface area TINSI = (T22 + T23)/2 K. .A . , K. .A . TINSO = [ n " S i n s * TINSI + HTC0I * A . * TR00M]/ ( ™l  i n s + • X i n s 0 1 n s / X i n s HTC0I * A . ) oins ' = (0.000205 * TINSI + HTC0I * Q .1748 * TR00M)/(0.000205 + HTC0I * 0.1748) HCINSU (KJ/S) = 0.000205 * (TINSI - TINSO) = 0.0367 TOTAL ENERGY OUT = 0.7651 222 ( i i i ) S p e c i f i c Heats o f Gases TEMP(I) = Reference temperature = 288.6 K TEMP(2) = Gas temperature jus t before entrance in to reactor = 17 TEMP(3) = Gas ou t l e t temperature = Upper reactor temperature = Tl3 5 S p e c i f i c heats of the gases are given by: -3 Hydrogen, CPH2(J) = [6.62 + 0.00081 * TEMP(J)] * C 4 - 1 8 6 ^ ^ 1 0 ) KJ /g K _3 Carbon Monoxide ,CPC0(J) = [6.60 + 0.0012 * TEMP(J)] * C 4 , 1 8 ^ 8 ^ 1 0 ) KJ/g K Carbon Dioxide,CPC02(J) - {10.34 + 0.00274 * TEMP(J) - ( 1 9 5 5 0 0 )> * [TEMP(J3 ,4.1868 x 1 0 " \ „ ( 4 0 T 1 } K J / g K Oxgyen CP02(J) = (8.27 + 0.000258 * TEMP(J) - ( 1 8 7 7 0 0 — - ) } * [TEMP(J)]^ ,4.1868 x 1 0 ~ \ „ \ 31 999 ) KJ/g K _3 Methane ,CPCH4(J) = [5.34 + 0.0115 * TEMP(J)] * ( ^ ' ^ Q ^ S ] ° ) K J / 9 K -3 Nitrogen,CPN2(J) = [6.5 + 0.001 * TEMP(J)] * ( 4 ' 1 ^ Q 8 ^ 1 0 ) KJ/g K where J = 1, 2 or 3. For N i t rogen , reference - entrance to reactor,CPN25 = [CPN2(1) + CPN2(2)] * 0.5 reference - reactor ou t le t , CPN27 = [CPN20) + CPN2(3)] * 0.5 transport ni t rogen i n l e t temperature,CPN2T1 = (6.5 + 0.001 * T5) * f 4.1868 x 10" 3 x [ 28.013 ; reference - t ransport nitrogen inlet ,CPN2T2 = [CPN2T1 + CPN2(1)] * 0.5 223 ( iv) C a l c u l a t i o n of Heat C o e f f i c i e n t s Run 10 (Al l temperatures are averaged over the seven samples obtained) (a) I n s u l a t i o n - A i r (HTCOI) TINSI TINSO TR00M ABESTOS INSULATION TROOM = 297.5 K TINSI = (T22 + T23)/2 = 443.5 Film Temperature = 370.5 K 46 For natural convect ion , Kato, Nishiwaki and Hirata recommended the fo l lowing re la t ions for v e r t i c a l p lates and c y l i n d e r s : 1 < N p r < 4 0 N N u - 0.138 N G r ° - 3 6 ( N p r ° - 1 7 5 - 0.55) N > 10 9 N, = 0.683 N r ° ' 2 5 [ N V N ]°-25 * N 0.25 pr Nu Gr L 0.861 + N^- 1 " p r h I where N., = Nussett Number -T L p / 3 f AT N„ = Grashof Number = — ^ — Gr u 2 N p r = Prandtl Number = ( ~ £ - ) f C p f = heat c o e f f i c i e n t of a i r (KJ/Kg K) y^ r = v i s c o s i t y of a i r (Kg/ms) K^ = heat conduct iv i t y of a i r (KW/ms) p.p = densi ty of a i r (Kg/m ) • Film temperature (K) AT = temperature d i f f e r e n c e = TINSI-TROOM (K) g = 9.81 m / s 2 h = heat t ransfer c o e f f i c i e n t (KJ/s m K) L = length i n s u l a t i o n exposed to a i r = 0.43815 m At f i l m temperature, N p r = 0.6929 y f = 2.16192 x 10" 5 Kg/ms P f = 0.953486 Kg/m 3 K f = 3.15306 x 10" 5 Kw/ms AT = 146 K the re fo re , ^ = 0 . 1 3 8 C ^ 9 ^ jO.36 [ N 0.175 _ Q > 5 5 ] = 0.138 * 1473.05542 * 0.387815374 = 78.83575 h = 0.005673259 = 0.00557 KJ/m 2 sK 225 (b) F lange -A i r (Convection) HTCOF TROOM TFLANG 1 47 For natural convect ion between f l u i d s and s o l i d s of d e f i n i t e geometric shape, the heat t rans fe r c o e f f i c i e n t equation i s of the form 3 2 L p- q$JJ C u n = b [N„ N ] . L Gr p r J f where b,n = constant L = length of hor izonta l square surface For hor izonta l p l a t e s , heated, fac ing upward b = 0.54, n = 0.25 when W = ]° 5 - 2 x ]°7 and for hor izonta l p l a t e s , fac ing down b = 0.27, n = 0.25 when N G r N p r = 3 x 10 5 - 3 x 10 1 0 The f lange i s 5 i n . i n diameter, therefore the equivalnet L can be ca lcu la ted from L = / T T ( 2 . 5 ) 2 = 4.43 inch = 0.1125 m Now, TROOM = 294.5 K TFLANG = (T20 + T21)/2 = 378.36 K AT = 83.86 K Flow temperature = 336.43 K Kf = 2.9015 x 10"5 KW/ms CP f = 1.00717 KJ/Kg K y f = 2.0137 x 10"5 Kg/ms p f = 1.0508 Kg/m3 6 f = 336.43 1 / K N = 0.6992 pr Since Ng^ N = 6630892.6 which is within the ranges for the upward and downward facing flanges, the heat coefficient for upward facing flange can be obtained from ^ - 0.54 (6630892.6) 0 - 2 5  K f and h = 0.00706 KJ/m2sK Similarly, for downward facing flange, ^ = 0.27 (6630892.6) 0 - 2 5  K f which gives h = 0.00353 KJ/m2s K An average value of 0.0053 is used as the heat coefficient. 227 (c) F lange -A i r (Radiat ion) HTR 46 The heat t rans fe r red by r a d i a t i o n i s often of s i g n i f i c a n t magnitude in the loss of heat, from surfaces to the surroundings because of the diathermanous nature o f atmospheric gases ( a i r ) . It i s convenient to represent rad iant -heat t r a n s f e r , for th is c a s e , as a r a d i a t i o n f i l m c o -e f f i c i e n t which i s added to the f i lm c o e f f i c i e n t for convec t ion , g iv ing the combined c o e f f i c i e n t for convect ion and r a d i a t i o n . From part ( i v ) - ( b ) , average f lange temperature = 378.4 K ( 2 2 1 . 7 ° F ) room temperature = 294.5 K ( 7 0 . 7 ° F ) 46 The r a d i a t i o n f i l m c o e f f i c i e n t obtained from F i g . 10-7 for e m i s s i v i t y = 1.0 was 0.00959 KJ/m 2 sK (d) Wall-Bed (HTCIR) Various c o r r e l a t i o n s have been devised by d i f f e r e n t inves t iga to rs for bed- to -ex terna l -wa l l heat t r a n s f e r , of these , the graphic c o r r e l a t i o n 48 of Wender and Cooper had the broadest data base. Since no c o r r e l a t i o n i s found for the heat t rans fe r c o e f f i c i e n t in the reverse d i r e c t i o n , as in the experiments performed where heat i s being t ransfer red from the furnace encast ing the reactor into the f l u i d i z e d bed, the Wender and Cooper's c o r r e l a t i o n i s assumed to be a p p l i a b l e . The range of v a r i a b l e s encountered during the experiments are wi thin that covered by t h e i r c o r r e l a t i o n . • Wall Furnace TRG = (T12 + T13)/2 = 843.64 K (T12 T13) TRS = (T10 + T i l ) / 2 = 933.64 K Assuming TRW = TRS (which i s v e r i f i e d by subsequent computed output) and taking the f i l m temperature to be the average of these two, f i l m temp. = 890.64 K. F l u i d i z i n g medium is a i r , therefore at f i lm temperature, y f = 3.78 x 10" 5 Kg/ms C p f = 1.1189 KJ/Kg K p f = 0 . 4 3 4 K g / m 3 K f = 6 . 1 5 6 x I O " 5 Kw/ms - 3 dp = sand d i a m e t e r = 0 . 5 4 7 5 x 10 m Pp = d e n s i t y o f sand = 2330 Kg/m Cpp = h e a t c a p a c i t y o f sand = 1 .2770 e f = bed v o i d a g e , l e t ' s assume a v a l u e o f 0 . 6 R e a c t o r p r e s s u r e = 1 1 0 . 8 8 KPa R e a c t o r t e m p e r a t u r e = T13 = 8 2 6 . 5 8 K F o r e s t i m a t i n g t h e s u p e r f i c i a l gas v e l o c i t y , l e t ' s use t h e v o l u m e t r i c -4 3 f l o w o f t he i n l e t gas o n l y , i . e . 5 . 8 4 5 x 10 s t d . m / s . • i II n • * . . / / \ ic OAC: - m - 4 1 0 1 . 3 2 5 8 2 6 . 5 8 x S u p e r f i c i a l V e l o c i t y , U f (m /s ) = ( 5 . 8 4 5 x 1 0 x 8 8 x jgVJT' ( 0 . 0 0 4 0 6 9 6 > = ° ' 3 6 9 d U p f The p a r t i c l e R e y n o l d s number , R e p = — ^ = 2 . 3 2 For t h e g r a p h i c c o r r e l a t i o n d e v e l o p e d by Wender and C o o p e r , t h i s c o r r e s -ponds to a v a l u e o f 0 . 0 0 1 5 f o r h d / [ K f ( l - e J u E P ^ ) ] 1 + 7 . 5 exp [ - 0 . 4 4 -f ( C p p . C p f ) * where D = 0 . 