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Sampling of the phases within a liquid-liquid extraction spray column Bergeron, Georges 1963

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SAMPLING OF THE PHASES WITHIN A LIQUIDLIQUID EXTRACTION SPRAY COLUMN  by  GEORGES BERGERON B. Sco A , U n i v e r s i t y o f Montreal, 1961. 0  A.THESIS SUBMITTED IN PARTIAL FULFILMENT THE  REQUIREMENTS FOR THE DEGREE OF MASTER OF APPLIED SCIENCE  i n the Department of CHEMICAL ENGINEERING  We accept t h i s t h e s i s as conforming to the r e q u i r e d standard  THE  UNIVERSITY OF BRITISH COLUMBIA November, 1963  In the  presenting  r e q u i r e m e n t s f o r an advanced  British  Columbia, I agree  available mission  for reference  for extensive  representatives.  cation without  Department  of  fulfilment of  s h a l l , make i t f r e e l y  I further  copying of t h i s thesis  agree  that  for f i n a n c i a l gain  permission.  CHEMICAL ENGINEERING Columbia,  NOVEMBER, 1963.  that  per-  for.scholarly  by t h e Head o f my Department  The U n i v e r s i t y o f B r i t i s h V a n c o u v e r 8 , Canada. Date  the L i b r a r y  I t i s understood  of this thesis my w r i t t e n  that  i n partial  degree a t the U n i v e r s i t y o f  and s t u d y .  p u r p o s e s may be g r a n t e d his  this thesis  o r by  copying, o r p u b l i -  shall  n o t be a l l o w e d  ii  ABSTRACT A study has been made of sampling techniques  in a liquid-  l i q u i d e x t r a c t i o n spray column u s i n g f i r s t a b e l l - s h a p e d and a hookshaped probe f o r the d i s p e r s e d phase and  f o r the continuous  respectivelyo  attempted f o r the d i s p e r s e d  phaseo  L a t e r a p i s t o n method was  The main i n t e r e s t i n t h i s r e s e a r c h was  the p o i n t  phase  concentration  i n s i d e the column. At f i r s t , in was  the time to reach steady s t a t e was  the absence of sampling*  L a t e r on, the r a t e of purging and  v a r i e d f o r the probes up to 14„2  and 28.2  0  to d i s t u r b the steady s t a t e .  c o n c e n t r a t i o n was  sampling  cc./min. f o r the continuous  c c / m i n . f o r the d i s p e r s e d phase<>  sufficient  considered  The  These r a t e s were not measured p o i n t  s t u d i e d as a f u n c t i o n of r a t e of sampling.  Coalescence at the d i s p e r s e d phase (bell-shaped) probe entrance not take  phase  did  place. Finally,  a p i s t o n sampler was  with the continuous  s e t up and used i n c o n j u n c t i o n  phase (hook-shaped) probe as a second way  point concentrations  to o b t a i n  of the d i s p e r s e d phase to compare with the  obtained with the b e l l - s h a p e d  results  probe.  From these experiments, i t can be concluded  t h a t sampling  rate, v a r i e d from zero to 34 0 cc./min. f o r the continuous 0  phase  and  from zero to 28 0 cc./min. f o r the d i s p e r s e d phase, does not i n f l u e n c e o  • •' the p o i n t c o n c e n t r a t i o n s measured f o r columhi..-. flows 3 and 72.4  ft /hr.-ft  of 54.8  3 ft /hr.-ft  2 f o r the water and ketone phases r e s p e c t i v e l y .  The  p o i n t c o n c e n t r a t i o n of the d i s p e r s e d phase measured with the p i s t o n do not check d e f i n i t i v e l y they do  the r e s u l t s obtained with the b e l l - s h a p e d  i n d i c a t e that such agreement i s f a i r l y  probable.  probe;  ACKNOWLEDGEMENTS  The author would l i k e to express s i n c e r e thanks to S. D. Cavers f o r the a s s i s t a n c e and c o n s t r u c t i v e c r i t i c i s m s o f f e r e d throughout  the course of t h i s p r o j e c t .  Thanks go a l s o to Canadian Chemical Co. of Edmonton, for supplying  1480 pounds o f methyl  The p r o d u c t i o n  i s o b u t y l ketone.  of a c o v e r i n g  f o r the p i s t o n , to permit  i t to operate without l e a k s , was s o l e l y the work o f R. Muelchen.  TABLE OF CONTENTS page INTRODUCTION  1  EXPERIMENTAL METHODS  11  P r e l i m i n a r y work  11  Procedure:  1.- probe method  19  2.- p i s t o n method  26  RESULTS  28  DISCUSSION  76  A) Study o f time needed to o b t a i n steady s t a t e  76  B) E f f e c t o f purging r a t e on the minimum purge time  77  C) I n f l u e n c e o f sampling r a t e on steady s t a t e  78  D) Drop coalescence a t the d i s p e r s e d phase probe entrance.. 82 E) E f f e c t o f sampling r a t e on measured p o i n t c o n c e n t r a t i o n . 84 F) D u p l i c a t i o n o f runs  88  G) C o n c e n t r a t i o n study i n the E l g i n head  88  H) P i s t o n r e s u l t s  90  SUMMARY  99  RECOMM EN DAT IONS  101  NOMENCLATURE  103  LIST OF REFERENCES  105  APPENDICES  107  I. Rotameter c a l i b r a t i o n s I I . Runs data  «  108 ..112  I I I . Study o f time needed to o b t a i n steady s t a t e . Runs data .118 IV. Study o f minimum purge time. Runs data  125  V. P o i n t c o n c e n t r a t i o n versus sampling r a t e . Runs data ....135  iv TABLE VI. VII.  Jet  characteristic  Sample c a l c u l a t i o n probe  VIII.  OF CONTENTS  data for  138 some k e t o n e  sample  Possible sources  cont.  in  the  water 140  of  errors  141  V LIST OF TABLES Table  Page  1  Key to F i g u r e 1  13  2  L o c a t i o n o f S t a i n l e s s S t e e l sampling probes  23  3  C o n c e n t r a t i o n study i n the E l g i n head  57  4  Piston results  6  Probe r e s u l t s corresponding to p i s t o n r e s u l t s o f  .. •  73  Table 4 5A  74  P i s t o n and probe r e s u l t s and t h e i r  corresponding  e q u i l i b r i u m values 6  75  C o n c e n t r a t i o n i n both phases f o r Run 8 and Choudhury's Run 65  89  7  Calibration  8  C a l i b r a t i o n of rotameter  110  9  Runs data  113  10  O v e r - a l l t r a n s f e r data  115  10A  Raw data o f c o n c e n t r a t i o n p r o f i l e s f o r Runs 5D and 8 . 117  11  Study of the time needed to o b t a i n steady s t a t e i n Runs 6 I  12  13  l f  o f rotaaieter  108  GJ, 6M, 9A, 9C, and 91  119  Study o f the time needed to o b t a i n steady s t a t e i n Runs 6K, 6L, 9B, and 9H  122  Summary o f the steady s t a t e s t u d i e s  124  14 to 23 Study o f the minimum purge time f o r s e v e r a l runs  126  24  Summary o f the minimum purge time  134  25  P o i n t c o n c e n t r a t i o n versus sampling 7F, 5F, 5G, 5H, 5B  and ID  rate.  Runs 9H, 7E, 136  vi LIST OF FIGURES Figure  Page  1  Schematicjflow diagram  12  2  S t a i n l e s s S t e e l tanks  15  3  P i s t o n with p o l y e t h y l e n e c o a t i n g  18  4  Lever to push the p i s t o n  5  T i p patterns  6  Steady s t a t e study, Run 61^  29  6A  Steady s t a t e study, Run 9A  31  7  Steady s t a t e study, Run 6 L  32  8  Summarizing p l o t o f the steady s t a t e r e s u l t s  33  9  Study o f the minimum purge time, Run 2  3G  10  Minimum purge time versus purging r a t e  37  11  Influence  of sampling r a t e on p o i n t concentration,Run 9H 39  12  Influence  of sampling r a t e on p o i n t concentration,Run  9H 40  13  Influence  of sampling r a t e on p o i n t concentration,Run  5G 42  14  Influence  of sampling r a t e on p o i n t concentration,Run  5H 43  15  Influence  of sampling r a t e on p o i n t concentration,Run  45  16  Influence  of sampling ra te on p o i n t concentration,Run 5F 46  17  Influence  of sampling r a t e on p o i n t concentration,Run 7E 48  17A  Influence  of sampling r a t e on p o i n t concentration,Run 7F 49  18  Influence  of sampling r a t e on p o i n t concentration,Run ID 50  19  Influence  of sampling r a t e on p o i n t  20  Influence  of sampling r a t e on steady s t a t e , Run 7F „. • •  53  21  Influence  of  sampling r a t e on steady s t a t e , Run 7E .. » 0  54  22  D u p l i c a t i o n <of Choudhury*s Run 65,  56  23  D u p l i c a t i o n <of Choudhury's Run 65,  58  . ...  20  f o r ketone n o z z l e . . . .  22  concentration,Run  ID. 51  vii LIST OF FIGURES  cont.  Figure  Page  24  C o n c e n t r a t i o n study i n the E l g i n head,.^.-.,.  59  25  E f f e c t o f p i s t o n sampling on steady s t a t e , Run 9C  62  26  E f f e c t o f p i s t o n sampling on steady s t a t e , Run 9D  63  27  E f f e c t of p i s t o n sampling on steady s t a t e , Run 9F  65  28  C a l i b r a t i o n of ketone rotameter  69  29  Behaviour of the drops at ketone probe entrance  83  29A  Two  93  30  Rotameter c a l i b r a t i o n s  109  31  Rotameter c a l i b r a t i o n s  Ill  p i s t o n samples having d i f f e r e n t holdup  1  INTRODUCTION  The  l a s t decade has seen the u n i t o p e r a t i o n c a l l e d  l i q u i d e x t r a c t i o n having a r a p i d growth. were due  These new  liquid-  developments  f i r s t l y to the i n d u s t r i a l users asking f o r more i n f o r m a t i o n  which showed the ne*ed f o r r e s e a r c h .  Secondly,  the i n t e r e s t  of  r e s e a r c h e r s i n mass t r a n s f e r operations caused the spray column type of l i q u i d - l i q u i d e x t r a c t o r to be analyzed by many workers  (1,2,  3,4,5,6,7,8,9,10,11,12,13). Mass t r a n s f e r c o e f f i c i e n t s were determined i n general u s i n g the i n l e t and o u t l e t c o n c e n t r a t i o n s and l o g a r i t h m i c mean d r i v i n g f o r c e . doing such c a l c u l a t i o n s .  One  i n v o l v e d were not back-mixing.  calculating  by  the  S e v e r a l assumptions were made i n  of these was  that the two  Another, was  liquids  that no mass t r a n s f e r  took p l a c e d u r i n g drop formation or during drop coalescence end of the column, or i n other words, that end e f f e c t s were  at the absent.  I t can be pointed out that d i l u t e s o l u t i o n s were assumed a l s o (or constant  flows)and  constant  slope of the e q u i l i b r i u m c u r v e d  These  were the p r i n c i p a l assumptions made before the work of many i n v e s t i g a t o r s mentioned l a t e r , i n t h i s In 1950, sampling  Geankoplis  survey.  and Hixon (1) employed a movable  device to remove i n t e r n a l samples of the continuous  d u r i n g o p e r a t i o n of a spray tower. of a 5 mm.  o u t s i d e diameter (0.12  of the column c r o s s s e c t i o n a l  end of the sampler, the descending  phase  T h i s sampler c o n s i s t e d p r i m a r i l y i n . i n s i d e diameter) g l a s s  which extended i n t o the e x t r a c t i o n s e c t i o n and occupied 1.7%  \.  area.  tube,  approximately  By means of a hook at the  continuous  phase was  withdrawn;  the sampler  tube touched the w a l l o f the column.  These workers  determined the continuous phase c o n c e n t r a t i o n p r o f i l e throughout the column and l o c a t e d a l a r g e end e f f e c t a t the i n l e t o f the continuous phase.  No end e f f e c t was found a t the d i s p e r s e d phase  inlet.  L a t e r on, Geankoplis, Wells and Hawk ( 2 ) , u s i n g the same method, found the same l a r g e end e f f e c t s a t the continuous phase i n l e t , and a l s o that these depended n e i t h e r on the type o f system employed, nor the d i r e c t i o n o f s o l u t e t r a n s f e r .  They a l s o  proved  that the e f f e c t o f i n t e r n a l sampling i s s m a l l on the m a t e r i a l b a l a n c e s . A l s o , the e f f e c t o f i n t e r n a l sampling was small s i n c e the d e v i a t i o n i n the o v e r - a l l m a t e r i a l balance, c a l c u l a t e d as f o l l o w s : N  w  =  A L (C w  t  =  N  =  N +N w t_ 2  =  N  N  % Deviation  A  L  t  (  c  t  2  - C ) w^ - \ >  -N  w N  * 100  averaged 4 % o r l e s s f o r a l l runs i n the towero In 1952,  Newman (3) entered the d i s c u s s i o n and maintained  that the end e f f e c t s found by Geankoplis and Hixson  (1) and by  Geankoplis, Wells and Hawk ( 2 ) , were the r e s u l t s o f v e r t i c a l o f the continuous phase due to the movement o f the drops. that the r e s u l t s o f Geankoplis and coworkers  mixing  He showed  (1,2) were midway between  the r e s u l t s t o be expected f o r t r u l y c o u n t e r c u r r e n t , unmixed flow o f the continuous phase, and the completely uniform c o n c e n t r a t i o n i n that phase which would b^e produced by very e f f i c i e n t  stirring.  One year l a t e r , Geankoplis with Kreager  (4) s t u d i e d the  e f f e c t o f the column h e i g h t on the mass t r a n s f e r c o e f f i c i e n t . c o n c l u s i o n s were the same as t o end effectsfat< the" .  .C  Their  continuous phase i n l e t which Geankoplis and Kreager (4) suggest to be due to the c o c u r r e n t flow o f continuous phase i n the form o f "atmospheres"  of continuous phase surrounding and t r a v e l l i n g with  the drops of d i s p e r s e d phase. In the same year, G i e r and Hougen (5) used two techniqueso  sampling  In the column i t s e l f , nine h o l e s were d r i l l e d 6 inches  apart along the length of a 6 i n . I.D. column to p r o v i d e an entrance f o r 3 i n . hypodermic needles which sampled the continuous phase. Each needle had a t h i n - w a l l e d b r a s s tube bent i n t o a hook shape so that the open end of the hook faced i n the d i r e c t i o n o f drop: movement. These sampling needles f i t t e d 29 mL hypodermic s p r i n g e s .  Later,  p r o v i s i o n was made f o r sampling the d i s p e r s e d phase by d r i l l i n g  eight  h o l e s along the length o f the column, opposite to and midway between the needle h o l e s a l r e a d y mentioned,,  The d i s p e r s e d phase  samplers  each c o n s i s t e d o f an i n v e r t e d 1 i n . g l a s s funnel connected by Tygon tubing to a s u i t a b l y formed  length of V* i n . copper t u b i n g .  They found  the c o n c e n t r a t i o n p r o f i l e s f o r the continuous phase s i m i l a r to those ' measured by Geankoplis and co-workers m a t e r i a l balance equation was  not a p p l i c a b l e when w r i t t e n as f o l l o w s : dN =  although, i t was  (1,2,4) and showed t h a t the  1  c  dC , c  true that: dN = L. dC^ d  d  .  (dN being the mass t r a n s f e r a c r o s s the i n t e r f a c e between phases i n a height dh of column)o  T h i s statement  i s c o r r e c t even i f the same  equations, i n t e g r a t e d , both h o l d f o r t e r m i n a l c o n d i t i o n s . for  the f i r s t equation f a i l i n g  phase.  reason  i s a s e r i o u s b u l k mixing of the continuous  The second equation holds because  They a l s o concluded that because of a t r a n s f e r u n i t  The  the drops do not back-mix  of the mixing, the measured h e i g h t  ( as d e f i n e d l a t e r by Miyauchi (6)$ must be  0  determined g r a p h i c a l l y from i n t e r n a l c o n d i t i o n s . Furthermore, i t i s pointed out by Smoot and Babb (7) that i f l o n g i t u d i n a l mixing i s e x t e n s i v e , even a g r a p h i c a l i n t e g r a t i o n of the r e s u l t i n g p r o f i l e to o b t a i n the measured Nox " t r u e " Noxo  may  T h i s i s e q u i v a l e n t to s t a t i n g that i n the Nox  this  the  equation:  = (Nox),. + C o r r e c t i o n term  even a g r a p h i c a l i n t e g r a t i o n u s i n g the experimental p r o f i l e and  not y i e l d  concentration  equation: (Nox).. = M  dx — — — — . X - X e w i l l not y i e l d the " t r u e " 'value of Nox as defined by t h i s Nox  = K  equation:  ah  x V  x unless the t h i r d term of the f i r s t negligible..  But  equation mentioned here, i s  t h i s t h i r d term i s a term which c o r r e c t s f o r back-  mixing i n the x phase. Then, i f the x phase i s the d i s p e r s e d phase, Nox and (Nox),. are i d e n t i c a l , s i n c e the c o r r e c t i o n term goes to zero M because of no mixing i n that phase.. In 1954,  H e e r t j e s , Holve and  Talsma (ti)  measured the  c o n c e n t r a t i o n of the continuous  phase of a spray column by d r a i n i n g  the column i n stages at the end  of runs and  The  c o n c e n t r a t i o n of the continuous  over the column's h e i g h t .  and  continuous  phase was  the r e s u l t s may  effluents.  phase appeared to be n e a r l y  These r e s u l t s appeared to show the  of good v e r t i c a l a x i a l mixing but Geankoplis  sampling the  they do not agree with those  constant  existence of  co-workers (1,2,4) where the c o n c e n t r a t i o n of the not constant  be due  with d i s t a n c e .  This difference i n  to mixing, t a k i n g place before d r a i n i n g and  caused by the c u r r e n t s produced by the f i n a l r i s i n g of drops a f t e r  5 flow i s shut o f f ;  perhaps  the d i f f e r e n c e may be a l s o due i n part  to mixing caused by d r a i n i n g , and a l s o to c o n v e c t i o n due to d e n s i t y differences. The  f o r e g o i n g summarizes the i n f o r m a t i o n a v a i l a b l e on  sampling techniques b e f o r e the s t a r t of the r e s e a r c h i n Canada by Cavers and Ewanchyna ( 9 ) .  These workers s t u d i e d c i r c u l a t i o n i n the  continuous phase o f a spray column and end e f f e c t s .  T h e i r techniques  c o n s i s t e d o f u s i n g movable v e r t i c a l probes based on those of Geankoplis and co-workers  (1,2(4) and those o f G i e r and Hougen ( 5 ) .  The f i r s t  set o f i n t e r n a l sampling tubes was c o n s t r u c t e d o f Pyrex t u b i n g , l / 8 - i n . OoD  0  and 0.08-in. I.D..  The continuous phase sampling  tube  had one end curved i n the form o f a hook with a 3/16-in,, I.D„ r a d i u s . The probe entrance faced upward, away from the r i s i n g drops.  The  d i s p e r s e d phase sampling tube had one end f l a r e d out to 34-in. O.D. i n order to c a t c h the ketone  The maximum percent of the i n t e r n a l  dropso  c r o s s - s e c t i o n n a l area of the column occupied by the two probes together was approximately 4.2%  6  taken  (The area o f two 1/8-in. diameter  c i r c l e s and one Ki-in. diameter c i r c l e i s 4.2% o f that o f a 1.5-in. diameter c i r c l e ) .  These Pyrex sampling tubes d i d not prove to be  very s a t i s f a c t o r y because functioning  o f breakage  problems;  i n other r e s p e c t s was good.  tubing.  »  A second s e t o f sampling  tubes was made out of 1/8-in. O.D. and 0.020-in. Type 304 s t a i n l e s s s t e e l seamless  however, t h e i r  wall thickness  The continuous phase  sampling tube had one end curved i n the form of a hook with a 3/32-in. I.D. r a d i u s .  The opening faced the top o f the column as b e f o r e .  The d i s p e r s e d phase sampling tube was f i t t e d i n t o a f l a r e d out s e c t i o n of 2 l / 6 4 - i n  0  maximum 0.D . o  In t h i s case, the maximum percent of the  i n t e r n a l column's c r o s s - s e c t i o n n a l area occupied by the two probes  6 taken together was 6 2 % 0  from the top.  0  These probes were lowered i n t o the column  T h i s approach t h e r e f o r e was s i m i l a r to that used f o r  the continuous phase o n l y b y Geankoplis and co-workers ?  slightly different  from that o f G i e r and Hougen ( 5 ) .  (1,2,4), but Cavers and  Ewanchyna (9) confirmed that the presence of sampling tubes i n the column d i d not change the column o p e r a t i o n .  They a l s o  demonstrated  t h a t the d i r e c t i o n of sampling ( i . e . from top to bottom o r bottom to top o f the column) d i d not i n f l u e n c e the measured p o i n t  concentrations.  I t was a l s o proved that the l o c a t i o n o f the tubes i n the h o r i z o n t a l c r o s s s e c t i o n had no e f f e c t on the c o n c e n t r a t i o n s o f samples  withdrawn.  These workers found no end e f f e c t s .where the d i s p e r s e d phase entered the column, but d i d f i n d end e f f e c t s a t the continuous phase i n l e t to the column, i . e . d i s c o n t i n u i t i e s i n the c o n c e n t r a t i o n profiles.  F o r the case of t r a n s f e r o f a c e t i c a c i d from a continuous  aqueous phase to a d i s p e r s e d , methyl i s o b u t y l ketone (M.I.B.K.) phase, they explained that the d i s c o n t i n u i t y i n the water phase p r o f i l e be broken i n t o two p a r t s :  could  one r e p r e s e n t i n g the e f f e c t of drop a g i t a t i o n  at the i n t e r f a c e , and the other the e f f e c t o f back-mixing i n the aqueous phaseo  The d i s c o n t i n u i t y i n the ketone phase c o n c e n t r a t i o n p r o f i l e  was a t t r i b u t e d to the a g i t a t i o n e f f e c t .  For t r a n s f e r o f a c e t i c  i n the reverse d i r e c t i o n , the d i s c o n t i n u i t y i n the ketone phase  acid profile  was absent, and that i n the water phase was a t t r i b u t e d s o l e l y to backmixing i n the continuous phase. Some years l a t e r , the work of Cavers and Ewanchyna (9) was continued by Choudhury (10) who used an apparatus s i m i l a r to that o f Ewanchyna(11)o  He d i d work a l s o on the sampling technique.  He  i n v e s t i g a t e d the minimum purging time r e q u i r e d to remove m a t e r i a l o f the wrong c o n c e n t r a t i o n from the probes.  Furthermore, he made these  measurements a t v a r i o u s r a t e s o f flow through the probes.  However,  he d i d not get an adequate p l o t f o r the minimum purge time, but i n s t e a d o n l y a few s c a t t e r e d pointso  Choudhury mentioned a l s o that the drops  sometimes c o a l e s c e d a t the ketone sampler's entrance. to check the e f f e c t o f such coalescence  He had planned  on the r e s u l t s f o r the d i s p e r s e d  phase sampler by v a r y i n g the sampling r a t e f o r the d i s p e r s e d phase. A l s o , a m a t e r i a l balance r e s u l t s o f analyses  has to be made i n i n t e r p r e t i n g the  o f d i s p e r s e d phase samples.  The problem a r i s e s  as to whether o r not the hook probe g i v e s a r e p r e s e n t a t i v e sample o f the continuous  phase c o n c e n t r a t i o n  f o r use i n t h i s  balance.  (Presumably the b e l l probe, i n removing drops, p r e f e r e n t i a l l y removes continuous  phase from near the drops).  Varying the sampling r a t e o f  both phases might change the r e s u l t s by changing the average phase c o n c e n t r a t i o n taken i n by one or both o f the probes.  continuous Choudhury  v a r i e d the sampling r a t e of $fc>th phases to measure i t s i n f l u e n c e on the c o n c e n t r a t i o n s measured at a p o i n t .  These experiments were made  at a c r o s s - s e c t i o n where the phases were not a t e q u i l i b r i u m even i f Hawrelak (12) thought so. T h i s statement i s made because the p o i n t concentrations equilibrium  r e p o r t e d a t 6.16 f t from the nozzle were 8.2% from  as compared with  19.7%, the maximum d e v i a t i o n between  the e q u i l i b r i u m c o n c e n t r a t i o n p r o f i l e concentration p r o f i l e  obtained.  ( p l o t o f C^*) (10) and the i Choudhury's r e s u l t s were n i g h t , and  they d i d throw l i g h t on the problem o f C  being r e p r e s e n t a t i v e f o r i However, the range o f r a t e s covered by W  the c o n d i t i o n s under study. Choudhury (10) was too s m a l l .  Choudhury (10) found c o n c e n t r a t i o n p r o f i l e s which had the same p a t t e r n as those measured by the e a r l i e r workers (1,2,4,9,11) *  T h i s percentage i s c a l c u l a t e d as ( C, . - C. . ) x 100 f ki ki a  8 He f i x e d f o r h i m s e l f the maximum p e r m i s s i b l e purging o r sampling r a t e to be 15 cc./min., without checking the e f f e c t on steady s t a t e . Hawrelak  (12) designed and c o n s t r u c t e d a p i s t o n - t y p e sampler  used i n c o n j u n c t i o n with hypodermic needles, or with the continuous phase but  (hook-shaped) probe, to sample the continuous phase, as a second,  not completely independent, way t o o b t a i n p o i n t c o n c e n t r a t i o n o f the  d i s p e r s e d phase to compare, with:the r e s u l t s obtained with the  b e l l - s h a p e d probe.  "  v •  The hypodermic s y r i n g e s were used to take  samples of the continuous phase immediately above and below the p i s t o n block;  the needles entered the column through theasbestos gaskets  s e a l i n g the g l a s s column to the p i s t o n b l o c k .  I t was d i s c o v e r e d  later  that an a p p r e c i a b l e volume o f ketone phase was e n t r a i n e d i n the continuous phase samples taken by the s y r i n g e s ;  the s y r i n g e samples  were d i s c o n t i n u e d because o f the near i m p o s s i b i l i t y of c o r r e c t i n g f o r t r a n s f e r between  two phases i n the continuous phase sample.  I t was  decided that the water phase probe sampler, which showed no ketone entrainment, could be used i n p l a c e o f the s y r i n g e samples, i f i t was assumed that the probe sample gave a r e p r e s e n t a t i v e sample o f the water phase.  T h i s probe was to be used to sample a t the a x i s o f the p i s t o n . A minimum leakage r a t e around the p i s t o n of one to two m i s /  min. was encountered a f t e r a few seconds; only when the p i s t o n was shoved to the l e f t  but t h i s leakage o c c u r r e d i n the b l o c k .  Sampling  was accomplished by shoving the p i s t o n from i t s r i g h t to i t s l e f t p o s i t i o n i n the b l o c k .  hand  The l'/fc-in. I.I), hole i n the p i s t o n that was to  s l i d e i n t o l i n e with the column was f i l l e d with e i t h e r water phase which had leaked from the p i s t o n , or with o u t l e t water phase from the column i f there was no such leakage.  In t h i s way when a p i s t o n  sample  was taken the column continued to operate with no a p p r e c i a b l e d i s t u r b a n c e .  