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Streamlined LCA of Wood Pellets: Export and Possible Utilization in UBC Boiler House Pa, Ann 2009

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     Streamlined LCA of Wood Pellets: Export and Possible Utilization in UBC Boiler House       CHBE 573  Ann Pa May 15, 2009   2 | P a g e   INTRODUCTION Wood pellets are a type of biofuels and are often made of wood residues. These residues include logging residues or industrial residues or municipal solid wastes. Like all biofuels, wood pellets are carbon-neutral and renewable and are very popular in Europe. In 2008, about 92% of the pellets produced in Canada were exported and 75% of these pellets were shipped to Europe (Melin, 2008).  This project has two parts and the objective of the first part is to produce a streamlined LCA (life cycle analysis) for exported British Columbia (BC) wood pellets to quantify the energy consumption and the environmental impacts in the forms of global warming potential (GWP), acid rain formation potential (ARP) and smog formation potential (SFP). The goal of the second part is to evaluate the changes in environmental impacts if BC wood pellets were used in UBC boiler house by performing LCAs. In addition, the health impact index of each scenario based on the threshold limit value (TLV) of each pollutant will also be reported and compared. This report will first look at Part I’s methods and results and analysis followed by Part II presented in a similar fashion. The final conclusion is for both parts and includes uncertainties in the study.   3 | P a g e   PART I - METHOD The function unit for Part I is one metric ton (MT) of wood pellets. The boundary is from the harvesting of trees (not including plantation and management) to arrival at Port Rotterdam, Netherlands. illustrates the different stages and transportation segments included in the analysis. Figure 1: Processing stages and transportation segments included in the LCA for exported wood pellets from Vancouver, The energy consumptions data for the harvesting stage is taken from operation values are taken from the Report from Simon Fraser University (Nyboer, 2008)obtained from industrial surveys analyzed by Pa allocated among products based on mass instead of market value. Table 1 shows energy consumption atTable 1: Energy consumption (MJ/MT pellets) for each processing stage in LCASource of energy  Harvesting Electricity  0.00  Natural Gas  0.00  Heavy Fuel Oil  0.00  Middle Distillates  719.75  Propane  0.00  Steam  0.00  Wood Waste  0.00  Gasoline  0.00   Emissions of different pollutants resulted from these energy consumptions are factors from LCA software and published studies. factor, related to production and transmission of fuel, and combustion emissions generated at point of fuel usage. non-methane volatile organic compounds (NMparticulate matters (PM). The emission factorsversion 3.11. The emission factors chemical plant.    Canada to Port Rotterdam, Netherlands  Sambo (2002CIEEDAC (Canadian Industry End-Use Data and Analysis Centre) .  Values for pellet mills and storage at ports are et al (2009). The energy consumed at each stage is    each stage.   Sawmill  Pellet Mill  174.08  489.59  126.16  0.00  13.66  0.00  40.19  23.49  3.45  6.16  44.58  0.00  253.94  1059.35  0.00  0.00  computed using emission The emission factor used consists of upstream emission factorThe pollutants investigated in the study are COVOCs), NOx in NO2 equivalent, SOx in SO used are mainly from US EPA AP 42 (1995) and GHGenius for steam are taken from Ecoinvent 2 under steam production in Figure 1  ) while the sawmill  Storage at Port  11.12  0.00  0.00  5.37  0.00  0.00  0.00  2.01  emission , related to 2, CH4, N2O, CO, 2 equivalent and 4 | P a g e   For transportation segments, the energy consumed in the hauling of trees to sawmill is already included in the harvesting stage while energy required for transportation A to D are estimated based on fuel consumption, mass of load and distance travelled. After obtaining the energy