0 7 2 0 m and l_H = 0 . 3 m , h c a l c u l a t e d was 0 .34048 K J / m 2 s K. * R e f e r p a r t ( i v ) - ( f ) (e) Wal l -Reactor Gas (HTG) Since the p a r t i c l e Reynolds number, Re = equals to 2.32, P u f the gas Reynolds number can be ca lcu la ted simply by m u l t i p l y i n g Rep by the r a t i o of the reactor inner diameter and the p a r t i c l e diameter, the value obtained for th is case i s 369. The flow of gas in the reactor i s thus laminar . Heat t rans fe r to a f l u i d flowing in laminar motion through a 50 v e r t i c a l tube was studied by P.igford , allowance being made fo r the e f f e c t of temperature on v i s c o s i t y and d e n s i t y . From part ( i v ) - ( d ) , u^ . = 3.18 x 10 Kg/ms C f = 1 .1189 KJ/Kg K p f = 0.434 Kg/m 3 K f = 6.156 x 10" 5 Kw/ms N = 0.6954 pr AT = TRS-TRG = 90 K therefore N G r = 46530 at f i lm temperature (890.6 K) Since L = 0.7 m (part ( i v ) - ( f ) ) and D = 0.072 m, N G r * N p r * <u> = 3 3 2 8 Graetz number = WCp^/K fL = 18 (W = mass f lowrate = 0.7017 g /s) Assuming the wall temperature TRW to be equal to TRS as for part ( i v ) - ( d ) , -5 y f the gas v i s c o s i t y y became 3.98 x 10 Kg/ms, i . e . — = 0.94. From F i g . 6 for no change in v i s c o s i t y , = 5 and thus the heat 2 t r a n s f e r c o e f f i c i e n t was ca lcu la ted to be 0.00433 Kw/m sK. 231 ( f ) Estimate of Expanded Bed Height The expanded bed height o f a f l u i d i z e d bed can be estimated v ia the 48 fo l lowing i t e r a t u r e procedure : (1) guess H H H (2) take j as the c h a r a c t e r i s t i c s he ight ; Z = ^ (3) d B (Z ) = 0.54 (U - l l m f ) ° - 4 (Z + 4 / ^ ) 0 . 8 g - 0 . 2 (4) U B (Z) = 0.711 / gd B (Z) + (U - U m f ) (5) e B (Z) = ( U - U m f ) / U B ( Z ) " ( 6 ) 1 - £ B = H m f / H where H = expanded bed height H ^ = bed height at minimum f l u i d i z a t i o n U = gas v e l o c i t y at reactor conditions=0.397 m/s U ^ = minimum f l u i d i z a t i o n v e l o c i t y 2 A = c r o s s - s e c t i o n a l area of d i s t r i b u t o r plate = 0.00407 m N = number of o r i f i c e hole = 16 or g = g r a v i t a t i o n a l constant dg = mean bubble diameter U B = bubble v e l o c i t y and £g = f r a c t i o n of bed occupied by bubbles From Table V - 2 , the minimum amount of gas required for f l u i d i z a t i o n at -4 3 25°C was exper imental ly determined to be 3.5 x 10 std.m . I f th is amount i s assumedto hold true for 596°C, the operating temperature of Run 10, then U ^ i s c a l c u l a t e d to be 0.27 m/s (genera l l y , l e s s e r gas i s required for f l u i d i z a t i o n at higher temperature and U m ^ i s thus overestimated) 232 Assuming e m f , the bed voidage at minimum f l u i d i z a t i o n for the 0.55 mm diameter Ottawa sand to be 0.43, the can be estimated by = 0.26 m when m = bed weight = 1.405 Kg 3 pp = p a r t i c l e densi ty = 2300 Kg/m L e t ' s guess H = 0.3 m Try z - H L 2 = 0. .15 m dB(z) = 0. ,044 m uB(z) = 0. .592 m/s e B (Z) = 0. .215 H = 0. .33 m H = 0. .33 m Z H 2 = 0.165 m d B (Z) -= 0.046 m U B (Z) = 0.605 m/s e B (Z) = 0.210 H = 0.33 m A value of 0.3 m is chosen to be the expanded bed height . This value i s assumed to be app l i cab le for a l l other runs s ince the U / l l ^ r a t i o for a l l runs l i e wi th in the range 1-1.5. APPENDIX 10. PROGRAM AND PRINT OUT ( i ) Program The program l i s t e d performed mass and energy balances fo r a l l runs except for runs 5, 6 and 7. For these three runs , another program, with the only d i f f e r e n c e being the use of carbon instead of ni trogen as the reference m a t e r i a l , i s used. ( i i ) Pr in t Out The sample pr intout l i s t e d i s obtained for Run 4, where N^ is used to f l u i d i z e the sand bed in the reactor operat ing at 600°C. ( i ) Program 1 C THIS PROGRAM CALCULATES MASS » ENERGY BALANCES FOR WOOD GASIFICATION 2 C INPUT DATA ARE IN SI UNITS 3 C STANDARD CONDITION IS 70F , 1 ATM. 4 C REFERENCE TEMPERATION IS 2BB.6K(60F) 5 REAL Md,MCSOL,NDSMPC,ODSMPC,N2V3,N2 V1,N2M1,N2DGVP,ODGMPC,NDGMPC € REAL N2M2 . N2M5 . N2M3 . D2M5 . M5 , OMI NP ; OMOUT .N2M4 . N2M6 . N21NP . N21NPV 7 REAL OH20M5,OH20M4.OCO2M5.OCOMS.OARGM5,0DSM4,OlNP.aH2DM7 8 REAL ODGM7.00UT 9 REAL N2 , MWWG , MWDR Y ,MF .M44 ,02 . Q20GVP 10 DIMENSION HEADER! 20) 11 DIMENSION N( 10) .N2N3( 10) ,N2V3( 10) .H20NK 10) .N2M1( 10) 12 DIMENSION COM 1(10).C02M1(10).C02VIt 10),DA1RM1(10) 13 14 DIMENSION AIRMK 10) .H20VK 10) .N2VK 10) .COVK 10), AIRV11 10) 15 DIMENSION HUMIOI10) 16 DI MENS I ON H20M2( 10).N2M2(10),02M2(10),ARGM2(10).C02M2 ( 10) 17 DIMENSION H20M5I10),M5(10) 18 DIMENSION N 2 M 5 I 1 0 ) . C 0 M 5 ( 1 0 ) . C 0 2 M 5 I 1 0 ) . » R G M 5 ( 1 0 ) . 0 2 M 5 I 1 0 ) 19 DIMENSION H20INP(10).MWORY(10),H2DGVP(10).COOGVP(10) 2 0 DIMENSION C02DGVI10).D20GVPI 10) 2 1 DIMENSION CH4DGVI10),N2DGVPI 10).N2M61 10).N2INPI 10).N2INPVI 1 0 ) 22 DIMENSION DGASV7(10),SV(10),H207(10),DGAS7(10).MF(IOI.MWWGI10) 23 DIMENSION WGAS7(10).OMINP(10).0GASM7(10).TAR(10).OMOUT(10) 24 DIMENSION HH20M5I10),OH20M5(10),0DGM7(10),CDGMPC(10).NDGMPC(10) 25 DIMENSION HINP(10),HH20M7(10),H20M7(10).HDGM7(10).HDGMPC(10) 26 DIMENSION 0C02M5(10),0C0M5(10).0ARGM5( 10).01NP( 10),0H20M7110) 27 DIMENSION ODGMPCI10),CC0M5(10).CC02M5I10),CINP(10),C0GM7(10) 28 DIMENSION COUT(10).TEMPI 10.3).CPH2I 10.3),CPCO( 10,3).CPC02I 10.3) 29 DIMENSION CP02(10.3>.CPCH4(10.3).CPN2(10.3).CPN25110).CPC05I10) 3 0 DIMENSION CPC025I10).CP025(10).CPN27(10).CPC07(10I.CPC027110) 31 DIMENSION CPH27(10).HCSTIN(10) 32 DIMENSION CPCH47(10).CP027I10),CPN2T1(10),CPN2T2(10).HCGINI101 33 DIMENSION HVSTIN(10).HCH20S(10),TROOMf10),HCTRN2(10),TRG(10) 34 DIMENSION TRS(10),TRW*10).HELECT(10).HCCCAT(10),CVGAS(10) 35 DIMENSION HCGOUT(10),HCSENS(10) 36 DIMENSION HVSTOUI10).HCSTOI10),HCTAR(10).HVTAR(10) 37 DIMENSION HCENDS(10),HCINSUI10).HLOSSI10).H2(10).C0(10) 38 DIMENSION N2( 10).CH4I 10).02(10).C02( 10) 39 DIMENSION GAS(10).CVf101 .PMANI(10) .PHOPI10).PLINEI10) .PPREI10) 40 DIMENSION PRE A(10) .POP(10) .PDIFF(10) .T1(10) .T2(10) .T3(10) .T4(10) 41 DIMENSION T5(1 0 ) ,T6 (101 .T7 (10 ) .TB( 10 ) .T9(10) .T10( 10) .T11 (10) 42 DIMENSION T12(10).T13(10).T14(10>.T15(10).T16(10),T17(10) 43 DIMENSION T IB(10 ) .T19(10) .T20( 10).T21( 10).T22(10).T23( 10) 44 DIMENSION TAIRD(10).TAlRW(10).TINSOI 10).TINSI(10).TFLANGI 10) 45 DIMENSION CATCHt10).CHAR(10),M4(10).H20M4(10).HH20M4(10) 46 DIMENSION N2M4(10).CCA7CHI 10).CCHAPI 10) 47 DIMENSION 0H20M4(10),H0SM4(10),00SM4(10).C0SM4(10) 48 DIMENSION ASHINP(10).ASHOUT(10).HCDSOL(10),HCCHAR( 10) 49 DIMENSION HE ATIN(10).HEATOU(10).OOUT(10).HOUT(10).HTT(10) 5 0 DIMENSION COEFF( 10).HTCIRI 10).HTCOH 10).HTCOF(10).HTG( 10I.HTRI 101 51 C 52 C ENTERING DATA 53 C 54 DATA R . T E M / O . 0 . 0 . 0 / 55 REAL L I S T ( ! ) / ' • ' / 56 RE AD(5. 10(HEADER 57 . 