9 I t was i n t e r e s t i n g to observe that when a p i s t o n sample was taken ( p o r t i o n o f column contents removed) a gap i n the ketone phase occured, which appeared to move up the column f o r one to two feeto The same d i f f i c u l t y  ( as s p e c i f i e d e a r l i e r ) arose about the  m a t e r i a l balance on which the i n t e r p r e t a t i o n o f the d i s p e r s e d phase samples depends.  To be more s p e c i f i c , does the hook probe g i v e s a  r e p r e s e n t a t i v e sample o f the continuous phase, the c o n c e n t r a t i o n o f which has to be used i n t h i s balance?  In a d d i t i o n , a n a l y t i c a l  d i f f i c u l t i e s were encountered due to the small d i s p e r s e d phase holdup o b t a i n e d . (Holdup = This d i f f i c u l t y as  volume percent d i s p e r s e d phase i n the column.)  arose i n u s i n g the m a t e r i a l balance equation w r i t t e n  f o l l o w s f o r the p i s t o n sampler: C ki  =  C kf  - V ( C - C ) w wi wf V  k  I t i s evident that the volume o f the ketone phase i n a sample should be l a r g e so that the e q u i l i b r i u m c o n c e n t r a t i o n o f s o l u t e i n the water phase i s c o n s i d e r a b l y d i f f e r e n t  from the i n i t i a l  value.  Only then does  one a v o i d the e r r o r r e s u l t i n g from having to s u b s t r a c t q u a n t i t i e s which are of about the same magnitude i n a p p l y i n g the equation. assumes one analyzes the p i s t o n sample a t e q u i l i b r i u m .  ( T h i s approach Other  p o s s i b i l i t i e s a r e d i s c u s s e d later.) The maximum holdup used by Hawrelak (12) was 12.7%,  3 3 corresponding to a value o f (C . - C . ) * o f o n l y 1.2 l b . - m o l e s / f t x l O ° wi wf 3 3 where C _ was approximately / 40.0 l b . - m o l e s / f t . x l O . I t i s d i f f i c u l t wf to compare Hawrelak's r e s u l t s with the p i s t o n , with those obtained with the of  b e l l - s h a p e d probe, because o f these a n a l y t i c a l d i f f i c u l t i e s , because 'th© leakage mentioned e a r l i e r , and a l s o because o f an e r r o r hie made  10 i n p o s i t i o n i n g the continuous  phase probe„  T h i s was  than the a x i s of the p i s t o n i n s e v e r a l runs.  one  inch higher  However, the p i s t o n  method appeared to give the c a l c u l a t e d i n i t i a l ketone c o n c e n t r a t i o n always lower than the c o n c e n t r a t i o n measured with the b e l l - s h a p e d The  probe.  present work i s a c o n t i n u a t i o n of that of Ewanchyna (11),  that of Choudhury (10), and  that of Hawrelak (12).  A l l three were  concerned, at l e a s t i n p a r t , with sampling of the phases. planned to a t t a c k the problem by with both sampling probes and c o n c e n t r a t i o n r e s u l t s , and  first  was  v a r y i n g the sampling r a t e used  n o t i n g any  secondly  It  change i n the d i s p e r s e d phase  by operating,  the p i s t o n sampler  under c o n d i t i o n s of very high holdup of d i s p e r s e d phase i n the column, when the a n a l y t i c a l problems a s s o c i a t e d with be comparatively  small  0  The  the p i s t o n sampler should  p o s s i b i l i t y of the hook-shaped probe not  p r o v i d i n g r e p r e s e n t a t i v e samples must be considered with respect to both sampling methods, and  i f these samples were not r e p r e s e n t a t i v e , v a r y i n g  the sampling r a t e s used with each of the probes might produce changes in  the r e s u l t s .  However, i f  i s considered  unrepresentative,  it  could only be  too h i g h , then C^/ comes out too  and  low:  C. , = C, . - V ( C . - C . ) ki kf w wi wf V  Hence, (C. .) . , i s too low: ki piston  k  then i t w i l l not check with the probe  sampling r e s u l t s which were obtained at high holdup where the c o r r e c t i o n term, V /V, (C . - C „ ) , i s l e s s important. w k wi wf samples were obtained with It  low  i  holdup).  i s i n t e r e s t i n g to*note  the water p r o f i l e s  ( R e c a l l that the p i s t o n  that i f  c a l c u l a t e d u s i n g p i s t o n flow  values were h i g h e r , a l l (10), would be  i n d i c a t i n g more backmixing than that assumed present  heretofore.  higher,  11 EXPERIMENTAL METHODS  A) P r e l i m i n a r y work. The  apparatus arrangement ( F i g . 1) was s i m i l a r to the one  used by previous workers (10, 11, 12, 13) except f o r a few m o d i f i c a t i o n s to be mentioned  later,  A general r e o r g a n i s a t i o n o f the apparatus and a c l e a n i n g were needed because the equipment had been p a r t i a l l y disasembled to f a c i l i t a t e the move o f the Department of Chemical Engineering a new b u i l d i n g . The  into  A rotameter had to be r e c o n d i t i o n n e d .  aluminum tanks used by Choudhury (10) and Rocchini (13)  were corroded.  Before  r e p l a c i n g them a survey was made o f p o s s i b l e  m a t e r i a l s to c o n t a i n M.I.B.K. and aqueous s o l u t i o n s o f a c e t i c a c i d . I t was found that Pyrex and s t a i n l e s s s t e e l were the only s u i t a b l e m a t e r i a l s which were a l s o r e a d i l y a v a i l a b l e at a reasonable  price  Taking  steel  i n t o account the s a f e t y requirements,  four s t a i n l e s s  tanks were chosen and made as s p e c i f i e d on F i g u r e 2.  0  To prevent any  leakage o f M.I.B.K. ( f l a s h p o i n t 75°F (15)) from the feed and storage tanks, s t a i n l e s s s t e e l tubing and f i t t i n g s were used to connect both tanks to the pumps.  Polyethylene  tubing (with some s t a i n l e s s  steel  f i t t i n g s and some Sa ran f i t t i n g s ) was used f o r the water phase. C o r r o s i o n i n f o r m a t i o n was obtained of m a t e r i a l s f o r tanks and t u b i n g . polyethylene  from i n d u s t r i a l s u p p l i e r s  The s u p p l i e r s reported  that  was not recommended to be used with M.I.B.K. except  where the M.I.B.K,, phase was flowing i n t e r m i t t e n t l y .  A stagnant  M.I.B.K. phase can destroy the p r o p e r t i e s o f p o l y e t h y l e n e by t a k i n g out the p l a s t i c i z e r .  12  13 TABLE lo KEY  TO FIGURE 1  A - Continuous phase feed tank B - Continuous phase r e c e i v e r and storage  tank.  C - Dispersed phase r e c e i v e r and storage tank D - Dispersed phase feed tank E - Continuous phase constant head tank F - Dispersed phase constant head tank G - Continuous phase H - Dispersed phase  rotameter rotameter  I - Continuous phase i n l e t ,  sample valve  - Continuous phase flow r a t e c o n t r o l v a l v e s  K , K  - Dispersed phase flow r a t e c o n t r o l valves  L - Dispersed phase i n l e t sample v a l v e M - 6 - i n . I.D.  Pyrex top end s e c t i o n  N - Continuous phase i n l e t s t a i n l e s s s t e e l  pipes  0 - Drain valve f o r top end s e c t i o n P^  - C e n t r i f u g a l feed pumps f o r continuous respectively  t  and d i s p e r s e d phases  Q - L e v e l of i n t e r f a c e R - Column proper l /&-in. I.D. 1  Pyrex  S - Dispersed phase n o z z l e T  l '  T  2'  T  3' 4 T  "  T  h  e  r  m  o  m  e  t  e  r  s  U - S p e c i a l Pyrex reducer 3 - i n . I.D. V - Vent connected  to lV&-in.  I.D.  to a l i n e going o u t s i d e b u i l d i n g  W - Pressure e q u a l i z i n g vent X - Control for interface  level  Y - Valve f o r d r a i n i n g the column Zj,  - O u t l e t sample v a l v e s f o r continuous respectively  and  d i s p e r s e d phases  14 TABLE lo CONTINUED PTS - P i s t o n  type sampler  PS^, PS^ - P i s t o n sample e x i t  ports  a - Dispersed phase sample probe b - Continuous phase sample probe c - T r a v e l l i n g b l o c k from which sampling probes are suspended d - Guide on framework f o r b l o c k " c " e - Continuous phase sampling r a t e c o n t r o l  valve  e' - C a p i l l a r y tubing f - Dispersed phase sampling r a t e c o n t r o l f  valve  - C a p i l l a r y tubing  h - Continuous phase sample b o t t l e k - Dispersed phase sample b o t t l e m~-  Mercury manometer  n - Water a s p i r a t o r (vacuum c o n t r o l l e d by a i r vent a t the bottom of a mercury column and a l s o by " r " ) r - Valve f o r r e l e a s i n g vacuum  15  FIGURE 2o  STAINLESS  S T E E L TANK  16 On the grounds that p o l y e t h y l e n e was l e s s expensive s t a i n l e s s s t e e l , and that p o l y e t h y l e n e was probably a t l e a s t resistant  to M. 1.13 .K.,  polyethylene  than fairly  tubing was i n s t a l l e d to r e p l a c e  Saran tubing which had been attacked by M.I.B.K. ( 1 3 )  0  However, to  prevent mechanical breakage and to give more o p e r a t i n g freedom to the author,  s t a i n l e s s s t e e l tubing was used l a t e r , i n p l a c e s where  the M.I.B.K. phase was f l o w i n g c o n t i n u o u s l y when the s o l u t i o n were being mixed or r e c i r c u l a t e d with the column proper not i n o p e r a t i o n . All prevent  rubber  tubing was removed from the sampling  any runnjng back o f l i q u i d , p o s s i b l y rubber  i n t o the column.  l i n e s to  contaminated,  F i n a l l y , p o l y e t h y l e n e tubing was i n s t a l l e d a l l the  way from the sample r e c e i v i n g f l a s k s to the s t a i n l e s s s t e e l probes. Initially,  the M.I.B.K. had to be d i s t i l l e d  as s p e c i f i e d  by the pamphlet "Ketones" (14) due to p o l l u t i o n from the use o f Saran tubing by e a r l i e r workers (12,13). pamphlet,  the M.I.B.K. d i s t i l l e d  Also as s p e c i f i e d by the  over was c o l l e c t e d only between  the temperatures of 114°C and 117°C measured j u s t before left  the d i s t i l l i n g f l a s k by the s i d e opening.  M.I.B.K. was p u r i f i e d i n t h i s way. the d i s t i l l i n g f l a s k . the d i s t i l l e d  the vapor  A l l the a v a i l a b l e  A b l a c k p r e c i p i t a t e was l e f t i n  By doing a chromatograph t e s t , the p u r i t y of  m a t e r i a l was obtained.  Preceding  this  verification,  a chromatographic a n a l y s i s was run f o r the M.I.]\K. reserved from the p r e v i o u s drums, s p e c i f i e d as being 99.0% pure by the s u p p l i e r s . One peak e x i s t s f o r the pure m a t e r i a l (as r e c e i v e d ) while three peaks were present  f o r the d i s t i l l e d  a c e t i c a c i d , and d i s t i l l e d  m a t e r i a l , which was composed o f M.I.B.K.,  water.  u n d e s i r a b l e i m p u r i t i e s were l e f t  T h i s r e s u l t showed that no i n the d i s t i l l e d m a t e r i a l , i f the  assumption i s made that the observed substances  mentioned.  peaks corresponded  T h i s assumption was not t e s t e d .  to the three  17 The  r e p a i r i n g of a rotameter  was  necessary.  New  stainless  s t e e l p l a t e s that compress the packing around the tube were made to r e p l a c e those of m i l d s t e e l which had been corroded by l e a k i n g m a t e r i a l  0  A l s o , the s c a l e s had been s h i f t e d r e l a t i v e to the tubes when s c a l e s were removed and r e p l a c e d . the r e s u l t s are recorded The designed  and  sampler, PTS  Both meters had  to be r e c a l i b r a t e d  and  i n Appendix I .  second p a r t of t h i s work was  done u s i n g a p i s t o n sampler  c o n s t r u c t e d by Hawrelak (12) i n i t i a l l y . i n Figure 1, was  The  piston-type  flanged to the g l a s s column by means  of standard Corning Type I f l a n g e s and hard asbestos gaskets.  In  all  In  cases the p i s t o n a x i s was  1.59-ft. above the n o z z l e t i p s .  normal o p e r a t i o n of the column, the phases pass through one h o l e s i n the p i s t o n .  The  p r i n c i p l e of t h i s sampling  of the  method c o n s i s t s  of t a k i n g out four inches of the column's phases by c u t t i n g through the o p e r a t i n g column with the p i s t o n which c o n t a i n s v e r t i c a l l y passages of the same i n s i d e diameter as the column. were c o l l e c t e d at p o i n t s PS^  and P S  2  P i s t o n samples  i n Figure 1, i n t o  f l a s k s by slamming the p i s t o n from one  drilled  volumetric  s i d e to the other of i t s  travel. Past experience  with a hard-chromed phosphor bronze c y l i n d e r  b l o c k and a brass p i s t o n coated with s o f t s o l d e r , and a l s o with aluminum p i s t o n , was  that there were always leaks (12).  to stop t h i s leakage  was  an  An attempt  made by c o v e r i n g the p i s t o n with a p o l y e t h y l e n e  sheet, h o l d i n g i t m e c h a n i c a l l y  as shown on F i g u r e 3.  T h i s approach  s o l v e d the problem of leaks between the p i s t o n and p i s t o n block; a l s o t h i s made i t unnecessary to c o n s i d e r p e r i o d i c replacement of the s o l d e r p i s t o n s u r f a c e due p o l y e t h y l e n e sheet was  to c o r r o s i o n or mechanical damage.  soft  The  attached mechanically because cements can  not  18  1/8  HIGH MOLECULAR W ALUMINUM PISTON 0.0015  POLYETHYL SHEET  OD : 4.0805 0.0015  THICKENED SECTION OF POLYETHYLENE COVER  T 1/4^1  I  I  11 1 1  Jut  I ' 1  1  6.0 >  1/2/"" <=  \\/z  I  t  H  -l-ll II  I rl  ri/4  II II II  1A.  FIGURE 3.  PISTON DESIGN  I  I L..I  19 be used due to the danger o f s o l u t i o n contamination, p a r t i c u l a r l y with s u r f a c e - a c t i v e m a t e r i a l s ; in  M.I.B.K. ( 1 5 )  i n a d d i t i o n , most cements are s o l u b l e  0  A l e v e r was b u i l t  to r e p l a c e the hand d r i v i n g handle.  The  p i s t o n diameter t o l e r a n c e s had been reduced by i n c r e a s i n g the p i s t o n diameter with the p o l y e t h y l e n e sheet to help reduce the leaks; as much f r i c t i o n had to be overcome', a the  p i s t o n was  required  0  but  l e v e r mechanism to d r i v e  Figure 4 i s a sketch r e p r e s e n t i n g the l e v e r  used to push the p i s t o n i n t o the b l o c k .  B)  Procedure 1- Probe method In  the  a l l the runs performed, mass t r a n s f e r took p l a c e from  continuous phase to the d i s p e r s e d phase.  The continuous phase  flowed by g r a v i t y downward from the top of the column while the d i s p e r s e d phase was  fed to the bottom  o f the column through  chamfered  n o z z l e s as d r o p l e t s . The r e q u i r e d flow r a t e s were s e t by means of the rotameters; during the time needed to reach steady s t a t e , the i n t e r f a c e was  a d j u s t e d to h o l d the i n t e r f a c e at one p a r t i c u l a r l e v e l .  all  the runs, the i n t e r f a c e remained  top  o f the top p l a t e of the E l g i n head.  During each run, the i n t e r f a c but v a r i e d over one  1  0  f o r a l l runs.  the course of a run, numerous checks were made on the  i n t e r f a c e h e i g h t and on the flow meter s e t t i n g s . little  inch  Thus the h e i g h t o f the column (nozzle t i p s to  i n t e r f a c e ) i s r e p o r t e d as 7 - f t . and 4 /£-in. £ i/i-in Throughout  Throughou  two'.tofour inches below the  e l e v a t i o n remained w i t h i n a range of %-in. range from run to run.  controller  or no readjustment was necessary.  I t was  found that  FIGURE 4.  LEVER TO PUSH THE PISTON  The  v e l o c i t y through  each of the n o z z l e t i p s was  a constant value of 0.357 f t . / s e c ,  except  h e l d at  f o r a few runs.  t h i s l i n e a r v e l o c i t y of the d i s p e r s e d phase through  To keep  the t i p s  constant  with v a r y i n g t o t a l ketone flow r a t e s through  the column, some of the  t i p s were blocked out by u s i n g T e f l o n caps.  A c c o r d i n g l y , the number  of open t i p s changed with ketone flow r a t e .  F i g u r e 5. shows the  v a r i o u s t i p p a t t e r n s used. The constant throughout  t h i s work.  continuous The  phase flow r a t e was  held  j e t s of f l u i d obtained at the  n o z z l e t i p s would produce uniform drops according to the Johnson and Bliss correlation claimed that two  (16), as r e p o r t e d i n Appendix V I  regions e x i s t :  one  at n o z z l e t i p s and another The  These  authors  d i f f e r e n t kinds of drop formation can take p l a c e at  the n o z z l e depending on the v e l o c i t y through that two  0  the n o z z l e .  They mentioned  r e g i o n below which drops cease  above which drops cease being  c o r r e l a t i o n of Johnson and B l i s s  (16) was  forming  uniform.  used as a guide  to  determine whether the v e l o c i t y used i n t h i s work was  low enough to  be w i t h i n the r e p o r t e d r e g i o n of Uniform  However, the  drop s i z e .  work of Rocchini (13), i n which a nozzle t i p v e l o c i t y of 0.362 F t . / s e c . was  used, shows that i n the present study v a r i o u s drop s i z e s must  have been p r e s e n t . expected  The  d i s t r i b u t i o n was  not measured but would be  to be c l o s e to that of R o c c h i n i (13). The probe method of o b t a i n i n g p o i n t c o n c e n t r a t i o n s used  by e a r l i e r workers (10,11, and 12) needed to be checked.  Samples  i n the present work were taken i n the upward d i r e c t i o n : from n o z z l e t i p s to i n t e r f a c e , except when the purging and sampling  rate studies  were done The sampling  was  done at d i s t a n c e s from the n o z z l e which  were the same as those used by Choudhury (10) and shown i n Table 2. * Thi6 v e l o c i t y was not used f o r probe samples taken f o r use with p i s t o n samples.  22  BLOCK  OUT  l_ = 7 2 . 7 K  V*=  FT^HR  0.357  p  O  L = 120.3 K  V*=  FIGURE 5o V*  Q;  q  o  FT//HR F T  0.338  2  FT/SEC  '0 p^:q o  FT  2  FT/SEC  TIP PATTERNS FOR KETONE N0ZZLE„  L i n e a r v e l o c i t y through t i p s i n ketone nozzle  ft./sec»  TABLE 2 LOCATION OF STAINLESS STEEL SAMPLING PROBES (TUBES).  P o i n t number  1 1A 2 2A 2B 3 3A 3B 4 4A 4B 5 5A 5B 5C 6 7 8  Distance above n o z z l e tips, f t .  0.078 0.161 0.445 1.161 0.911 0.755 2.161 1.661 1.060 3.161 2.411 1.379 1.355 4.161 3.786 5.161 6.161 7.286  24 T h i s approach was  decided on to permit easy comparison with the work  of Choudhury (10) which had the o b j e c t of o b t a i n i n g c o n c e n t r a t i o n profiles. The probe sample taken were r e c e i v e d i n t o c l e a n dry Erlenmeyer f l a s k s .  These were c l o s e d immediately to prevent as much  e v a p o r a t i o n as p o s s i b l e . day as the sample was day  0  Each sample was analyzed e i t h e r on the same  taken, or, at the worst, not l a t e r than the next  The volumes of the phases were measured by p o u r i n g the mixture  c o l l e c t e d i n a v o l u m e t r i c f l a s k i n t o a graduate.  From each of the  continuous phase samples, a volume o f 10 ml. was measured with a p i p e t t e and analyzed by t i t r a t i o n with a p p r o x i m a t i v e l y 0.1 N sodium hydroxide with p h e n o l p h t h a l e i n i n d i c a t o r .  A s i m i l a r method was  used f o r  the d i s p e r s e d phase samples, but b e f o r e t i t r a t i o n o f 10 ml. from each ket one l a y e r , 25 ml. of SDAG-IK mixture were added. (SDAG-1K mixture i s made i n d u s t r i a l l y by mixing 100 g a l l o n s of dehydrated e t h y l a l c o h o l with 5 g a l l o n s o f dehydrated methyl a l c o h o l . ) s i n g l e phase i n which  The r e s u l t was a homogeneous,  the end p o i n t could be determined e a s i l y  (or much  more e a s i l y than would have been true i f two phases had been p r e s e n t ) . Sometimes a f t e r the a n a l y s i s had been completed, a ketone l a y e r v i s i b l e on the s u r f a c e of the mixture i n the f l a s k . volume of a l c o h o l should have been used.  Perhaps a l a r g e r  A blank s o l u t i o n was  f o r the case o f the d i s p e r s e d phase a n a l y s e s .  was  prepared  The blank s o l u t i o n  was  the same as a t y p i c a l s o l u t i o n analyzed except t h a t the 10 ml. d i s p e r s e d phase were not added. hydroxide was  Less than a drop of 0.1 N  sodium  needed to change the c o l o r of the blank s o l u t i o n .  amount o f t i t r a t i n g agent was  This  c o n s i d e r e d n e g l i g i b l e and not s u b s t r a c t e d  from the t o t a l amount needed to t i t r a t e the d i s p e r s e d phase  samples.  Sodium hydroxide and g l a c i a l a c e t i c a c i d were reagent grade  25 ( A.C.S. s p e c i f i c a t i o n ) and were obtained from N i c h o l s Chemical Co., Ltd, Montreal. this projecto  Laboratory d i s t i l l e d water was used f o r a l l runs i n The M.I.B.K. was t e c h n i c a l grade f u r n i s h e d  by the  Canadian Chemical Co., Edmonton, except that i n the e a r l i e r runs (Run 1 up to and i n c l u d i n g Run 3 ) the d i s t i l l e d ketone, d e s c r i b e d i n the preliminary  work, was used, because  d e l i v e r f r e s h M.I.B.K..  the s u p p l i e r s were not ready to  However, as soon as the f r e s h chemical a r r i v e d ,  the apparatus i n c l u d i n g the tanks were washed with t h i s M.I.B.K.. For a l l runs, the rate o f t r a n s f e r o f a c e t i c a c i d a c r o s s the i n t e r f a c e i n the'column equationso  was c a l c u l a t e d  i n lb.-moles/hr. by two d i f f e r e n t  One was based on the t o t a l change i n c o n c e n t r a t i o n o f the  water phase, and the other on the corresponding t o t a l change i n c o n c e n t r a t i o n o f the ketone phase. The equations were: N = L A ( C - C ) W  \  W  - *1c  W^  A  (  C  k  2  -  1  W,j  V .  2  These were a p p l i e d without i n c l u d i n g the volume o f samples taken out by the probes.  Values o f  and N^ were s l i g h t l y d i f f e r e n t i n g e n e r a l ,  and an average value was determined by use o f the f o l l o w i n g e x p r e s s i o n : N  s N  w  + N, k 2  3  T h i s value was estimated to be b e t t e r than e i t h e r N w  o r N, f o r f u r t h e r k  calculation. The percentage d e v i a t i o n was c a l c u l a t e d f o r each run as a measure o f the q u a l i t y o f the experimental work.  The equation used  was: Percentage d e v i a t i o n =  (N  - N, ) N * The f r e s h M.I.B.K. then was used f o r a l l runs from and i n c l u d i n g run 3A. A  26 The p o i n t c o n c e n t r a t i o n s i n the u n i t s o f l b . - m o l e s / f t ^ were r e a d i l y o b t a i n e d by t i t r a t i o n .  With these t i t r a t i o n r e s u l t s the  f o l l o w i n g equation was used to c a l c u l a t e back to the d i s p e r s e d phase c o n c e n t r a t i o n at the time o f sampling: C. . = C. _ - V ( C . - C _ ) ki kf __w wi wf V  5  k  As f a r as the probe method i s concerned, the g e n e r a l c a l c u l a t i o n s stopped a t t h i s p o i n t because  the emphasis was put on the  p o i n t c o n c e n t r a t i o n , r a t h e r than on H. T. U. as i n p r e v i o u s work.  2. P i s t o n method. When the p i s t o n method was used, the e x t r a c t i o n process was the same as mentioned  e a r l i e r and used with the probe method. But,  when the p i s t o n sampler was i n c o r p o r a t e d i n t o the apparatus, the procedure was s l i g h t l y d i f f e r e n t .  When steady s t a t e c o n d i t i o n s were  achieved, the probes were lowered to the e l e v a t i o n o f the a x i s o f the p i s t o n where purging and sampling o f both phases simultaneously.  Purging and sampling r a t e s and purging times were used  as p r e s c r i b e d by the f i r s t F i g u r e 10.  took p l a c e  p a r t of the present work and recorded on  I n l e t and o u t l e t samples o f both phases were taken r e g u l a r l y  from the s t a r t to the end o f a run and consequently when the probe samples were being taken.  When s u f f i c i e n t volumes of both phases had  been o b t a i n e d , the probes were removed from the path o f the p i s t o n . The l / ^ - i n . I.D. hole i n the p i s t o n that was to s l i d e i n t o 1  with the column was f i l l e d  with o u t l e t water phase from the column.  t h i s way, when a p i s t o n sample was taken, the column continued to operate with no a p p r e c i a b l e d i s t u r b a n c e . been taken, s u f f i c i e n t i  A f t e r a p i s t o n sample had  time was allowed to r e s t o r e the steady s t a t e ,  line In  27 which time had been s t u d i e d as a p a r t of t h i s work. The  p r i n c i p a l change made i n the e x t r a c t i o n process  consisted  i n i n c r e a s i n g the d i s p e r s e d phase flow r a t e to g i v e a l a r g e r holdup of d i s p e r s e d phase i n the column, and,  consequently, i n the p i s t o n sample.  Figure 5. shows the setup to the nozzle necessary f o r t h i s change of flow.  I t was  planned to use  mentioned e a r l i e r . v e l o c i t y , was  the l i n e a r v e l o c i t y of 0.357 f t . / s e c .  However, the flow r a t e f o r 21 t i p s to g i v e  The  v e l o c i t i e s c a l c u l a t e d on the b a s i s of the l a t t e r diameter are 10,  actual  recorded  Appendix I I .  An a c e t i c a c i d m a t e r i a l balance has initial  this  c a l c u l a t e d using the nominal nozzle diameter o f 0.10-in.  i n s t e a d of the a c t u a l average diameter of 0.1029-in. (10).  i n Table  as  to be made between the  c o n d i t i o n s p r e v a i l i n g i n the column at the time of sampling  with the p i s t o n , and  the f i n a l c o n c e n t r a t i o n  p i s t o n sample at the time of a n a l y s i s . as Equation  5 just given.  concentration  quantity C ^  equation  used was  i s found by u s i n g  the same the  given by the continuous phase probe at the a x i s of  p i s t o n j u s t before taken, C, „ and ' kf  The  The  e x i s t i n g i n the removed  t a k i n g a p i s t o n sample.  C _ can be measured and wf  c a l c u l a t e d : the q u a n t i t y r e a l l y needed.  