consumed, emission factors can be applied. Emission factors for transportation are different from those used for process stages since more specific emission factors are available for each type of transportation. The emission factors from GHGenius v3.11, 2005-2006 BC Ocean-Going Vessel Emissions Inventory Report (The Chamber of Shipping, 2007) and fuel consumption data from Railway Association of Canada’s 2006 Locomotive Emissions Monitoring Program report (2008), Transport Canada (2007) and Ocean Policy Research Foundation’s (OPRF) document (2000) are used in the calculations. Furthermore, distance travelled and load per vehicle are from industrial surveys. Table below summarizes each transportation segment.  Table 2: Summary of all transportation segments included in the LCA Transportation  A  B  C  D  Via  Truck  Truck  Train  Marine vessel  Fuel type  diesel  diesel  diesel  low sulfur (<1.5% S)  HFO  Distance (km)  25.65  99.13  840  16668  Load per unit (MT)  20.63  15.26  368  40000  Energy Consumed (MJ/MT Pellets)  30.47  99.36  193  2644   After obtaining the emission data, GWP, ARP and SFP can be obtained by transforming the emissions to kg CO2 equivalent/MT of pellets, kg of SO2 equivalent/MT of pellets and kg base organic mixture equivalent/MT of pellets, respectively.   Table 3 displays the relevant GWP, ARP and SFP values  Table 3: Environmental impact indices Pollutant  GWP for 100 year time Horizon (kg CO2-eqv.)  ARP (kg SO2-eqv)  SFP (kg organic base-eqv.)  CO2  1  0  0  CH4  23  0  4.84E-03  N2O  296  0  0  CO  1.57 (assume all converted to CO2) 0  0  NMVOCs  3.38 (assume all as benzene and converted to CO2)  0  1  NOx  0  0.7  0  SOx  0  1  0  PM 0  0  0  Base reactive organic gas mixture  0  0  1  **GWPs are from IPCC 2007 reports while ARPs are from Heijungs et al (1992) and Allen and Shonnard (2002). SFPs are from Allen and Shonnard (2002) and Carter’s (1994).  The method and results of Part I of this report is explained in greater detail in Pa et al’s work in 2009.   5 | P a g e   PART I - RESULTS AND ANALYSISThe two graphs below summarize the emissions and environmental impacts of BC exported wood pellets obtained from the LCA performed.  Figure   0%10%20%30%40%50%60%70%80%90%100%CO₂ CH₄HarvestingStorageTransportation C16.61%6.19%12.18%0.39%64.64%0%10%20%30%40%50%60%70%80%90%100%GWPHarvestingStorage at Port Figure 2: Stage-wise emissions  3: Stage-wise environmental impacts N₂O CO NMVOC NOx SOx PMSawmill Pellet MillTransportation A Transportation BTransportation D 17.72%31.98%1.85%4.42%2.82%8.47%0.16%0.42%77.45%54.72%ARP SFPSawmill Pellet MillTransportations  6 | P a g e   From Figure 2 one can see that Transportation D is either the highest or second highest cpollutants except for N2O. This is especially true for SOx emission factors compared to all other fuel sources. Thtype of fuel used for marine transportation Pellet mill operation also stands out as a hot spot for most pollutants. COrelated to electricity. However, BC’s electricity matrix is already extremely low in COthan 90% of the electricity is generated by hydro power. If similar energy consumption is happening elsewhere in the world, the CO2 emission would be significantly higher. In BCemission from electricity would be to increase the portion of electricity generated by biomass. power also generates a lot of CH4 emission (compare to other forms of electricity, according to GHGenius v3.11) thus explaining for the high CHthe pellet mill stage is linked to combustion of Contributions from harvesting are quite significant too. It is shown in Figure 3 that the majority of the GWP comes from transportation, mainly marine. Furthermore, marine transportation is responsible for more than 70% ofemission. Based on these results, in order to mitigate the impact on global warming, more energy efficient harvesting operation and unit operations in pellet mills will be beneficial. Furthermore, improvement in emission controls or energy efficiency for by utilizing the pellets locally would decrease environmental impact significantly as