1 0 FORMAT(30A4) 58 RE A D ( 5 . L I ST)NN.SAND.HE IGHT.DENS.SITE.Y 59 RE AD( 5 . LIST ) M 4 4 .MCSOL . CDSMPC ,HOSMt>c .NDSMPC . ODSMPC . ASHDS 60 READfS.LISTtWATER.WATERl.WATERO.TARR.CYL.CHARR.CCATMP 6 1 62 63 64 READ(5.LIST)HVDS0L 65 C 66 00 20 1*1.NN 67 READ(5.LIST)HVSTIN(I).HVSTOUI I ( 68 READI5.LIST)HUM1D( I ).SVI I ) 69 READ!5.LIST >COEFFI I ) .HTCIRII).HTCOI(I),HTCOF(I).HTGII),HTRI I ) 70 READ! 5.LI ST)N2V3(I).H2DM1(1).N2V11I).C0V111).AIRV1II).C02V111) 7 1 RE AO(5.LI ST)H2DGVP(I ).CODGVPI1 >.CH40GVII).C020GVII) 72 RE AO 15.LIST)N2DGVPII).02DGVPII) 73 READ(5.LIST)DDGMPC(I).NOGMPCII).HOGMPCII),CDGMPC11) 74 READI5.L1ST JPMANI11).PHOPII).PLINEII),PPREII).PRE AI I) 75 READI5.LIST)POP(I) .PDIFFII) 76 RE A D IS.LIST)TROOM(I).TAIRD(I).TAIRWf I ) 77 RE AO!5.LI ST)T1( I ) .T2 I I ) .T3( I ) .T4 I I ) ,T5( I ) .T6( I ) ,T7 I I ) 76 READIS.LIST(TBI I) .TBI I) .T10(I>.T11(I>.T1211) .T1311).T14<I).T15(I) 79 READIS.LIST)T 16(1).T17<I) .T1B(I) ,T19(I) .T20II ) .T211 I).T221 I) BO READI5.LISTIT23I1) Bl C 82 NIII-I 8 3 M4(I)-M44 64 TARI1)"TARR B5 C 86 87 89 C CALCULATION 90 C 91 C INPUTS INPUTS INPUTS INPUTS INPUTS INPUTS INPUTS INPUTS INPUTS 92 C TRANSPORT NITROGEN 93 N2M3II)'N2V3(I)"I 28.013/22.4E-3>•(273. /284.1 1 ) 94 C GASIFYING STREAM 95 N2M1(1) -N2V1II) '1160 8169 96 COMKI) -COVK I )• 1160.7173 97 C02M1III-C02V1II)'1B23.71 IB 98 AIRMK 1 )-AIRV1( I )* 1300.22 99 100 C SUB-AIR STREAM 101 H20M211 CHUMIDII CAIRMK I ) 102 DAIRMK I )-AIRM1( I )-H2DM2( I ) 103 02M2II)*0.2314*OAIRM1( I ) 104 ARGM2 ( I )"0.012B*DAIRMKI) 105 C02M2(I)"0.0005'OA IRM1(I) 106 N2M2 ( I ) "0. 7 553*0AIRM1 (I ) 107 C GASIFYING STREAM AT MANIFOLD 108 N2M5II)BN2M2(I)*N2M1(1) 109 H20M5I1)"H2OM2(l)*H20M1(I) 110 C0M5II)"C0M1|I) 111 C 0 2 M 5 I I ) - C 0 2 M 2 ( I ) » C 0 2 M 1 < I ) 112 ARGM5III-ARGM2II) 113 02M5II )*02M2I I ) 114 M5( I I -N2M5I I ) -H20M5<I )»C0M5( I ) *C02M5( I>*ARGM5<I ) *02M5( I ) 115 C SOLIOS 116 H20M44.(MCS0L/1OO)'M44 117 H20M4I) )-H20M44 118 H20INP11)"H20M5I1)+H20M411) 119 0S0LM4"M4(I)-H20M4(I) 120 C OUTLETS 121 MWDRV<I)'((H2DGVP(I)*2.0158)*(CODGVP(I)*28.011) 122 1 *(CH4DGV<I)•t©;0268)+(N2DGVP(I)*28.013) 123 2 *(C02DGV(I)'44.01)*<02DGVP(I)*31.999))/100. 124 C 125 C MASS BALANCES MASS BALANCES MASS BALANCES MASS BALANCES 126 c 127 c NITROGEN BALANCE 126 129 N2M4(I)-(NDSMPC/100)*DSOLN4 130 N2M6(I)*N2M5(I)+N2M3(I) 131 N21 NP ( I ) -N2M4 ( I ) *N2M6 ( I > 132 N 2 I N P V I I ) > N 2 I N P ( I ) / 1 1 6 0 . 8 1 6 9 133 c TOTAL DRV GAS FLO* BASED ON CALCULATED N2INPV 134 DGASV7(I>-N2INPV(I)•100.0/N2DGVP(I) 135 c HET GAS FLOW 136 c --H207 IS THE STREAM AT ORIFICE PLATE TEMP. • PRESSURE 137 K-0 13S L-0 139 H 2 0 7 I I > - ( S V ( I ) * Y ) / 1 0 0 0 . 140 D G A S 7 U ) - 0 G A S V 7 ( I ) • ( T 1 7 < I ) / 2 9 4 . ) • ( 1 0 1 . 3 2 0 / P O P I I ) ) 14 1 IF(SVM).EO.O.O) GOTO 60 142 40 M F ( I ) - H 2 0 7 ( I ) / < H 2 0 7 ( I > * 0 G A S 7 ( I ) ) 143 M¥»G< I )-MWDRY<I )•( 1-MFd ))•< 18 015'MF<I>) 144 »GAS7(I)-C0EFF(I)*O 0 0 1 5 0 1 1 * < ( P D I F F < I ) * T 1 7 ( I ) ) / 145 1 (MWKGI I )*POP(I l l l " 0 . 5 146 IF(WGAS7<I).LE.DCAS7(I)) GOTO 35 147 X"HGAS7(I)-(DGAS7<I)*H207(I)) 146 K*K*1 149 IF(K.GT.SOO)G0T0 44 150 I F ( A B S m . L E . 0 . C O 0 0 0 5 ) B 0 T 0 50 151 H207(I).»GAS7(I)-DGAS7(I) 152 GOTO 40 153 c 154 c 155 35 H207U)-ABS(»GAS7(I)-DGAS7(I))•(10.0+L-20) 156 L-L» 1 157 I F ( L GT 5O0IG0T0 43 156 GOTO 40 159 50 H 2 0 M 7 ( I ) . ( W G A S 7 ( I ) - D G A S 7 ( I ) ) • ( 1 0 0 0 . / S V ( I > ) 160 GOTO 70 161 60 H20M7CI)•¥ 162 KGAS7I I I-DGAS7U ) 163 164 C 165 C OVERALL MASS BALANCE 166 c 167 70 OMINPII)-M5(I)+M4(I)»N2M3(I) 166 DGASM7II)"DGASV7(I)•((H20GVPU>*83.S319)»<CODGVP(I)•1160. 7173) 169 1 *(CH4DGV(I)»664.7623)*(C020GV(I)•1823 7 118) 170 2 «<N2DGVP(I)>1160.8189)*(02DGVP(I)•1325.966) 17 1 3 )/100.0 172 TAR(I)-TARR 173 CATCHfI)"CVL*DS0LM4 174 OMOUT(I)"DGASM7(I)*TAR(I>+H20M7(I)»C»TCH(I)*CHARR 175 CHAR(I)"CHARR 176 C 177 C H2 BALANCE 176 C 179 HH20M5( I )-H20l<5( I > • ( 2 .0158/16 .015 ) 180 HH20«4( I)-H20M4( I ) • (2.0158/16.015) 16 1 HDSN4II>"<H0S«PC/100.)'0SOLM4 162 HINPII>-HH20M5(I)*HH20M4(I)»H0SM4(1) 183 MH20»7(I).H20«7(I)-(2.0156/18 015) 164 HDGM7(I)-(HDGMPC(I1/100.>*DGASM7(I> 165 HOUTI1>-»«0M7(I)+HDGM7(I) 186 C 187 c 02 AND ARGON BALANCE 186 c 169 0H20M5II(-H20M5II)"(15.9994/18.015) 190 OH20M4(I)>H20M4<I)•(15.9994/18.015) 191 0C02»I5( I ) BC02M5(I )•( 15 .9994/44 .01 >*2 . 192 0C0M5I1)"C0M5(I)•(15.9994/28.011) 193 0ARGM5 ( I)'ARGM5( I ) 194 O0SM4II).<0DSMPC/1O0.>*DS0LM4 *00SM4(I ) 195 , OINPII)>OH20M5(I)»OH20M4<I)*0C02M5(I)»OC0M5(I)*0ARGM5(I> 196 1 *02M5(I) 197 0H20M7(I)"H20M7(1)•(15 9994/18 015) 198 00GM7(1)'<ODGMPC(I)/100 )*DGASM7(I) 199 OOUT(1)"0H20M7(I)'00GM7(I) 200 c 201 c CARBON BALANCE-'ASSUME CHAR ACCUMULATED IN BEO IS 10O7. CARBON 202 c 203 CC0M5U)-C0M5(I)•(12.011/28.011) 204 CC02M5U )-C02M5<I)•(12.011/44.011) 205 CDSM4CIWCD5MPC/100.)"DS0LM4 206 CINP(I)*CC0M5(I)«CC02M5(I)+CDSM4(I) 207 CDGM7( I )" (CDGMPC(I)/100.)*DGASM7( I ) 206 CCATCH(I)*(CCATMP/1CO. C C A T C H ( I ) 209 CCHAR(I)>CHARR 210 COUT ( I ) -CDGM7 ( I )»CCATCH< I HCCHAR(I ) 211 c 212 c ASH BALANCE 213 c 214 ASHINPII)-(ASHDS/100.)*DS0LM4 215 ASHOUTU )•<1.-(CCATMP/100.I)'CATCH(I) 2 16 c 2 17 c CALCULATE SPECIFIC HEAT OF OASES 216 219 c c TEMPI DEREFERENCE TEMP.(288.6K)/TEMP(2)-PREHEATER OUTLET/TEMPI 3)-REACTOR 220 T R G ( I ) * ( T 1 2 ( I ) * T 1 3 ( I ) > / 2 . 221 TEMP(I . 1 )'2B8.6 222 TEMP(I.2)-T7<1) 223 T E M P ( I , 3 ) - T 1 3 ( I ) 224 DO 30 0-1.3 225 C P H 2 I I . d ) * ( 6 . 6 2 * 0 . 0 0 0 8 1 * T E M P ( I , 0 ) ) • ( 0 . 0 0 4 1 8 6 8 / 2 . 0 1 5 8 ) 226 CPC0{I,d)"(6.60+0.00120*TEMP(I.d))•(0.0041868/28.011) • 2 ) ) ) * 227 CPC02II,d)-(10.34*0.O0274*TEMP(I.d)-(195500./(TEMPO.d>* 226 1 (0.0041868/44.01) 2 ) ) ) * 229 CP02(I.d)-(8.27+O.OOO25B'TEMP(I.d)-(167700./(TEMP(I.d)** 230 1 (0.00041868/31.999) 231 CPCH4(I,d)-(5.34»0.0115*TEMP(I.d))*(0.0O4186B/16.0246) 232 C P N 2 ( I . d ) * ( 6 . 5 * 0 . 0 0 1 0 0 * T E M P ( I . d ) ) • ( 0 . 0 0 4 1 8 6 8 / 2 6 . 0 1 3 ) 233 SO CONTINUE 234 C P N 2 5 ( I ) • ( C P N 2 ( I . 1 ) * C P N 2 ( I . 2 ) ) / 2 . 235 CPCOSII)-(CPC0(I.1)*CPCO<1.2))/2. 236 CPC025II)*(CPC02<I.1>*CPC02<1.2))/2 237 C P 0 2 5 ( I ) • ( C P 0 2 ( 1 . 1 ) * C P 0 2 ( 1 . 2 ) ) / 2 . 238 CPN27 <I)-(CPN2 <1.1> »CPN2(I.3))/2. 239 CPC07(I )»(CPCO(1. 1 H C P C O U .3) )/2. 240 C P C 0 2 7 ( I ) - ( C P C 0 2 ( I . 1 H C P C 0 2 ( I . 3 ) ) / 2 . 24 1 CPH27( I )"(CPH2(I .1)*CPH2(I .3) ) /2 . 242 CPCH47(I)•(CPCH4(I .1)+CPCH4(I ,3)) /2. 243 CP027(I ) - (CP02(I .1)*CP02(1 .3)1 /2 . 244 C 245 CPN2TM I ) - (6 .5*0.001-T5( I ) )•( 0.004 1868/28 013 ) 246 CPN2T2( I ) - (CPN2T1(1 )»CPN2( I .1 ) ) / 2 . 247 c ENERGY BALANCE AROUND THE REACTOR (REFERENCE- 288.6K) 246 c 249 c 250 c ENERGY INPUTS 251 c HEAT CONENT OF FEED 252 253 HCDSOL(I)-D50LM4-HVDS0L 254 255 c HEAT CONTENT OF GASIEXCLUOES STEAK IN OUTLET GAS » TRANSPORT GAS) 256 HCGINd )-( (N2H5U )-CPN25(I ) )-(C02M5< I )-CPC025(I )) 257 268 ^ 1 »((ARGM5( I )*02M5< I ))-CP025( I ))*IC0M5( I) 'CPC05II>)) 259 2 * (T7( I ) -288.6) 260 c 261 c HEAT CONTENT OF STEAM 262 c 263 HCSTIN(I)-H20M5(I)-(HVSTIN(I>-0.004 19725-1 286 .6-273 )) 264 265 c 266 c HEAT CONTENT OF WATER IN SOLID 267 c 26B HCH20SII)-H20M4(I)•(0.004183)•<TROOMII)-288 6) 269 c 270 c HEAT CONTENT OF TRANSPORT N2 271 c 272 HCTRN2II)-N2M3(I)-CPN2T2(I)•(T5(I)-288.6) 273 c 274 c ELECTRICAL HEAT INPUT. ROUGH ESTIMATE. 275 c 276 277 T R S ( I ) - ( T 1 0 ( I ) » T 1 1 ( I ) ) / 2 278 H T T ( I ) - 0 . 3 * H T C l R ( I ) » 0 . 