the  When the l a t t e r sample i s  a l s o V, and k  V . w  Then C. . can kx  be  This c a l c u l a t i o n i s  p e r m i s s i b l e on the b a s i s t h a t : ki  kf  k  and V . = V wi These l a s t two  = V wf  . w  statements probably  are very c l o s e to the t r u t h , and  are assumed to be c o r r e c t w i t h i n the experimental should  a l s o be understood that the c o n c e n t r a t i o n  l i n e a r l y i n s i d e the four inches previous  results(10,11)  long p i s t o n .  e r r o r of a run. i s assumed to  It  vary  T h i s assumption i s based  which show that the c o n c e n t r a t i o n  versus  the  on  27A d i s t a n c e from the n o z z l e i s almost l i n e a r over seven feet o f the column's l e n g t h .  28  RESULTS A)S.teady s t a t e It  requirements:  was d i s c o v e r e d that the c o n c e n t r a t i o n i n s i d e the column  i n f l u e n c e d the length of time needed to achieve making an e x t r a c t i o n run. with the continuous  a steady  state i n  The c o n c e n t r a t i o n 6"f the column  filled  phase feed s o l u t i o n d i f f e r e d from that e x i s t i n g  i n s i d e the column which had been operated was due to the e x t r a c t i o n process  before;  this difference  which took p l a c e .  Then, two ways of s t a r t i n g a run needed to be i n v e s t i g a t e d . The f i r s t  one c o n s i s t e d i n u s i n g a column f i l l e d  only with  the c o n t i -  nuous phase at feed c o n c e n t r a t i o n and with no d i s p e r s e d phase above the i n t e r f a c e .  ( In run 61^ ( F i g . 6) a s l i g h t v a r i a t i o n i n t h i s  procedure took p l a c e :  some d i s t i l l e d water had been l e f t  i n the  E l g i n head from the back-washing o p e r a t i o n which preceded).  The  second way was the s t a r t - u p of a run u s i n g a column f i l l e d  with the  continuous  phase l e f t  i n the column at the end of a previous run and  with the corresponding  d i s p e r s e d phase above the i n t e r f a c e .  To o b t a i n the time needed to reach a steady for  the f i r s t way of s t a r t u p i n v e s t i g a t e d , the column f i r s t  with continuous in  state condition was  filled  phase feed s o l u t i o n only, up to the i n t e r f a c e l e v e l  the E l g i n head.  A flow of d i s p e r s e d phase then was s t a r t e d .  Samples o f both feed s o l u t i o n s were taken three times during the e x t r a c t i n g o p e r a t i o n whereas the outgoing every  f i v e minutes-.  initial lb.  continuous  moles,'of ^.acetic  s o l u t i o n s were sampled  Figure 6 shows the r e s u l t s of a run u s i n g an  phase c o n c e n t r a t i o n s l i g h l y d i f f e r e n t  acid/  from 50.4  cu. f t . of water due to the presence of  d i s t i l l e d water i n the E l g i n head before  the column was f i l l e d  with  ro*  DISTILLED  27  •I—  CO  w o  26  3  25  WATER  IN THE  COLUMN  BEFORE  RUN  WATER  S I.  O  I O  24 23h  - O O  3  -J O 22 o 0  10  j  WATER P H A S E KETONE PHASE  L  20  30  40  50  J  60  L  1  70  80  TIME, MINUTES FIGURE 6. Steady s t a t e study, Hun 6  1^  £0 «9  continuous phase feed s o l u t i o n .  (Consequently,  i n the r e s u l t s given on F i g u r e 8.)  Run 61^ i s not i n c l u d e d  The continuous phase feed 3  c o n c e n t r a t i o n , of 50.4  lb.-mdles/cu.  ft.xlO  , was  which were done u s i n g the same c o n d i t i o n s except which was  drained before beginning to f i l l  an example of the r e s u l t s of one  used i n other runs f o r the E l g i n head  the column.  such run.  F i g u r e 6A shows  A l l these r e s u l t s are  recorded i n Table 11, g i v e n i n Appendix I I I . To r e a l i z e the second way mentiomed)  the column was  of beginning a run (as j u s t  not operated f o r one or two  e a r l i e r run had been completed.  T h i s time was  days a f t e r an  allowed to elapse i n  order to permit the c o n c e n t r a t i o n s w i t h i n the column to approach more uniform and,  i n a d d i t i o n , lower values than those which a p p l i e d at the  end of the e a r l i e r run;  e x t r a c t i o n continued at a low r a t e beyond the  end of the e a r l i e r run.  A new  e x t r a c t i o n run then was  s t a r t e d with the  o b j e c t of f i n d i n g the time r e q u i r e d to reach steady s t a t e f o r these initial  conditions.  s o l u t i o n s was  The method of sampling  the i n l e t and toutl'et  the same as mentioned e a r l i e r .  F i g u r e 7 r e f e r s to a run  s t a r t e d with a column where the c o n c e n t r a t i o n was lb,-moles/cu.  f t . xlO  new  due to a p r e v i o u s run.  lower than  50.4  Table 12, g i v e n i n  Appendix I I I shows the r e s u l t s of f o u r others runs performed  u s i n g the  same procedure. T h i s i n v e s t i g a t i o n was  c a r r i e d out f o r a constant  continuous  3 2 phase flow r a t e of 54.8 f t . / h r . - f t . while the d i s p e r s e d phase flow r a t e 3 2 3 2 was v a r i e d from 72.4 f t . / h r . - f t . up to 208.0 f t . / h r . - f t . . F i g u r e 8 summarizes a l l the r e s u l t s obtained. lists  (Table 13, given i n Appendix I I I ,  the same r e s u l t s . ) These runs were a l l performed  to g i v e the r e s u l t s d e s c r i b e d  without u s i n g any i n t e r n a l method of sampling.  However, a f t e r very long  32  ro  O  28  ro  Q O < CO LJ  CD  27  26  25  o <  24  Ld O  - O O W A T E R PHASE - Q - C h K E T O N E PHASE  z 23 o o hLU _ J 22 h3 O 10  20 30 40 TIME , MINUTES.  i t CUPS 7. Steady s t a t e study, Run  6L*  50  \  50  \  L  = CONSTANT = 54.8  FT /HR."FT^ 3  40 \  LLI  \  /\" LLi  / - F E E D WATER /  PHASE  FILLING THE COLUMN.  20 ^COLUMN OPERATED " PREVIOUSLY.  ^  \ \  Q  i  0  50  100  150  , i  200  \  .  i  250  .  i -  300  i  I  350  DISPERSED PHASE FLOW R A T E , F T . /.HR.-FT. FIGURE 3. Suimnarizing p l o t o f the steady s t a t e r e s u l t s .  J  L_  34 times when the steady s t a t e had been reached, some of the runs were continued, and i n t e r n a l samples were taken, as p a r t o f the study of the e f f e c t of such sampling on the steady s t a t e .  B) Purging study: The purging time i s the time needed to achieve a uniform c o n c e n t r a t i o n a f t e r the p o s i t i o n of the probes i n the column has keen changed.  The p u r g i n g time depends on the amount of vacuum a p p l i e d to  the probes, and the r e s u l t a n t r a t e o f purging which i s c o n t r o l l e d  also  by the i n s e r t i o n o f l e n g t h s of c a p i l l a r y tube i n s i d e the sampling  lines.  The vacuum, and these c a p i l l a r i e s c o n d i t i o n a l s o the r a t e of sampling, obviously. The procedure f o l l o w e d was  to e s t a b l i s h a steady s t a t e  o p e r a t i o n of the e x t r a c t i o n column, and then to p l a c e the probes a t some convenient d i s t a n c e from the n o z z l e t i p s .  The probes were  filled  at t h i s p o s i t i o n f o r f i f t e e n minutes at the purging r a t e to be s t u d i e d . The probes then were moved to a second p o s i t i o n where p u r g i n g was c a r r i e d out f o r measured times.  The p o s i t i o n s o f the probes  mentioned  here were s p e c i f i c a l l y those of sampling p o s i t i o n s 2, 2A, 3B, 4A, 7 as g i v e n i n Table 2.  and  (On F i g u r e s sampling p o s i t i o n i s a b b r e v i a t e d to  " P o s i t i o n " or"Pos'.*) In each run, s e v e r a l samples were taken a t v a r i o u s sampling rates.  A f t e r the probes had been moved to a second  p o s i t i o n , a sample was  taken every minute.  (or to a  subsequent)  The c o n c e n t r a t i o n o f the  samples  obtained a f t e r s u f f i c i e n t purging i n a l l the runs done f o r t h i s  purpose  (Runs lG,2,2A,2B,2C,7,7B,7C,and 7D) check w i t h i n approximately  0.5% a t the worftt i n the r e s p e c t i v e phase.  The sampling r a t e s used f o r  each run i n the present work appear i n Table 24 (Appendix IV) which  also  shows the minimum purging time f o r each p a r t i c u l a r value o f the purging rate.  A t y p i c a l example o f what was obtained  shown i n F i g u r e 9.  A l l the r e s u l t s obtained  the minimum purge time appear i n Tables  f o r a p a r t i c u l a r run i s f o r each run concerning  14, 15, 16, 17, 18? 19,120? 121!,  22, and 23, l o c a t e d i n Appendix IV. A summarizing p l o t o f the r e s u l t s of a l l these runs i s given as F i g u r e 10 f o l l o w i n g .  T h i s F i g u r e shows reasonably  minimum purge time to o b t a i n uniform rates.  a c c u r a t e l y the  concentration at various  sampling  To be on the s a f e s i d e f o r normal e x t r a c t i n g o p e r a t i o n s , a t  l e a s t 2 to 3 minutes should be allowed beyond the value o f the purge time obtained  from F i g u r e 10.  Table 24 corresponding  to F i g u r e 10 i s  given i n Appendix IV.  C) The i n f l u e n c e o f sampling r a t e on p o i n t  concentrations:  A l l research work done i n the p a s t , u s i n g the sampling probe method, appeared u n c e r t a i n because o f the u n d e r l y i n g assumption: that the measured water phase probe c o n c e n t r a t i o n s , C  , are r e p r e s e n t a t i v e  samples o f the aqueous phase f o r use i n the m a t e r i a l balance f o r calculating An attempt was made to e s t a b l i s h c o n c l u s i v e l y the continuous phase c o n c e n t r a t i o n p r o f i l e .  The method used c o n s i s t e d i n p l a c i n g the  probes a t v a r i o u s sampling p o s i t i o n s i n the columm where were reasonably  f a r from e q u i l i b r i u m c o n d i t i o n s .  Choudhury's e q u i l i b r i u m curve  concentrations  Incidentally,  (10), a v a i l a b l e i n the l a b o r a t o r y p l o t t e d  to a l a r g e s c a l e , was used throughout the work f o r g e t t i n g e q u i l i b r i u m concentrations. the n o z z l e t i p s .  The s p e c i f i c d i s t a n c e s used were 1.59 and 1.66 f t . from At these  l o c a t i o n s experiments were made to f i n d any  apparent e f f e c t o f sampling r a t e on p o i n t  concentration.  36  40 -POS. 7  35  PURGING RATE = 13.9 C C / M I R P0S.4A PURGING RATE=II.2 CC/MIN.  !~ ^ O Ll_ CO LU  o 25  P0S.2A  CD  O  20  z o o  P0S.7 POS 4 A \  LU _J  PURGING R A T E = 15.9 C C / M I N ~  •  POS. 4 A PURGING RATE=I4.7 C C / M I N O POS. 2 A  Z> O UJ CD O  cr  - O O WATER  PHASE  - O - O KETONE PHASE Q  '0  i  2  4  6  1  8  PURGING T I M E , MIN FIGURE 9. Study of the miniunm purge tiiao, Rum 2.  10  PURGING R A T E , FIGURE 10.  Minlciu® purge ilaje versus jkwrging r a t e .  CC./MIN.  38 Two d i f f e r e n t k i n d s o f sampling procedure were f o l l o w e d . one  the probes were purged f o r 10 minutes a t a c e r t a i n r a t e .  t h i s p e r i o d t h i s r a t e was maintained enough to provide a reasonable rate  In  Following  f o r an a d d i t i o n a l p e r i o d long  volume of sample f o r a n a l y s i s *  sampling^was changed, the sampling l i n e s were purged again  When the  f o r 10  minutes at the new sampling r a t e b e f o r e t a k i n g the new sample.  This  procedure was i d e a l * f o r o b t a i n i n g c o n c e n t r a t i o n values which would d i f f e r from each other i f the c o n c e n t r a t i o n v a r i e s g r e a t l y with the sampling r a t e .  Run 9H was performed f o l l o w i n g t h i s sampling procedure  f o r both phases.  F i g u r e s 11 and 12 ( data i n Tabic 25, Appendix V) give  the r e s u l t s of t h i s run and show that great d i f f e r e n c e s i n p o i n t c concentrations  do not e x i s t even i f the r a t e s v a r i e d from 6.2 to 16.0  cc./min. f o r the water probe and from 8.2 to 15.6 cc./min. f o r the ketone probe.  However, i t was discovered  l a t e r that these samples were taken  at a p o s i t i o n where the c o n c e n t r a t i o n s were only 5% (% =(C* KX  - C  )xl00)  ^ ,.„f£*j^  Cki away from the e q u i l i b r i u m c o n c e n t r a t i o n s .  Perhaps even i n t h i s  case,  some changes i n c o n c e n t r a t i o n would be p o s s i b l e f o r high r a t e s o f sampling. Run 5 G was performed i n a manner s i m i l a r to the method used f o r Run 9H, except that the purge time was a p p l i e d as p r e s c r i b e d by F i g u r e 10 i n a l l cases.  Other d i f f e r e n c e s were that only the ketone  probe*sampled f o r a l l the run, and that the c o n c e n t r a t i o n s a t the sampling p o s i t i o n were f a r from e q u i l i b r i u m c o n c e n t r a t i o n s .  (This  statement i s a l s o true f o r a l l the other runs, with the p o s s i b l e exception  ID where c o n c e n t r a t i o n s were s t i l l n o t i c e a b l y away from  equilibriumj  The water probe sampled j u s t a t the beginning  and the  * except that i n one case a longer purge time would have been r e q u i r e d to p r o v i d e s a f e t y f a c t o r i n a d d i t i o n t o the requirements o f F i g u r e 10. a  ro • O x  ro  CO  17  LJ  CD  SAMPLING POSITION 1.59FT  16 WATER PHASE  8  1 5  I3 O  14  UJ CD O  8  1  10 12 14 16 SAMPLING R A T E , CC/MIN.  FIGURE IIo Influence of sampling rate ©a point concentration, Kun  9H»  18  20 Ci*  JO  o  ro* r— LK.  IE  >^ CO  9-  CD* -J  8-  o  SAMPLING POSITION  1.59 F T  •  O  , z o o 7-  -Q KETONE  h-  o UJ CO  PHASE  6-  o  56  8  10  J  12  L  14  16  18  SAMPLING R A T E , C C / M I N . FIGURE 12.  Influence•of sampling rat© ©n point coseeatr^t'iofs., tea ©BU  20  end o f the run, and at only one sampling r a t e . not  The water probe was  used f o r the i n t e r v e n i n g f i v e samples because i t was planned to  study whether or not the ketone probe c o n c e n t r a t i o n v a r i e d when samples" were not b e i n g removed with the water probe.  F i g u r e 13 records the  r e s u l t s obtained i n Run 5G f o r the ketone probe and Table 25 i n Appendix V g i v e s the corresponding d a t a . Another Run, 5H, was performed to study f u r t h e r the question of  any v a r i a t i o n s i n the ketone probe c o n c e n t r a t i o n with sampling r a t e  when the water probe d i d not operate.  At the b e g i n n i n g of t h i s Run,  the  sampling l i n e s were purged f o r 15 minutes.  Then a sample was taken  for  3 minutes.  for  the next two samples, but were f o r the remaining three samples. •  The l i n e s were not purged as p r e s c r i b e d by Figure 10  This meant that four samples were obtained a c c o r d i n g to the f i r s t sampling procedure and two a c c o r d i n g to the second procedure to be described s h o r t l y .  F i g u r e 14 records the r e s u l t s o f Run 511. (See Table  25, Appendix V f o r the t a b u l a t e d r e s u l t s of Run 5H.)  The method o f  p l o t t i n g t h i s f i g u r e i s that used f o r F i g u r e 15 and d e s c r i b e d when that Figure i s presented. The second sampling procedure c o n s i s t e d i n p l a c i n g the probe at  l o c a t i o n 3B (1.66 f t from the n o z z l e t i p s ) and purging f o r a  s u f f i c i e n t time to purge the probe.  A f t e r t h i s o p e r a t i o n , one sample  was taken a t the same r a t e used f o r p u r g i n g .  Then, i n s t e a d of purging  the  probe again, another sampling r a t e was s e t , and used t o sample a t  the  same l o c a t i o n .  T h i s sampling procedure was employed  i n Runs 5B^, 5F,  * 7E, 7F and ID „ In  Each o f these runs must be d e s c r i b e d here s e p a r a t e l y .  Run 5B^, a purge o f nine minutes was c a r r i e d out before  t a k i n g the f i r s t sample o f each phase. *  Then, without p u r g i n g , another  In Run ID a probe l o c a t i o n o f 6.16 f t . was used.  ro X  ro  (f) 15  SAMPLING POSITION 3B  Ld  m 14  o Z> O LU QQ O (XL  CL  •  I3h  KETONE PHASE  12  I I  8  10  -12  SAMPLING R A T E , FIGUHE 13o  14  16  CC./MIN.  Xafltteace ®t ssBBpiing r a t e oa p o i a t c o n c e n t r a t i o n , tea §6  18  j  L  20  X  SAMPLING POSITION  CO LU  CD  o z o o  3B  a  •  14  13  o o  o o  — I  o KETONE  LU CD O  cr  Q.  I I  8  10  12  SAMPLING R A T E , FIGURE 14.  PHASE i  14  16  CC./MIN  I n f l u e n c e o f s a i l i n g r a t e on p o i n t c o n c e n t r a t i o n , Run  SH,  18  20  44 sample was Two  taken a t a d i f f e r e n t r a t e and only with the ketone  f u r t h e r samples were obtained i n a s i m i l a r way.  first  sample which was  done a c c o r d i n g to the f i r s t  taken a f t e r were made up of mixtures column at d i f f e r e n t r a t e s . v a r i a t i o n s of sampling  Except  those  of s o l u t i o n s sucked out from  the  However, i f c o n c e n t r a t i o n v a r i a t i o n s due  r a t e are p r e s e n t , the r e s u l t of t h i s  that c o n c e n t r a t i o n s corresponding to d e f i n i t e sampling  to  procedure I t i s true  r a t e s were not  n e v e r t h e l e s s , an absence o f • c o n c e n t r a t i o n change would  i n d i c a t e no e f f e c t of sampling 15 shows the r e s u l t s of Run sampling  f o r the  procedure,  would be a change i n c o n c e n t r a t i o n from sample to sample.  obtained;  probe.  r a t e on measured c o n c e n t r a t i o n s . F i g u r e  5B^.  Each s q u a r e * i s p l o t t e d at the  r a t e being used when the r e s p e c t i v e samples passed  sample f l a s k .  The  l i n e s drawn from each square*  reach t h a t a x i s a t the sampling  The  percentage  approximate volume percentage  i n t o the probe entrance  of the sample which passed  c o n c e n t r a t i o n corresponding to an average T h i s average  r a t e was  liquids  marked on each of these l i n e s i s the  entrance at the r a t e i n d i c a t e d by the l i n e .  entrance.  to the a x i s of a b s c i s s a s  r a t e s which were i n use when the  found i n the r e s p e c t i v e sample a c t u a l l y passed from the column.  i n t o the  The  i n t o the probe  t r i a n g l e s represent the  r a t e of passage i n t o the probe  obtained by weighting the r a t e  i n d i c a t e d by each o f the l i n e s a c c o r d i n g to the corresponding volume percentage. Run  (These r e s u l t s a l s o are recorded i n Table 25, Appendix 5F was  25) shows these  performed  e x a c t l y as Run  sampling  procedure  No purging took p l a c e before sampling two  F i g u r e 16 (and Table  results.  The second  first  5B^.  V.)  a l s o was  was  used to perform  Run  begun with the r e s u l t that the  samples i n Table 25 c o u l d not be used.  Ten minutes samples of  each phase were taken s i m u l t a n e o u s l y a t v a r i o u s r a t e s ranging up to * For F i g u r e s 17, and  7E.  18 c i r c l e s are used i n s t e a d of  squares.  SAMPLING R A T E , FIGURE 15.  CC./MIN.  Influence of sampling rate on point concentration, Run 5B  SAMPLING R A T E , CC/MIN  47 14.2 cc./min. f o r the water probe and from 5.4 ketone probe.  the continuous phase probe;  as Figure 15.  cc./min. f o r the  Each sample r e p r e s e n t s the r e s u l t s corresponding to more  than one r a t e o f sampling i n t o the probes. for  to 9.8  F i g u r e 17 shows the r e s u l t s  the same method of p l o t t i n g was used  Results f o r both probes appear i n Table 25, Appendix  V.  (The ketone phase r e s u l t s have not been p l o t t e d because only a narrow range o f ketone sampling r a t e s was  investigates.)  No  significant  v a r i a t i o n s i n p o i n t c o n c e n t r a t i o n were found. Run 7F was performed as Run 7E,  The f i r s t  two samples i n  Table 25 could not be used because of f a i l u r e to purge. of  Several  each phase were taken at v a r i o u s r a t e s r a n g i n g up to 28.2  for  the ketone phase probe.  samples  cc./min.  Simultaneous samples were taken with the  water probe at a constant r a t e of 2.8 cc./min..  The r e s u l t s are shown  on Figure 17A and recorded i n Appendix V, Table 25.  (The water  phase  r e s u l t s have not been p l o t t e d because only a s i n g l e r a t e of sampling was  investigated.) Another Run, ID, was done a l s o by using the second procedure  (except, of course, that the f i r s t by the f i r s t 6.16  procedure).  f t . from the nozzle t i p s .  The sampling l i n e s were purged 20 sample of each of the phases.  Samples  each phase were taken at the same time at v a r i o u s r a t e s f o r 5 minutes,  again without p u r g i n g between samples. the  taken, i n e f f e c t ,  In Run ID, the probes were p l a c e d t h i s time  minutes b e f o r e t a k i n g the f i r s t of  sample again was  However, as mentioned  earlier,  c o n c e n t r a t i o n s measured under these c o n d i t i o n s should vary i f the  sampling r a t e i n f l u e n c e d the p o i n t c o n c e n t r a t i o n .  No  significant  changes i n the c o n c e n t r a t i o n s were found even though the water sampling r a t e was v a r i e d from 11 to 34 cc./min. and the ketone sampling r a t e from 12.9 to 28.4 c c o / m i n . o  F i g u r e s 18 and 19 r e c o r d the r e s u l t s f o r each  SAMPLING R A T E ,  CC./MIN.  PI602SS 17. Influence ©£ sampling rate on point concentration, Sun  73.  ro O  h  X  SAMPLING POSITION  4A  ro  UJ  KETONE PHASE  19  - J  O  18 O Z  o o  17  O  16  LU QQ O cc  CL  15 0  8  12 SAMPLING  FIC*U£?B 17Ao  RATE,  CC./MIN.  I n f l u e n c e o f e a n p l i n g rate- on p o i n t c o n c e n t r a t i o n , Saa».7F.  SAMPLING POSITION  7  49 WATER  16  20  24  28  SAMPLING R A T E , FIGURE 18 o  32 CC./M!  I n f l u e n c e o f sampling r a t e on p o i n t c o n c e n t r a t i o n . Run  ID.  PHASE  36  40 8  ro g ro  x  CO  w  CD -J  b z o o o  SAMPLING POSITION  25  7 KETONE PHASE  24  23  22  LU QQ O  cr  2 I 12  14  16  18  20  22  SAMPLING R A T E , FIGURE  $9i.  24 CC./MIN  laflueaee « f sampling rate on.point e o Q e e a t r a t i o x t , Him IB,  52 as does Table 25 i n Appendix V.  D) The i n f l u e n c e o f sampling procedure on the steady During  state concentrations.  Runs 7£ and 7F o f the i n v e s t i g a t i o n of sampling r a t e  v a r i a t i o n f o r both phases d e s c r i b e d p r e v i o u s l y , the column i n l e t and o u t l e t c o n c e n t r a t i o n s were measured.  The o u t l e t samples were taken to  i n v e s t i g a t e the i n f l u e n c e o f the r a t e o f sampling on the steady  state  concentrations. At f i r s t , while  the continuous  phase sampling r a t e was kept  constant  the d i s p e r s e d sampling r a t e was V a r i e d over a wide range of r a t e s .  F i g u r e 20 records the c o n c e n t r a t i o n s sampling r a t e in,Run 7F. continuous  obtained  i n r e l a t i o n to the  The next o p e r a t i o n c o n s i s t e d i n v a r y i n g the  phase sampling r a t e and h o l d i n g the other one constant.  These r e s u l t s are shown on F i g u r e 2.1 f o r Run 7E. mentioned was done to study  The procedure j u s t  i f the c o n c e n t r a t i o n p r o f i l e o f e i t h e r  phase would change i f e i t h e r r a t e i s v a r i e d with the other one h e l d constant.  The c o n c e n t r a t i o n p r o f i l e s were not measured i n d e t a i l .  However, change i n the o u t l e t c o n c e n t r a t i o n would i n d i c a t e a change i n the  profile. On F i g u r e s 20 and 21, the column's length (nozzle t i p s to  i n t e r f a c e ) has been i n c l u d e d , as w e l l as the sampling r a t e , shown as a percentage of the r e s p e c t i v e phase flow.  A maximum d e v i a t i o n i n  e i t h e r run i n the o u t l e t c o n c e n t r a t i o n s was 2.3% from the mean value. The  i n l e t c o n c e n t r a t i o n s were constant because they were f i x e d  beginning continuous  before  a run. (A maximum r a t e o f 14.2cc./min. was used on the phase probe while  the maximum used on the d i s p e r s e d phase  probe was 28.2 cc./min..)  (Note a l s o that the probes were i n o p e r a t i o n  only f o r the times shown.  There was no a d d i t i o n a l purging.)  S3  INTERFACE LEVEL OF 7 - 5.5" ASAMPLING TIME , POS. 4 A. W=,K=.  SAMPLING RATE A S % OF PHASE FLOW. MAXIMUM DEVIATION OF  CONCENTRATION  FROM AVERAGE : W = 2 . 3 % , K=l.2%. W=0.9% K =5.0%  8 25.5! FIGTOJE 20. Inflwouc© o f  40  50  60  70  saapllgg pate on steady s t a t e , tea, ?p.  80  90  100  TIME FROM S T A R T , MIN.  54  INTERFACE L E V E L OF 7'-4.7". A  4.2" 1 SAMPLING TIME.POS. 4 A.  i 26.2  V)  UJ  STEADY  W= , K=  STATE  SAMPLING RATE AS % OF PHASE FLOW.  1% = 3.1 CC./MIN. OF WATER = 3.5 CC./MIN. OF KETONE  26.0  MAXIMUM OF  o ori o o o H _  l  DEVIATION  CONCENTRATION'  W = 1.8 %  25.8M  25.6  25.4  I—  o  WATER PHASE  25.2 o o  25.0 20  W=I.O % K=2.0% 30  W=3.6°/« K = l.6%  W=2.0% K= l.8% 40  50  60  70  80  i  90  T I M E , MINUTES. (FROM START) FIGURE 21. I n f l u e n c e o f sampling r a t e on steady s t a t e , Run 7E.  W=4.4% k=2.8%  W=2.6 % K=l.5 % 1  100  1  110  120  J  130  L  140  150  E) C o n c e n t r a t i o n p r o f i l e s : As mentioned  i n the l i t e r a t u r e survey, Choudhury's work d i d  not i n c l u d e the steady s t a t e requirements, or an adequate  study of the  minimum purge time to change the s o l u t i o n i n s i d e the probe a f t e r a relocation.  Furthermore  probe sample was performed  Choudhury assumed that the continuous phase  representative.  The present  work, was  >•..•.'  to study these e f f e c t s and consequently i t became obvious  that the d u p l i c a t i o n of at l e a s t one of Choudhury's runs was  a  necessity. The f i r s t attempts to d u p l i c a t e the r e s u l t s obtained by Choudhury were made a f t e r knowing the steady s t a t e requirements  and  a l s o the time needed to change the c o n c e n t r a t i o n i n the probe when r e l o c a t i o n took p l a c e .  Run 65 of Chouchury's t h e s i s (10) was  repeated  f i v e times. A comparison are  shown f o r Run  t h i s run.)  o f the r e s u l t s obtained with those o f Choudhury  5D o n l y , i n F i g u r e 2 2 .  