marine transportation alone is 49.7%, 72.3% and 45.5% of the total GWP, ARP and SFP, respectively. The total energy consumption for pellet production and transportation distributions of energy usage are illustrated in  Figure 4: Stage-wise breakdown of upstream energy consumption for exported wood pelletsAs transposition is responsible for more than 50% of the environmental impacts for all of GWP, ARP and SFP, it is no surprise that it contributes to almost 50% of the entire life cycle’s energy consumption. Within the transportation segment, 88% of the energy is consumed during marine transportation and 7% is allocated to train operation. There is no doubt that Transportatiotransportation stage but if the unit used is MJ per MT of pellets per km travelled, transportation D has a value of 0.16 MJ/MT pellets/km. The corresponding values for transportation A to C are 1.18, 1.00 and 0.23 MJ/MT pellets/km, respectively, indicating that marine transportation is the most energy efficient mode. In order to lower the overall energy consumption in transportations, one can decrease the distances between sites or increase energy efficiency of the transportHarvesting12.12%Sawmill11.04%Pellet Plant26.58%Storage0.31%SOx and NOx emissions as HFO has is observation can be explained by both the  and the long distance involved. 2 emission, one way to decrease CO4 emissions during pellet mill operation. The high PM emission in wood waste on-site as an energy source for the dryer.   the ARP mainly due to NOmarine transportation or perhaps even eliminating this segment is 5,940 MJ/MT pellet and the Figure 4 for different life cycle stages.  n D is the most energy intensive ation vessels. One can also optimize Transportation A0.51%Transportation B 1.67%Transportation C 3.25%Transportation D 44.51%Transportation49.95%ontributor for all the highest NOx and  during this stage is 2 emissions as more 2 Hydro-x    7 | P a g e   transportation route as a combination of train and marine transportation to minimize energy consumptions. On the other hand, pimprovement in is definitely desirable.  The composition of the energy sources is illustrated in to the distance involved in marine transportation.  Figure 5: Breakdown of consumption of energy from different sourcesAs energy generated by biomass and electricity generated by wind, biomass and hydro are considered renewable, energies consumed can be either fossil fuel based or required to produce the pellet over the heating value of the pellet fuel, can be found given that the heating value of 1 MT of pellet is 18,000 MJ.  Table 4 shows the composition of energy used, energy penalty and fossil fuel content of wood pellets:Table 4: Energy distributions of domestic and exported wood pellets Energy Consumption  (MJ/MT) Energy PenaltyPellets delivered to Port Rotterdam 5,940 33.0%Pellets stored at Vancouver Port 3,296 18.3%   Propane0.16%Steam0.75%ellet plant operation also is quite energy-intensive indicating that  Figure 5. The high HFO consumption again relates    Energy    Renewable based energy (MJ/MT) Fossil Fuel Content kg CO2emitted/MTpellets 1,938 22.2% 401  1,938 7.5% 192 Electricity11.36%NG2.12%HFO44.74%Middle Distillates18.72%Wood Waste22.11%Gasoline0.03%  penalty, defined as      kg CO2-eqv emitted/MT pellets 445 224 8 | P a g e   PART II-METHODS UBC boiler house has 4 boilers. The newer lower emissions. More than 99% of the time the boilers run on natural gas oil is utilized due to NG shortage. Figure  Figure 6: Schematic diagram of the current system in U The stages included in the LCA are production of fuels (both NG and oil), their tremission during end usage. The emission factorsGHGenius v3.14b for NG and fuel oil. boiler house (2009), EMEP CORINAIR Emission Inventory Guidebookdocuments (1995). For the Combustion Test Rdifferent capacities. The emissions were higher if the equipment was operating at a lower capacity. It was suggested to assume 50% capacity. The emissions were reported as concentration (in ppm) of the flue gas so material balance had to be carried out to NG here