7 - H T G ( I) 279 TRW(I)-(( 1,7359-TRSII) )* IHTT(I)-0.21B3-TRGI I ) ) ) / 280 1 ( 17359'HTTII 1-0-2183) 26 1 HELECTII)-HTCIRI1)-0.06784•|TRW 11)-T121 I ) ) » H T G ( I ) - 0 . 1 5 8 3 * ( T R W I I ) • 282 c 283 c TOTAL ENERGY IN 284 c 285 HE AT INI I)"HCDSOLI I)*HCGIN(II'HCSTINII1*HCH20SI I 1 286 1 *HCTRN2(I 1*HELECT(I 1 287 c 288 c 289 c ENERGY OUTPUT 290 c HEAT OF DRY GAS 291 CVGASII)•(I12 109.-H2DGVPII)/100.)•(11997.-COOGVPI11/100.) 292 1 •(37743.-CH4DGVII)/100.1) 293 HCGOUTII)-DGASV7(I)-CVGAS(I 1 294 c 295 c SENSIBLE HEAT OF DRY GAS 296 c 297 HCSENSII I-DGASV7II ) - (T13(I ) -268.6)- I 298 1 (H2DGVPI I)-CPH2711J-B3.5319) 299 2 •ICOOGVP11)-CPC07I I)• 1160.7173 1 300 3 *ICH4DGVII1-CPCH47II)-664.7623) 301 3 •(C02DGVII)-CPC0271 I)•1823.7118) 302 4 * IN2DGVP1 II-CPN2711 )-1160 6189) 303 3 •(02DGVPII)-CP027|1)•1325 988)) /100.0 304 c 305 c HEAT OF STEAM 306 c 307 308 HCSTOII)-H2DM71 I)-(HVSTOUII)-10.00419725 >•I 388.6-273. )) 309 c 310 c HE AT CONTENT OF ELUTRIATED CARBON IN CYCLONE. NEGLECT SENSIBLE HEAT 311 HCCCATIIl-CCATCHII)-32.737 312 c 313 c HEAT CONTENT OF TAR 314 HVT AR I I ) * 29 . 99288375 315 HCTARII)-TAR(I)-HVTAR( I> 316 c 317 c HEAT CONTENT OF CHAR IN BED. NEGLECT SENSIBLE HEAT. 318 HCCHARII)»CHARR-32.7 37 319 c 320 c HEAT LOSS 321 c SUB - - THROUGH 2 FLANGES 322 TFLANG!1 ) -0.5*(T20(I ) + T21(I)) 323 HCENDSII)- IHTCOF(I)*HTR(I)-0.79)•(0.012668)•(TFLANG!I)-TROOMII)) 324 c — THROUGH INSULATION 325 T INSI( I ) -0 .5- IT22I I ) -T23I I ) ) 326 TINSOII)-tO.0002051511-TINS I(I 1*HTCOIII)-0.174614-TROOMII)) 327 1 /(0.0002051511*HTCOI(I)"0.174814) 328 329 HCINSU!I ) -0.0002051511-(TINSI( I ( -TINSO!I)1 330 HLOSS(I l -HCENDSlI I 'HCINSU!I) 331 332 c TOTAL OUT 333 HEATOU!I)-HCGOUT(I)*HCSENS(I)+HCSTO(I)*HCCCAT(IHHCTARtI) 334 1 »HCCHAR|I ) *HLOSS{I ) 335 336 c 337 c CALCULATION CALORIFIC VALUE OF GAS WITHOUT TRANSPORT NITROGEN 338 H2II I-H2DGVPI I )-DGASV7(I ) 339 CO! I )-CODGVPII )-DGASV7(1 ) 340 N2(I)-N2DGVPII)-0GASV7(I) 341 CH4(I)-CH4DGV!I) 'DGASV7(I) 342 C02(I)-C02DGV!I)-DGASV7(I) 343 0 2 ( I ) « 0 2 D G V P ( I ) - D G A S V 7 ( I ) 344 c 345 N2 ( I ) -N2( I ) -N2V3 ( I ) -100 . 346 GAS! I ) -H2 ( I ) *C0< I ) *N2< I ) »CH4( I ) *C02 ( I ) *02< I ) 347 H2(1 ) -H2 ( I ) /GAS ( I ) 348 CO(I ) -COII ) /GAS(I ) 349 N2( I ) -N2( I ) /GAS ( I ) 350 CH411)-CH4(I)/GA5(I) 351 0 2 ! I ) - 0 2 ( I l / G A S ! I ) 352 C02(I1 -C02II) /GAS(I) 353 C V ( I ) « ( 1 2 1 0 9 . - H 2 ( I ) ) * ( 1 1 9 9 7 . - C 0 ( I ) ( » ( 3 7 7 4 3 . * C H 4 ( I ) ) 354 H2 ( I ) -H2( I ) -10O. 355 C O ( I ) - C O ( I ) - 1 0 0 . 356 N2(I )"N2( I )" 100. 357 CH4 ( I ) -CH4 ( I ) - 100 . 35B C02( I ) -C02( I ) •100. 359 021 I )-02( I )* 100. 360 R-TRGII)+R 361 362 363 364 365 366 367 366 369 370 37 1 372 373 374 375 376 377 378 379 380 36 1 382 363 384 385 366 387 388 369 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 4 1 1 4 12 4 13 4 14 4 15 4 16 4 17 4 1 8 4 19 420 421 422 423 424 425 42G 427 428 429 4 30 431 432 433 434 435 436 437 436 439 440 44 1 442 443 444 445 446 447 446 449 450 451 452 453 454 455 456 457 456 459 460 461 462 463 464 465 466 467 466 469 470 471 472 473 474 475 476 477 476 479 480 TEM-T14(I)+TEM CONTINUE R-R/NN TEM-TEM/NN OUTPUT OUTPUT OUTPUT OUTPUT OUTPUT OUTPUT OUTPUT OUTPUT 105 1 10 WRITEI6.105)HEADER FORMAT!' ' .20A4) WRITEI6.100) WR1TE(6.110) FORMAT!//'OPERATING CONDITIONS SAWDUST'/ 1 ' M0tn>0000M0* 0000000') WRITE(6,1151R.M44.TEM.SIZE.MCSOL.CDSMPC.SAND,MD5MPC,HEIGHT.NDSMPC 1 DENS.ODSMPC.ASHDS.MCSOL FORMATI' ' / 1'RE AC TOR TEMP(K) ' . F 1 0 . 6 2F10.6 / 3'PREHEATER BED TEMP(K) ' . F 1 0 . 6 4F10.6 / S'M.C.FEED(XW) ' . F 1 0 . 6 6F10 6 / 7'SAND USED(G) • . F 1 0 . 4 , ' BF10 6 / 9 IN1T1AL BED HT(CM) ' . F 1 0 . 6 AF10.6 / B'SAND BULK OENSITY(KG/M3) ' .F10.4.• CF10 .6 / WET FEED1G/S) SIZE(MM) CONTENT (DRY , XW ) C 125 D' E . F 1 0 . 6 / F ' G.F10.6) WRITEI6.120) FORMAT(//'HEAT EXCHANGER 1 '00000000000000 WRITEI6.1251WATER.TARR.WATERI.CYL.WATERO.CCATMP.CHARR FORMAT(' ' / .F10 .6 . ASH (WET.XWIH20 OUTLETS'/ 0000000'> 1 FLOW RATE(ML/S) 2F10.6 / 3'WATER IN TEMP(C) 4F10 .6 / 5'WATER OUT TEMP(C) 6F10 .6 / TAR CONTENT(G/S) ' . F 1 0 . 6 . ' CYCLONE CATCH(G/G DRY SOLID) ' ' . F 1 0 . 6 . ' CYCLONE CATCH C CONTENT(%W) CHAR ACCUMULATED IN BED!G/S I 130 135 140 150 155 160 170 175 180 185 C 190 200 205 2 IO 215 220 223 C 225 230 235 240 C 245 250 255 260 265 270 275 260 C 265 290 295 8 .F10.6) WRITE(6.130) FORMA T( ' ' / ' # # « * » * 1000000000000000000 WR!TE(6.135) i FORMAT(' ' / / 70X . 'SAMPLE NUMBER' /70X. '»»»»»»««»«»»» 1 WRITEI6.140)(N(I) . I•1.NN) FORMAT!/' ' .13X.10(7X.13)) WRITE!6.150)(HUMI0(I ). I • 1 .NN) FORMAT 1 ' V AIR HUMID ' .10*10.6) WRITE! 6. 155KN2V3! I ). I • 1 .NN I FORMAT!' ' . 'TR,N2(STD M3/S) ' .10F10.6) WRITE(6.160) FOPMATI ' ' / / 'GASIFYING STREAM' ) WRI TE(6. 170XN2V1! I) . I - 1 .NN) FORMAT|' ' . ' N2 (STD.M3/S) ' .10F10.6) WRITE(6.175)(COV1(1),I•1.NN) FORMAT!' CO !STD.M3/S)'.10F10.6) WRITE(6.180)(C02V1(I).1-1.NN) FORMAT!' ' . ' C02ISTD.M3/S) ' .10F10.6) WRITEI6.165)!AIRV1!I).1-1.NN) FORMAT!' ' . ' AIRISTD.M3/S) ' .10F10.6) WRITE(6.190) FORMAT!• 'It'DRY RESULTANT GAS COMPOSITION) WRITE(6.200)(H2DGVP(I).I•1.NN) FORMAT(' ' / ' H2 (%V)'.10F10.6) WRITE I 6.205)(CODGVP!I) . I -1.NN) FORMAT!' ' . ' CO (XV) ' .10F10.6) WR1TE(6.210)(CH4DGV(I).1-1,NN) F O R M A T ! ' - ' . ' CH4 (XV )' . 10F 10.6 ) WRITE(6.215)(C02DGV(I).I•1.NN) FORMAT(' ' . ' C02 (XV) ' .10F10.6) WPITE(6.220)(N2DGVP(I).I-1.NN) FORMAT(' ' . ' N2 (XV) ' .10F10.6) WR1TE(6.223)(02DGVP(I ), I • 1 ,NN) FORMAT!' ' . ' 02 (XV) ' .10F10 6) WRITE(6.225)(0DGMPC(I).I-1.NN) FORMA T ( ' ' / - 0 (XW1-.10F10.6) WRITE(6.230)(NDGMPC(I).I ' l .NN) FORMAT(' ' . ' N (XW)•.10F10.6) WRITE(6.235)(HDGMPC(I).1-1.NN) FORMAT(' - . ' H (XWI-.10F10.G) WRITE(6.240)(COGMPC(I).1-1.NN) FORMAT!- - . - C (XW)'.10F10.6) WRITE(6 FORMAT( WRITE(6. FORMAT!1 WRITE(6 FORMAT( WR1TE(6 FORMAT) WRITE(6 FORMAT( WRITE(6 FORMAT! WRITE(6 FORMAT( WRITE(6 FORMAT( 245) • / / ' P R E S S U R E ' ) 250)(PMANI(I).I•1.NN) / ' MANIFOLD(KPA)' .1OF 10.6) 255)(PH0P(I).1 - 1,NN) ' . ' HOPPER (KPA) ' .10F10.C) 260)(PLINE(I ) . I -1.NN) ' ' . ' FEEDLINE(KPA)' .10F10.6) , 265)(PPRE(I) , I -1.NN) ' ' . ' PREHEATER(KPA)'.10F10.6) . 270)(PREA11).1-1.NN) ' ' . ' REACTOR (KPA) ' ,10FI0 .6 ) .275)(P0P<I), I - 1,NN) ' ' , 'UP.ORIF ICE(KPA) ' .10F10 .6 ) ,280)(PDIFF(I ) .1-1,NN) ' ' . 'OIFFERENC(CMHG)' ,10F10.6) WRITE(6.265) FORMATC ' / / 'TEMPERATURES') WRITE(6.290)(TR00M(I).I-1.NN) FORMAT ( ' ' / ' ROOM (K) ' . 10F 10.6 ) WRITE(6.295)(TAIRD(I). I-1.NN) FORMAT(' ' , ' A I R DRY BULB(K) ' ,10F10.6) WR1TE(6.296)(TAIRW(I).I-1.NN) 238 481 296 482 483 300 485 305 466 487 310 468 489 315 490 491 320 492 493 325 494 495 330 496 497 335 498 499 340 500 501 345 502 503 350 504 505 355 506 507 360 508 509 362 510 511 512 366 513 514 368 5 1 5 516 370 517 518 372 5 1 9 520 375 52 1 522 380 523 524 385 525 526 390 527 528 395 529 530 396 53 1 532 397 533 C 534 535 400 536 537 538 405 539 540 54 1 4 10 542 54 3 5 4 4 5 4 5 546 547 548 4 15 549 550 420 5 5 1 552 425 5 5 3 554 4 30 555 556 435 557 558 440 559 560 445 561 562 450 563 564 455 565 C 566 FORMAT ( ' ' . -A IR WET BULB(K)' , 10F10-6) WRITE(6.300)<T1(1).1-1.NN) FORMAT*' ' , ' C 0 2 (K ) ' .10F10.6) WR IT E (6 . 