There was  (Table 10A g i v e s the data o f  a significant difference in results.  b e l i e v e d that the d i f f e r e n c e was  It i s  caused mainly by an e r r o r i n a n a l y t i c a l  procedure made by the present i n v e s t i g a t o r . At  the b e g i n n i n g o f the present work, two  10 ml. p i p e t t e s  were c a l i b r a t e d and used to measure the samples to be analyzed.  The  c a l i b r a t i o n o f both p i p e t t e s showed that the d i f f e r e n c e i n volume from each other and from 10 ml. was  negligible.  A f t e r three months o f  experiments, a c a l i b r a t e d p i p e t t e was broken and r e p l a c e d by a new However, due  to the p r e v i o u s experience, the new  p i p e t t e was  calibrated.  However, a f t e r long use t h i s p i p e t t e was  found to d e l i v e r 5% more than those used i n i t i a l l y .  one.  not  c a l i b r a t e d , and A second cause of  e r r o r c o n s i s t e d o f an e v a p o r a t i o n o f some d i s p e r s e d phase from the feed  ss  L = 51.1 F T 3 / H R - F T w  HEIGHT, FT. FIGURE 22.  :  Duplication oS Caoudnury^s Run 65, Run  57 tank through  the vent system,,  T h i s evaporation caused  a gradual  i n c r e a s e i n the d i s p e r s e d phase feed c o n c e n t r a t i o n . These e r r o r s were r e a d i l y c o r r e c t e d , and to recheck o f both  Run  Run  5D and Choudhury's Run  65.  8 and of Choudhury's Run 65.  i n Appendix I I , Table  Run 8 was  performed  Figure 23 shows the r e s u l t s These r e s u l t s are given a l s o  10A.  F) C o n c e n t r a t i o n study i n the E l g i n head: I t should be i n t e r e s t i n g to mention here an attempt which made to study s o l u t e c o n c e n t r a t i o n s i n the E l g i n head. was  i n t r o d u c e d i n t o a vent  the c e n t e r of the column.  was  A g l a s s tube  l i n e i n s t a l l e d on the E l g i n head, c l o s e to From t h i s l o c a t i o n , s e v e r a l samples of water  phase and of ketone phase were taken at d i f f e r e n t d i s t a n c e s from the column i n t e r f a c e .  Table 3 and F i g u r e 24 g i v e the r e s u l t s  obtained.  Since these c o n c e n t r a t i o n s were not r e l a t e d to the p o i n t c o n c e n t r a t i o n s i n s i d e the column, t h i s study was  not c a r r i e d any  further.  TABLE 3 C o n c e n t r a t i o n study i n the E l g i n head. Height of column. ft.  Distance from n o z z l e . ft.  Concentration, ^ Ib.-moles/ft xl0 . 3  Located on Figure 24 as:  7'-  3.8"  7'-  0.25"  34.45  A  7'-  3.8"  7'-  3.30"  34.42  B  7'-  3.8"  7«- 3.55"  34.20  C  7'-  3.8"  7'-  4.05"  15.85  D  7'-  3.8"  7«- 4.30"  15.00  E  7'-  3.8"  7'-  14.86  F  6.80"  S3  L w = 5 4 . 8 FT /HR.-FT. Lk = 72.7 FT3/HR.-FT2 INTERFACE  KETONE PHASE PROFILE - - - - CHOUDHURY I  2  J  I  I  HEIGHT, FT. FIGURE 23.  D u p l i c a t i o n o f Choudhury's Run 65, RUES 8<  l  l _  FIGURE 24. Concentration study i n the E l g i n head  60 G) P i s t o n sampling. L-  I n f l u e n c e on steady  state:  Three runs were c a r r i e d out to determine  the l e n g t h of time  r e q u i r e d to achieve steady s t a t e c o n c e n t r a t i o n s under c o n d i t i o n s of 3 2 normal o p e r a t i o n u s i n g a d i s p e r s e d phase flow r a t e of 120 2 f t / h r . - f t 3 2 o  and a continuous phase flow r a t e of 54.2 i n f l u e n c e on steady s t a t e was  ft /hr.-ft  .  In a d d i t i o n , the  i n v e s t i g a t e d of the removal of a p o r t i o n  of the contents of the column and simultaneous  i n s e r t i o n of  distilled  water, o r , on other o c c a s i o n s , of o u t l e t water phase, by means of the piston. For the f i r s t column was  run, the E l g i n head was  d r a i n e d completely,  the  f i l l e d with continuous phase feed s o l u t i o n , and the e x t r a c t i o n  process s t a r t e d u s i n g the flow c o n d i t i o n s j u s t mentioned.  Both  inlet  s o l u t i o n s were sampled three times each d u r i n g the run, while both o u t l e t s o l u t i o n s were sampled every f i v e minutes from the s t a r t .  At  f i f t y - t w o minutes from the beginning of the e x t r a c t i n g o p e r a t i o n , the p i s t o n was  operated with d i s t i l l e d water i n the hole which was  i n t o l i n e with the column proper.  D i s t i l l e d water was  used  to s l i d e  to show the  e f f e c t of r e p l a c i n g a column s e c t i o n by a water s o l u t i o n which w i l l g i v e the maximum d i s t u r b a n c e of the steady s t a t e .  Just a f t e r t a k i n g a p i s t o n  sample, samples of the o u t l e t s o l u t i o n s were taken every two f o r 10 minutes.  Another sample of each o u t l e t s o l u t i o n was  eighteen minutes a f t e r the p i s t o n sample had been o b t a i n e d . p i s t o n sample was sampling  minutes taken Another  taken 20 minutes a f t e r , and the same procedure  the o u t l e t s o l u t i o n s was  repeated.  for  From t h i s run, i t was  found that the time to o b t a i n steady s t a t e a f t e r the s t a r t o f the run was  comparable to the previous r e s u l t s .  Taking a p i s t o n sample using  d i s t i l l e d water i n the p i s t o n hole which was  moved i n t o l i n e with the  61 column proper r e s u l t e d i n 15 minutes being r e q u i r e d f o r r e e s t a b l i s h i n g the  steady s t a t e f o r the water phase.  The d i s p e r s e d phase o u t l e t  c o n c e n t r a t i o n was not changed by the p i s t o n sample being taken u s i n g d i s t i l l e d water to r e p l a c e the column's s e c t i o n .  These r e s u l t s are  g i v e n i n F i g u r e 25. •  Run 9D was performed s t a r t i n g with a column which had been  operated p r e v i o u s l y .  The flow r a t e s were the same as f o r Run 9C.  s i m i l a r procedure was a p p l i e d to o b t a i n samples of i n l e t solutions.  A  and o u t l e t  At t h i r t y - t w o minutes from the beginning o f the run, a  p i s t o n sample was taken, r e s u l t i n g i n the replacement o f a p p o r t i o n of the  column by a p o r t i o n o f d i s t i l l e d water.  a shorter result,  As expected, t h i s run gave  f o r the length of time needed f o r the column to  achieve steady s t a t e when samples were not being taken.  In t h i s  Run  some d i s t u r b a n c e of the o u t l e t ketone phase c o n c e n t r a t i o n a p p a r e n t l y took p l a c e ;  however, only one sample showed a d e v i a t i o n from the  normal steady v a l u e , and the r e s u l t may not be s i g n i f i c a n t .  The  d i s t u r b a n c e o f the water phase e x i t c o n c e n t r a t i o n was much more pronounced ( as expected from the previous r e s u l t s ) . was r e s t o r e d i n a l i t t l e " over 10 minutes. r e s u l t s of Run  Steady s t a t e  Figure 26 r e c o r d s the  9D.  Run 9F was performed u s i n g e x a c t l y the same c o n d i t i o n s o f flow as those of 9D and 9C. at for  the p i s t o n a x i s with a purging and sampling r a t e o f 10.0 cc./min. the continuous phase and 9.4  purging time was the  In Run 9F, the probes were used to sample  10 minutes.  cc./min. f o r the d i s p e r s e d phase.  The  R e f e r r i n g to Figure 10 which s p e c i f i e d  minimum purging times f o r s e v e r a l purging r a t e s , i t can be seen  that 6.2 minutes were the minimum needed to purge the continuous phase probe at a r a t e of 10.0 cc./min., and 5.2 minutes were the minimum  COLUMN OUT. CONC, LB. M O L E S / F T  89''-.  xlO:  X  TIME , MINUTES. FIGURE 26. E f f e c t o f p i s t o n sampling on steady state,  3  Run 9D.  ;  M  64 needed to purge the d i s p e r s e d phase probe a t a r a t e o f 9.4 cc./min.. It was decided to use 10 minutes to be on the safe s i d e as mentioned earlier.  A p i s t o n sample was taken h a l f a minute a f t e r the probe sample.  The p i s t o n hole which had to s l i d e i n t o l i n e with the column proper was filled the  t h i s time with the o u t l e t continuous phase s o l u t i o n .  (This was  s o l u t i o n to be used i n the d i s p e r s e d phase sampling runs.)  sampling procedure was repeated three, times.  The  F i g u r e 27 shows the  r e s u l t s which i n d i c a t e that the steady s t a t e i s not d i s t u r b e d by a p i s t o n sample when the p i s t o n hole s l i d i n g i n t o l i n e with the column is  f i l l e d with o u t l e t continuous phase s o l u t i o n .  The c a r r y i n g out of  probe sampling d i d not a f f e c t the steady s t a t e , as would have been expected from the r e s u l t s given under the heading o f sampling r a t e i n f l u e n c e on steady s t a t e .  2.- P i s t o n p o i n t  concentrations:  F i v e runs were performed t o o b t a i n i n f o r m a t i o n about the sampling procedure by means o f a p i s t o n sampler. For  the f i r s t  Run, 9K, flow r a t e s o f 120.0 ft°/hr.-ft 3  d i s p e r s e d phase and 54.8 f t / n r . - f t  2  f o r the  2 f o r the continuous phase were used.  Samples were taken at the a x i s of the p i s t o n by means o f the probes; h a l f a minute l a t e r a p i s t o n sample was taken. were a v a i l a b l e a t the end o f t h i s Run.  Three o f these samples  The purging and sampling r a t e s  used with the water probe was 12.0 cc./min. and with the ketone probe 13.0 cc./min.  The purging time used was 10 minutes as compared  with  5.2 minutes and 3.8 minutes r e q u i r e d to purge adequately the water and ketone probes r e s p e c t i v e l y a c c o r d i n g to F i g u r e 10 f o r the r a t e s mentioned.  just  The average volume percent ketone i n the ketone probe sample  was 89.6% while that f o r the p i s t o n sample was 14.5%.  25  —. PISTON  23  T  PURGING TIME. SAMPLING TIME. SAMPLE TAKEN I  1  1  1  tro-  21  KETONE PHASE  19  WATER PHASE  17 I 5 10  J  20  i  I  30  u_—L  40  50  60  TIME , MINUTES. FIGURE 27.  Effect of piston sampling on steady state„ Run  9F  L  70  80  90  66 A second Run, 9F, was performed to check Run 9E. d i s p e r s e d phase  The  3 2 flow r a t e was 119.8 f t / h r . - f t and the continuous phase 3 2  flow r a t e , 54.8 f t / h r - f t c  at the a x i s o f the p i s t o n ;  0  As b e f o r e , the probes were used to sample but, a f t e r the second sample had been taken,  i t appeared d e s i r a b l e t o check whether the probes were r e a l l y a t the p i s t o n a x i s when sampling. low.  I t was found that they were one inch too  T h i s meant that the probe samples o f run 9E and those of 9F  obtained to t h i s p o i n t were not s u i t a b l e f o r comparison with the p i s t o n samples.  The e r r o r was c o r r e c t e d and Run 9F was c o n t i n u e d .  The purging  and sampling r a t e s used were 10.0 cc./min. f o r the continuous phase probe and 9.1 cc./min. f o r the d i s p e r s e d phase probe.  The purging time  was 10 minutes whereas the minimum purging time was 5.2 minutes f o r the ketone probe and 6.2 minutes f o r the water probe a c c o r d i n g t o Figure 10 f o r the r a t e s mentioned above.  Out o f four p i s t o n samples  Run 9F, the r e s u l t s of the l a s t  two were almost e x a c t l y the same as those  taken with the d i s p e r s e d phase probe.  taken i n  Run 9E and the p a r t of Run 9F i n  which the probes were i n the wrong p o s i t i o n were not d i s c a r d e d . course was taken because  the p i s t o n r e s u l t s obtained were  This  comparable  with one another and with those of Run 9G which was performed u s i n g the same c o n d i t i o n s .  Table 4 r e c o r d s the r e s u l t s ,  from which i t can  be seen that the d i s p e r s e d phase c o n c e n t r a t i o n s of the p i s t o n  samples  o f Runs 9E and 9F at the time of a n a l y s i s , C j ^ , are equal to c l o s e approximation f o r a l l the samples. The next Run to be d e s c r i b e d , Run 9G, was a r e p e t i t i o n of 9F.  Run 9G was done to v e r i f y the r e s u l t s o f the p r e v i o u s runs but  with the e a r l i e r wrong probe l o c a t i o n s avoided. were o b t a i n e d i n t h i s Run;  Four p i s t o n  they reproduce p r e v i o u s d i s p e r s e d  results phase  c o n c e n t r a t i o n s a t time of a n a l y s i s very c l o s e l y as shown i n Table 4.  67 All  the runs performed to o b t a i n p i s t o n r e s u l t s to t h i s p o i n t  were o b t a i n e d f o r a drop v e l o c i t y through the n o z z l e t i p s of 0,338 ft./sec.  Reference to Table 4 shows that a maximum volume percent  ketone i n the column of 14 8  was  0  v e l o c i t y i n Runs 9E, 9F, and 9G.  found u s i n g t h i s d i s p e r s e d phase I t was  linear  suggested that t h i s ketone  holdup be i n c r e a s e d f o r the purpose of g e t t i n g more ketone phase i n a p i s t o n sample  0  Other t h i n g s b e i n g e q u a l , the a n a l y s i s  ( i f done a t  e q u i l i b r i u m ) would be l e s s c r i t i c a l , and, consequently, the p i s t o n d i s p e r s e d phase c o n c e n t r a t i o n s would be more a c c u r a t e . the  To  increase  holdup, i t became necessary to i n c r e a s e the v e l o c i t y i n the n o z z l e  t i p s w e l l above the v a l u e s used so f a r . Run 9H was done u s i n g the maximum c a p a c i t y o f the ketone rotameter a v a i l a b l e a t the b e g i n n i n g o f the work; used, and a v e l o c i t y of 0.475 f t . / s e c . i n them. 3  21 noz/.le t i p s were For Run 9H, the  2  d i s p e r s e d phase  flow r a t e was  169.5  flow r a t e , 54,8  f?./hr.-ft?.  In t h i s Run, the probes were used again to  sample a t the p i s t o n a x i s . a f t e r the probe sample. d i s p e r s e d phase probe was probe 6.2  cc./min..  ft./hr.-ft.  and the continuous phase  The p i s t o n sample was  taken h a l f a minute  The purging and sampling r a t e used with the 8.7  cc./min. and with the continuous phase  The purging time was  10 minutes.  F i g u r e 10 shows that the r a t e s j u s t mentioned  Reference to  r e q u i r e a minimum purging  time o f 5.4 minutes f o r the ketone probe and 10 minutes f o r the water probe.  Thus the 10 minutes allowed was ample f o r the ketone probe but  i n c l u d e d no s a f e t y f a c t o r i n the case o f the water probe. f a c t o r was  not added  safety  i n t h i s case because the s o l u t i o n s i n the feed  tanks were running out very q u i c k l y . p i s t o n sample now was  The  22.2%.  The volume percent ketone i n a  (The volume percent ketone f o r the  corresponding d i s p e r s e d phase probe samples averaged  92 G%.)  The  a  d i s p e r s e d phase p i s t o n c o n c e n t r a t i o n s , found a t the time o f a n a l y s i s €. _, were lower than p r e v i o u s l y because o f h i g h e r d i s p e r s e d phase flow xv X  r a t e used.  These r e s u l t s a l s o are recorded i n Table 4. For the f i r s t  time some ketone was present with one continuous  probe phase,sample out o f f o u r as a r e s u l t o f the high ketone holdup.  A  c o r r e c t i o n to the water c o n c e n t r a t i o n was made by w r i t i n g Equation 5 f o r each probe.  The value o f  f o r the ketone present i n the water  was taken to be the e q u i l i b r i u m v a l u e .  The two equations  were then s o l v e d s i m u l t a n e o u s l y to f i n d the value o f C .. wi  resulting (This  J  c a l c u l a t i o n i s g i v e n i n Appendix VIL) A new rotameter was i n s t a l l e d and c a l i b r a t e d f o r the purpose of b e i n g able to f u r t h e r i n c r e a s e the d i s p e r s e d phase flow r a t e and t h e r e f o r e the column (and p i s t o n sample) holdup. t h i s rotameter  The c a l i b r a t i o n o f  i s given i n F i g u r e 28, f o l l o w i n g .  Run 91 was performed u s i n g a d i s p e r s e d phase flow r a t e o f 3 2 3 2 208.0 f t . / h r . - f t . and a continuous phase flow r a t e o f 54.8 f t . / h r . - f t . . A v e l o c i t y o f 0.584 f t . / s e c . was used through  the 21 t i p s of the n o z z l e .  The probes were used to sample a t the p i s t o n a x i s u s i n g a d i s p e r s e d phase probe r a t e o f 7.3 cc./min. 6.5 cc./min..  and a continuous phase probe r a t e o f  Based on F i g u r e 10 minimum purge times o f 6.4 minutes  and 9.6 minutes were r e q u i r e d f o r the ketone and f o r the water prober, respectively; the second  however, 10 minutes were allowed as purging time.  For  time, some ketone was present with two continuous phase  samples out o f a t o t a l o f f i v e as a r e s u l t o f the high Ketone i n the column, i n s p i t e o f low purging and sampling  rates.  holdup  As done  f o r Run 9H, c o r r e c t e d values were c a l c u l a t e d u s i n g Equation 5 f o r each probe.  T h i s c a l c u l a t i o n was done f o r Samples 3 and 5, but o n l y i n  69  of 6.0 x KETONE PHASE ROTAMETER  5.0  72 ° F  O  0.0  0.1  0.2  1  i  0.3  ROTAMETER  0.4  0.5  READING  FIGURE 28. C a l i b r a t i o n o f t h e r o t a m e t e r , s e r i a l Number 20,789 f o r a k e t o n e p h a s e h a v i n g a c o n c e n t r a t i o n o f 6.43 l b . - n o l e s / f t  70 Sample 3 was  athene any change i n the f i g u r e s ? (See Appendix VIL) —3  i n Sample 3 the c o r r e c t i o n was C ., and n e g l i g i b l e f o r C. .. wi ki the  very s m a l l , +0.03 xlO The ketone was  volume of water i n Sample 3, and was  0.9%  only 1.2%  of Sample 5.  Even  3 lb.-moles/ft. for of the  total  The h i g h e s t  holdups as measured by the p i s t o n sampler were obtained i n t h i s Run the average  holdup  f o r f i v e samples b e i n g 28.4%.  91,  The volume percent  ketone i n the d i s p e r s e d phase probe samples f o r t h i s Run averaged  96.5%.  The d i s p e r s e d phase p i s t o n c o n c e n t r a t i o n s at time of a n a l y s i s , a g a i n were found to be lower than before due d i s p e r s e d phase flow r a t e . c l o s e to e q u i l i b r i u m .  I t was  to the i n c r e a s e i n the  found l a t e r that the phases were  T h i s i s probably why  the i n i t i a l d i s p e r s e d  phase c o n c e n t r a t i o n (determined by u s i n g the m a t e r i a l balance as a p p l i e d to the p i s t o n samples) checked l e s s than 2.0%  the probe d i s p e r s e d phase r e s u l t s w i t h i n  d e v i a t i o n as d e f i n e d i n connection with Table 4„ ( For the  case of one sample out of f i v e i n t h i s Run, The  the % d e v i a t i o n was  higher.  r e s u l t s of t h i s Run appear i n Table 4 a l s o . ) Table 5 shows i n d e t a i l the probe data corresponding to  each p i s t o n sample.  In a few cases there was  too l i t t l e aqueous phase  i n the d i s p e r s e d phase sample f o r i t to be p o s s i b l e to o b t a i n C  by  analysis.  The value of C „ was then assumed to be the e q u i l i b r i u m value wf corresponding to C^f' * ^ *- e q u i l i b r i u m value was used as C i n the m a t e r i a l balance c a l c u l a t i o n o f C. .. In these cases, the c o r r e c t i o n ki a n <  a p p l i e d to C ^ C  n:  to produce  s  was  always s m a l l , never exceeding  1.5%  of  ki°  S u b t r a c t i n g from the C . values of Table 5 the C , values of ° wi wf Table 4, produces d i f f e r e n c e s (C . - C 3 which do not i n c r e a s e with ' wi wf i n c r e a s e d holdup as was  expected;  i n f a c t t h i s d i f f e r e n c e d i d not  change g r e a t l y except f o r Run 91 where i t was  comparatively  low.  * Change or c o r r e c t i o n from the values obtained i f the ketone i n the water probe sample was n e g l e c t e d .altogether.  71 Increasing between C  the holdup was  , and wi  supposed to h e l p  C _ bigger, wf 0 0  to make the  but u n f o r t u n a t e l y  mass t r a n s f e r r e s i s t a n c e i n the  column by  area between continuous phase and  drops.  difference  the holdup lowers  i n c r e a s i n g the The  the  interfacial  r e s u l t i s that  equilibrium  between the phases i s approached a t the l o c a t i o n of the sampler as holdup  the  increases. Table 5A records  the probe i n i t i a l r e s u l t s , the  r e s u l t s at time o f a n a l y s i s , and  piston  t h e i r corresponding e q u i l i b r i u m  values.  I t a l s o g i v e s the mass t r a n s f e r d r i v i n g f o r c e s , at the l o c a t i o n of p i s t o n c a l c u l a t e d from the probe r e s u l t s . doubled between Run be a f a c t o r of 7 7 a  9G and  Run  91,  i t was  Run  91 was  3.4.  0.32,  The  f o r the ketone phase.  As shown by Table 5A,  f o r c e f o r the water phase i n Run 9G  5.6  very c l o s e to each other f o r constant  o f the e q u i l i b r i u m curve.)  was  these d r i v i n g f o r c e s were cut down  f o r the water phase, and  (These f a c t o r s should be  and  Although the holdup  the  91 was  0.44,  slope  t h i s average d r i v i n g  whereas f o r Runs 9E,  9F,  average d r i v i n g f o r c e f o r the ketone phase i n  whereas f o r Runs 9E,  9F, and  9G  i t was  1.8.  be noted that the v a l u e s of the ketone phase c o n c e n t r a t i o n a n a l y s i s * , f o r the p i s t o n ' ^ J  ((C, _) . . , Table 5A) kf piston  approximately 2% beyond the e q u i l i b r i u m values (C£ (C „) . , by means of the e q u i l i b r i u m curve. wf p i s t o n J  1  be made, of course, with reference ' '  I t should  at time of  a l l seem to  be  ) c a l c u l a t e d from  A s i m i l a r comment  to the values of (C  .) . , . wf p i s t o n  can These  are a l l l e s s than the e q u i l i b r i u m values (C* ) c a l c u l a t e d from wf (0, _) , . again by means of the e q u i l i b r i u m curve, kf piston M  The  probe r e s u l t s of Table 5A show that both phases w i t h i n  the column were almost at e q u i l i b r i u m at 1.59 *  f t from the nozzle  tips  For the p i s t o n samples, the analyses a l l were done a f t e r the phases had reached e q u i l i b r i u m .  72 f o r Run 91.  T h i s r e s u l t was caused by the e x t r a c t i o n t a k i n g  mainly i n the upper part of the column. present  place  The l a r g e amount o f ketone  e x t r a c t e d much more a c i d from the water e n t e r i n g the column than  that removed i n the runs at lower holdup.  The c o n c e n t r a t i o n  of a c e t i c  a c i d i n the water phase when i t reached the p i s t o n then was s m a l l , and n e a r l y i n e q u i l i b r i u m with the c o n c e n t r a t i o n  i n the ketone  phase.  F u r t h e r d e t a i l s w i l l be given i n the d i s c u s s i o n on t h i s s u b j e c t , i n the t h e s i s .  later  73 TABLE 4 Piston results. Run Volume number. of sample cc. V. k  Volume percent ketone  V w  Average piston and probe results  Concentrations l b .-raoles/ftV xlO  c. „ c. . c „ kf wf ki piston results  % deviatii of p i s t o l results from average.  c, ki probe s  *9E  17.0 100.0  14.5  10.34  20.50  6.22  8.34  7.28  -14.3  *9E  17.0 101.0  14.4  9.87  19.50  9.51  7.98  8v75  + 8,7  *9E  17.5 100.0  14.8  9.90  19.68 10.59  7.98  9.29  +14.0  *9F  17.0 100.0  14.5  10.54  20.96  9.48  8.61  9.04  + 4.8  *9F  17 cO 100.0  14.5  10.45  20.79 10.45  8.44  9.45  +10.6  9F  17.0 100.0  14.5  10.34  20.55  8.28  8.43  8.34  - 0.7  9F  16.0 101.0  13.7  10.22  20.55  7.38  8.08  7.73  - 4.5  9G  16.0 101.0  13.7  10.22  20.30  6.45  8.36  7.41  -13.0  9G  16.0 101.0  13.7  10II5  20.35  6.30  8.30  7.30  -13.7  9G  17.0 100.0  14.5  10.15  20.15  7.44  8.33  7.89  - 5.7  9G  17.0 100.0  14.5  10.15  20.30  8.33  8.28  8.31  + 0.2  a9H  26.0  91.0  22.2  8.00  16.00  8.21  7.20  7.71  + 6.5  J9H  26.0  91.0  22.2  7.77  15.80  7.25  7.33  7.29  - 0.5  9H  26.0  91.0  22.2  7.65  15.39  6.64  7.05  6.85  - 3.7  9H  26.0  91.0  22.2  7.65  15.53  6.00  7.10  6.55  - 8.4  91  33.5  83.5  28.6  7.59  15.24  7.02  7.15  7.09  - 1.0  91  33.5  83.5  28.6  7.09  14.25  5.94  6.14  6.34  - 6.9  :9i  33.0  84.0  28.2  7„09  14.25  6.58  6.76  6.67  - 1.4  91  33.0  84.0  28.2  7.07  14.39  6.84  6.76  6.80  + 0.6  91  33.0  84.0  28.2  7.07  14.39  6.84  6.82  6.83  + 0.2  *  Runs performed with probes l . - i n . below the a x i s of the p i s t o n  a  Runs which had a negative (C .- C „) d i f f e r e n c e ° wi wf C o r r e c t i o n was a p p l i e d f o r the ketone i n the water probe sample.  I  74 TABLE 5 Probe r e s u l t s corresponding to p i s t o n r e s u l t s o f Table 4. Run number.  Volume o f sample c c . (ketone probe)  \  Volume percent ketone.  V w  Concentrations l b . - m o l e s / f t ? xlO  C  C . wi water  wf kf ketone probe C  *9E  61.5  S7.5  89.2  8.76  17.75  8.34  21.20  *9E  38.0  4.0  90.5  8.29  16.64  7.98  19.56  *9E  31.0  3.0  91.2  8.29  16.35  7.98  19.56  *9K  23.7  1.0  96.0  8.73  #18.20  8.61  21.14  *9F  28.0  2.0  93.4  8.64  #18.00  8.44  20.79  9F  81.0  5.0  94.1  8.64  17.52  8.43  20.90  9F  42.0  5.0  89.3  8.70  15.75  8.08  21.00  9G  m.o  4.0  90.9  8.70  17.51  8.36  20.90  9G  48.5  4.0  92.3  8.58  17.51  8.30  20.96  9G  51.5  4.0  92.8  8.58  17.37  8.33  20.61  9G  53.5  5.0  91.5  8.58  17.37  8.28  20.61  9H  39.0  3.0  95.2  7.30  14.60  7.20  15.94  J9H  15.6  0.4  97.5  7.30  14.95  7.33  15.95  9H  38 „0  3.0  92.7  7.15  14.31  7.05  15.68  9H  19.0  1.5  92,7  7.18  #15.00  7.10  16.00  91  41.5  2.5  94.3  7.18  #15.00  7.15  15.47  91  36.0  2.0  94.8  6.77  #14.15  6.74  14.71  :9i  28 oO  1.0  96.5  6.77  #14.15  6.76  14.45  91  28.0  1.0  96.5  6.77  #14.15  6.76  14.48  91  40.0  2.0  95.2  6.83  #14.20  6.82  14.48  Runs performed with probes  * J #  l . - i n . below the a x i s of the p i s t o n  C o r r e c t i o n was a p p l i e d f o r the ketone i n the water probe sample. C  r e s u l t s are equ i l i b r i u m values corresponding to C wf was too s m a l l to be a n a l y z e d .  