contains negligible sulfur. The table below listed the total on NG and fuel oil. The sources of emission factorsTable 5: Estimated total emission factors for UBC boiler house Pollutant Fuel oil-firing boilerTotal emission factor (g/GJ of fuel used) Source of emission factorUpstream CO2 85,137  GHGenius v3.14b (2008) EMEP CORINAIInventory Guidebook (CH4 94.03  N2O 8.30  CO 27.42  US EPA APNMVOCs 23.00  EMEP CORINAIInventory Guidebook (NOx 111.85 UBC Combustion Test Report (2009) SOx 250.71  Mass balance based on input S content from Engineers' Handbook (8th Edition)PM 6.00  EMEP CORINAIInventory Guidebook (     2 of the 4 are used more often due to higher efficiency and (NG) but during winter, 6 illustrates a much-simplified diagram of the BC boiler houseansmissions to UBC and  for production and transmission are obtained from The combustion emission factors are from the data  (2007) and US EPA APeport, the boilers were fired with different fuels and at find the flow gas produced. For NG firing, SOemission factors of  are also specified.  and their sources NG-firing boiler Total emission factor (g/GJ of fuel used) Source of emission factorCombustion Upstream R Emission 2007) 53,779 GHGenius v3.14b (2008) UBC Combustion T(2009)111.10  EMEP Inventory Guidebook (1.71  -42 (1995) 11.21  UBC Combustion Test Report (2009)R Emission 2007) 6.00  EMEP CORINAIInventory Guidebook49.89 UBC Combustion Test Report (2009)Perry's Chemical  8.00  Mass balance based on input S contentR Emission 2007) 0.1  EMEP CORINAIInventory Guidebook (#2 fuel current system.   provided by UBC -42 x emissions is 0 as UBC boiler running    Combustion est Report  CORINAIR Emission 2007) ) R Emission  (2007)   R Emission 2007) 9 | P a g e   The proposed system using wood pellets is illustrated in a schematic diagram below:Figure 7: Schematic diagram of the proposed gasification system utilizing wood pelletsGasification system is proposed instead of a combustion system because gasification generally PM, CO, VOC (volatile organics) and NOGuidebook, 2007). The gasification unit uses air as the oxidizing agent thus the syngasheating value as compared to steam gasification where syngas of medium heating value can be produced (Bridgewater, 2003). The temperaturdifferent regions within the gasifier as gasification involves many stepspyrolysis to form vaporized tar, char and gas, partial oxidation of the tar, highest temperature within this region(highly endothermic) (Skreiberg, 2005; Bridgewater, 2003).oxidizer and the flue gas is used to heat up water in the boiler to generate steam. The flue gas can be treated with electrostatic precipitator (EPS) to remove PM if desired. The efficiency of this system depends on the moisture content of the fuel. Typical efficiency for fuel w~10% moisture content is 78%. This number is used here despite BC pellet’s moisture content is usually to 6%. Combining efficiency and the 2008 annual report from the boiler house which indicated that 770,655 klbs of steam at 165 psig was produced inrequired annually to produce the same amount of steam. consumed 1,034,166 GJ of NG and 7,844GJ of fuel oil, which translates to a 93% overall efficiency. are two scenarios for the gasification system, without and with the controlled unit for cleaning the flue gas.   Knowing the amount of pellets required, part of the LCA result from the Part I can bepellets are trucked to UBC from the harvesting of wood to end usage on UBC campus.obtained from industrial contact for typical wood waste gasification. gasification is not available thus is estimated based on US EPA APThe VOC emission factor given is much smaller than the CHthus is taken to be emission factor ofbut everything is presented in emissions produced per year 165 psig per year for all scenarios for     x emissions (Sparica, 2009; EMEP CORINAIR Emise difference in gasifier and the syngas produced . These steps are char and gases (exothermic) and lastly the reduction of the remaining char and CO The syngas produced is combusted in the   2008, it is deduced that 69,348 MT of wood pellets are Just for comparison, in 2008 the boiler house Vancouver port and are utilized on campus. The boundary is from  The emission factors for the gasification system are The emission factor-42 (1995)’s value for wood combustion. 