305 I ( T2 ( I ). I • 1 . NN ) FORMAT(' ' , ' C O (K) ' .10F10.6) WRITE*6.310)(T3*I) , I -1.NN) FORMAT{' - , 'N2 (K) ' .10F10.6) WRITE(6.315)(T4(I) .1*1.NN) FORMATC ' . ' H 2 0 (K) ' . 10F10.6) WRITE(6.320)(T5(I) .1 -1.NN) FORMAT*' '.'TRANSPORT N2(K) ' ,10F10.6) WRITE16, 325KT6* I ). I-l .NN) FORMAT*' ' . 'PREHEAT IN (K) ' .10F10.6) WRITE(6.330)*T7(1 ) . I -1.NN) FORMAT*' ' . 'PREHEAT OUT *K) ' .10F10 .6 ) WRITE(6.335)(TBI I ) .1 -1 .NN) FORMAT( ' ' . ' F U R N . SHELL 1(K) ' .10F10.6) WRITE(6.340)(T9(I) . I -1.NN) FORMATC ' , ' F U R N . SHELL2 (K) ' . 10F 10.6 ) WRITE*6.345)(T10(I) . I -1.NN) FORMAT*' ' , ' R E A C . SHELL 1*K) ' .10F10.4) WR1TE(6.350)*T11(I) , I -1.NN) FORMAT*' ' , ' R E C . SHELL2 *K) ' .10F10 .4 ) WRITE*6.355)(T12(I) .1-1.NN) FORMAT*' ' , ' R E C . BOTTOM (K) ' .10F10 .6 ) WRITE(6.360)(T13*1) . I - 1.NN) FORMATC ' , ' R E C . TOP ( K 1 . 1 0 F 1 0 6 1 WRITE*6.362MT14* I ). I - 1 .NN) FORMAT*' ' . 'PREHEAT BED IK1 ' ,10F10.6) WR1TE*6.366) (T15 (1 ) ,1 -1 , NN) FORMATC ' . ' RE AC . OUT LET (K ) ' . 10F 10.6 ) WR1TE(6.36B)(T16II) .1-1.NN) FORMAT*' ' , 'CYCL-OUTLET IK ) ' , lOF10.6) WRITE* 6. 370MT 17(1 ) . I- 1 .NN) FORMAT(' ' . 'OP.UPSTREAM (K ) ' .10F10.6) WRITE (6 . 372 ) * T 16 ( 1 ) , I - 1 . NN) FORMAT*' ' . ' IMPING. OUT (K) ' .10F10.6) WR1TE(6.375)(T19(I) . I -1,NN) FORMAT(' ' , 'SAMPLING (K) ' ,10F10.6) WRITE(6,380)(T20(I) , I -1,NN) FORMAT*' ' . 'TOP-FLANGE (K>'.10F10.6) WRITE (6, 385 KT21 ( I ) . I - 1 . NN I FORMAT*' ' , ' B 0 T FLANGE 1 (K)' ,10F10.6) WRITE(6.390)1T22*I 1.1-1.NN) FORMAT* ' ' . ' T O P . E HP. (K1 ' ,10F10.61 WRITE 16.395 X72311 ). I - 1 ,NN) FORMAT( ' ' , 'BOT. EXP. (K) ' . 10F10.6 I WRITE I 6.396)(TRG(I) ,1 - 1,NN > FORMAT*' ' , ' T R G * K 1 ' .10F10.6) WRITE f6.397 )(TRW*I 1.I - 1.NN1 FORMAT * ' ' , 'WALL TEMP (KI' . 10F10.61 WRITE(6.400) FORMAT*' ' / / ' R E S U L T S RESULTS RESULTS RESULTS RESULS RESULTS RESULT IS RESULTS RE5ULTS RESULTS RESULT5 RESULTS RESULTS RESULTS RESULT') WRITE(6.405 I FORMAT(' ' . ' * * * * * - » * * » • * * * * * * » » « # # # * » » • • » » # * * # # * • # * * * * * • • - * * * * * » » * WRITE* 6.4 10)M44 .0S0LM4 .H20M44 FORMAT*' ' / 1'WE1 FEED RATE ( G / S I ' . F 1 0 6/ 2'DRY FEED RATE ( G / S ) ' . F 1 0 . 6 / 3'WATER IN SOLID (G/S )' .F10.6) WRITE*6.135) WRITE(6. 140KN* 1 ) , 1-1 .NN1 WRITE(6.415)(N2M31I).1-1,NN) FORMAT*' ' / 'TRANS.N2 (G /S) ' .10F10 .6 ) WRITE(6.420) FORMAT(' ' / / 'GASIFYING STREAM-) WRITE(6.42S KN2M5I I ) . I - 1 ,NN) FORMAT!' ' . ' N2 IG/S1' ,10F10.61 WRITE(6,4301(H20M5*I).I - 1,NN) FORMAT!' ' . ' H20 (G /S) ' .10F10 .6 ) WRITE(6.435)(C0M5II).I-1.NN) FORMAT(' ' . ' CO (G /S) ' . 10F10 .6 ) WRITE (6 .440XC02M5* I ) , I - 1 . NN) FORMAT* ' ' , ' C02 (G /S ) ' . 10F 10.6) WRITE(6.4451*ARGM5*I).I-1.NN) ' F O R M A T * ' . ' . ' ARGON (G/S) ' .10F10 .6 ) WRITE(6.450)(02M5II).I-1,NN) FORMAT(' ' . ' 02 (G /S) ' .10F10 6) WRITE(6.455)(M5(I 1.1-1,NN) FORMAT(' ' . ' TOT.GAS (G /S) ' . 10F10 .6 ) WRITEI6.460) 567 460 FORMAT(' ' / / 'OVERALL MASS B A L A N C E ' / ' * * * . 568 WRITE*6,4651(M4(11.1-1.NN1 569 465 FORMAT(' ' / ' WET SOLID (G/S) ' .10F10 6) 570 WR1TE(6.470)(N2M3 * I).I - 1.NN) 571 470 FORMAT * ' ' . 'TRANS.N2 (G/S) ' .10F10.61 572 WR1TE(6.475)(M5(II.I-1.NN) 573 475 FORMAT(' ' , ' T O T . GAS (G /S) ' . 10F10 .6 ) 574 WRITE(6,460)(OMINP(I),1 - 1,NN) • 575 480 FORMATC ' , ' T O T A L IN (G/S ) ' . 10F 10 6) 576 WRITE(6.4B5)(DGASM7(I).I - 1,NN) 577 485 FORMAT(' ' / ' DRY GAS (G /S) ' . 10F10 .6 ) 578 WRITE(6.490)(H20M7(11,1-1, NN 1 579 490 FORMAT(' ' , ' H 2 0 IN GAS(G/S) ' .10F10-6) 580 WRITE(6.4951(TAR(I1 ,1-1,NN1 5B1 495 F ORMAT(' ' . ' T A R (G /S1 ' , 10F10 .61 582 WRITE(6.500)(CATCH(I), I-1.NN) 583 500 FORMATC ' . ' C A T C H (G/S )' . 10F 10.6 1 584 WRITE(6.5051(CHAR(11,1-1,NN) 585 505 FORMAT(' ' . 'CHAR (G /S) ' . 10F10 .6 ) 586 WRITE(6,510)(OMOUT 11 ) , I - 1,NN) 587 510 FORMAT(' ' . ' T O T A L OUT (G/S) ' .10F10.6) 588 C 589 WR1TE(6.515) 590 515 FORMATC ' / / ' N 2 B A L A N C E ' / ' » * « * » * « » * * ' ) 591 WRITE(6,520)(N2M4(I),I - 1,NN) 592 520 FORMAT(' ' / ' IN SOLID (G /S) ' , 10F10 .6 ) 593 WRITE(6.525)(N2M6(I).I-1.NN) 594 525 FORMATC ' . ' IN GAS <G/S)' . 10F 10. 6) 595 WRITE(6.530)(N2INP(I), I-1,NN) 596 530 FORMATC ' . ' T 0 T . N 2 IN (G /S) ' . 10F10 .61 897 C 598 WRITE(6.535) 599 S35 FORMATC ' / / ' G A S O U T L E T ' / ' * * » * » » » * » » ' ) 600 WRITE(6.540)(DGASV7(I).I-1.NN) 601 540 FORMAT(' • / ' DRY ( STD.M3 /5)' .10F10.6) 603 WRITE(6.545XDGAS7(I) .1-1,NN) 603 545 FORMAT(' ' , 'DRY p DP (M3/S) ' .10F10.6) 604 WRITE(6.550HWGAS7(I>.I-1.NN) 605 550 FORMATC ' . ' M E T • OP (M3/S)'.IOF10.6 I 606 C 607 WRITE(6.555) 608 555 FORMAT( '. ' / / ' H 2 0 B A L A N C E ' / ' * * * ' " * * * * * ' ) 609 MR IT E (6 , 560) (H20M5 (I ), I • 1. NN) 610 560 FORMAT(' ' / • IN IN. SAS(G/S) ' .10F10 .6 ) 611 MR IT E(6,565)(H20M4(I ). 1" 1 ,NN) 612 565 FORMAT(' ' . ' I N SOLID (G/S >' . IOF 10. 6 ) 613 WRI7E(6.570)<H20M7(I).1-1,NN) 614 570 FORMATC ' / • IN OUT.GASIG/S) ' . IOF10.6) 615 C 616 WRITE(6.575> 617 575 FORMAT(' • / / ' H 2 B A L A N C E ' / ' » » » » » » » * * » ' ) 618 VRITE(6.5BO)(HH20M5(I).I-1.NN) 619 580 FORMAT(' ' / ' IN IN.GAS IG/S) ' .10F10 6) 620 MRITE(6.5B5)(HH20M4I I ). I » 1 ,NN) 621 585 FORMAT(' ' . ' I N M.SOL. ( G/S > ' . 10F 10.6 ) 622 *RITE(6.59O)(H0SM4(1).1-1.NN) 623 590 FORMATC - . ' I N O.SOL. (G /S I ' . 10F10 6) 624 MR IT E(6.600)(HINP(I ) , I •1,NN) 625 600 FORMATC ' . ' T O T H2.IN (G /S ) ' . IOF10 .6 ) 626 » R I T E ( 6 . 6 0 5 ) ( H H 2 0 M 7 ( I ) . I - 1 . N N ) 627 605 FORMAT(' ' / ' IN H20 GAS(G/S) ' .10F10.6 ) 628 W R I T £ ( 6 . 6 1 0 H H D G M 7 ( I > , I - 1 . N N ) 629 610 FORMAT(' ' . ' I N DRY GAS1G/S) ' .10F10 6) 630 MRITE(6.615)(HOUT(I>.I•1,NN) 631 615 FORMATC ' . ' T 0 T . H 2 OUT ( G/S )' , 10F 10.6 ) 632 C 633 MRITEI6.620) 634 620 FORMAT!• ' / / • 02 B A L A N C E ' / ' * * * * * * * * * * ' ) 635 WRITEI6.625)(0H20M5!I).I•1,NN) 636 625 FORMAT(' ' / ' IN H20 GAS!G/S) ' .10F10 .6 ) 637 WR)TE(6,626)(02M5( I ) , I" 1,NN) 638 626 FORMAT(' ' , ' I N 02 GAS (G /S ) ' . 10F10 .6 ) 639 WRITE!6.630)(0H20M4(I).1.i ,NN) 640 630 FORMAT(' ' . ' I N H20 SOL(G/S) ' .10F10 .6 ) 641 WRIT E(6.635)(DC02M5(I ).1•1,NN) 642 635 FORMAT(' ' . ' I N C02 GAS!G/S )' . IOF10.6) 643 WRITE(6.640 K 0C0M5!I).I•1.NN) 644 640 FORMAT( ' ' . ' I N CO GAS!G/S >'.10F10.6) 645 WRITE(6.645)(0ARGM51I).I•1,NN) 646 645 FORMAT(' ' . ' I N ARGON (G/S)'.10F10.6) 647 WRITE(6.65O)(0DSM4(I).I•1.NN) 648 650 FORMAT(' ' , ' 1 N DRY SOL(G/S) ' .10F10.6) 649 WRITEI6 .655M0INP! I ) . I- 1 .NN) 650 655 FORMAT!• ' . ' T O T . 0 2 IN IG /S) ' .10F10 .6 ) 651 W R I T E < 6 . 6 6 0 ) ( 0 M 2 0 M 7 ( I ) . 1 » I . N N ) 653 660 FORMAT!' • / ' IN-H20-GAS!G/SI ' .10F10.6) 653 WRITEI6.665 ) (00GM7(I) . I ' l .NN) 654 665 FORMAT(' ' . ' I N DRV GAS(G/S) ' .10F10 6) 655 WRIT E!6.668)(OOUT(I) . I •1.NN) 656 668 FORMAT!' ' . ' T O T . 