R f  .  The volume  TABLE 5A P i s t o n and probe r e s u l t s and t h e i r corresponding Run number.  P i s t o n Results C  Probe R e s u l t s  C* kf wf wf l b . -moles/ft"? x 1 0 C  equilibrium  V J  C* . C . ki Wl l b . -moles/ft°x 10°  Driving f o r c e at probe locat ion. C*.-C . C* -C Wl Wl k i * 3.8 1.9  8.34  17.38 21.20 10.25  20 c 50 19.50 . 9 „5Q  7.98  16.65 19.56  9.45  2.9  1.5  20.60 19.68  9.55  7.98  16.65 19.56  9.45  2.9  1.5  10.54  21.70 20.96 10.30  8.61  17.91 21.14 10.25  3.2  1.6  9F  10.45  21.60 20.79 10.00  8.44  17.60 20.79 10.15  3.2  1.7  9F  10.34 .21.30 20.55 10.00  8.43  17.60 20.90 10.20  3.3  1.8  9F  10.22  20.90 20.55 10.05  8.08  16.85 21.00 10.20  4.2  2.1  9G  10.22  20.90 20.30  9.85  8.36  17.40 20.70 10.20  3.5  1.8  9G  10.15  20.70 20.35  9.90  8.30  17.30 20.96 10.20  3.7  1.9  9G  10.15  20.70 20.15  9.80  8.33  17.33 20.61 10.00  3.3  1.8  9G  10.15  20.70 20.30  9.85  8.28  17.28 20.61 10.00  3.3  1.7  9H  8.00  16.50 16.00  7.70  7.20  15.00 15.94 7.70  0.9  0.5  9H  7.77  16 J.5- 15.80  7,53  7.28  15ol5 15.95 7.G5  0.7  0.4  9H  7.65  15.95 15.39  7.38  7.05  14.70 15.68 7.55  1.0  0.5  9H  7 65  15.95 15.53  7.40  7.10  14.80 16.00 7.75  0.6  91  7.59  15.80 15.24  7.30  7.15  14.90 15.47 7.40  0.6  0.3  91  7.09  14.75 14.25  6.80  6.74  14.08 14.71 7.10  0.6  0.4  91  7.09  14.75 14.25  6.80  6.76  14.09 14.42 6.90  0.3  0.1  91  7.06  14.70 14.39  6.90  6.76  14.08 14.48 7.20  0.4  0.4  91  7.06  14.70 14.39  6.90  6.82  14.20 14<:»8 7.20  0.3  0.4  9£  10.34  9E  9.87  9E  9.90  9F  #  a  21.30 20.50  9.90  C  values.  The s t a r r e d values are e q u i l i b r i u m values corresponding values o f the preceeding column o f the T a b l e .  to the  ... ,0.3  76 DISCUSSION A) Study of time needed to o b t a i n steady  state;  The p r e v i o u s work (10,11,12,13) on a l i q u i d - l i q u i d e x t r a c t i o n spray column, d i d not i n c l u d e an adequate study of the length of time r e q u i r e d to reach a steady e x t r a c t i n g o p e r a t i o n .  I t i s evident that a  steady s t a t e must be achieved before r e l i a b l e data can be In the present work, an i n v e s t i g a t i o n was a c c u r a t e l y t h i s length of time.  obtained.  performed to determine  As would be expected,  there i s a  r e l a t i o n between the s t a t e of the column a t the beginning of a run, the d i s p e r s e d phase flow r a t e , and  the minimum length of time necessary f o r  steady s t a t e c o n c e n t r a t i o n s to be reached. r a t e was  (The continuous  not v a r i e d i n t h i s study but would a l s o have an  phase flow important  b e a r i n g , of course^ As would have been supposed f o r the flow r a t e s and of  the  direction  mass t r a n s f e r s t u d i e d here, the h i g h e r the c o n c e n t r a t i o n i n s i d e  the  column at the beginning of a run, the longer i s the time needed to achieve steady s t a t e .  The  time r e q u i r e d , of course, depends on  the  d i s p e r s e d phase flow r a t e when the continuous phase flow r a t e i s kept constant as summarized i n F i g u r e 8 given There are two steady s t a t e .  The  earlier.  f a c t o r s which i n f l u e n c e d t h i s time to reach  first  one  i s the i n i t i a l  i n s i d e the column mentioned above.  concentration prevailing  A r e d u c t i o n of approximately  20  minutes i n the time to reach steady s t a t e at a d i s p e r s e d phase flow r a t e 3 of  72.5  °  ft./hr.-ftT  i s achieved when.the column has been operated  b e f o r e so that low c o n c e n t r a t i o n s e x i s t phase.  T h i s time r e d u c t i o n i s reduced  flow r a t e i s i n c r e a s e d and  to begin with i n the  l i n e a r l y as the d i s p e r s e d phase  f i n a l l y reaches a r e d u c t i o n of two  minutes as f l o o d i n g i s approached.  continuous  to three  These r e s u l t s a l l are f o r a constant  continuous phase flow r a t e o f 54.8 f t . / h r . - f t . .  The second f a c t o r  was the p r e c i s i o n o f l e v e l c o n t r o l a t the i n t e r f a c e achieved by the interface controller.  The length o f time to reach steady s t a t e i s very  long when the column as s t a r t e d c o n t a i n s only continuous phase feed s o l u t i o n , perhaps p a r t l y because the i n t e r f a c e takes between t h i r t y to f o r t y minutes to s t a b i l i z e a t a reasonable l e v e l .  When the column has  been used b e f o r e , the i n t e r f a c e i s a l r e a d y a t t h i s reasonable  level.  T h i s second f a c t o r was o f o p e r a t i o n a l  nature and c o u l d be s o l v e d by  the i n s t a l l a t i o n o f an automatic l e v e l  controller.  B) E f f e c t o f purging r a t e on the minimum purge time to achieve a uniform c o n c e n t r a t i o n i n the probe samples: As expected, the minimum purging time was reduced when the r a t e o f purging was i n c r e a s e d as shown i n F i g u r e 10 which gave the r e s u l t s obtained from the i n v e s t i g a t i o n o f the minimum length of time needed to have a uniform c o n c e n t r a t i o n i n each of the probe samples a f t e r r e l o c a t i o n of the probes. On the F i g u r e 10 j u s t mentioned, Choudhury's r e s u l t s were included.  These are shown by means o f dashed l i n e s .  The present study  covered a wider range o f r a t e s : from 2 to 13 cc./min. f o r the water phase and from 2 to 16 cc./min. f o r the ketone phase.  A purging r a t e  of 2 cc./min was considered to be the minimum a t which sampling c o u l d proceed because about 22 minutes purge time i s needed even b e f o r e c o l l e c t i o n o f a sample can begin.  The upper ends of the ranges were,  r e s p e c t i v e l y , a r a t e o f 13 cc./min. f o r the water phase, and 16 cc./min. f o r the ketone phase.  These r a t e s were considered t o be f a i r l y high  because a t t h i s time i n the r e s e a r c h , i t was not known i f high r a t e s perhaps could i n f l u e n c e the p o i n t c o n c e n t r a t i o n obtained and a l s o d i s t u r b  78 the steady s t a t e .  A f t e r the s t u d i e s o f the r a t e of sampling versus  the p o i n t c o n c e n t r a t i o n , and of steady s t a t e d i s t u r b a n c e , i t was that the r a t e s , j u s t mentioned, were s u f f i c i e n t l y high f o r the  proved  purpose  of determining c o n c e n t r a t i o n p r o f i l e s . The present r e s u l t s are s i m i l a r to those of Choudhury f o r the continuous phase, but more complete.  The present d i s p e r s e d phase r e s u l t s  i n F i g u r e 10 are low compared to those of Choudhury.  Choudhury's high  values f o r the d i s p e r s e d phase minimum purge time were probably due to d i f f e r e n t tube lengths i n the sampling l i n e s from those used here.  The  curves o f F i g u r e 10 were used i n the present work.  or  For s a f e t y , two  three minutes o r d i n a r i l y were added to the i n d i c a t e d minimum purge as mentioned were low always  v  earlier.  time  Sometimes by design when feed s o l u t i o n s u p p l i e s  or 'sometimes i n a d v e r t e n t l y , t h i s e x t r a amount o f time was  included.  However, the purge time was  not  never l e s s than the  minimum recommended i n F i g u r e 10 except f o r s p e c i j i l cases where the sampling r a t e was  v a r i e d to see i t s i n f l u e n c e on the p o i n t c o n c e n t r a t i o n .  C) I n f l u e n c e o f sampling r a t e on steady s t a t e : The data o f F i g u r e s 20 and 21, showed that sampling r a t e s from 0.3  to 8.75%  * of the d i s p e r s e d phase flow o f 72.8  3 ° f t . / h r . - f t T and  /* * 0.9  to 4.5%  3 /  of the continuous phase flow of 54.8  r e a l v a r i a t i o n of outlet concentration;  from  a  f t . / h r . - f t . , caused  and t h e r e f o r e no r e a l  no  effect  on the steady s t a t e . For most samples the sampling time used was f o l l o w i n g t h i s , 20 minutes u s u a l l y was b e g i n n i n g to take the next sample.  10 minutes,  and,  allowed to elapse before  During the ten minutes  sampling  p e r i o d the volume o f ketone phase i n the E l g i n head ( 2 . 5 . - i n . o f ketone * 0.3% = 1.1 cc./min. and 8.75% = 28.2 cc./min. ** 0.9% p 2.9 cc./min. and 4.50% =14.2 cc./min.  80 i n a 6 . - i n . I.D. c y l i n d e r ) would be r e p l a c e d four times, and any changes i n o u t l e t c o n c e n t r a t i o n (caused by sampling the ketone phase at a given r a t e ) t h e r e f o r e should have shown up, i f not i n the 10 minutes sampling p e r i o d , t h e n near the beginning of the time between samples.  For the water phase a time of 6.7 minutes i s needed to sweep  out by p i s t o n flow the volume o f continuous phase i n the column from the l e v e l of the probe down to the column bottom p l u s that i n 10 f t . of 3/8.-in. tubing and i n the i n t e r f a c e c o n t r o l l e r .  The amount i n the  column was c a l c u l a t e d as the volume of the whole empty column below the probe i n c l u d i n g that of the expanded p o r t i o n , minus the volume of the n o z z l e f o r d i s p e r s i n g ketone, and minus the volumes occupied by the drops. For the flow r a t e s used i n Runs 7E and 7F, Choudhury (10) has shown that the value of the d r i v i n g  force f a c t o r f o r back-mixing, F^ (10), i s  about 0.9, so t h a t , under the c o n d i t i o n s of these Runs, back-mixing i s not very s e r i o u s .  Therefore d u r i n g the time o f 10 minutes used f o r  sampling, or near the beginning of the p e r i o d f o l l o w i n g , before the next sample was taken, any change i n c o n c e n t r a t i o n caused by sampling would be expected to show up i n the a n a l y s i s o f the water l e a v i n g the column. In Runs 7E and 7F the c o n c e n t r a t i o n o f a water phase i n e q u i l i b r i u m with the l e a v i n g ketone phase was about 5% different', i n c o n c e n t r a t i o n from the a c t u a l e n t e r i n g  water phase.  at the top o f the column been i n e q u i l i b r i u m l i t t l e  Had the phases change might have  been expected i n the o u t l e t ketone c o n c e n t r a t i o n as a r e s u l t of removing samples o f the phases w i t h i n the column. The s m a l l d i s t u r b a n c e s o f the steady s t a t e found i n the study seem to be caused by the i n t e r f a c e c o n t r o l l e r . 3 to 4% due to an i n t e r f a c e change of l . - i n .  The c o n c e n t r a t i o n s vary T h i s statement i s made  on the b a s i s of the steady s t a t e study, shown i n Tables 11 and 12, where  ai the steady s t a t e i s not reached i f the i n t e r f a c e v a r i e s b y i t h a t much. Then s m a l l e r i n t e r f a c e changes can produce  the c o n c e n t r a t i o n v a r i a t i o n s  found as part o f the work d e s c r i b e d i n the present s e c t i o n . mentioned  As  e a r l i e r , an automatic device should be i n s t a l l e d to r e g u l a t e  the i n t e r f a c e l e v e l and h o l d i t at a f i x e d d i s t a n c e from the n o z z l e t i p s . I t i s i n t e r e s t i n g to remark here that the steady s t a t e c o n c e n t r a t i o n s can not be d i s t u r b e d due to the amount of l i q u i d  taken  out by both probes i n Runs 7E and 7F i f purging and sampling r a t e o f 14.2  cc./min. i s not exceeded  the d i s p e r s e d phase. are c o n d i t i o n e d one was  f o r the water phase and 28.2  I t i s to be understood that these sampling  by the phase flow r a t e s , and, as j u s t mentioned  and 14.2  rates only  i n v e s t i g a t e d f o r each phase. The sampling r a t e of 14.2  flows.  cc./min. f o r  and 28.2  cc./min. are s a f e f o r these  Higher sampling r a t e s than 28 cc./min cc./min.  f o r the d i s p e r s e d phase  f o r the continuous phase might w e l l have produced  n o t i c e a b l e d i s t u r b a n c e of steady s t a t e c o n d i t i o n s .  Indeed,  e i t h e r sampling r a t e i n d e f i n i t e l y would be bound to produce  increasing this  effect  at some sampling r a t e , and beyond t h i s l i m i t the e f f e c t on steady s t a t e would, of course, be more and more e v i d e n t .  The present r e s u l t s d i d  not extend to values as high as some of those used i n s t u d y i n g the i n f l u e n c e of the sampling r a t e s on the p o i n t c o n c e n t r a t i o n s .  However,  the high sampling r a t e s used to study i f the p o i n t c o n c e n t r a t i o n s Kary with the sampling r a t e , were a p p l i e d o n l y f o r that study. were not and should not be used i n normal runs because  These r a t e s  of possible  i n f l u e n c e s on the steady s t a t e . N e v e r t h e l e s s , the present r e s u l t s do show that the steady s t a t e c o n d i t i o n would not be d i s t u r b e d by the sampling r a t e s used by the present author i n determining c o n c e n t r a t i o n p r o f i l e s i n the column, and  82 i n s t u d y i n g the p i s t o n method o f sampling, i n both o f which the r a t e s of 14.2 cc./min f o r the water phase, and that of 28.2 cc./min. f o r the ketone phase, were not exceeded, o r , indeed, approached even c l o s e l y , i n the case of the ketone phase.  The present r e s u l t s suggest  also  that  the sampling r a t e s used by Choudhury (10) would have no e f f e c t on the steady s t a t e i n almost a l l o f h i s runs.  D) Drop coalescence a t the d i s p e r s e d phase probe entrance: When the column was i n f u l l o p e r a t i o n the sampling process was c a r r i e d out u s i n g s e v e r a l r a t e s . entering  At the time o f sampling, the drops  the b e l l - s h a p e d probe were observed c a r e f u l l y .  Three models,  of b e h a v i o r can be observed depending on the r a t e o f sampling. First  of'all,  i f the sampling process i s not going on, an  i n t e r f a c e e x i s t s a t the end o f the probe.  When the sampling r a t e i s  low, drops gather a t the entrance and come i n t o the probe  slowly.  Sometimes two o r three drops were pushed out ©f the way by the drops t r a v e l l i n g upward i n t o the probe.  However, no coalescence was ever  observed during o p e r a t i o n o f the probe.  When the sampling r a t e i s  i n c r e a s e d , the drops come d i r e c t l y i n t o the d i s p e r s e d phase  probe  without touching each o t h e r , and without s t o p p i n g a t the probe entrance. T h i s o b s e r v a t i o n was made i n answer to Hawrelak's statement (12) that the r e s i d e n c e time o f ketone drops a t the ketone probe entrance i s too long. there.  Hawrelak a l s o s a i d that an i n t e r f a c e was "sometimes" F i g u r e §9  created  shows the r e s u l t s o f the present study o f the  behaviour o f drops a t the ketone probe entrance and shows what r e a l l y happens t h e r e . observed. worker.  Never, during purging or sampling was an i n t e r f a c e  The statement o f H a w r e l a k i s not b e l i e v e d by the present Hawrelak  a p p a r e n t l y d i d not have d e t a i l e d i n f o r m a t i o n on which  83  FIGURE &9:».- Behaviour of the drops at ketone ps?©ls© entrance at various sampling rates*  to base h i s statement.  Thus he does not say f o r what c o n d i t i o n s an  i n t e r f a c e was c r e a t e d a t the ketone probe entrance.  In the present  work, o b s e r v a t i o n s were made also a t much f a s t e r r a t e s and consequently ever a b i g g e r range o f r a t e s than those used by Hawrelak;  a b s o l u t e l y no  change from the behaviour sketched i n F i g u r e 29 occurred at the ketone probe entrance.  The d i f f i c u l t y o f the r e s i d e n c e time b e i n g too long,  mentioned by Hawrelak, may be something o f a problem f o r the lower r a t e cases as F i g u r e 29 i m p l i e s . accumulation o f drops.  T h i s problem a r i s e s as a r e s u l t o f the  But drops accumulate only a t very low sampling  r a t e s i . e . from 2.0 cc»/min  0  up to 5.0 cc./min.; f o r the range between  5.0 cc./min. and 18 cc./min. a c l e a r i n g up o f accumulated drops i s observed and the s i t u a t i o n i s intermediate between that o f the second sketch i n Figure 29 and the t h i r d sketch (which r e p r e s e n t s a sampling r a t e beyond  the normal o p e r a t i o n ) .  In other words, the r e s i d e n c e time  of a drop at the ketone probe entrance i s not a s e r i o u s problem as £bng as the r a t e i s kept above 5.0 cc./min..  As mentioned  l a t e r , an upper  value perhaps would be needed to a v o i d the problem of f a l s e p o i n t c o n c e n t r a t i o n s due to other l i q u i d coming sampling p o s i t i o n should t h i s happen. discussed  E)  from above or under the  T h i s p a r t i c u l a r matter w i l l be  later.  The e f f e c t o f sampling r a t e on measured point  concentrations:  The e f f e c t was s t u d i e d o f changing each of the probe sampling r a t e s on the premise t h a t , i f changing e i t h e r sampling r a t e produced a change i n the corresponding measured c o n c e n t r a t i o n , then the r e s u l t s with the corresponding probe would be s u s p e c t .  (The absence o f such a  change would not, however, o f i t s e l f prove that the r e s p e c t i v e probe was producing the c o r r e c t r e s u l t f o r c e r t a i n . )  Thus such experiments with  85 the continuous phase probe would r e s u l t i n an apparent decrease i n c o n c e n t r a t i o n as the sampling r a t e increased i f by i n c r e a s i n g the sampling r a t e the r e g i o n s near drops made up a l a r g e r percentage of the sample.  In the case o f the d i s p e r s e d phase probe, i n c r e a s i n g the  sampling r a t e would have been expected to lower the c o n c e n t r a t i o n i f coalescence at the probe mouth had been t a k i n g p l a c e at low sampling r a t e s with a corresponding mass t r a n s f e r i n t o the drops d u r i n g coalescence.  (However, coalescence i s not observed.)  I f increasing  the d i s p e r s e d phase sampling r a t e r e s u l t e d i n continuous phase d i s t a n t from the drops making a l a r g e r c o n t r i b u t i o n to the continuous phase taken i n t o the d i s p e r s e d phase probe along with the drops, then i n c r e a s i n g the d i s p e r s e d phase sampling r a t e would have been expected to produce a l a r g e r volume o f higher average c o n c e n t r a t i o n aqueous phase as p a r t of the d i s p e r s e d phase sample.  Intthe equation used f o r  c a l c u l a t i n g C. . , ° ki' ki  kf  _w  wi  wf  \ the term C, . would have been l a r g e r , the f a c t o r (C .- C .) would have kf ' wi wf been s m a l l e r ( s i n c e C  ;,s g i v e n by the continuous phase probe, presumably  would have stayed c o n s t a n t ) , and the f a c t o r V^/V^ would have been  larger.  Depending on the r e l a t i v e magnitude of the e f f e c t s of the changes i n these two f a c t o r s some change i n C  , e i t h e r up or down, would be>  KX  expected as a r e s u l t o f the combination of t h e i r product with the increased  P a r t i a l anwers to the questions posed above are given  by the r e s u l t s obtained by v a r y i n g the sampling r a t e s and observing the e f f e c t s on the measured p o i n t  concentrations.  Looking at the r e s u l t s presented on t h i s s u b j e c t shows that little  or no v a r i a t i o n o f c o n c e n t r a t i o n occurred even i f the sampling  86 r a t e s were as high as 28 cc./min f o r the d i s p e r s e d  phase probe and  34  cc./min. f o r the continuous phase probe. One  i n t e r e s t i n g aspect  of the behaviour of the ketone probe  t h a t , as p r e d i c t e d e a r l i e r , the volume percent  of ketone contained  ketone sample (probe) decreases as the sampling r a t e i n c r e a s e s . e f f e c t does not present  always above 90.0%  where the volume percent The  in a  This  too s e r i o u s a problem with the ketone probe  r a t e s used i n t h i s work, because the volume percent sample was  was  ketone i n the ketone  except f o r some h i g h e r  ketone was  around 85.0%  r a t e s o f sampling  of the ketone sample.  important p o i n t i s that when the volume percent  of ketone i s t h i s  h i g h , the c o r r e c t i o n f o r mass t r a n s f e r a f t e r sampling i s o n l y s m a l l , whether the water sample i s r e p r e s e n t a t i v e  i s of comparatively  and  small  importance. As i n d i c a t e d i n Table 4 and phase c o n c e n t r a t i o n s o f the probe and two  obtained  as d i s c u s s e d  with the p i s t o n d e v i a t e  one  i n each of the Runs 9F and  were not c l o s e t o a e q u i l i b r i u m c o n d i t i o n s . c l o s e to e q u i l i b r i u m , 91 more so than 9H.)  four  Runs show d e v i a t i o n s  .results •  dispersed  from the average  p i s t o n r e s u l t s w i t h i n b e t t e r than £ 1 per cent  r e s u l t s obtained,  these two  l a t e r , the  (Runs 9H and The  markedly b e t t e r agreement than t h i s .  which Huns ' 91 were  fairly  other nine r e s u l t s f o r  from the average of up  i n a d d i t i o n to the two  9G,  for  to - 14%;  however,  a l r e a d y mentioned e x h i b i t  (The a r i t h m e t i c average of  the  percentage d e v i a t i o n i s c a l c u l a t e d to be -1.24% f o r Runs 9E,9F and I f 9H  i s i n c l u d e d a l s o the r e s u l t i s -1.31%.)  These r e s u l t s do  9G.  not  prove d e f i n i t i v e l y that the p i s t o n r e s u l t s check the probe ones, but they do i n d i c a t e that such agreement i s f a i r l y  probable.  I f t h i s agreement i s assumed f o r the moment, and r e c a l l e d that i n the probe samples the volume percent  i f i t is  water i s very  low,  87 so that the problem of whether the water sample i s r e p r e s e n t a t i v e i s not too important, then agreement between  r e s u l t s from the p r o b e r , and  r e s u l t s from the piston, where the volume percent water i s very much h i g h e r , does seem to i n d i c a t e that the water probe g i v e s samples which are r e p r e s e n t a t i v e of the water p a r t of the p i s t o n Furthermore, and as a separate argument,  sample.  i f the r e s u l t s f o r the  p i s t o n and f o r the probe agree with one another, the i n f e r e n c e i s very s t r o n g that the continuous phase probe g i v e s water c o n c e n t r a t i o n s which are r e p r e s e n t a t i v e f o r use i n the c a l c u l a t i o n o f (C. .) . . * kx probe.  After  all,  the hook probe p r e f e r e n t i a l l y samples the main body of the continuous phase.  The v a l u e s of C  so obtained would seem to be more a p p r o p r i a t e  f o r use with the p i s t o n samples, where ketone holdup i s low, than with the probe samples, where ketone holdup i s h i g h , and where the water phase probably i s d e r i v e d on the average from nearer the drops. Agreement between °  (C, .) , and (C, .) . , , when the same C . i s used kx probe kx p i s t o n ' wi  i n e v a l u a t i n g each of these, i n d i c a t e s that the r e g i o n c l o s e to the drops does not c o n t r i b u t e s u f f i c i e n t s o l u t e to sample to make  the water p a r t o f the probe  i n a p p r o p r i a t e f o r use i n g e t t i n g  ^^^p  r o  b  e  One should r e a l i z e that with coalescence at the probe entrance not a problem, the comparison of a p i s t o n sample and probe sample where the ketone holdups were the same i n each would produce l i t t l e  or no  c o n f i r m a t i o n of e i t h e r sampling method. Here i t i s convenient to mention that the drops are o f d i f f e r e n t s i z e s and t h e r e f o r e do not a l l r i s e a t the same r a t e .  T h e r e f o r e , a t any  e l e v a t i o n i n the column, the c o n c e n t r a t i o n o f a drop should depend on its size.  F o r t u n a t e l y the small drops are o n l y  a small percentage of  the d i s p e r s e d phase (13) and the l a r g e drops are i n a f a i r l y small s i z e range (13), a l l r i s i n g a t n e a r l y the same speed.  F) D u p l i c a t i o n o f Runs: Figure 23 r e p r e s e n t s s c h e m a t i c a l l y what the author would  like  to c a l l good r e p r o d u c t i o n o f Choudhury's r e s u l t s c o n s i d e r i n g that feed c o n c e n t r a t i o n s are always a b i t hard  to copy, and r e p r o d u c i b i l i t y i s  r a r e l y p e r f e c t when mass t r a n s f e r i s the s u b j e c t t r e a t e d . As mentioned e a r l i e r , the d u p l i c a t i o n appeared to be much b e t t e r a f t e r the small e r r o r s of a p i p e t t e d e l i v e r i n g wrong volume and of evaporation  t a k i n g p l a c e from the contents  had been c o r r e c t e d .  o f the ketone feed tank,  Thus, f o r Run 8, which i s most n e a r l y comparable  with Choudhury's Run 65, the average d e v i a t i o n of the r e s u l t s from  those  of Choudhury was 1.6% f o r the continuous  phase c o n c e n t r a t i o n s , and 2.2%  f o r the d i s p e r s e d phase c o n c e n t r a t i o n s .  (These d e v i a t i o n s are given  without obtained  regard to s i g n . )  Table 6 records the p o i n t  i n Run 8 and a l s o those o f Choudhury.  d e v i a t i o n and the percent  concentrations  Also, i n c l u d e d are the  d e v i a t i o n o f the r e s u l t s o f Run 8 from  Choudhury's Run 65, a t v a r i o u s d i s t a n c e s from the n o z z l e  G) C o n c e n t r a t i o n The  study  tips.  i n the E l g i n head:  r e s u l t s obtained  i n the b r i e f survey o f the c o n c e n t r a t i o n s  i n the E l g i n head showed that the c o n c e n t r a t i o n o f the water phase changed from the value a p p l i c a b l e at the p o i n t o f e n t r y o f the water phase i n t o the column, to a lower value, before i n t e r f a c e or entered  the column proper.  