0 2 OUT(G/S) ' .10F10.6) 657 C 658 WRITE(6.670) 659 670 FORMAT!' ' / / 'CARBON B A L A N C E ' / ' * * * * * * * * * * * * * * ' ) 660 WRITE (6.675HCC0M5I I ). I' 1 .NN) 661 675 FORMAT!' • / ' IN CO-GAS (G/S1 ' .10F10.6 ) 662 WRITE(6.680)<CC02M5(1).I-1,NN) 663 680 FORMAT!' ' . ' I N C03-GAS(G/S) ' .10F10 6) 664 WRITE!6,685)(CDSM4( I ) . I • 1,NN) 665 685 FORMAT(' ' . ' I N DRY SOLIG/S>'.10F10.6> 666 WRITE(6.660)(CINP(I ) . I •1 , NN) 667 690 FORMAT!' ' . ' T O T . C . IN!G/S>' .10F10.6) 66B WRITE(6,695)(CDGM7(I).I.1,NN) 669 695 FORMAT!' • / ' IN DRY GAS!G/S) ' .10F 10.6) 670 WRIT E(6,700)!CCATCH!I ) . I •1 ,NN) 671 7O0 FORMAT( ' ' . ' I N CATCH <G/S I ' .10F10.6 I 672 WR 1TE ( 6 , 705 )! CCHAR( I ). I " 1 ,NN) 673 705 FORMAT!' ' . ' I N CHAR (G /S ) ' . 10F10 .6 ) 674 WRITE(6.710)(COUT( I ). I • 1 ,NN) 675 710 FORMAT(' ' . ' T O T . C OUT (G/S I ' . IOF10 .6 ) 676 C 677 WRITE(6.720) 676 720 FORMAT 1 ' ' / / ' A S H B A L A N C E ' / ' * * * * * * * * * * * ' ) 6 79 WRITE(6. 725MASHINP! 1 ). I• 1.NN) 680 735 FORMAT!' • / ' IN SOLIOS ! G / S ) ' . 1 0 F 1 0 . 6 ) 68 1 WRITE(6.730)1ASHOUT!I 1.1-1.NN) 682 730 FORMAT(' ' . ' I N OUTLETS!G/S) ' .10F10.6) 683 C 684 WRITE(6.73S) 685 735 FORMATC ' / / 'ENERGY B A L A N C E ' / ' » » « * » • » » » » » » » » ' ) 686 WRITE(6,740)(HCDSOL(I).I - 1,NN) 687 740 FORMAT(' ' / ' FEED (KJ/S) ' .10F10.6> 688 WRITE(6,745)(HCGIN(I). I •1,NN) 669 745 FORMAT(• ' . ' I N L E T G A S ( K J / S ) ' . 1 0 F 1 0 . 6 ) 690 WRITE(6.750)(HCSTIN(11,1-1.NN) 691 750 FORMATC ' , STEAM ( K J / S ) ' . ' O F 10.6) 692 WRI TE (6 .755 ) (HCH20S( I ). I - 1, NN) 693 755 FORMATC ' , 'H20/S0LID(KJ/S>'.10F10.6) 694 WRITE(6.760)(HCTRN2(I).1-1,NN) 695 760 FORMATC ' . ' T R A N S . N2(KJ /S) ' .10F10 .6 ) 696 WRITE(6.765)(HELECT(1I.1-1.NN) 697 765 FORMAT(' ' , ' E L E C T R I . (KJ/S)'.10F10 .6) 698 WRITE(6.770)(HEATINI I ) .1 -1 .NN) 699 770 FORMATC ' . 'ENERGY INIKJ/S)'.10F10.6) 700 WRITEI6.775MHCG0UT1I I.I-1.NN) 701 775 FORMAT!' ' / • HC DRY G (KJ/S)'.10F10 .6) 702 MRITE(6.7B0)(HCSENS(I).1-1.NN) 703 780 FORMAT)' ' , ' S E N S . D . Q (KJ/S)'.10F10 .6) 704 WRITE(6,785)(HCSTO(I),I - 1,NN) 705 785 FORMATC ' , 'STEAM (KJ/S)'.IOF10.6) 706 WRITE(6,790)(HCCCAT(I) , I - 1,NN) 707 790 FORMATC ' . ' E L U C T . C IKJ/5 )' . 10F 10.6) 708 WRITE(6,785)(HCTAR(I).I - 1,NN) 709 795 FORMATC ' . ' T A R I K J / S ) ' . 1 0 F 1 0 . « ) 710 WRITE(6.B00)(HCCHAR(I).I-1.NN) 711 BOO FORMAT(' ' . 'CHAR ( K J / S ) ' . 1 0 F 1 0 . 6 ) 712 MR IT E16,805)IHCINSUII), I-1.NN) 713 805 FORMAT I' ' . ' INSUL.L0S(KJ/S) ' ,10F10 . 6 ) 714 WRITE(6,B10)(HCENDS(I),I -1.NN) 715 B10 FORMATC ' , 'OPEN ENDS(KJ/5) ' , 10F 10.6) 716 MRITE(6.815)(HEAT0U(I). I-1.NN) 717 815 FORMATC ' . 'ENERGY OU(KJ/S) ' . IOF 10.6) 718 C 719 WRITE(6.B20)(CVGAS(I).I-1.NN) 720 820 FORMAT(' • / / ' C V D GAS(KJ/M3) ' . IOF10.2) 721 WRITEI6.825) 722 825 FORMAT(' ' / ' CV DRY GAS WITH'.10F10.1) 723 WRITE(6.830)(CV(I) ,1-1.NN) 724 830 FORMATI' ' . ' - O U T N2(KJ/M3) ' ,10F10.2) 725 WRITE(6.835) ' / 726 835 FORMAT(' ' / / ' D R Y GAS CONTENT WITHOUT TRANSPORT N2 727 1 ' » * # # # # # # * # # * * # # # # # # * * # # # * * * # ' # * ' * # * * * ' ) 726 WRITE(6.840)(H2(I) . I - 1.NN) 729 840 FORMATC ' / ' H2 (XV) ' .10F10.6) 7 30 WRITE(6.845)(C0(I) . I -1.NN) 731 845 FORMAT(' ' . ' CO (XV) ' .10F10.6) 732 WR1TE(6.850)(CH4(I).1-1.NN) 733 850 FORMAT ( ' ' . ' CH4 (XV )' . 10F 10.6 ) 734 WRITE(6,655)(C02(I), I - 1,NN) 735 855 FORMAT(' ' . ' C02 (XV) ' .10F10 6) 736 WR1T E(6.660)(N2( I ) . I -1 .NN) 737 860 FORMAT(' ' . ' N2 (XV) ' .10F10.6) 738 WRITE(6.861)(02(I) . I -1.NN) 739 861 FORMATC 02 ( X V ) ' , 10F10.6) 740 WR1TE(6.865)(HVST!N(I), I-1.NN) 74 1 865 FORMAT ( ' ' / / ' STEAM H V K K J / G ) ' . 10F10.6) 742 743 WRITE(6,870)(HVSTOUII).I - 1.NN) 744 870 FORMATC ' . 'STEAM HVOt K J / G ) ' . 10F 10. 6 ) 745 WRITE(6.B75)(SV(I),1-1.NN) 746 875 FORMATC ' . ' S V . » O P • IM3/G) ' .10F10.6) 747 WR IT E 16 . 8B0) I COE F F11 ). 1 • 1. NN) 748 880 FORMAT(' ' / / ' DIS.COEFF. ' .10F10.6) 749 WRITE(6.885)1HTCIRII1.I-1.NN) 7 50 885 FORMATC ' . ' H T IN REAC.<KJ/ ' .10F10.6) 751 WRITEI6.890)(HTC0I(I) . I-1.NN) 752 890 FORMAT I ' ' . ' H T OUT INSU. M2 ' . 10F 10.6 ) 753 WRITE(6.895)(HTCOFI I ) . I -1 .NN) 754 895 FORMATC ' . ' H T 0 FLANGE SK ) ' , 10F 10.6) 755 WRITE(6.B96)IHTG( I).I - 1.NN) 756 896 FORMATC ' . ' H T OF GAS ' .10F10.6) 757 WRITEI6.B97)!HTRI I) .1-1.NN) 756 897 FORMATC ' . ' H T OF RAD I AT ION' . 10F 10.6 ) 759 GOTO 46 760 43 WRIT EI 6.905)L.K .13) 76 1 905 FORMATC ' / / ' WGAS7 IS LESS THAN DGAS7 ; L- ' .13. 'K" ' 762 GOTO 45 763 44 WRITE(6.910)K,L 764 9 10 FORMAT I ' ' . ' ITERATION IS GREATER THAN 50: K- ' .13. ' L - ' .13 765 45 WRITE(6.900)1 766 9O0 FORMAT I ' ' / / ' S A M P L E NUMBER -'.13) 767 46 STOP 768 END 769 End of F t l e 1. ( i i ) P r i n t Out 00,00 0000000000000000000000000000 00000000 0000 0''i>ii'iiii'iiii""i""ii>""»iiii»iii""i"" 14 JULY 1961:RUN 4:TRAN.N2;W00D*68(-20+35):SAND-6" AT 600 DEGREE C 00 0000000000000000000000 0 0000000000000000000000»0'llll'll'lllt»10'» •""""•"""»"*"" 00000000000000000000*0 0000000000000000000000 9 10 1 1 OPERATING CONDITIONS 00000000000000000000 REACTOR TEMP(K) PREHEATER BED TEMPIK} M.C.FEEDCJW) SAND USEOIG) INITIAL BED HT(CM) SAWDUST 0000000 857. 299605 WET FEEOIG/S) 0 .053012 0. .0 SIZE(MM) 0 .670500 5 864000 CONTENT!DRY.XW) C 48 .970001 1405 OOOO H 6 .090000 20 .320007 N 1 .160000 1700 OOOO 0 42 .809998 ASH 0 .890000 (WET.XW1H20 s .864000 25 26 27 28 29 30 HEAT EXCHANGER FLOW RATE(ML/S) WATER IN TEMP1C) WATER OUT TEMP(C) 0.0 0.0 0.0 OUTLETS 0000000 TAR CONTENT(G/S1 0.003032 CYCLONE CATCH(G/G DRV SOLID) 0.038373 CYCLONE CATCH C CONTENT(XW) 80.880005 CHAR ACCUMULATED IN BED(G/S) 0.002946 SAMPLE NUMBER 33 34 35 AIR HUMID TR N2(STD M3/S) 0.0 0.000748 0.0 0.000748 0.0 0.000752 0 0 0.000762 0.0 0 000772 0.0 0.000772 0.0 0.000781 0.0 0.000790 0.0 0.0 0.000790 0 0007 96 GASIFYING STREAM N2 (STD.M3/S) 0 .0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 CO (STD M3/S) 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0 . 0 . 0 .0 0.0 C02(STD M3/S) 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 AIRIST0.M3/S) 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0 0 0.0 0.0 DRV RESULTANT GAS COMPOSITION CO CH4 C02 N2 (XV) (XV) (XV) (XV) .683000 .804000 .361O00 .312000 (XW) 1.301300 (%w> (XW) 0.099500 1.114 100 0 757000 0 676000 0. 153000 0. .568000 0 490000 0 .593000 0. 813000 0 756000 0. 4980OO 1 751000 1 . 884000 0. 784000 1 .378000 1 , 548000 1 .356000 1 724O00 1 . 31 10OO 0 565000 0 362000 0 .322000 0 2560O0 0 312OO0 0 .321000 0 .289000 0 347000 0 303000 0 228090 0 .328000 0 .326000 0. 131000 0 .316000 2 .088000 0 .322000 0 379000 0 261000 0 163000 96 802002 96 .792007 98 675995 97 .425995 95 .641998 97 .4 38004 96 737000 97 369O03 9B 526001 0 .0 0 .0 0 0 0 .0 0 .0 0 .0 0 0 0 0 0 0 1 .053500 1 4574O0 0. 502900 0 864000 3 .247600 0 .648100 1 .427900 1 054500 0 .522900 97 .455002 97 .355606 98 B50601 97 .895996 94 .987198 97 917892 97 .405701 98 037796 9B 967793 0 . 107OO0 0 O95300 0 .047800 0 .086000 0 .O807O0 0 .0845O0 0 1089O0 0 .098500 0 .O68eO0 1 .384500 1 .091700 0 .598700 1 .154000 1 684300 1 .149500 1 .057500 0 809200 0 . 4205O0 PRESSURE MANIFOLO(KPA) 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 O.O 0.0 HOPPER ( KPA) 123.388107123.388107123.38B107123.388107124.767105124.767105125.1 11801125.456604125.4 56604126. 