t h i s phase reached the  However, i t should be noted  that Choudhury (10), and a l s o Ewanchyna (11), assumed that the water entered a t i t s i n l e t  c o n c e n t r a t i o n a t the i n t e r f a c e and that  this  c o n c e n t r a t i o n changed over almost zero height of column to some lower value.  These workers a l s o assumed that no f u r t h e r r i s e i n ketone  c o n c e n t r a t i o n occurred above the i n t e r f a c e .  Both assumptions are not  TABLE 6 C o n c e n t r a t i o n s i n both phases (smoothed values) f o r Run 8 o f t h i s work and Run 65 o£ Choudhury. Phase.  Concentration of a c e t i c a c i d i n the phase, l b . - m o l e s / f t ? x 1 0 a t d i s t a n c e from n o z z l e t i p s ( f t . ) of O.d 0.5 1.0 2.0 3.0 4.0 5.0 6.0 3  0.0  7.0  Inlet  Height of column, ft.  Run 8  Water  25.93  26.30  28.20  30.80  36.30  40.50  43.50  45.80  47.40  49.00  50=40  7.383  Choudhury Run 65  Water  26.30  27.00  29.60  32.50  36.90  40.40  43.60  46.20  47.70  49.10  50.40  7.383  from Run 65  -0.37  -0.70  -1.40  -1.70  -0.60  +0.10  -0.10  -0.40  -0.30  -0.10  0.00  % deviation  1*4  2.6  4.7  5.2  1.6  0.2  0.2  0.9  0.6  0.2  0.0  Deviation of Run 8  ;  Outlet Run 8  Ketone  6.75  7.20  9.00  11.10  15.25  17.80  20.50  22.20  23.40  24.30  24.96  7.383  6.50  7.10  9.30  11.40  15..00  17.80  19.90  21.60  22.90  24.00  24.30  7.383  from Run 65  +0.25 +O.10  -0.30  +0 30.  +0.25  0.0  +0.60  +0.60  +0.50  +0.30  +0.66  % deviation  3.5  3.2  2.6  1.7  0.0  3.0  2.8  2.2  1.3  2.7  Choudhury Run 65 Ketone Deviation of Run 8  1.4  o  oo CO  90 i n a c c o r d with the present  experimental  results.  In f a c t ,  the  c o n c e n t r a t i o n of the ketone phase appears to decrease above the interface.  I t appears that both assumptions used by the  previous  i n v e s t i g a t o r s are o v e r - s i m p l i f i c a t i o n s .  H) P i s t o n r e s u l t s : 1.-  E f f e o t of a p i s t o n sample on the steady s t a t e : The  the steady  f i r s t o p e r a t i o n done with the p i s t o n c o n s i s t e d o f  s t a t e requirements:  on the o u t l e t c o n c e n t r a t i o n s .  mainly the  finding  i n f l u e n c e of a p i s t o n sample  In F i g u r e s 25, 26,  i t can be seen that a  p i s t o n sample d i s t u r b s the steady s t a t e f o r at l e a s t 15 minutes i f d i s t i l l e d water i s used as a l i q u i d taken out by the sampler. disturbances  f o r r e p l a c i n g the column l i q u i d  F i g u r e 27 shows that l i t t l e or no  e x i s t when o u t l e t continuous  d i s t i l l e d water. from the steady  The  first  t e s t was  phase i s used i n s t e a d of  done to l e a r n the maximum d e v i a t i o n  s t a t e l i k e l y to be encountered, that o c c u r r i n g when a  s o l u t i o n of minimum c o n c e n t r a t i o n : d i s t i l l e d water, was p i s t o n hole through which the column was  put i n t o the  not o p e r a t i n g .  In normal  o p e r a t i o n of the p i s t o n sampling d e v i c e , the f i l l i n g up of t h i s p i s t o n hole with  o u t l e t continuous  phase g i v e s a maximum d e v i a t i o n of l e s s than  1% i n the e x i t c o n c e n t r a t i o n o f the continuous of the d i s p e r s e d phase. was  phase and  of zero i n that  With the use o f d i s t i l l e d water, the d e v i a t i o n  always 7% f o r the continuous  phase and  zero f o r the d i s p e r s e d phase  (except as a l r e a d y noted f o r one measurement shown on F i g u r e These d e v i a t i o n s were obtained u s i n g a continuous 54.8  phase flow r a t e of  f t ? / h r . - f t ? and a d i s p e r s e d phase flow r a t e of 120.5  ft?/hr.-ft?.  Knowing the e f f e c t o f a p i s t o n sample on the steady permits  one  to operate  26).  the sampler only when steady  state  s t a t e has been  r e s t o r e d a f t e r the t a k i n g o f any p r e c e d i n g ^ sample. 2.-  Comparison of p i s t o n and probe d i s p e r s e d Runs 9F, 9 F  phase samples:  9G, 9H and 91 were made with the purpose of  9  g e t t i n g comparisons between C . given by the p i s t o n and C the  probeo  given b y  Table 4 shows the r e s u l t s obtained i n these Runs.  The  author would l i k e to mention here that these Runs were made a t v a r i o u s dispersed  phase flow r a t e s with a view to have?--; a holdup o f d i s p e r s e d  phase which i n c r e a s e d  i n a stepwise f a s h i o n as runs progressed.  The  same continuous phase flow r a t e of 54 8 f t ? / h r . - f t ? was used f o r a l l the 0  runs i n Table 4. Cut,  unfortunately,  and as learned  l a t e r , the l a s t Run, 91 was  performed with the s o l u t i o n s near e q u i l i b r i u m c o n d i t i o n s at the a x i s of the p i s t o n . 91,  have not been considered  r a t e o f the d i s p e r s e d  i n the column  Due to t h i s f a c t , the f i v e r e s u l t s o f Run i n this discussion.  phase was always increased  The f a c t that the flow caused the mass t r a n s f e r  r e s i s t a n c e i n the column to be lowered as a r e s u l t o f the increased i n t e r f a c i a l area.  The lowered r e s i s t a n c e created  c o n d i t i o n s mentioned above.  the e q u i l i b r i u m  In the Run preceding 91, Run 9H, c o n d i t i o n s  a l s o were not as f a r from e q u i l i b r i u m as might be d e s i r a b l e . Run  91 perhaps was c l o s e to f l o o d i n g c o n d i t i o n s .  to Sherwood and P i g f o r d  (17) (P. 442 Figure  According  212, curve D) the f l o o d i n g  3 , 2 phase should be roughly 245.0 f t . / h r . - f t . 3 2 f o r a continuous phase v e l o c i t y o f 54.8 f t . / h r . - f t . . The highest 3 , 2 d i s p e r s e d phase flow r a t e used i n t h i s work was 208.3 f t . / h r . - f t . .  v e l o c i t y f o r the d i s p e r s e d  The  increase  o f the holdup, as mentioned e a r l i e r , was  supposed to make the d i f f e r e n c e r  (C . - C _) b i g g e r . wi wf 0  0  The f o l l o w i n g  example e x p l a i n s why t h i s procedure was adopted. Suppose two samples a r e taken with the p i s t o n sampler, but  92 with d i f f e r e n t ketone flow r a t e s to the column so that the holdups i n the column (and i n the corresponding sample) are d i f f e r e n t o  Suppose  a l s o that the feed c o n c e n t r a t i o n s to the column are a d j u s t e d so that i n both runs the v a l u e s o f C, . and C . a t the sampler l o c a t i o n are the same. ki wi (Such adjustments were not c a r r i e d out i n the present experiments with 1  the r e s u l t that i n Table 4, C. ., and i n Table 5, C ., are seen to ' ki' ' wi' decrease as the holdup i n c r e a s e s . )  Suppose t h a t the two phases o f the  p i s t o n are allowed to come to e q u i l i b r i u m and are then a n a l y z e d . mentioned  e a r l i e r , Equation 5 i s used, C. . = C. , - V (C , - C .) ki kf w wi wf V  Now  As  suppose  k  that o f the two samples, numbered one and two  sample 1 has the lower ketone holdup. V  w  k  2  < ^  2  respectively,  Hence  V  k  5  w  x  l  and  The s i t u a t i o n i s as shown i n Figure-29A.  For the experiments o f t h i s  work t r a n s f e r i s out o f the water and i n t o the ketone phase. wf  wi C Now  ki  ^  wf  *  C kf  at equilibrium: C  2 C  kf  Hence wi Furthermore, r e c a l l  ki  that: (C .).=(C . ) _ wi 1 wi 2  Hence  ®3  A/,  KI  SAMPLE I  SAMPLE 2  FIGURE 29A<»  TETO  piston samples having d i f f e r e n t holdup  and  Considering.ythe r e l a t i v e volumes of water and ketone i n samples 1 and  2  shows that there i s more t o t a l s o l u t e a v a i l a b l e i n sample 1 than i n satmple 2, and, t h e r e f o r e , (C . ) _ > wf 1  (C  wf  2  Then (C . - C wi  <  (C . - C  wf 1  and a n a l y s i s i s l e s s c r i t i c a l  wi  J wf  0  2  f o r sample 2 where the d i f f e r e n c e i s  greater. Compare now  two  f u r t h e r runs, one at low holdup and one a t  high holdup f o r which the feed c o n c e n t r a t i o n s to the column are manipulated so that when the holdup i s i n c r e a s e d the d i f f e r e n c e (C .-C wi w r  r  i s maintained  constant„  For these two  runs, i t i s evident that the  c o r r e c t i o n term w (C . - C J „ • wi wf  V  k  i n Equation 5 becomes l e s s important  a t the higher holdup because V ~~V  i s lower.  k As mentioned b e f o r e the s i t u a t i o n as between samples i n the  present work i s not as simple as i n e i t h e r of the two just discussed. decreased  Thus i n i n c r e a s i n g the holdup, •  and so d i d t h e i r d i f f e r e n c e .  illustrations  C . and C, both wi ki  T h i s p o i n t w i l l be  considered  again f o l l o w i n g a look at the e f f e c t on the r e s u l t s of when the a n a l y s i s i s done: before the phases of the p i s t o n sample have  reached  e q u i l i b r i u m , or a f t e r they have done so. Although  the p i s t o n samples were analyzed at e q u i l i b r i u m as  assumed i n the d i s c u s s i o n of the l a s t  paragraph,  the accuracy i s not  a f f e c t e d i f a n a l y s i s i s done before t h i s c o n d i t i o n i s reached.  Suppose  that the phases of the p i s t o n sample can be separated very q u i c k l y , j u s t a f t e r the sample has been taken.  Then C . and C . w i l l be wx wf p r a c t i c a l l y i d e n t i c a l , and even though the d i f f e r e n c e (C - C ) can wi  be determined  only very i n a c c u r a t e l y the value of  w  f  w i l l be known  q u i t e a c c u r a t e l y , because there i s almost no c o r r e c t i o n to be a p p l i e d to  i n determining  from  it.  (Refer to Equation 5.)  On the  othe  hand, i f e q u i l i b r i u m i s reached before the phases are separated and analyzed, (C , - C _) w i l l be l a r g e r , and much more a c c u r a t e l y known, wi wf ° as i t w i l l have to be i n order that the comparatively l a r g e c o r r e c t i o n which i s now obtained.  necessary can be a p p l i e d to C, _,, and an accurate C. . kf ki  For intermediate cases where e q u i l i b r i u m has not been reache  but s e p a r a t i o n of the phases has taken p l a c e some time a f t e r  sampling,  the c o r r e c t i o n w i l l be o b t a i n a b l e with only intermediate accuracy. However, s i n c e the c o r r e c t i o n w i l l be of only intermediate s i z e , accuracy i s a p p r o p r i a t e .  such  E v i d e n t l y , then, and as one would have  i n s t i n c t i v e l y assumed, whether or not e q u i l i b r i u m i s reached between the phases o f the p i s t o n sample before they are separated should not a f f e c t the accuracy of the f i n a l value d e s i r e d : C, . . But what of the * • • kx e f f e c t of i n c r e a s i n g the holdup i n the s e r i e s of p i s t o n runs? When one examines the d i f f e r e n c e (C . - C „ ) , o b t a i n a b l e from Tables 4 and 5, i t wx wf becomes apparent  that as the holdup  i n c r e a s e d t h i s d i f f e r e n c e remained  of  the same order of magnitude.  T h i s r e s u l t i s due  to the lower  levels  of  c o n c e n t r a t i o n s C , and C, . mentioned e a r l i e r , which correspond i n wi ki r  these experiments  to the phases i n the column being c l o s e r to  e q u i l i b r i u m than they were a t lower holdup.  In f a c t , the phases were  almost at e q u i l i b r i u m i n the column at the p i s t o n l o c a t i o n f o r Run  91.  96 The  idea of i n c r e a s i n g the holdup to decrease the e f f e c t of  small e r r o r s i n a n a l y s i s on the  f i n a l valuesof  enthusiasm but  f o r other r e s u l t s of i n c r e a s i n g  without a l l o w i n g  C, . was ki  s e i z e d on with  holdup, i n p a r t i c u l a r that whereby the phases come more n e a r l y e q u i l i b r i u m at the p i s t o n l o c a t i o n i n use.  of the column as noted e a r l i e r . )  at a c o n c e n t r a t i o n  high  The  An a l t e r n a t i v e would be  therefore  The  concentration  to move the  the column was  p r o f i l e s i n the a x i a l holdup runs of  the to  detail.  not near e q u i l i b r i u m with  91.  to Table 4, which g i v e s the r e s u l t s obtained with  both methods of sampling the d i s p e r s e d seen that the probe f i g u r e s and  indeed i n f i v e cases.  phase: p i s t o n and  probe, i t can  the p i s t o n f i g u r e s are very d i f f e r e n t  In these r e s u l t s , the percent d e v i a t i o n ,  i n connection with Table 4,  exceeded 10%.  average d e v i a t i o n of the r e s u l t s f o r Runs 9E, c a l c u l a t e d to be  sampler  the conditions of the phases with respect  the ketone l e a v i n g the column f o r Run  defined  ! J  in equilibrium  toward the top of the column are not known i n any  However, the water e n t e r i n g  be  (Most  present work teaches that as ketone  d i r e c t i o n of the column are not known f o r the high  Referring  one  i n the upper p a r t  enough so that the phases are not  toward the top of the column.  equilibrium  finally  arrangements must be made to feed the water phase  at the sampler l o c a t i o n .  present work, and  and  i n the lower r e g i o n of the column.  of the e x t r a c t i o n of a c i d from the water took place  holdup i s i n c r e a s e d ,  to  Thus, as the holdup i s  i n c r e a s i n g the mass t r a n s f e r r e s i s t a n c e i s decreasing gets e q u i l i b r i u m c o n d i t i o n s  the  -1.31%.  Also,  9F,  i f the d i s p e r s e d  But, 9G and phase  the  as  arithmetic  9H i s concentration  at time of a n a l y s i s , (C, „) . , , i s observed, i t i s seen that these k f piston'. r e s u l t s of each Run are i n reasonable agreement. The d i f f e r e n c e between (C, . ) . and (C, . ) . , appearing i n Table 4 probably are due to k i probe k i piston ' ° . r  97 three major e r r o r s caused  by the manipulations a s s o c i a t e d with the  a n a l y s e s , as shown i n Appendix V I I I . if  An e r r o r of 21.3%  the e r r o r s are supposed to be cumulative.  can be obtained  This result explains  why  some values of the d i s p e r s e d phase c o n c e n t r a t i o n s obtained with both methods are so  different.  None of the new  values of (C, .) determined ki  with the p i s t o n  are comparable with those obtained by Hawrelak, because d i f f e r e n t r a t e s were employed by each worker.  flow  However, i t i s p o s s i b l e to compare  Hawrelak's d e v i a t i o n s and the d e v i a t i o n s obtained i n t h i s work. values under ten percent d e v i a t i o n i n t h i s work are  The  comparatively  numerous (10 out of 15 values i f only Ruin 91 i s excluded, or 6 out of 11 v a l u e s i f both of Runs 9H and 91 are excluded).  Hawrelak had  only  3 values out of 20 i n t h i s range of from zero to 10% d e v i a t i o n . Another i n t e r e s t i n g remark concerning Hawrelak's r e s u l t s as shown i n h i s t h e s i s page 65,  i s that as many as 6 p i s t o n r e s u l t s are compared  with a s i n g l e probe r e s u l t .  In other words, Hawrelak u n f o r t u n a t e l y d i d  not take a probe sample each time he took a p i s t o n sample.  (He even  uses a probe sample from one run with a p i s t o n sample from another done on a d i f f e r e n t day.) these remarks. was  He was  An examination  run  of h i s data books confirms  of course operating on the assumptions that he  able to maintain t r u e steady s t a t e , that he could reproduce h i s  p r o f i l e s very a c c u r a t e l y , and that he could take probe samples very reproducibly. However, Hawrelak's Run 84, performed of 90.0  u s i n g a water flow r a t e  f t ^ / h r . - f t ? , and a ketone flow r a t e of 90.5  a volume percent ketone of 11.6, (C . - C . ) , 1.0 wi wf other runs.  shows that the average  '3 3 l b . - m o l e s / f t . x l O , was  T h i s average  f t ? / h r . - f t ? , to g i v e difference  b i g g e r i n t h i s run than i n h i s  d i f f e r e n c e i s a l s o b i g g e r than those of the  * Should be halved f o r comparison with the f i g u r e s of Table  4.  98 present work.  However, the percentage d e v i a t i o n o f h i s p i s t o n  results  from the average of h i s probe and p i s t o n r e s u l t s i s g e n e r a l l y h i g h e r f o r Run 84 than f o r h i s other Runs, (except f o r Run 79) and a l s o h i g h e r than the present d e v i a t i o n s . below 10% i n Run 84.) (C  This  (None of Ilawrelak's  generally  values are  i s another i n d i c a t i o n that the d i f f e r e n c e  . - C „) must be made h i g h e r ( by i n c r e a s i n g the i n l e t wi wf  concentration  o f the water phase), but that a l s o the volume r a t i o , ^^/V  , i n Equation  5 must be  smaller. Considering  the present r e s u l t s , the author b e l i e v e s  that the  check between the two methods of sampling has been put on the r i g h t track.  I t i s now known that the d i f f e r e n c e between C . and C „ must be wi wf  increased  by i n c r e a s i n g the column feed water c o n c e n t r a t i o n .  Then a t  high holdups agreement between the two methods of sampling could be expected assuming that the u n c e r t a i n t i e s o f the a n a l y s i s can be overcome.  99 SUMMARY The  f o l l o w i n g statements  described i n t h i s 1. - A r e l a t i o n was  can be made based  on the measurements  thesis: found between the d i s p e r s e d phase flow r a t e and  time to reach the steady s t a t e .  T h i s was  3 phase flow r a t e of 54.8  done f o r an average  the  continuous  2  ft./hr.-ft  .  The  time depended on the  initial  c o n c e n t r a t i o n l e v e l i n s i d e the column and on whether an i n t e r f a c e with ketone above i t e x i s t e d i n the E l g i n head. 2. - A c a l i b r a t i o n was  done to get the r e l a t i o n between the purging r a t e  and the minimum purging time r e q u i r e d to change the s o l u t i o n present i n the sampling  probes.  3. - No coalescence can be seen at the d i s p e r s e d phase probe entrance. Such coalescence takes p l a c e only when not  sampling.  4. - The steady s t a t e seems t o be i n f l u e n c e d more by the c o n t r o l l e r than by the sampling e f f e c t of sampling to 8.8%  r a t e used with the probes.  on the steady s t a t e was  of a d i s p e r s e d phase flow of 72.8 3  continuous phase flow r a t e of 54.8 cc./min.  were 28.2  interface No  found f o r sampling ft?/hr.-ft 2  ft./hr.-ft..  2  real r a t e s up  and 4.4%  (These sampling  of a rates in  and 14.2 r e s p e c t i v e l y . )  5. - The p o i n t c o n c e n t r a t i o n of e i t h e r phase as measured by the r e s p e c t i v e probe d i d not vary with sampling for  the water probe and 28.4  6. - Choudhury's Run 65 was for  r a t e even i f r a t e s as high as 34  cc./min.  f o r the ketone probe were reached.  d u p l i c a t e d w i t h i n 2,2%  the d i s p e r s e d phase c o n c e n t r a t i o n s and  the continuous phase c o n c e n t r a t i o n s . inlet  cc./min.  1,6%  (average d e v i a t i o n )  (average d e v i a t i o n ) f o r  I t should be pointed out that the*  c o n c e n t r a t i o n s were always as c l o s e as p o s s i b l e to those of  Choudhury, but not e x a c t l y the same. 7. - The d i s p e r s e d phase i n i t i a l  c o n c e n t r a t i o n s obtained by the p i s t o n  100 method v e r i f y those o b t a i n e d by means of the probes w i t h i n 2% d e v i a t i o n f o r three samples  (not i n c l u d i n g Run 91) and w i t h i n 10% d e v i a t i o n f o r  ten o t h e r r e s u l t s out of fifteen,,  A f i n a l check of the probe sampler  by the p i s t o n sampler has not been obtained„ agreement  However, much c l o s e r  has been demonstrated i n the p r e s e n t work than had appeared  i n the e a r l i e r i n v e s t i g a t i o n .  I f a l a r g e d i f f e r e n c e between  and  can be o b t a i n e d a t the same time as a high holdup of ketone then a check o f (C, .) . . and (C, . ) ' k i piston k i probe  i s expectedo *  But the holdup should  not be as high as i n the probe sample :then, as noted e a r l i e r , the methods become i d e n t i c a l .  101 RECOMMENDATIONS A f t e r having worked f o r almost  two years with the apparatus  d e s c r i b e d p r e v i o u s l y , i t can be recommended that an automatic  level  c o n t r o l l e r f o r the i n t e r f a c e would r e s u l t i n a g r e a t improvement o f the operation.  I n s t a l l a t i o n o f a s t r i p p i n g column would permit work with  the spray column to be c a r r i e d out on a more r e g u l a r b a s i s . back-washing procedure obtained.  c o u l d be c a r r i e d out while data were being  As f a r as the apparatus  would f a c i l i t e  the r e s e a r c h work  Concerning  The lengthy  :  i s concerned,  these two suggestions  considerably.  the t h e o r e t i c a l aspect of the r e s e a r c h , more study  with the p i s t o n i s needed.  A study c o u l d be made by v a r y i n g the  continuous phase c o n c e n t r a t i o n and flow r a t e , so that the phases are not i n e q u i l i b r i u m a t the l o c a t i o n o f the sampler even i f the d i s p e r s e d phase flow r a t e i s a l s o h i g h . an attempt  In the l i g h t o f the previous suggestions,  to i n c r e a s e the holdup  o f the column would be welcome, i n  order to get more and more volume percent ketone i n a p i s t o n sample. However, to do t h i s , new d i s p e r s e d phase pump would be needed because the maximum c a p a c i t y of the present pump was reached  i n Run 91. I t  should be borne i n mind, however, that the column may have been o p e r a t i n g c l o s e to the f l o o d i n g c o n d i t i o n i n t h a t run, and much h i g h e r holdups may not be p o s s i b l e . Along with these s u g g e s t i o n s , a recommendation i s made that i n measuring the volumes o f the phases o f the p i s t o n samples the procedure  o f p o u r r i n g from a f l a s k i n t o a graduate be changed back to  the method of Hawrelak, where the phases o f each p i s t o n sample were c o l l e c t e d d i r e c t l y i n a graduated graduated  flask.  Such f l a s k s should be  over a l a r g e r range than were those o f Hawrelak.  range i s necessary to p r o v i d e f o r h i g h e r holdups  than those  The l a r g e r encountered  102 by him.  The graduated p o r t i o n should extend from 0 to 40 ml. About the a n a l y s i s technique, i t i s a l s o recommended  that  a b i g g e r p i p e t t e should be used f o r purpose o f g e t t i n g the l e a s t p o s s i b l e e r r o r due to measurement of the volume of the samples.  103 NOMENCLATURE Except where noted otherwise, the wafe used throughout the  f o l l o w i n g nomenclature  Thesis:  Symbols 2 area of column, f t . .  A  Cross-sectionnal  a  I n t e r f a c i a l area per u n i t volume of e x t r a c t i o n column,  C*  Phase s o l u t e c o n c e n t r a t i o n  which could be  2 3 ft./ft..  i n e q u i l i b r i u m with  3 3 of the other phase, l b . - m o l e s / f t . xlO . 3 3 c o n c e n t r a t i o n , l b . - m o l e s / f t . x 10 .  the c o n c e n t r a t i o n C  Solute  C, . ki  I n i t i a l concentration  of s o l u t e i n ketone phase during i n t e r n a l ° 3 3  sampling, l b . - m o l e s / f t . x C^ C . wi  Concentration  . wf  10  of s o l u t e i n ketone phase of ketone sample as  measured at time of a n a l y s i s , l b . - m o l e s / f t ? x 10? I n i t i a l c o n c e n t r a t i o n of s o l u t e i n water phase during i n t e r n a l sampling, lb.-moles/ft°. x  C  r  Concentration  1Q^.  of s o l u t e i n water phase of ketone sample as  3 3 measured at time of a n a l y s i s , l b . - m o l e s / f t . x 10 , h K.  E f f e c t i v e height of e x t r a c t i o n s e c t i o n of column, f t . , (measured from n o z z l e t i p s to i n t e r f a c e . ) O v e r - a l l mass t r a n s f e r c o e f f i c i e n t , lb.-moles (hr.) ( f f r ) ( l b . - m o l e s / f t ? )  Ka  Over-all extraction capacity c o e f f i c i e n t ,  L  Phase flow r a t e ,  N  Amount of s o l u t e t r a n s f e r r e d based on i n l e t and concentrations,  NN"/A N  Not  ox V  hr  ft?/hr.-ft?. outlet  lb.-moles/hr..  applicable.  Number of o v e r - a l l t r a n s f e r u n i t s based on x phase, Volume of ketone phase i n the ketone.sample, c c .  IV  V  w  Volume of -Water  phase i n the ketone*, sample, cc,  Integral sign. Differential  d  sign.  Subscripts 1  Inlet.  2  Outlet.  k  Ketone phase.  w  Water phase.  c  Continuous phase.  d  Dispersed phase.  M  Measured.  X  Phase x.  i  initial.  f  Final.  t  Toluene.  Superscript *  Equilibrium value.  105 LIST OF REFERENCES 1.  Geankoplis, C. J . and Hixson, A. N., Ind. Eng. Chem. 42:1141,1950.  2.  Geankoplis, C. J . , Wells, P. L., and Hawk, E. L., Lnd. Eng. Chem. 43  : 1848, 1951.  3.  Newman, M. L,, Ind, Eng. Chem.  44 : 2457, 1952.  4.  Geankoplis, C. J . and Kreager, R. M,, Ind. Eng. Chem. 45: 2156, 1953.  5.  G i e r , T. E. and Hougen, J . 0., Ind. Eng. Chem. 45 : 1362, 1953.  6.  Miyauchi, T., U. S. A t . Energy Comm. Kept. UCRL 3911,  7.  Smoot, L. D. and Babb, A. L. , IS EC Fund. jL : 93, May 1962.  8.  H e e r t j e s , P. M., Holve, W. A., and Talsma, H., Chem. Eng. S c i .  AUGUST 1957.  3 : 122, 1954. 8.  Cavers, S. D. and Ewanchyna, J . E., Can. J . o f Chem.Eng. 35 : 113, 1957.  10.  Choudhury, P. R., M. A. Sc. T h e s i s , U n i v e r s i t y o f B r i t i s h Columbia, 1959.  11.  Ewanchyna, J . E. , M. A. Sc. T h e s i s , U n i v e r s i t y of Saskatchewan, 1955.  12.  •  Hawrelak, R. A., M. A. Sc. T h e s i s , U n i v e r s i t y o f B r i t i s h  Columbia,  1960. 13.  R o c c h i n i , R. J . , M. A. Sc. T h e s i s , U n i v e r s i t y o f B r i t i s h  Columbia,  1961. 14.  Carbide and Carbon Chemicals Co., Pamphlet "Ketones",; 34, 1953.  15.  K i r k , R. E., and Othmer, 0. F. , E n c y c l o p e d i a o f Chem. Tech. 1st  16.  Sup. : 317, 1957.  Jonhson,  H. F. and B l i s s , H., Trans. Am. I n s t . Chem. Engrs. 42 :  331, 1946.  106 17.  Sherwood, T. K. , and I'igford, R. L. , ABSORPTION and EXTRACTION, 2nd ed. : 442.  Mc G r a w - f l i l l Book Co., Inc., New York, 1952.  A P P E N D I C E S  108 APPENDIX I RotametersCalibrations. The the  rotameters used throughout t h i s work were c a l i b r a t e d  cleaning  research.  after  and re-assembly o f the apparatus at the beginning of the  The continuous phase rotameter was c a l i b r a t e d u s i n g  distilled 3  water (saturated  with M.I.U.K.) and c o n t a i n i n g 50.2 l b . - m o l e s / f t . xlO  of a c e t i c a c i d .  For the d i s p e r s e d phase rotameter, M.I.B.K.  3  (saturated  with d i s t i l l e d water) and c o n t a i n i n g 6.54 l b . - m o l e s / f t ? x l O ^ o f a c e t i c a c i d was used. The  Both c a l i b r a t i o n s were c a r r i e d out a t room temperature.  r e s u l t s are g i v e n i n Table 7 and p l o t t e d  on F i g u r e 30.  Since the s m a l l e s t d i v i s i o n s of the s c a l e s  of the rotameters j u s t  mentioned were one q u a r t e r o f the next l a r g e s t d i v i s i o n s , i t became obvious that a change o f s c a l e the p r e c i s i o n used d i r e c l y ; be  to cm. and mm. d i v i s i o n s would inprove  o f the readings s i n c e i n addition,  smaller i n actual  then the decimal system c o u l d be  the s m a l l e s t d i v i s i o n s of the s c a l e would  magnitude than p r e v i o u s l y .  A second c a l i b r a t i o n  was done and the r e s u l t s are shown i n Table 8 and p l o t t e d TABLE 7 Rotameter Water Rotameter.  on Figure 31.  Calibrations. S e r i a l number 14143.  Room and l i q u i d temperature: 72.5 °F L i q u i d : d i s t i l l e d water s a t u r a t e d with M.I.B.K. and c o n t a i n i n g 50.2 lb.-moles/f t"? xlO of a c e t i c Rotameter Reading. 0.02 0.04 0.06 0.08 0.10 0.12 0.14  acid. Rate o f flow, f t ? / h r . 0.1615 0.3415 0.5080 0.6675 0.8315 0.9915 1.1420  109  KETONE P H A S E ROTAMETER  WATER PHASE ROTAMETER  72.5  0.04  0.08  0.12  ROTAMETER FIGURE 30.  Rotameter C a l i b r a t i o n s .  0.16  F.  020  READING  Rotameter S e r i a l No.: 14143. No.: 14142.  Ketone Rotameter. Room and l i q u i d  S e r i a l number 14142.  temperature: 72.5 °F  L i q u i d : M.I.B.K. s a t u r a t e d with  distilled  water and c o n t a i n i n g 6.53 lb.-moles ft"? x 10^ Rotameter Reading,  of acetic  acid.  Rate o f flow, f t ? / h  0.02 0.04 0.06 0.08 0.12 0.16  0.2320 0.4150 0.6150 0.7850 1.1850 1.5510  TABLE 8 Rotameter  Calibrations.  Water Rotameter.  S e r i a l number 14143.  Room and l i q u i d temperature: 74 °F. L i q u i d : d i s t i l l e d water s a t u r a t e d with M.I.B.K. and c o n t a i n i n g 50.0 l b . - m o l e s / f t ^ x 10^ of a c e t i c  3 Rate o f flow, f t . / h r .  Rotameter Reading. mm. 2S 50 75 100 125 150 175 200 225  0.0739 0.1680 0.2682 0.3885 0.5115 0.6273 0.7500 0.8840 1.0200  Ketone Rotameter. Room and l i q u i d  acid.  S e r i a l number 14142.  temperature: 73  °F.  L i q u i d : M.I.B.K. s a t u r a t e d with d i s t i l l e d water 3 3 and c o n t a i n i n g 6.53 l b . - m o l e s / f t . x 10 of a c e t i c a c i d . 3 Rotameter Reading.(mm.) Rate o f flow, f t . / h r . 50 0.2120 75 0.3830 100 0.5800 125 0.7860 150 1.0220 175 1.2780 200 1.5150 225 1.7980  Ill  ROTAMETER FIGURE  31.  Rotameter C a l i b r a t i o n s .  READING  Mm Scale.,  MM.  APPENDIX I I Run data. The  f o l l o w i n g Tables ( 9 and 10) show the purpose of each o f the  runs and the o v e r - a l l t r a n s f e r data. which were used l i s t e d here. concerned sampling  A l l Runs done i n the present work,  to produce the r e s u l t s r e p o r t e d i n t h i s t h e s i s are  Also i n c l u d e d are the f o l l o w i n g c h a r a c t e r i s t i c s which  the sasupling probes: r a t e as a percentage  and the temperature  sampling  r a t e f o r both phases, the  of the phase flow r a t e , the purging  a t which the run was performed.  time,  Also i n c l u d e d  i n Table 10A are the data o f Runs 5D and 8 f£©m which the c o n c e n t r a t i o n s p r o f i l e s were o b t a i n e d .  113 TABLE 9. Run  number.  i  Purpose of  Sampling r a t e , cc./min .  Run.  Water Ketone phase. phase. *1C ID *1E •IF 1G 2 2A 2B 2C 2D *3 *3A *3B *3C 4 *5A 5B, 1 5D *5E 5F 5G 5H  6J *6H *6I *6G" 6K 6L 6M 1  0  Sampling r a t e study Sampling r a t e study Sampling r a t e study Sampling r a t e study Sampling rate study Sampling r a t e study Sampling r a t e study Sampling r a t e study Sampling r a t e study Sampling r a t e study Sampling r a t e study D u p l i c a t i o n of Run 65 o f Choudhury D u p l i c a t i o n of Run 65 o f Choudhury Point c o n c e n t r a t i o n versus r a t e D u p l i c a t i o n of Run 66 of Choudhury Reproduction of Run 3A D u p l i c a t i o n of Run 65 o f Choudhury D u p l i c a t i o n of Run 65 of Choudhury D u p l i c a t i o n of Run 65 of Choudhury Point c o n c e n t r a t i o n versus sampling r a t e Point c o n c e n t r a t i o n versus sampling r a t e Point c o n c e n t r a t i o n versus sampling r a t e Steady s t a t e study Steady s t a t e study Steady s t a t e study Steady s t a t e study Steady s t a t e study Steady s t a t e study Steady s t a t e study Steady s t a t e study  V V V V V V V V V V V  V V V V V V V V V V V  9.0  13.0  2.9  3.9  9.0  75  9.0  13.0  2.3  3.3  9.0  75  V  V  V  V  V  74  8.2  12.4  4.1  3.8  8.0  72  8.0  14.0  2.8  4.2  9.0  72  9.3  13.8  3.2  4.2  9.0  76  8.9  14.3  3.0  4.3  9.0  76  8.9  13.0  2.9  3.9  9.0  78  V  V  V  V  V  71  V  V  V  V  V  74  V N/A N/A N/A N/A N/A N/A N/A N/A  V N/A N/A N/A N/A N/A N/A N/A N/A  V N/A N/A N/A N/A N/A N/A N/A N/A'  V N/A N/A N/A N/A N/A N/A N/A N/A  V N/A N/A N/A N/A N/A N/A N/A N/A  72 74 73 76 73 72 69 74 73  * Runs which were not used i n t h i s V = Varied. N/A  = Not  applicable.  Sampling Purging Tern] °F time. as % of phase min. (ave, flow r a t e . Water Ketone phase; phase. V V V 77 V V V 78 V V V 78 V V V 77 V V V 75 V V V 76 V V V 74 V V V 78 V V V 78 V V V 72 V V V 74  thesis.  114 TABLE 9 Cont.. Run number.  Purpose  o f Run.  Sampling r a t e , cc./min.  Water Ketone phase, phase. 7 *7A 7B 7C 7D 7E 7F 8 *8A *8B 9A 9B 9C 9D 9E 9F 9G 9H 91  *  Sampling r a t e study V Sampling rate study V Sampling r a t e study V Sampling r a t e study V Sampling r a t e study V Steady s t a t e versus sampling r a t e V Steady s t a t e versus sampling r a t e V D u p l i c a t i o n of Run 65 o f Choudhury 10.0 Point concentration versus sampling r a t e 7.1 Point c o n c e n t r a t i o n versus sampling r a t e 7.9 E f f e c t of a piston sample on steady s t a t e N/A E f f e c t of a p i s t o n sample on steady s t a t e N/A E f f e c t of a piston sample on steady s t a t e N/A E f f e c t of a p i s t o n saiisple on steady s t a t e N/A P i s t o n samples taken 12 0 P i s t o n samples taken 10.0 P i s t o n samples taken 9.6 p i s t o n samples taken 6.2 P i s t o n samples taken 6.5 o  Runs which were not used i n t h i s  V =  Varied.  N/A  = Not  applicable.  Sampling Purging as % o f time. phase min. flow r a t e . Water Ketone phase, phase.  Temp, o F (ave.)  V V V V V  V V V V V  V V V V V  V V V V V  75 75 74 75 72  V  V  V  V  75  V  V  V  V  75  10.0  3.2  2.5  8.0  75  V  10.0  76  V V  2.5  V  10.0  75  N/A  N/A  N/A  N/A  76  N/A  N/A  N/A  N/A  76  N/A  N/A  N/A  N/A  76  N/A 13.0 9.4 8.8 8.2 7.6  N/A 3.8 3.2 3.0 1.9 2.1  N/A 2.3 1.7 1.6 1.1 0.8  N/A 10.0 10.0 10.0 10.0 lOcO  74 76 76 75 77 73  thesis.  TABLE 10 O v e r - a l l t r a n s f e r data. Run number  Water phase.  1C ID -4-E IF 1G 2 2A 2B 2C 2D 3 3A 3B 3C 4 5A 5C 5D 5E 5F 5G 5H l 6J 6H 6  I  1  2 6G 6K 6L 6 I  Flow r a t e s ft /hr.-ft?  Concentrations, l b . - m o l e s / f t ? x 10?  3  Ketone phase. Water. Ketone,  wl  w2  kl  k2  50.2 50.7 53.7 37.9 39.8 37.6 38.3 39.4 40.3 39.5 39.7 38.4 38.4 34.7 34.4 50.6 50.4 51.6 51.0 51.1 50.3 51.4 49.9 49.9 49.7 49.9 50.1 50.3 50.7  26.2 26.5 28.9 21.5 22.5 20.4 22.2 20.5 21.8 19.9 21.3 19.5 19.5 17.9 12.1 25.0 24.8 24.9 24.9 25.6 26.3 25.6 24.4 25.7 24.6 25.1 25.1 25.1 25.3  6.3 6.1 6.7 5.4 5.8 5.0 5.5 5.2 5.8 4.9 5.7 4.8 4.9 4.7 4.9 6.6 6.5 6.5 6.5 6S5 6.5 6.4 6.5 6.6 6.5 6.6 6.6 6.8 6.7  24.9 24.8 26.3 18.5 17.3 18.4 18.8 19.0 19.6 19.1 19.3 18.6 18.8 16.4 14.9 25.0 24.1 24.5 24.2 24.5 24.4 24.6 24.6 24.8 24.3 24.9 24.9 25.1 25.3  Linear V e l o c i t y through the nozzle t i p s , ft/sec.  w 55.8 54.6 54.6 54.8 54.1 54.6 55.1 54.6 54.6 52.9 52.9 52.7 52.4 54.7 36.3 52.7 51.2 51.1 51.2 52.9 54.1 52.9 54.9 54.9 54.9 54.9 54.9 54.9 54.8  68.7 67.4 67.4 70.6 65.9 68.6 68.7 72.7 $9.0 71.7 71.8 71.7 72.7 71.8 71.5 72.7 72.7 71.7 71.7 72.7 72.7 71.7 72.9 73.6 72.9 73.1 72.9 72.9 72.8  0.338 0.332 0.332 0.347 0.324 0.335 0.335 0.357 0.338 0.352 0.353 0.352 0.357 0.353 0.352 0.357 0.357 0.352 0.352 0.357 0.357 0.352 0.358 0.362 0.358 0.359 0.358 0.358 0.358  Over-all acetic acid transfer rates. lb.-moles/ ft? x 10 . N N. w  Percent deviation  3  16.4 16.2 16.6 11.0 11.5 11.5 10.9 12.6 12.* 12.7 11.9 12.2 12.2 11.3 9.9 16.5 16.1 16,7 16.4 16.5 15.9 16.7 17.1 16.3 16.9 16.0 16.8 16.9 1711  15.7 15.4 16.2 11.3 10.9 11.3 11.2 12.3  11.§ 12.5 12.0 12.1 12.4 10.3 8.8 16.4 15.8 15.8 15.6 16.0 15.9 16.0 16.2 16.4 16.3 16.4 16.3 16.4 16.6  N  w" k xlOO N  4.2 5.1 2.4 2.7 5.4 1.8 2.7 2.4T §.6 1.6 0.8 0.8 1.6 9.3 11.8 0.6 1.9 5.5 5.0 3.1 0.0 4.3 5.4 0.6 3.6 2.4 3.0 3.0 3.0  OI  TABLE 10 Cont. Over-all transfer Run number  Concentrations, l b . --moles/ft? x 1 0 Water phase. C  6M 7 7A 7B 50. 7D 7E 7F 8 8A 8B 9A 9B 9C 9D 9E 9F 9G 9H 91  wl  50.7 48.7 49.7 49.6 49.5 50.7 51.3 51.9 50.4 51.6 51.5 43.5 43.4 51.4 51.4 49.5 49.9 50,6 50.8 50.5  C  w2  25.5 24.4 24.8 25.0 25.1 25.9 25.4 25.8 25.9 27.2 27.1 16.5 16.7 17.6 17.6 16.5 16.9 17.6 14.4 13.9  Flow r a t e s ft /hr. -ft? 3  3  Ketone phase. Water. Ketoi C  kl  6.7 614 6.9 6.6 6.7 7.0 6.6  7.0  6.8 7.8 8.0 6.8 6.8 6.8 6.8 6.4 6.4 6.5 6.6 6.7  C  k2  25.5 24.3 24.6 24.5 24.6 25.3 25.5 25.8 25.0 25.8 25.7 18.3 18.3 21.8 21.5 21.1 21.3 21.7 18.3 16.3  L  w  54.8 54.8 54.8 54.8 54.6 54.8 54.8 54.8 54.8 55.0 S5.Q 54.3 54.2 54.2 54.2 54.8 54.8 54.8 54.8 54.8  data.  Linear V e l o c i t y through the nozzle t i p s . ft./sec.  3  N  \ 73.2 72.8 72.8 72.8 72.8 72.8 72.8 72.8 72.7 72.8 73.2 120.0 119.6 120.5 120.5 120.5 119.6 120.5 169.2 208.0  Over-all acetic Percent acid transfer deviation rates. lb.-moles/ ft?x 10 .  0.360 0.358 0.358 0.358 0.358 0.358 0.358 0.358 0.357 0.358 0.360 0.337 0.335 0.338 0.338 0.338 0.335 0.338 0.475 0.584  w  16.9 16.5 16.7 16.5 16.3 16.6 17.4 17.5 16.5 16.4 16.4 17.9 17.7 22.4 22.4 22.2 22.2 22.2 24.4 24.6  N, k 16.9 16.0 15.8 16.0 16.0 16.3 16.9 16.8 16.2 16.1 15.9 16.9 16.8 22.1 21.7 21.7 21.8 22.4 24.3 24.5  N -N. w k: N 0.0 1.9 5.5 3.1 1.9 1.8 2.9 4.1 1.8 1.8 3.1 5.7 5.2 1.4 3.2 2.3 1.8 0.9 0.4 0.4  TABLE 10A.  \  \  0.078  Data o f c o n c e n t r a t i o n p r o f i l e s f o r Runs 5D and 8. (not smoothed). Run 5D Run 8 Volume i n a toncemrations, Height Volume i n a Concentrations, ketone sample. lb.-moles/ft3x 10. o f the sample.(ketone) lb.-moies/ft xlO? probes. V C . C . V ft. kf wf wi k wf ki wi kf ki w 0.078 0.8 7.11 0.0 48.0 6.57 6.57 26.40 32 .6 7„11 26.25  0.445  5.4  37.6  18.90  9.11  27.78  1.161  2.3  29 .3  24.50  12.00 11.44 31.60  1.060  5.0  37.0  22.40 12.00 10.78  31.35  2.161  2.2  28 .6  31.55  15.90 15.49 37.20  1.661  5.0  36.0  26.85 13.86 12.97  33.32  3.1G1  2.2  28 .2  35.65  18.20 17.81 40.60  2.411  4.8  36.2  30.30 15.90 15.00  37.20  4.161  2.4  28 .4  39.90  20.40 20.04 44.15  3.161  4.0  35.5  33.45 17.52 16.80  39.84  5.161  2.0  28 .2  41.30  22.08 21.75 46.00  4.161  *1.0  34.8  36.45 18.87 18.23  42.00  6.161  2.4  26 .4  45.30  23.50 23.28 47.75  5.161  3.8  33.7  90.35 18.87 20.69  46.29  7.286  2.0  26 . 2  45.15  24.70 24.36 49.60  6.161  4.2  31.4  42.20 23.16 22.25  48.99  7.286  4.0  30.0  43.50 24.96 23.86  51.72  neignt of the probes. ft.  3  C  C  3  C  C  C  C  -  -  9.24  Average i n l e t water c o n c e n t r a t i o n : 51.61  Average i n l e t  Average o u t l e t water c o n c e n t r a t i o n : 24.70  Average o u t l e t water c o n c e n t r a t i o n : 25.95  Average i n l e t ketone c o n c e n t r a t i o n :  Average i n l e t ketone c o n c e n t r a t i o n :  6.50  Average o u t l e t ketone c o n c e n t r a t i o n : 24.50  water c o n c e n t r a t i o n :  50.40 6.75  Average o u t l e t ketone c o n c e n t r a t i o n : 24.96  1 APPENDIX I I I Study of time needed t o o b t a i n steady s t a t e i n s i d e the column. As mentioned e a r l i e r i n the t h e s i s , two d i f f e r e n t  concentra-  t i o n p r o f i l e s e x i s t i n s i d e the column before beginning a run.  These  c o n c e n t r a t i o n s depend on the l i q u i d f i l l i n g  time.  If  the column i s f i l l e d  with continuous  the run s t a r t s , and the column hasn't needed to reach  phase feed before  been operated  before, the time  the steady s t a t e i s longer than i t i s when the column  has been operated to  the column a t that  before and contains both phases.  T h i s r e s u l t i s due  the higher average c o n c e n t r a t i o n which e x i s t s i n the column i n the  former case and a l s o i n c r e a s e d d i f f i c u l t i e s i n s t e a d y i n g out the interface.  Table  11 records the r e s u l t s obtained i n f i v e runs* where  the c o n d i t i o n s of the former case a p p l i e d . o u t l e t s o l u t i o n s : continuous as f u n c t i o n s of time. same Table \\,  The c o n c e n t r a t i o n s of both  phase, and d i s p e r s e d phase, were sampled  The height of the column has been noted  i n the  The i n l e t c o n c e n t r a t i o n f o r the continous phase feed 3  3  s o l u t i o n averaged 5 0 . 4 l b . - m o l e s / f t . xlO • and, f o r the d i s p e r s e d phase 6.6  lb.-moles/ft? xlO^. As j u s t mentioned, i f the c o n c e n t r a t i o n p r o f i l e s i n s i d e the  column r e s u l t e d from a previous run, the time needed to reach the steady  s t a t e i s s h o r t e r , due to the s m a l l e r average c o n c e n t r a t i o n  e x i s t i n g a t the s t a r t of the run, and due to the e x i s t e n c e o f a l i q u i d liquid  i n t e r f a c e a t the s t a r t o f the run.  obtained All  for this  case.  the runs of t h i s  sort.  Table  12 records the r e s u l t  TABLE 1 1 . Steady s t a t e study. Time, min.  0  *Run 6 1 . Concentrations l b . - m o l e s / f t ? xlO? c c C C k2 wl w2 kl 4 9 . 9 0  —  _  6 . 5 3  •Run 6 J . Concentrations, l b . - m o l e s / f t xlO? C , C „ C, k l k2 wl w2  Column height, ft.  3  n  _  6 . 5 0  4 9 . 8  29.1  2 5 . 3  2 4 . 2  2 9 . 1  2 5 . 3  2 4 o 5  2 7 o 2  2 5 . 1  20  2 5 . 0  2 4 . 6  2 6 . 7  25  2 5 . 3  2 4 . 8  30  2 5 . 2  2 4 . 8  3 5  2 5 . 3  2 4 o 9  40  2 5 . 2  2 4 . 9  7 . 4 6  2 5 . 1  2 4 . 9  7 . 4 4  5  1 9 . 2  2 3 . 4  10  2 3 . 0  15  2 4 . 6  4 5  2 6 . 3  2 5 . 0 6 . 6  2 4 . 9  7 . 4 6  2 6 . 4  2 4 . 9  7 . 4 4  2 5 o 9  2 4 . 8  7 . 4 3  2 5 . 7  2 4 . 8  7 . 4 2  2 5 . 7  2 4 . 8  7 . 4 1  2 4  8  7 / 3 8  2 4 . 7  7 . 3 8  2 4 . 9  2 5 . 7  55  2 5 . 2  2 4 . 9  2 5 . 5  60  2 5 . 1  2 4 . 9  2 4 . 7  7 . 3 8  2 5 . 1  2 4 . 9  55.43  2 5 . 2  2 4 . 6  7 . 3 7  2 5 . 1  2 4 . 9  7 . 4 3  2 5 . 3  2 4 . 6  7 . 3 6  7 5  2 5 . 1  2 4 . 9  7 . 4 2  80  2 5 . 1  2 4 . 9  50  4 9 . 9  6 5 70  2 5 . 1  6 . 5 3  4 9 . 9  Column height ft.  7 . 4 3 4 9 . 9  2 5 . 4  6 . 6  u  8 5 90  *  4 9 . 9  2 4 . 9  6 „ 4 7  2 4 . 8  7 . 4 3  Runs s t a r t e d with continuous phase feed f i l l i n g the column. In the blank spaces, no readings were taken.  +  In t h i s r u n there was d i s t i l l e d water i n the annular space o f the E l g i n head  TABL6 11 Cont. Steady s t a t e study. Time, min.  *Run 6M Concentrations, lb.-moles/ft? x l O . 3  wl 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75  w2  51.0  •Run 9A Concentrations, l b . - m o l e s / f t xlO? 3  wl  k2  w2  kl  Column h e i g h t , ft.  k2  6.6  50.5  50.7  kl  Column h e i g h t , ft.  31.9 28.3 27.3 26.7 26.3 26.2 26.2 25.9 25.7 25.5 25.3 25.5 25.2 25.7  26.3 26.2 43.6 6.8  25.9 25.7 25.3 25.5 25.7 25.5 25.5 25.5 25.5 25.5 25.2  43.3 7.46 7145 7.43 7.42  43.4  27.9 21.6 20.6 19.4 17,7 17.0 16.6 16.5 16.5 16.5  6.7 6.8  21.8 21.0 20.4 20.2 18.7 18.2 18.2 18.3 18.3 18.3  7.29 7.24 7.24 7.25 7.27 7.28 7.29 7.30  6.8  7.41 7.41  6.7 * Run s t a r t e d with continuous The blank spacesmean  phase feed f i l l i n g  the column.  that no reading was taken.  to  o  TABLE 1 1 Cont. Steady s t a t e Time, min.  'Run 9 C . Concentrations, lb.-moles/ft x 1 0 ? 3  w2  wl  kl  study. •Run 9 1 . Concentrations, lb.-moles/ft x 1 0 .  Column height, ft.  3  wl  k2  3  Column height, ft.  k2  Wi  0 5  2 8 . 9  5 1 . 3  6 . 8  2 5 . 2  1 4 . 2  1 4 . 6  2 3 . 9  1 3 . 9  1 6 . 0  10  2 Q . 9  15  2 0 . 8  2 3 . 6  20  1 9 . 2  2 2 . 9  1 4 . 2  1 7 . 6  2 2 . 5  1 4 . 2  1 7 . 4  1 3 . 9  1 6 . 3  1 3 . 9  1 6 . 1  1 3 . 8  1 6 . 2  1 3 . 9  1 6 . 3  25  1 8 . 8  5 1 . 5  6 „ 8  30  1 8 . 5  35  1 6 . 3  2 2 . 2  40  1 8 . 2  2 2 . 2  45  1 8 . 0  2 2 . 0  5 1 . 4  2 2 . 2  6.8  5 0 . 4  7 . 3 6  7 . 4 2  1 4 . 0  6 . 7  1 7 . 2  1 3 . 9  1 6 . 2  55  1 3 . 6  1 6 . 3  60  1 3 . 8  1 6 . 3  1 3 . 9  1 6 . 2  1 3 . 9  1 6 . 4  1 8 . 0  50  2 2 o 0  7 . 4 0  65 70 5 0 . 4  75  ?  Run s t a r t e d with continuous  a  I n t e r f a c e c o n t r o l l e r raised, l . - i n . The blank spacesmean  1 3 . 9  phase feed f i l l i n g after this  6 . 7  1 6 . 4  a7.28 7 . 2 9  7 . 3 7  the column, reading.  that no reading was taken.  to  TABLE 12. Stendy s t a t e Time, min.  'Run 6K. Concentrations, lb.-moles/ft xl0 . 3  wl 0 5 10 15 20 25 30 35 40 45 50  viJi  50.1  3  kl 6.5  26 4 24.8 24.8 25.0 25.0 25.2 25.1 25.0 25.1 25.1 0  50.3  50.3  C k2  6.8  6.8  23.6 24.4 24.8 25.0 25.0 24.9 25.0 25.2 25.1 25.1  Column height, ft. 7.45 7.45 7.45 7.45 7.40 7.40 7.40 7.40 7.40 7.447.41  study. **Run 6L. Concentrations, lb.-moles/ft x 10 . 3  C Cwl  C  w2  50.8  50.6  50.5  with a column which  C kl  Column height, ft.  3  C k2  6.5 26.6 24 o 5 24.6 25.0 25.2 25.2 25.5 25.4 25.3 25.2  6.7  6.7  operated b e f o r e .  Blank space means that no reading was tnken.  23.2 24.6 25.1 25.3 25.3 25.4 25.2 25.3 25.3 25.3  7.40 7.39 7.39 7.38 7.38 7.38 7.38  TABLE 1 2 Cont. Steady s t a t e study. ••Run 9B Concentrations lb. -moles/ft x 1 0 .  Time, min.  3  3  C  G w2  c  4 3 . 5  16.6  6.8  wl  kl  c  Column height, ft.  k 2  ••Run 9 H Concentrations, lb . - m o l e s / f t x 1 0 . 3  C . wl  C „ w2  Column height, ft.  3  C, , kl  C, „ k 2  0 5  18.2  10  1 6 . 7  18.3  15  16.6  18.3  20  16.6  18.3  1 6 . 5  25 30  43  o 4  16.6 1 6 . 7  35 40  18.3  6.8  7.33  50.6  7.34  1 8 . 4  6 . 6  1716  1 4 . 7  1 7 . 5  14.1  1 8 . 4  a  7 . 3 7  7.35  18.3 18.3  7.37  14.4  1 8 . 7  7.38  1 4 . 4  1 8 , 7  7.38  1 4 . 4  1 8 . 4  6.8  4 3 . 2  45  17o0  1 8 . 5  50  1 6 . 5  18.4  55  1 6 . 5  18 o 5  7 . 3 7  60 6.6  50.9  65  **  Run s t a r t e d with a column which had been operated b e f o r e .  a  I n t e r f a c e c o n t r o l l e r lowered Blank spaces mean  7 . 3 7  1 . - i n . a f t e r t h i s reading.  that no r e a d i n g was  taken.  to  OJ  Table 13 summarizes the r e s u l t s obtained i n a l l these  runs.  T h i s Table shows, f o r each d i f f e r e n t way of s t a r t i n g a run, the time i n minutes which one should wait to get steady s t a t e u s i n g the d i s p e r s e d phase flow r a t e mentioned.  The continuous  phase flow r a t e used was  at a value o f 54A8 f t ^ / h r . - f t ?  TABLE 13. Summary o f the time needed to o b t a i n steady s t a t e depending on the c o n c e n t r a t i o n i n the column . L = constant = 54.8 f ? . / h r . f t ? w Continuous phase feed f i l l i n g the column b e f o r e the s t a r t of a run and no d i s p e r s e d phase p r e s e n t . Time, min,  Run number.  Dispersed phase flow r a t e , L^  Runs s t a r t e d from a column which had been operated before.  Run number.  Time, min.  Dispersed phase flow r a t e , 1^  6J  40.0  73.60  6K  20.0  72.90  6M  45.0  73.20  6L  25.0  72.80  9C  30.0  120.00  9B  15.0  120.20  9A  35.0  120.00  911  12.5  169.40  91  12.5  208.00  Note:  The  time values were taken from graphs made o f the r e s u l t s  given i n Table 11 and 12.  For s a f e o p e r a t i o n , 5 minutes more  should be added.  Run 6 1^ has not been i n c l u d e d ; t h i s run was begun with d i s t i l l e d water i n the E l g i n head.  125 APPENDIX IV Study o f the minimum purge time f o r changing the c o n c e n t r a t i o n o f the s o l u t i o n i n the probes u s i n g various rates. The f o l l o w i n g T a b l e s , 14 to 25, give the r e s u l t s of eleven Runs (1G, 2, 2A, 2D, 2C, 2D, 7, 7tf, 7C and 7D) performed to study the time r e q u i r e d to change the c o n c e n t r a t i o n of the m a t e r i a l i n the probes u s i n g v a r i o u s r a t e s of p u r g i n g . It can be remarked  that i n these Tables (14 to 25), f o r  some Runs a complete a n a l y s i s of the ketone sample was  i s not given;  this  due to the presence of only a small volume of water i n the ketone  sampleo  The smallness o f t h i s volume was  caused by the low p u r g i n g  r a t e which c o l l e c t e d 90 to 95% by volume of ketone phase i n the d i s p e r s e d phase sample.  The e f f e c t o f such a small volume of water  on the r e s u l t s would be l e s s than 2% at the worst. A summarizing Table (number 24) i s given a t the end o f t h i s Appendix.  The purge time was  as would be expected.  found to f a l l as the p u r g i n g r a t e  increased  TABLE 14. Study of minimum purge time. Run 1G. Note: Probe f i l l e d with l i q u i d a t sample p o s i t i o n 4A and moved a t zero time to sample p o s i t i o n 7. Average continuous phase probe sampling r a t e 4.9 cc/min. Average d i s p e r s e d phase probe sampling r a t e 13.7 cc./min. Time, min. (a) From  to  0 1 2 3 4 5 6  1 2 3 4 5 6 7  Volume o f i n ketone cc. V w 2„2 2.2 2.3 1.9 2.1 2.4 2.1  phases sample  Concentrations, lb.-moles/ft? x 10 . 3  C , wf 27.9 27.5 33.1 34.2 34.8 34.1 34.5  k 11.3 12.0 11,8 11.6 11.6 11.4 11.8  C, _ kf 16.2 15.7 18.1 19.0 19.0 19.1 19.0  C . wi 32.8 33.1  ki 15.2 14.7 18.1 18.5 18.5 18.3 lcs.5  -  37.2 37.6 37.8 —  TABLE 15. Study of the  minimum purge time.  Run 2 Note: Probe f i l l e d  with l i q u i d a t sample p o s i t i o n 7 and  moved a t zero time to sample p o s i t i o n 4A. Average continuous phase probe sampling r a t e : 13.8 cc./min. Average d i s p e r s e d phuise probe sampling r a t e : 15.7 cc./min. Time, min. (a) From 0 1 2 3 4 5 6 7 (a)  to 1 2 3 4 5 6 7 lit  Volume o f phases i n ketone sample cc, V, fe k 13.3 2.4 2.4 13.3 13.2 2.4 2„6 13.3 13.6 2.4 13.4 2.5 13.8 2.6 7.4 38.0  one minute sample.  Concentrations, lb.-moles/ft x 10 . 3  C _ wf 33.1 32.3 27.3 27.2 27.0 27.2 26.4 27.6  C, „ kf 18.0 17.5 14.6 14.5 14.4 14.5 14.5 14.4  ki 1C.6 16.7 13.5 13.5 13.6 13.7 13.5 13.6  3  C . wi 36.4 36.2 33.4 32.1 31.7 31.7 31.7 31.8  TABLE 15 Cont. Study o f the minimum purge time. Run 2 Note: Probes f i l l e d with l i q u i d at sample p o s i t i o n 4A and moved a t zero time to sample p o i n t 2A. Averaged continuous phase sampling r a t e : 10.7 cc./min. Averaged d i s p e r s e d phase sampling r a t e : 14 5 cc./min. 0  Time, min. (a) From 0 1 2 3 4 5 6 7  to 1 2 3 4 5 6 7 ia  Volume o f phases i n ketone sample cc. V w  Concentrations, lb.-moles/ft? x 10 . 3  \  2.4 2.4 2.3 2.4 2.4 2.0 2.5 11.0  C  12.0 12.6 13.0 12.4 12.8 12.0  wf  26.9 27.6 19.5 19.7 20.2 20.5 19.6 20.2  62.5  C  kf  14.6 14.7 10.4 1011 10.1 10.2 10.3 10.1  C  ki  13.6 13.5 8.6 80S  9.1 9.4 9.1 9.2  C . wi 32.0 31.9 29.9 26.a 25.8 25.6 25.6 25.6  TABLE 16. Study o f the minimum purge time. Run 2A. Note: Probes f i l l e d with l i q u i d a t p o s i t i o n 2A and moved at zero time to p o s i t i o n 4A. Averaged continuous phase probe sampling r a t e : 3.8 cc./min. Averaged d i s p e r s e d phase probe sampling r a t e : 8.7 cc./min. Time, min. (a) From to 0 1 2 3 4 5 6 7 8 9 10 11 12  1 2 3 4 5 6 7 8 9 10 11 12 13  Volume o f phases i n ketone sample cc • V V, w k 8.2 1.1 1.2 8.0 8.3 1.0 8.0 1.1 6.1 1.1 7.3 1.0 7.3 1.0 7.8 0.9 7.4 0.9 0.8 7.6 0.8 7.5 7.4 0.9 0.9 7.5  Concentrations, l b . - m o l e s / f t ? x 10°.• b  C „ wf .11. Z.:.  C, , kfi. 10-45 10.13 10.39 13.62 14.35 14.46 14.10 14.55 14. 55 14.61 14.61 14.54 14.54 B  C . • ki wi 10.45 25,32 10.13 25 o*0 10.39 25.50 13.62 25.52 14.35 25.70 14 .,48 26.50 14 .10 26.25 14.55 29.68 14.55 29.72 14.61 31.10 14.61 31.00 14 „ 54 31.10 14.54 30.85  c  ,  TABLE 1 6 Cont. RUN 2 A cont. Note: Probes f i l l e d with l i q u i d a t sampling p o s i t i o n 4 A and moved a t zero time to sampling p o s i t i o n 7 . Averaged continuous phase probe sampling r a t e : 1 0 . 5 cc./min. Averaged d i s p e r s e d phase probe sampling r a t e : 1 1 . 7 c c o / m i n . Time, min. (a) From  to  Volume of phases i n ketone sample  Concentrations, lb.-moles/ft V x 1 0  ° .  •  V  V  w  (b) wf  k  C  0  1  1 . 8  9 . 6  °kf 15c  40  C . Wl  ki  C  1 5 . 4 0  3 2 . 4  1  2  1 . 8  1 0 . 2  1 5 . 5 5  1 5 . 5 5  3 2 . 3  2  3  1 . 6  1 0 . 4  1 6 . 1 8  1 6 . 1 8  3 3 . 6  3  4  l o 4  1 0 . 1  1 8 . 2 0  1 8 . 2 0  3 4 . 4  4  5  1 . 6  10oO  lb.  20  1 8 . 2 0  3 6 . 7  5  6  1 . 4  1 0 o l  18 c 20  1 8 . 2 0  36 o 7  6  7  1 . 4  1 0 . 6  1 8 . 3 2  1 8  3 2  3 6 . 8  7  8  1 . 7  1 0 . 1  1 8 . 1 5  1 8 . 1 5  3 6 . 6  8  9  1 . 