14 5996 FEEDLINEfKPA)125.456604125.456604125.456604125.456604126.145996126.145996126.835495127.180206127.180206127.524994 PREHEATER1KPA > 0.0 O.O 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 REACTOR (KPA)110.977600110.97 7600110.97 7600111.667099111.667099111.667099112.356598113 . 046005113 .046005 113.7 35504 UP .ORIFICE (KPA)1 10.9776001 10.9776001 10.97760011 1.3224031 1 1.32240311 1.3224031 1 1.6670991 1 1.667099111.6670991 12.356598 DIFFERENC(CMHG) 6.60OOOO 6.6OO000 6.700000 6.9OOOO0 7.000000 7.000000 7.400000 7.400000 7.4000O0 7.40OOO0 83 84 9 1 92 99 100 101 102 103 104 • 105 106 107 108 109 1 10 1 11 112 113 114 115 116 117 118 119 120 TEMPERATURES ROOM (K AIR DRY BULB(K AIR WET BULB(K C02 <K CO (K N2 (K H20 (K TRANSPORT N2(K PREHEAT IN (K PREHEAT OUT (K FURN. SHELLKK FURN. SHE L L2(K REAC. SHE LL1(K REC. SHE LL2 (K REC. BOTTOM (K REC. TOP (K PREHEAT BED (K REAC.OUTLET (K CYCL.OUTLET (K OP.UPSTREAM (K IMPING. OUT (K SAMPLING TOP.FLANGE BOT FLANGE 1 TOP. EXP. BOT. EXP. TRG WALL TEMP 299 0OOO00299 OOOOO0299 .000000299 . 00OO0O299 .000000299 .000000299 .000000299 .000000299 00OOO0299 OOOOOO 0.0 0.0 ) 0 .0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 o o o.o 0.0 0.0 0.0 0.0 o.o o.o 0.0 0.0 0.0 0.0 o.o o.o 0.0 0.0 0.0 0.0 0.0 0.0 0.0 o.o 0.0 0.0 0.0 0.0 0.0 0.0 0 0 0.0 0.0 0.0 0.0 0.0 0.0 0 0 0.0 o.o 0.0 0.0 0.0 1293.000000293.000000291 .000000291 .000000291 .000000291 .00OOO0291 . 0OOOOO291 .00OO0029 1 . OOO0O0292 . OOOOOO ) 293 .000000293.000000291 .000000291 .0O0OO0291 .000000291 -00O000291 .0OOOO0291 .000000291 .O0OOO0292 . OOOOOO )293 .000000293.000000291 .000000291 .000000291 .000000291 .0O0000291 .000000291 .000000291 .000000292 .OOOOOO 1320.000000320.000000320.000000321 .000000321 .000000321 .000O0O32 1 .OO0O0O322 .000000322 .0O0O0O32 2 . OOOOOO )328 OOOOO0328 000000330.000000331 .000000332 .000000332 .0000O0333 . 000000336 .000000336 .000000339 . OOOOOO ) 1003.OOOO 1003.0000 997.OOOO 992.0000 986 OOOO 986.0000 980.OOOO 974.0000 974.0000 971.OOOO ) 943 OOOO 943.OOOO 942.OOOO 935.OOO0 925.0000 925.0000 917.0000 907.OOOO 907.0000 904 OOOO )855 . 0OOOOO855 .000000833 .000000826 .00000O823 . OOOOOOB23 .000000823 .000000625 . 00OOO0825 .000000828 . OOOOOO )883 . OOOOOOB83 . 0OOOO08B3 000O00883 00000O883 .000000883 .000000883 . 0OOOOO883 .000000883 .000000883 OOOOOO ) 0 .0 0.0 0.0 0.0 0 .0 O.O 0.0 0.0 0.0 0 0 ) 307 .000000307 .00000030B . 000000309 .000000308 .000000308 .000000307 .000000309 000000309 .000000310 OOOOOO )446.000000446.000000469.000000476.00O00O488.00000048B . 000000486.000000469 000000489.000000490.000000 )346 .00O000346 . 0OOOO028 1 . OOOOO0370.000000380.000000380.000000383 .000000387 .000000387 . 0OOOOO387 . OOOOOO ) 300.000000300.000000303 . OOOOO0303 .000000303 .000000303 .000000303 .000000303 .000000303 .0000O0303 . OOOOOO )299.0OOOOO299 OOOOO0299.0OOOO0299.000000299 000000299 000000299 000000300 000000300.0OOOO030O OOOOOO )458 00O0O0458 000000460.000000462 .000000466.000000466 .000000469 .000000466 000000466 .000000465 OOOOOO >3 16 .00O0O0316 .000O0O3 16 .00O000316 .000000315 .000000315 .000000315 .000000315 .000000315 .0000O0315 OOOOOO I633.000O00633 000OO0649 000000655.000000661 .000000661 .000000663.000000666 .000000666 .0000OO657 .OOOOOO 1361 .0O0O00361 .000000359.000000358.000000357 .000000357 .000000357 .000000357.000000357 .000000358 OOOOOO )B69 .000000869 .000OO0858 .000OO08S4 .500000853 .000000853 .000000853 .000000854 .000000854 .000000855 . 500000 )968.596680968.5966B0964.779053958.885010951.160156951.160156944.456543936.837646936.837646934 028076 RESULTS RESULTS RESULTS RESULTS RESULS RESULTS RESULTS RESULTS RESULTS RESULTS RESULTS RESULTS RESULTS RESULTS RESULT 000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000 WET FEED RATE DRY FEEO RATE WATER IN SOLID ( G / S ) ( G / S ) ( G / S ) 0.053012 0.049903 0.003109 SAMPLE NUMBER 0000000000000 1 2 3 4 5 6 7 8 9 10 TRANS.N2 (G/S) 0.86B725 0.866725 0.872412 0.BB4B7B 0 895694 0.895694 0.906547 0.917435 0 917435 0.823889 GASIFYING STREAM CB -J CD UI lU KJ - O <0 n> ~J cr> u > — O <o to ~J cti m i 0 > - * r i - i r H ( / i u » l m m H I ui - * z -• — - O Z I > f - - < m n Z r s w - t Z r t * m z z m i / ) » u c r n z nt rw • o m r- m * jrj Z C » f l > O W n z ^ . r> rw O * O O u i r- - < Z - n o H 1/1 ^ i H C O m • O -< JD • o » n r § r~ O • — r- O * rj> r--> O 0 0 - Z « > m o l / i Ut Z W O n r - -4 Ci _ A , - . .A A T«; r» l/l 7 c * x * x x x * x x x x * x x % z > c c c c c c c c t t t t c t c . * r> o o VI VI (/)</< Ul Ul (/> Irl 1/1 l / l l/l 1/1 1/1 1/1 l / l l / l l / l O O O O O O O O U M O O O O O O O b b b b o o o m - J -o o g o o <o o o u u i o o m o f f D o — cn o o A . O o - . M 0 1 O O M - J C -J - J U fj (fl o o ^ l b t > ( 0 - J M U C I ) — to co — to CO M U l V I i O O O - l CD CJ CD CO U 01 ft B ^ U M U I I & M M U I O U I U 01 It O O O O O O O O ( J M O O O O O o o o b g o o o m u - j ^ r j g b o u o o U U V U U I O 0 I U — 01 O Q Ck Q o - M d O O w - J i O - J - J U O cn O O — ftftto-otoiD.- — to oo — u u t> u u » t > O Q a > u CD CJ oo to u cn ft ft-JutoUOTUio M U O U I cu cn ft O O O O O O O O * U O O O O O O O O O O Q O O W U • " Q Q O O U o o U U V I 0 U I O « I U ft CO O Q ft Q O ' U K O O M O U ( T I O M O cn O O • ( H M D > j i o u i r t» CD — ro CJ ft • j a » a O O O - > cn - j to to u cn & a u u u u a i < j u »o O m tn u cn & O O O O O O O O feOOOOOO O O b o b b b b in - - M Q o b b t o b b U U I O I O v l O i n O l . f l M O Q Q Q — i o c n o O k o o " > — r» --> ro o ui O O C D l O f t t D - J K J C J ^ I 0D U — -» ftO (Oft U I O H a O Q I D M CJ O IP CJ CO Cn Ck M U U U U A D O »o io tn cn U cn Ck O O O O O O O O » u O O O O O O O b b b b b b o , M b-*bbbblo b b U u i o t D U i O a > - i Oi O O o ft O O M k O l O O M ' O O U IO O UI O O f O f t f t U j - J K J U I C D f J D U - k - > *o u ft « i O « - « 0 0 » < > - j u v u co en ik KJKJcJKJCJCnCn-O 00 CD K> UI cj 01 ft O O O O O O O O - U O O O O O O O b o b b o b b i M b - b o b b b bb u u v v m o i f i u u o o o * o o u t - m o o u m o i o u u o m O Q U f t t t l D ' J M K I d l CD CO — — to u ft i n o i • o o u u FO a> CJ CJ cn ft M M U M U t l B O IB 0) M UI CJ (Tl Ck O O O O O O O O U to o o o o o oo o o o o o o m u a o o o b o o b b U U « I O U l O l ) l ~ l CD CJ O Q Ik O O M t V g l Q O r J O U l 01 IB U O Ol O O CDcnck<o~Jkj{w~j t> a KJ • • ro to ft to cn ft ft o Q CJ CJ w ui o ui cj en ft U A U U U O l s O tD CJ CD tn CJ A b 0 0 0 0 0 0 0 0 u ro O O O O O O O O O Q O O Q t n u 0 ) o O O O <D oo c j c j t D t D u i O O t n mooo tk 5o r o c k t u o o w o c n — ft KJ o Ut O O U O B O - J U U D I CD KJ KJ - • IO U ft 01 — ftftOQlDCJ U M U U CJ 01 ft u K i u u u t i i n - & u tn u) to c n * O O O O O O O O U M O O O O O o o O O O O O O O i M Hi - l O O O O f f l • o o U t o C 0 ( O U > O ( O O u o o o * o o r o f t c n O O K j u i f t — Ck ro o cn O O cjCDt>(0~JK>~jLo aaroro— to u c » Cl — ftftOQCDCD M M U U U (Jl Ck M W U W U f f l O O B U U I U I CO 0> Ck O O O O O O O O U M O O O O O o o O O O O O Q O l — W O i O O O O t O oo U IO ID (D UI O ID H - 0 1 O O Ck 0 0 M f O I O O M M U l KJ CJ CJ O UI O O M O ^ k i J O ro - J — ro CJ Ck c o c n f t f t O Q t o c j <o CJ co CJ ui m tk u i - j u w c j c n o i o ui io is tr cj cn tk o z z z o z z z •-^ - \ \ ^ l/l l/l l/l l/l o o o o l/l l/l l/l l/l O O O O O O O O tk 10 UJ to tk tk CJ Ck Ck CJ to to O Cl IO UI CD CD 0 0 0 0 O O O O b o o b b b b b — O O — K> KJ 01 ro — M tk tk CD 10 (Jl (J ft h ft ft tk Ot CJ CJ UI tn (D O CD CD O O O O O O O O ft 01 (D (0 o o o o §88§ OB 10 UI CJ UI ft ft 01 03 01 (0 U O O O O b b b b o o o o b b b b o o o o ro ro ft ft °882 S CD UI S tn ft tk cn O oi ID m o o o o 8882 o »o - U> u u> ui os 00 ft ft (0 -o tn to t j o o o o o o o o UI tO -k O _ io Ui cn ft ft ft ft ft tn to to O O O O o o o o ft to - (6 ft ID U» 10 tn ft ft cn — 01 (0 -O o o o o o o o o 2888 M M ^ g O IO IH UI -JJ ft ft -O M cn to - J O O O O O O O c > > -4 (/» 1/1 O O O "N. ^ N. O O O ° ° § — tn ui U O u IO ft UI O O O b o o u to 5 O D O O ^ CJ a z z z z z z z • a > o n i o i o n j j o o k j k j k j ro -< O -J O O O O O O O O O O l / l l / l v i VI l / l VI l / l l / l O O O O O O O O b b b b o b o o UI (J UI u to u ro - J m O O O O O O O O b b b b b b b o O O O O O O O O O O O O O O O O O O O O O O O O b b b b b b b o O O O O O O O O b b b b o g b o — to M tn tn ft u 2 th to to ui O O O m ft C £ ui ti O t, O in ti 888 CD -J O ft ID UI •k— CJ UI O UI O O O O O O O O O O O O O O O O O O O b o b b b b b b O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O b b b o ft ft — O O O O O O O O o o b o b b o o o z z z • a n -o o O O O O O o o o o o o o -J tD CD o o o o j O to 4 10 t» -J (D CD o o o o ^0 " o u CD Cn CD CJ tk -J -O -4 IO CD O O O O O O O O O O O O O O O O O O ~j io 09 O O O O O O O O O O z z z O tn — c o z O o o l/l l/l o o o X X X CJ CJ to O O O O O CD CD kj O O O to ta co -I -t - . 01 01 CD IO 10 09 O O to O O O l / l IA (/I CD 00 C 01 01 c to m £ O O O 03 C9 Q 01 01 Q ID CD O 2 M to CD CD C UI ft c O O O OB CD Q (O CO Q 01 UI Q ID 10 Q tn ui o to tn ui -J ID -I O O O 10 03 Q CD -J CJ O * m — to ~4 ft (Jl UJ ft UI (0 O O O - . n o - i i o - , - ( - * • £ « < . a I > t> K> n o o a m > m H t» - t n o *. *H —i r> —^  ttxj t. u n > * z » > r- x — O r~ v i i f l * f -z > o • a % r-O ui « » Z r » C O Z W M H -« ft o * » l / l % l / l — — — . tttn o o o o o o o o o o * » CD u i ifl ifl I/i ui l / l ui u i i/i i/i * > * r -» > » Z O O O O O O O O O O * o * m 1 0 0 0 0 0 ° ID O CD o 8 O O O Q 1 0 to a i m U - > U O ' -k CD (J KJ to tO O ul -~i -j O M ft — C l O M U r o - ' ui tn LA KJ to to -~i in u O O O O O O O O O O ( O O O O O O ) CO O CD O 8 O O O Q 1 0 M cn UI to — tO Q to CD 10 cn ID to O a* Q -o -tO 8 A - 1 0 O O U KJ -<n <JI KJ KJ J> ~j ui KJ O O O O O O O O O O • O O O O O * 0 to o CD o O O O O Q t O K> ~4 U» u> KJ — CJ o cn tp KJ u to ID o cn - J ft ft o IS ft - L> O O K> -. ^ O 01 IX U U U ft M M O O O O O O O O O O § Q o o g • n o o o O O O O t f ) tO CD t> to — io Q m - i ftto KJ to co o cn rs CD o ft ft - U O U U> -4 — cn cn cn KJ KJ o o»to O O O O O O O O O O D Q Q O O V t S O O B O KJ O O O 0 — * ID CO ft U - U Q U 0) U» CJ O ID io O ff) ui -o cn o U) ft — CJ O W Q CO — O cn Ui KJ KJ ft cn t» KJ O O O O O O O O O O • Q Q Q Q * V O B O U l O O O Q f t ft ID UI KJ KJ - CJ Q co os ui u S w i o o o i u i -o t n o ft - U O -J Q CO — in j . tn u u - en ft KJ O O O O O O O O O O O O O O O O to O ID o CJ O O O Q KJ Ut QUI ft KJ — CJ Q cn to cn to to to to o cn ft tn m o O f t — < o o — u* ft — io cn UI KJ K) CJ (0 ~J KJ o o o o o o o o o o ( o o g o g i o o o w o m O O O g f t — ui O K> — to 0 ^ O CJ 101010001ft ft ft o UI ft — to o 01 ft to - * CD cn UI KJ M (O -J UI K> O O O O O O O O O O O O O O O O o o o o ftOoogu - J — ui ft KJ CJ o cn Q -J. CJ co <o to o cn CJ ft ft o CO ft — CJ O CD ft to — KJ cn tn KJ KJ cn -o uito o o o o o o o o o o O O O O O O o o o o ft O O O Q U ~J KJ UI KJ KJ -• CJ p CJ tn u u ft to to o (Ti to to o o — ft — to o KJ o CD — UI 01 ui u u O — to KJ * o > n o x z 3 u n • O u M * O KJ o o o o o o o o l/l l/l l/l l/l l/> l/l t/l o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o b b b b b b o o o o o o o b b b b b b b o o o o o o o b b b o b b b o o o o o o o o o o o o o o o o o o o o o b b o b b b b o o o o o o o b b b b b b b o o o o o o o b b o b b b b ro 241 242 243 244 245 2 4 5 247 248 249 2 5 0 251 252 253 254 255 256 257 258 259 2 6 0 26 1 262 263 264 265 266 267 268 269 2 7 0 27 1 E n o o f I ENERGY 0 U 1 K J / S ) 1 . 2 0 1 0 3 0 1 . 2 1 0 9 5 8 CV D G 4 S I K J / M 3 ) 4 3 5 . 3 8 4 3 8 . 3 6 CV ORY GAS WITH - O U T N 2 ( K J / M 3 ) 1 3 4 9 7 . 3 4 1 3 4 3 7 . 0 7 ORY G A S CONTENT WITHOUT TRANSPORT N2 000000000000000000000000000000000000 1 . 2 0 9 3 0 3 1 . 0 3 4 2 3 4 1 . 1 6 7 4 5 0 1 . 2 0 O 9 2 6 1 . 1 7 1 9 1 6 1 . 2 6 4 3 9 5 4 2 9 . 4 1 2 0 9 . 2 1 3 5 1 . 8 6 3 6 6 . 2 0 3 4 3 . 8 0 4 3 6 . 2 4 1 3 1 2 3 . 6 3 1 5 0 6 8 . 2 6 1 3 3 4 4 . 0 4 8 1 2 2 . 2 1 1 3 1 0 1 . 9 5 1 3 1 2 4 . 4 9 1 . 1 9 8 2 3 6 1 . 0 7 3 8 6 0 3 6 3 . 1 9 2 1 6 . 5 4 1 3 4 8 9 . 9 1 1 4 1 0 1 . 5 3 H2 ( X V ) 21 . 1 7 3 7 6 7 23 . 2 0 4 2 3 9 2 0 . 6 5 9 7 7 5 11 . 0 2 0 0 1 0 21 . 5 4 1 2 4 5 10 . 8 6 7 9 8 9 22 . 5 9 8 5 8 7 24 .459351 28 . 0 8 0 3 0 7 32 . 4 3 0 8 7 8 CO ( X V ) 5 5 . 9 2 6 0 4 1 5 3 . 6 7 3 2 1 8 57 . 5 7 6 4 7 6 56 4 6 B 5 5 2 52 . 2 6 0 3 0 0 34 . 3 3 3 9 8 4 51 . 7 6 1 9 0 7 51 . 8 6 7 0 9 6 48 . 6 9 4 8 2 4 38 . 0 9 6 5 2 7 CH4 ( X V ) 1 1 . 191398 11 . 0 9 6 3 4 0 9 . 6 4 0 8 9 9 I B . 4 3 8 7 0 5 11 . 8 3 2 5 1 7 7 119637 11 . 0 1 3 4 7 7 10 . 4 3 9 5 9 8 11 . 2 5 4 3 9 9 14 . 8 4 7 8 8 0 C02 ( X V ) 9 6 7 2 3 4 9 10 .054 141 9 . 9 6 3 1 5 5 9 4 3 5 4 3 2 11 . 9 8 4 2 1 1 46 . 3 1 0 9 5 9 12 . 2 7 1 0 7 0 11 . 4 0 2 3 3 2 9 . 6 9 4 3 9 1 10 . 6 1 4 9 3 1 N2 ( X V ) 2 . 0 3 6 4 3 1 1 9 7 2 0 3 8 1 9 5 7 6 7 3 4 . 6 3 7 3 1 3 2 . 3 8 1 7 0 7 1 3 6 7 3 9 2 2 . . 3 6 4 9 3 4 1 .831595 2 . 2 7 6 0 5 7 4 . 0 0 9 7 7 4 02 ( X V ) 0 . O 0 . 0 0 . 0 0 . 0 0 0 0 . 0 0 . 0 0 . 0 0 . . 0 0 . 0 S T E A M H V K K J / G ) 0 . 0 0 0 0 . 0 0 . 0 0 0 0 0 0 . 0 0 . 0 0 . 0 0 . 0 S T E A M H V 0 1 K J / G ) 3 7 2 7 1 4 3 3 . 7 2 7 1 4 3 3 7 2 7 1 4 3 3 . 7 2 7 1 4 3 3 . 7 2 7 1 4 3 3 . 7 2 7 1 4 3 3 7 2 7 1 4 3 3 7 2 7 1 4 3 3 . 7 2 7 1 4 3 3 . 7 2 7 1 4 3 S V . P O P ( M 3 / G ) 0 0 0 0 0 . 0 0 . 0 0 . 0 0 . 0 0 . 0 0 . 0 0 . 0 0 . 0 0 1 S . C O E f r . 0 . 6 2 8 0 0 0 0 . 6 2 8 0 0 0 0 6 2 8 0 0 0 0 6 2 8 0 0 0 0 . 6 2 8 0 0 0 0 . 6 2 6 0 0 0 0 . 6 2 8 0 0 0 0 . 6 2 8 0 0 0 0 . 6 2 8 0 O O 0 6 2 8 0 0 0 HT IN R E A C . ( K J / 0 . 3 5 1 5 6 4 0 3 5 1 5 6 4 0 3 5 1 5 6 4 0 . 3 5 1 5 6 4 0 3 5 1 5 6 4 0 3 5 1 5 6 4 0 . 3 5 1 5 6 4 0 . 351564 0 3 5 1 5 6 4 0 3 5 1 5 6 4 HT OUT I N S U . M2 0 0 0 4 6 5 2 0 0 0 4 6 5 2 0 0 0 4 6 5 2 0 0 0 4 6 5 2 0 . . 0 0 4 6 5 2 0 0 0 4 6 5 2 0 . 0 O 4 6 5 2 0 . 0 0 4 6 5 2 0 . 0 0 4 6 5 2 0 0 0 4 6 5 2 HT 0 F L A N G E S K ) 0 . 0 0 5 9 4 2 0 0 0 5 9 4 2 0 0 0 5 9 4 2 0 0 0 5 9 4 2 0 0 0 5 9 4 2 0 0 0 5 9 4 2 0 . 0 0 5 9 4 2 0 0 0 5 9 4 2 0 . 0 0 5 9 4 2 0 . 0 0 5 9 4 2 HT OF GAS 0 . 0 0 4 3 2 8 0 0 0 4 3 2 8 0 0 0 4 3 2 8 0 . 0 0 4 3 2 8 0 0 0 4 3 2 8 0 0 0 4 3 2 8 0 . 0 0 4 3 2 8 0 0 0 4 3 2 8 0 0 0 4 3 2 6 0 0 0 4 3 2 8 HT HT R A D I A T I O N 0 . 0 1 0 1 5 0 0 0 1 0 1 5 0 0 0 1 0 1 5 0 0 0 1 0 1 5 0 0 0 1 0 1 5 0 0 0 1 0 1 5 0 0 . 0 1 0 1 5 0 0 0 1 0 1 5 0 0 . 0 1 0 1 5 0 0 0 1 0 1 5 0 

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