5  9 c 8  1 8 . 8 3  1 8 . 8 3  3 6 . 4  (a) one minute  0  sample  (b) Not enough water i n the ketone sample  for analysis.  TABLE 1 7 . RUN  2 B .  Study o f the minimum purge time. Probes f i l l e d with l i q u i d a t sampling p o s i t i o n 4 A and moved a t zero time to sampling p o s i t i o n 7 .  Note:  Averaged continuous phase probe sampling r a t e : 6 . 5 cc./min. Averaged d i s p e r s e d phase probe sampling r a t e : 7 . 0 cc./min. Time, min. (a) From to 0  1  1  Volume o f phases i n ketone sample cc. V w  \  Concentrations, l b . - n i o l e s / f t V x 106' (b)°wf  C  kf  C  ki  C . Wl  3 1 c 8  0 . 7  5 c 2  1 4 . 7  1 4 . 7  1 . 0  9 . 0  1 4 . 4  1 4 . 4  3 1 . 4  1 4 . 6  1 4 . 6  3 1 . 9 3 3 c 9  2  3  1 . 2  7 . 9  3  4  0 . 7  7 . 6  }5.2  1 5 . 2  4  5  0 c 4  4 . 6  1 8 . 0  1 8 . 0  3 5 . 9  1 . 0  8 . 7  1 8 . 5  1 8 . 5  3 6 .  1 8 . 3  3 7 . 2  5  6  6  7  0 , 5  5 . 1  1 8 . 3  7  8  0 . 5  3 . 5  1 8 . 3  1 8 . 3  3 7 . 2  8  9  0 . 3  3 o 5  1 9 . 0  1 9 . 0  3 7 . 3  (a) One minute sample. ( b ) Not enough water i n the ketone sample  for analysis.  5  TABLE 1 8 . Study o f the minimum purge time. RUN 2C Note: Probes f i l l e d with l i q u i d a t sampling p o s i t i o n 4A and moved a t zero time to sampling p o s i t i o n 2A. Averaged continuous phase probe sampling r a t e : 7 . 7 cc./min. Averaged d i s p e r s e d phase probe sampling r a t e : 1 1 . 9 7 cc./min. Time, min. (a) From  to  Volume of phases i n ketone sample cc • V V, w k  Concentrations, lb.-moles/ft? x 1 C „ , . wf  0 ° .  C, , kf  c, .  14,2  ki  C . wi  0  1  1.3  '10.2  1 4 . 2  3 2 . 4  1  2  1.3  11.2  13.6  13 o 6  31o6  2  3  1.0  11.1  12c4  12.4  3 1 . 0  3  4  1.2  1 1 . 2  9 . 5  9 . 5  2 9 . 1  4  5  1.2  1 1 . 2  9 . 5  9 . 5  2 6 . 6  5  6  1.4  11.4  9.6  916  2 5 . 3  6  7  1.2  1 0 . 2  9.6  9.6  2 4 . 6  7  8  1.2  9 . 5  9 . 7  9 . 7  2 4 . 4  (  b  )  -  (a) One minute sample. (b) Not enough water i n the ketone sample  for analysis.  Note: Probes f i l l e d with l i q u i d a t sample positiinaSSdand moved a t zero time to sampling p o s i t i o n 4A. Averaged continuous phase probe sampling r a t e : 1 . 6 cc./min. Averaged d i s p e r s e d phtise probe sampling r a t e : 5 . 6 cc./min. Time, min. (a) From  to  Volume o f phases i n ketone sample cc. V V, w k  Concentrations, lb.-moles/ft"^ x 1 C „ wf  0 ° .  C, , kf  c, • ki  C . Wl  0  1  0 . 1  3 , 9  1 8 . 7  1 8 . 7  1  2  0 . 0  3.8  18.9  1 8 . 9  3 5 . 9 3 6 . 3  2  3  0 . 0  7.0  J 8 . 5  1 8 . 5  3 4 . 7  3  4  0 . 0  6.2  18.6  18.6  3 6 . 9  4  5  0 . 0  4 . 4  19.0  19.0  3 4 . 9  5  6  0 . 3  5.8  17c6  17.6  3 6 . 0  6  7  0 . 1  6 . 2  15.6  15.6  36  7  8  0 . 5  6.0  14.8  14.8  3 6 . 4  8  9  0 . 2  5.6  1 4 . 9  14.9  3 6 . 3  9  10  0 . 2  6.6  1 4 . 9  14.9  3 6 . 0  (a) One minute sample. (b) Not enough water i n the ketone sample  for analysis.  .6  TABLE 18 Cont. RUN 2C cont. Note: Probes f i l l e d with l i q u i d a t sampling p o s i t i o n 2A and moved at zero time to sample p o s i t i o n 4A. Averaged continuous phase sampling r a t e : 9.0 cc./min. Averaged d i s p e r s e d phase sampling r a t e : 11.5 cc./min. Time, min. (a) From  to  0 1 2 3 4 5  1 2 3 4 5 6  Volume of phases i n ketone sample cc. V k w 1.2 10.4 1.2 10.4 10.4 1.2 3.8 0.0 0.8 7.2 1.6 11.6 V  Concentrations, lb.-moles/ftV x 10°. (b) wf C  (a) One minute sample. (b) Not enough water i n the ketone sample  °kf 10.8 11.0 11.8 15.8 15.5 15.8  ki 10.8 11.0 11.8 15.8 15.5 15.8 C  C . wi 27.3 27.4 28.2 30.7 32.9 33.9  for analysis.  i TABLE 19. Study o f the minimum purge time. RUN 2D Note: Probes f i l l e d with l i q u i d a t sampling p o s i t i o n 4A and moved a t zero time to sampling p o s i t i o n 2A. Averaged continuous phase sampling r a t e : 10.4 cc./min. Averaged d i s p e r s e d phase sampling r a t e : 12.4 cc./min. Time, min. (a) From  to  0 1 2 3 4 5 6 7  1 2 3 4 5 6 7 8  Volume of phases i n ketone sample V w 1.4 1.1 1.4 1.4 1.6 1.5 1.6 1.6  '' k 11.6 9.9 10.6 10.4 11.2 11.3 11.7 11.6 V  Concentrations lb.-moles/ft? x 10 . 3  (b?wf  (a) One minute sample. (b) Not enough water i n the ketone sample  °kf 13.6 13.8 12.7 9.3 9.2 9.2 9.5 9.4  ki 13.6 13.8 12.7 9.3 9.2 9.2 9.5 9.4 C  for analysis.  C . wi  -  29.9 29.1 26.7 24.9 24.0 24.3 24.3  TABLE 19 Cont. RUN 2D cont. Note: Probes f i l l e d with l i q u i d at sampling p o s i t i o n 2A and moved at zero time to sample p o s i t i o n 4A. Averaged continuous phase sampling r a t e : 1.9 cc./min. Averaged d i s p e r s e d phase sampling r a t e : 6.5 cc./min. Time, min. (a) From 0 1  to 1 2  Volume of phases i n ketone sample cc. V w  \  1.0  1.2  5.2 5.2  2  3  1.0  5.4  3  4  1.0  5.0  4  5  1.1  4 . 8  5  6  0.8  6.6  6  7  0 . 4  6.9  7  8  0.6  6.4  8  9  0 . 5  6o3  9  10  0 . 0  6.8  10  11  0 . 8  6 . 0  (a) One minute sample. (b) Not enough water i n the  Concentrations, lb.-moles/ft? x 10 . 3  (b) w f C  C  -  ketone sample  kf  C  C . Wl  ki  2 2 . 2  10o9  10.9  10.9  10.9  24.4  10.8  10.8  2 3 . 7  10.8  10.8  2 0 . 2  10.1  10.1  24.2  12.3  12.3  26.3  14.0  14.0  24.0  14.0  14.0  2 4 . 5  13.9  13.9  24.1  14.0  14.0  24.3  14.0  14.0  2 5 . 1  for  analysis.  TABLE 20 Study of the minimum purge time. RUN 7. Note: Probes f i l l e d with l i q u i d at sampling p o s i t i o n 4 and moved a t zero time to s a m p l * n p p n s i t i o n 4A. Averaged continuous phase probe sampling r a t e : 2.8 cc./min. Averaged d i s p e r s e d phase probe sampling r a t e : 5.4 cc./min. 0  Time, min. (a)  Volume of phases Concentrations, i n ketone sample lb.-moles/ft? x 10 . cc. . From to V V, ..^C _ C C. . w k (b) wf f ki 0 3 0.8 16.2 11.7 11.7 3 6 0.8 16.4 12.2 12.2 6 9 0.8 15.1 17.7 17.7 9 12 0.8 14.8 17.7 17.7 12 15 0.8 15.0 17.7 17.7 15 18 2.0 24.0 17.4 17.4 18 21 2.0 26.0 17.4 17.4 (a) Three minutes sample. (b) Not enough water i n the ketone sample f o r a n a l y s i s . 3  k  C . wi 29.8 29.6 29.7 32.5 36.4 38.9 38.7  132 TABLE 21. Study o f theminimum purge time. RUN  7B.  Note: Probes f i l l e d with l i q u i d at sampling p o s i t i o n 1A and moved a t zero time to sampling p o s i t i o n 4A. Averaged continuous phase probe sampling r a t e : 2.8 6c./min. Averaged d i s p e r s e d phase probe sampling r a t e : 2.1 cc^/min. Time, min. (a) From  to 3 6 9 12 15 itz 19 21 23  0 3 6 9 12 15 17 19 21  Volume of phases i n ketone sample cc. V v, w k 2.6 3.1 6.4 0.4 7.3 0.0 6.8 0.0 5.7 0.3' 4.2 0.0 4.0 0.0 4.0 0.0 3.8 0.0  Concentrations, lb.-moles/ft? x 10 . 3  (b> wf C  kf 12.4 12.4 11.8 11.5 12.4 17.0 18.0 18.0 18.0 C  (a) Three or two minutes samples. (b) Not enough water i n the ketone sample  C . wi 30.8 30.5 30.9 32.6 38.1 38.8 39.3 39.3 39.4  ki 12.4 12.4 11.8 11.5 12.4 17.0 18.0 18.0 18.0  for analysis.  TABLE 22. Study of the minimum purge time. RUN  7C.  Note: Probes f i l l e d with l i q u i d at sampling p o s i t i o n 4A and moved at zero time to sampling p o s i t i o n 1A. Averaged continuous phase probe sampling r a t e : 5.0 cc./min. Averaged d i s p e r s e d phase probe sampling r a t e : 4.8 cc./min. Time, min. (a) From 0 3 6 9 11 13 15 17  to 3 6 9 11 13 15 17 19  Volume of phases i n ketone sample  C o n c e n t r a t i ons, lb.--moles/ft. x 1 0 . 3  cc • V w 0.6 0.8 0.6 0.3 0.4 0.3 0.6 0.3  k 8.2 10.8 13.2 8.4 8.8 7.9 8.2 8.0 V  C  wf  -  (a) Three or two minutes sample. (b) Not enough water i n the ketone sample  kf 18.0 18.2 17.5 16.0 11.7 11.8 11.8 11.8 C  ki 18.0 18.2 17.5 16.0 11.7 11.8 11.8 11.8 C  for analysis.  C . wi 39.6 38.6 33.0 30.0 30.6 30.6 30 o 6 30.8  133 TABLE 22 Cont. RUN 7C cont. Note: Probes f i l l e d with l i q u i d a t sampling p o s i t i o n moved a t zero time to sampling p o s i t i o n 4A«. Time, min. (a) From  to  0 3 6 10 12 14 16  3 6 10 12 14 16 18  Volume of phases i n ketone sample cc. V, V w k 12.8 0.6 13.5 0.6 16.0 0.8 7.4 0.6 9.6 0.6 9.7 0.5 20.2 1.0  1A and  Concentrations, lb.-moles/ft x 10 . 3  wf  3  kf 11.9 11.7 15.7 18.0 17.7 18.0 18.0  ki 11.9 11.7 15.7 18.0 17.7 18.0 18.0  C . Wl 30.7 33.8 39.0 39.0 39.7 39.7 39.7  (a) Four, three and two minutes samples. (b) not enough water i n the ketone sample f o r a n a l y s i s . TABLE  23.  Study o f the minimum purge time. RUN 7D. Note: Probes f i l l e d with l i q u i d a t sample p o s i t i o n 1A and moved a t zero time to sample p o s i t i o n 4A. Averaged continuous phase probe sampling r a t e : 3.7 cc./min. Averaged d i s p e r s e d phase probe sampling r a t e : 2.5 cc./min. Time, min. (a) From  to  0  3 6 9 11 13 15 17 19 21  3 6 9 11 13 15 17 ' 19  Volume o f phases i n ketone sample cc. V k w 6.6 0.6 7.8 0.7 4.8 0.0 4.8 0.0 4.9 010 5.2 0.0 4.5 0.0 5.0 0.0 4.9 0.0  Concentrations, lb.-moles/ft x 10 . 3  wf  kf 12.1 12.2 12.1 12.8 12.8 17.1 18.8 18.8 18.8  (a) Three o r two minutes sample (b) Not enough water i n the ketone sample  3  ki 12.1 12.2 12.1 12.8 12.8 17.1 18.8 18.8 18.8  for analysis.  C . wi 31.2 31.5 34.1 38.7 40.1 40.4 40.7 40.7 40.7  134  TABLE 2 4 . Summary o f a l l r e s u l t s to deternime the minimum time. (Smoothed v a l u e s ) . Run  number.  Continuous phase. Sampling rate, cc./min  Minimum purge time, min.  purge  Dispersed phase. Sampling rate, cc./min  Minimum purge time min  1G  12.8  5.0  13.8  3 . 5  2  11.0  6.0  15.9  3 . 0  2  1 3 . 0  5.0  1 4 . 9  3 . 5  8 . 7  5.5  _ *  2A  3.8  2A  1 0 . 5  6.0  1 1 . 7  4 . 0  2B  8 . 5  7.0  8.6  5.5  2C  7.7  12.0  4 . 0  2C  9.0  1 1 . 5  4 « 0  2C  1.6  2D  1.0  5.0  _*  5.6  8.0  _ *  6 . 5  7.0  10.4  7.0  12.4  5.0  7  2.8  2 0 . 0  5.4  9 . 0  7B  2 . 8  19.0  2 . 1  18a3  7C  5.0  12.0  4 . 1  13.0  7C  6.3  10.0  4 . 5  12.0  7D  3 . 7  16.0  2 . 5  16.8  2D  * The minimum purge time was not obtained i n these runs^ the time was too s h o r t f o r the c o n c e n t r a t i o n curve to f l a t t e n out.  135 APPENDIX V. Point c o n c e n t r a t i o n The  f o l l o w i n g Table,  25,  versus sampling r a t e .  represents  thfe r e s u l t s of the  done to demonstrate that the sampling r a t e d i d not concentration.  runs  i n f l u e n c e the  point  TABLE 25. P o i n t C o n c e n t r a t i o n Versus Sampling Kate. Run number.  Purge time, min.  Sampling time, min.  Minimum Purge Time according to Figure 10. min. Water Ketone phase. phase.  Rate of Sampling, cc./min.  Volume o f Concentrations^ phases i n lb.-moles/ftVxlO , ketone sample.  66.  Water phase.  Ketone phase.  w  V,  9H  10 10 10 10  5 5 5 2  6.0 4.0 10.0 6.4  5.6 3.0 5.6 4.8  10.4 16.0 6.2 9.4  8.4 15.6 8.2 10.3  3.0 7.0 3.0 1.5  7F  0 0 0 0 0  10 10 10 414 8  18.6 18.6 18.6 18.6 18.6  25.0 18.6 9.4 1.0 3.0  2.8 2.8 2.8 2.8 2.8  1.1 2.0 5.2 28.2 16.2  0.6 1.8 2.0 24.0 19.0  10.4 17.8 50.0 103.0 111.0  0 0 0 0 0  10 10 10 10 10  18.6 9.8 5.2 7.6 4.3  6.8 7.4 8.6 9.2 5.0  2.9 6.4 11.3 8.1 14.2  7.0 6.2 5.7 5.4 9.8  14.0 4.0 3.0 3.0 6.0  15 5 5 8 7 10 5  5 5 5 6 3 3 3  6.8 13.8  3.6 4.8 6.6 9.4 3.4 3.0 2.0  9.0 4.5  13.8 10.2 7.2 5.3 14.5 15.5 18.7  5.0 4.0 2.5 0.0 5.0 5.5 7.0  7E  5H  * *  f0.6 *  Probe location.  J  -  6.0  -  —  :  C  wf  39.0 14.6 69.0 15.0 38.0 13.3 19.0 a l 5 . 0  kf  ki  wi  7„2 7.2 7. 1 7. 1  15.8 16.2 15.7 16.2  1.59 1.59 1.59 1.59  28.4 28.0 27.7 28.6 28.5  19. 1 18.9 18.8 f a . 4 18, 4 -18. 3 18, 4 |8.5 19<. Ik48.4  41.4 41.2 41.3 41.3 41.4  4A 4A 4A 4A 4A  56.0 58.0 54.0 50.5 82.0  29.2 27.7 27.7 27.7 27.3  19.6 18.6 18.6 18.6 18.3  16.6 17.7 17.8 17.7 17.3  41.2 41.2 41.3 41.2 41.2  4A 4A 4A 4A 4A  64.0 47.0 33.3 26.5 38.5 41.0 48.2  26.7 27.0 27.0  13.5 13.8 14.0 14.0 14.4 14.5 14.5  ^2.9 13.2 13.5 14.0 13.7 13.9 13.9  33.3 34.8  3B 3B 3B 3B 3B 3B 3B  -  28.2 28.6 28.6  7^3 7.3 7.2 7.2  :  #  -  35.0  -  OJ  TABLE 25 Cont. Run number.  5G  5F  5B,  ID  Purge time, min.  Sampling time, min.  Minimum Purge Time a c c o r d i n g to Figure 10. min. Ketone Water phase. phase 3.6 6.6 * 4.1 * 5.6 * 5.6 * 3.2 » 2.6 6.4 0.5  Rate of Sampling, cc./min. Water phase. 9.3 .-  18 7 8 9 5 5 6  3 3 3 3 3 3 2  9 0 0 0 0 0  3 3 3 9% 6 7.  7.0 13.2  9 0 0 0 0 0  3 5 5 5 5 5  6.6 13.4  6.6  *  9.2  4 0 0 0  5 5 5 5  0.5 1.0 5.2 4.0  1.0 1.0  34.0 21.0 11.0 16.0  a * + #  = = = =  *  *  • *  *  — — — —  -  3.6 4.6 4.0 3.2 2.6 2.3  8.8 4.7  3.7 4.8 2.7  9.3 4.6  -  -• -  -  8.9  7.0 *  •  0.5  3.8 2.6  -  3  Ketone phase. 13.7 12.3 8.3 8.3 15.0 17.0 20.3  V,_ k  V, k  4.0 3.8 2.0 2.0 5.8 7.0 5.0  13.7 10.7 12.7 15.0 17.0 17.6  4.0 3.0 3.0 14^0 9.0 17.0  13.6 18.4 16.6 -  23.3 -  28.4  21.0  12.9 17.0  Probe location.  Volume o f Concentrations, phases i n lb.-moles/f&10 . ketone sampl e.  C . Wl  C . IV f  kf  37.0 33.2 23.0 23.0 39.2 44.0 35.5  27.3 27.1 25.5 23.4 25.8 28.0 27.3  14.1 13.8 13.9 13.7 14.1 14.3 14.7  13.2 12.8 13.0 12.7 12.6 13.1 13.6  37.0 29.0 35.0 125.0 109.8 105.2  26.1 27.6 26.7 28.4 28.1 29.0  14.0 14.0 13.9 14.1 14.2 14.3  ^2.9 13.2 13.1 13.4 13.5 13.2  35.5 35.6  5.5 6.0 11.3 20.0 -  36.3 46.0 71.0  24.6 24.6  12.6 12.5 12.8  ?2.5 12.4 12.7 12.4  32.1 32.2  27.7 25.0 10.2 12.2  104,3 80.0 54.0 72.6  -  96.6  -  25.9 27.4 -  45.7 45.6 44.2 45.1  -  13.3 -  •  23.8 23.8 23.5 23.5  E q u i l i b r i u m value, not analyzed. Not sampled. Average water c o n c e n t r a t i o n was used to c a l c u l a t e these values. F i r s t c o n c e n t r a t i o n of water used to do the c a l c u l a t i o n s .  ki  -  23.1 23.1 22.6 23.1  35.4 -  -  .35.7  -  -  -  3B 3B 3B 3B 3B 3B 3B 3B 3B 3B 3B 3B 3B  3a.7  3B 3B 3b 3B 3B 3B  47.7 47.8 47.9 47.9  7 7 7 7  -  32.0 -  CJ •si  138 APPENDIX VI Jet  characteristic  data. (Jonhson and  Reference to R o c c h i n i ' s t h e s i s used a v e l o c i t y  Bliss).  (13) page 63, showed that  through the n o z z l e of 0.3623 f t . / s e c .  he  However,  Choudhury (10) used a v e l o c i t y o f 0.357 f t . / s e c . as r e p o r t e d i n h i s t h e s i s , page 26.  I t was  d i s c o v e r e d that t h i s d i f f e r e n c e  the use of s l i g h t l y d i f f e r e n t After  recalculating  was  caused by  flow r a t e s of d i s p e r s e d phase. the v e l o c i t y of these previous workers  (10,13) and checking the above values to c l o s e approximation, i t was decided to use a value of 0.357 f t . / s e c . based on the average of the n o z z l e t i p s p r e s e n t l y a v a i l a b l e .  T h i s i s 0.1029.-in. (10).  I t became necessary to check i f t h i s v e l o c i t y n o z z l e would be expected to g i v e uniform drops. and B l i s s was  (16), i t was  diameter  through  R e f e r r i n g to  the  Jonhson  d i s c o v e r e d that the v e l o c i t y used i n t h i s work  h i g h enough so that the drops would have ceased forming at the  nozzle t i p s uniform.  but not so h i g h that the drops would have ceased being  In other words, the v e l o c i t y o f 0.357 f t . / s e c .  utilized  would g i v e uniform drops. Although a l i n e a r i n t e r p o l a t i o n Jonhson  and B l i s s (16) i n d i c a t e s  0.103.-in.  I.D.,  o f Table II o f the paper by  that drops should, f o r a n o z z l e of  cease being uniform when the v e l o c i t y  i n nozzle t i p s  reached 0.350 f t . / s e c , a c c o r d i n g to t h e i r curve i n t h e i r F i g u r e 3, the v e l o c i t y plotted  plotted  velocity  a t 0.11-in. I.D. appears to be too low.  i s the one from the Table.)  In f a c t , a t 0.111-in.  n o z z l e diameter they draw t h e i r curve c o n s i d e r a b l y above the point.  I t i s on the b a s i s o f t h i s f a c t that the statement  the t i p v e l o c i t y  (This I.D.  plotted  i s made that  o f 0.357 f t . / s e c . should produce uniform drops  + Not always used. * I t was observed that the drops formed s t r a i g h t (not sinuous) j e t s except f o r one t i p ; at'' t h i s ' ' t i p the j e t was sinuous. A l l j e t s were app. Vfe-in. i n l e n g t h .  139 a c c o r d i n g to Jonhson and B l i s s ( l 6 ) .  APPENDIX VII Sample c a l c u l a t i o n of the m a t e r i a l balances used i n connection with Run 9H water Sample no. 2 which contained ketone. As a r e s u l t of a high flow r a t e of d i s p e r s e d phase and perhaps o f too high a sampling r a t e f o r such a flow, the f o l l o w i n g c a l c u l a t i o n s have to be made to c o r r e c t the  f o r the presence of ketone i n  water probe sample. Equation 5 i s a p p l i e d f i r s t  to the sample obtained with the  water probe: (C, .) ki  =  (6,k fJ water . - (V /V, ) . (C . - (C .) ' ) w k water wi wf water probe  probe  probe  The same equation i s a p p l i e d a l s o to the ketone probe sample: (C. .) ki  =  (C, _). . - (V /V, ), . (C . - (C ,). . ) k f ketone w k ketone wi wf ketone probe  probe  probe  Where the volume of one phase i n the sample i s s m a l l , as compared the  with  volume of the other phase, an e q u i l i b r i u m value i s taken i n s t e a d of  m aking use of a n a l y s i s . and C ., are l e f t . wi In  In the two equations only two unknowns, C  These, of course, can be s o l v e d f o r .  Run 9H, Sample number 2, the water probe sample  2.6 c c . o f ketone and 10.2 c c . of water. Table 5 the f o l l o w i n g are obtained a f t e r (C, .) = 7.62 ki  contained  From the values l i s t e d i n substitution:  - 10.2/2.6 (C . - 15.88) wi  and  (C, .) 7.36 - 0.4/15.6 (e . - 14.95) ki wi S o l v i n g f o r C ... i t was found t h a t : ° wi C . = 15.95 wi  lb.-moles/ft x 3  10  3  Using t h i s i n i t i a l value f o r the water probe g i v e s a values of 7.33 for  f o r the probe d i s p e r s e d phase.  Using  of 15.95 i n the  m a t e r i a l balance f o r the p i s t o n sample produces a C ^  of 7.25.  141 APPENDIX VIII Possible  sources of e r r o r s  probe dispersed  phase  causing  discrepancies  between p i s t o n  and  results.  Problems a r i s i n g i n the a n a l y s i s of the s o l u t i o n s i n the p i s t o n samples were suspected by Hawrelak (12) as being the sources of much e r r o r i n the values of  (C^^ - S f ^ The  a  PP  i  e a r s  concentrations  n  In Equation 5, the  factor  the second term to the r i g h t of the equal sign a  i n v o l v e d are of about the same order of magnitude  as mentioned e a r l i e r , and e r r o r s important.  (C, .) . , . k i piston  substracting  them tends to make a n a l y t i c a l  An example would i l l u s t r a t e B e t t e r the  difficulty  j u s t mentioned. In Sample no. concentrations  9G done with the p i s t o n , the phase  2 of Run  _,) . , , and (C. _) . . , wf p i s t o n ; kf piston* 3 3 3 3 20„35 l b . - m o l e s / f t . x 10 and 10.15 l b . - m o l e s / f t . x 10 respectively. This sample contained 101 c c . of continuous phase and 16 c c . o f dispersed  at time of a n a l y s i s were (C  phase.  The  a n a l y s i s of the continuous phase taken with  probe, or (C .) . , was ' wi probe 1  i n Equation  3 3 20.96 l b . - m o l e s / f t . x 10 .  Now,  the  substitution  5:  (c, .) . . ki piston  =«;._)•..  - v /v, ((c .)  kf piston  w  k  .  - (c _) . ,  wi probe  wf  )  piston  produces, (C  ) k i p i s t o n = 10 16  - 101/16(20.96  0  (C  ) k i p i s t o n = 6.30  This concentration by  the probe method which was  = 8.58  20.35)  3 3 l b . - m o l e s / f t . x 10 . has  to be compared with the one  8.30  volumes were 4 cc. of water and (C, .) . k i probe  -  obtained  3 3 l b . - m o l e s / f t . x 10 , f o r which  48.5  c c . of ketone.  - 4/48.5(20.96 - 17.52)  the  142  dispersed  I t seems l o g i c a l now  to c o n s i d e r  i f i t i s p o s s i b l e that  phase c o n c e n t r a t i o n s  obtained by the  two  methods do not  because of p o s s i b l e m a n i p u l a t i v e e r r o r s i n a n a l y s i s . can bo  the e f f e c t of a p i p e t t i n g e r r o r on the  the c a l i b r a t i o n s of the  For example, what  final results?  IVhat can be  o f water can be  cc. i n V ^ .  0  the e f f e c t of adding one  reveal  drop past  the  of the p i s t o n samples?  end p o i n t  on  in  the and  F i n a l l y , what can  be  i n the  of  titrations  C a l c u l a t i o n s have been done to  the e f f e c t s of the p o s s i b l e e r r o r s mentioned above. F i r s t of a l l ,  to be able  some of the a n a l y s i s v a l u e s , separately; First  their influence  on considered  the r e s u l t s are presented i n four cases:  case:  o f the probe sample, 10.04 ml  to r e a l l y see  the e f f e c t of each e r r o r has been  suppose that i n p i p e t t i n g 10 ml.  9.96  At  taken as p o s s i b l e e r r o r s i n V ^ ,  corresponding to these e r r o r s , - 0 5  the probe and  Based  the e f f e c t of e r r o r s  i n measuring the volumes of the phases i n a p i s t o n sample? ceo  check  10-ml. p i p e t t e s , a p o s s i b l e e r r o r of - 0.4%  the volume d e l i v e r e d can be expected.  worst, - 0.5  the  ml.  of water from the continuous phase  a c t u a l l y was  d e l i v e r e d , and,  from the water phase of the p i s t o n sample.  similarly,  A l l other q u a n t i t i e s  measured i n the a n a l y s i s were assumed to have the values used to c a l c u l a t e the r e s u l t s of Sample 2 of Run Appendix.  earlier in this  Replacing i n Equation 5 f o r the p i s t o n sample:  A value of 7.32 with 6.30  9G given  C, . = 10.16 - 101/16 (20.88 -20.43) ki 3 3 l b . - m o l e s / f t . x 10 i s found f o r (C, .) . . as compared k i piston  as given  earlier.  (The  d i f f e r e n c e i s 16.4%  of  6.30.)  Replacing i n Equation 5 f o r the probe sample: C, . = 8.58 ki A value of 8.30  lb.-moles/ft?  - 4/48.5  x 10  3  (20.88 - 17.52)  i s found f o r (C, .) , k i probe as compared  143 with 8.30  calculated  earlier.  Second case: suppose that i n p i p e t t i n g 10 ml. of water from the continous phase of the probe sar.ple, 9.96  ml. a c t u a l l y was d e l i v e r e d , and, s i m i l a r l y ,  10.04 ml. from the water phase of the p i s t o n sample. other q u a n t i t i e s measured  As b e f o r e a l l  i n the a n a l y s i s are taken to be  unchanged.  In Equation 5, f o r the p i s t o n sample, then: C, . = 10.16 S 101/16 (21.04 - 20.27) ki 3 3 Then a value of 5.30 l b . - m o l e s / f t . x 10 i s found f o r (C, .) . . as k i piston compared  to 6.30.  (The d i f f e r e n c e i s 15.9% o f 6.30J  Equation 5 f o r  the probe sample then i s C, . = 8.58  - 4/48.5 (21.04 - 17.52)  k i  A value of 8.29  3 3 l b . - m o l e s / f t . x 10  i s found f o r (C, .)  ,  k i probe as with 8.30  calculated  compared  earlier.  T h i r d case: suppose that the volume of water i n the p i s t o n sample was a c t u a l l y 100.5 c c . i n s t e a d of 101.0 as measured and suppose that the corresponding volume of ketone was r e a l l y 16.5 c c . i n s t e a d A l l other q u a n t i t i e s measured  of 16.0  cc.  i n the a n a l y s i s were as used i n the  c a l c u l a t i o n given at the beginning o f t h i s Appendix. Equation 5 f o r the p i s t o n sample becomes f o r these c o n d i t i o n s : C, . = 10.16 - 100.5/16.5 (20.96 - 20.35) ki The r e s u l t i n g ( C , .) . . would have been 6.44 l b . - m o l e s / f t ? x 10^ ° k i piston i n s t e a d o f 6.30  the o r i g i n a l v a l u e .  (The d i f f e r e n c e i s 2.2% o f C.30.)  Fourth case: suppose that the t i t r a t i o n s o f each phase of the p i s t o n sample, one drop was added past the end p o i n t  i n each a n a l y s i s .  i t would be much e a s i e r to overun the end p o i n t  (In the t i t r a t i o n ,  then to add too l i t t l e  144 sodium hydroxide.)  Once again, a l l the other measurements  i n the b a s i c c a l c u l a t i o n s a r e assumed c o r r e c t . -6  = 10.13 - 101/16(20.96  Then the r e s u l t i n g (C, ,) . , k i piston 0  involved  In Equation 5, then:  - 20.32)  3 3 would have been 6.09 l b . - m o l e s / f t . xlO  as compared with 6.30 obtained o r i g i n a l l y .  (The d i f f e r e n c e i s 3.3% o f  6.30.) A c a l c u l a t i o n was made o f the e f f e c t o f s e v e r a l e r r o r s o f the s o r t d i s c u s s e d i n cases 1 to 4 t a k i n g p l a c e a t the same time i n connection with one p i s t o n sample and the probe sample corresponding to i t . '  An e r r o r o f 21.3% over the o r i g i n a l value o f 6.30 lb.-moles  3 3 / f t . xlO f o r (C. .) . . i s c a l c u l a t e d i f due to p i p e t t i n g e r r o r , the ki piston * * 1  &  volume analyzed f o r the probe continuous phase had been 10.04 ml. i n s t e a d o f the 10 ml. assumed and, i f both phases o f the p i s t o n  sample  analyzed had been 9.96 ml. i n s t e a d o f the 10 ml. assumed and, i f the measured volume of the phases o f the p i s t o n sample had been measured too  low by -0.5 c c . and too high by +0.5 c c . f o r the water and ketone  phases r e s p e c t i v e l y , and f i n a l l y i f 1 drop o f 0.1 N NaOH had been added past the end p o i n t phase sample.  i n the t i t r a t i o n o f the water o f the continuous  Equation 5 f o r t h i s case i s ( f o r the p i s t o n sample): C  ki  =  1  0  o  2  ° " 100.5/16.5(20.85  - 20.43)  For the probe sample an e r r o r o f 0.4% over the o r i g i n a l o f 3 8.30  lb.-moles/ft.  3 xlO  i s cumulated i n t h i s way:  a) i f the volume analyzed had been 10.04 ml. i n s t e a d of the 10 ml. assumed  f o r the probe continuous phase sample.  b) i f the volume analyzed had been 9.96 ml. i n s t e a d o f the 10 ml. assumed  f o r the ketone o f the probe d i s p e r s e d  phase sample.  145 c) i f the volume of water o f the continuous phase probe had been t i t r a t e d one drop past the end p o i n t . C  =  8„61  -  Equation 5 f o r t h i s case i s :  4/48.5(20od5  -  17 = , 5 2 )  I f one can e l i m i n a t e these p o s s i b l e e r r o r s by a n a l y z i n g b i g g e r volumes and by u s i n g the highest accuracy to measure the volumes of  the phases of a p i s t o n sample, then i t would appear that  d i f f i c u l t i e s should no longer be a problem,,  o  analysis  

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