4 emission factor values found in literature  NMVOC. The functional unit is still per MT of pelletsin order to generate 770,655 klbs of steam at the ease of comparison.    has lower sion Inventory  produced has low probably lies in the drying of fuel,  thus 2 to CO ith 5 There  used, however,  for CH4 for  for calculation 10 | P a g e   PART II - RESULTS AND ANALYSISFigure 8 and Figure 9 illustrate UBC boilbased on 2008’s data. Note that Transportation D now refers to the transportation between Vancouver port and UBC via trucks running on diesel. be contributing the most to the emissions and environmental impacts, it is important to note that more than 99% of the energy input was from NG thus the graph below does not suggest that fuel oil burning is cleaner than NG. However, do note that thless than 1% of the energy input was from fuel oil.  Figure 8: Stage Figure 9: Stage-wise 0%10%20%30%40%50%60%70%80%90%100%CO₂ CH₄NG production and transmissionNG combustion13%0.19%86%0.99%0%10%20%30%40%50%60%70%80%90%100%GWPNG production and transmissionNG combustion er house’s current annual emissions and environmental impacts Despite that NG combustion and upstream operations ere is significant SOx emission from oil combustion despite only  -wise emissions for current scenario  environmental impacts for current scenario N₂O CO NMVOC NOx SOx PMOil production and transmissionOil combustion79%47%1.2%1.07%19%50%0.5% 1.90%ARP SFPOil production and transmissionOil combustionseem to   11 | P a g e   The average PM removal efficiencies emissions factors of pollutants with and without the ESP unit were obtained from two different systems at different locations. Moreover, in theory, ESP only removes PM and is not effective at all for the removal of other pollutants. Thus the variations in the nonare probability irrelevant to ESP itself. Figure 10 and Figure 11 are the stagecleaning unit, respectively. Cleaning unit would affect the contribution of the “gasification” stage and by placing the two graphs side by side, one can easily reduced significantly if a cleaning unit is installed.  Figure 10: Stage-wise emissions for pellet burning scenario without cleaning unit 0%10%20%30%40%50%60%70%80%90%100%CO₂ CH₄Harvesting SawmillTransportation A Transportation Bof an ESP attached to the system is 97.8% (Sparica, 2009)-PM emissions between the scenario with and without ESP  -wise emissions for the pellet burning scenario without and with a observer that CO, NMOVC and PM emissions can  N₂O CO NMVOC NOx SOxPellet Mill GasificationTransportation C Transportation D . The be   PM12 | P a g e   Figure 11: Stage-wise emissions for pellet burning scenario Figure 12 and Figure 13 illustrate how directly to the amount of organic compounds significant.  Figure 12: Stage-wise environmental impa0%10%20%30%40%50%60%70%80%90%100%CO₂ CH₄Harvesting SawmillTransportation A Transportation B27%16%33%12%7%0%10%20%30%40%50%60%70%80%90%100%GWPHarvestingGasification (uncontrolled)Transportation C with cleaning unitSFP can be reduced greatly if cleaning unit is added and CO emitted. But the cleaning unit’s afcts for pellet burning scenario without cleaning unit N₂O CO NMVOC NOx SOxPellet Mill GasificationTransportation C Transportation D 42% 45%4% 6%7%12%35% 24%11% 12%ARP SFPSawmill Pellet MillTransportation A Transportation BTransportation D  as SFP is linked fect on GWP is not   PM13 | P a g e   Figure 13: Stage-wise environmental impacts for pellet burning scenario with cleaning unit Figure 14 reveals the emissions of the entire life cycle for all three scenarios. There is obvious decrease in CO2 emission if wood pellets are used and lower CHinvolves leakage while this is not an issue for wood pellets. There are also large increases in NOfor both pellet scenarios due to mainly pellets scenarios are mostly tied to pellet mill operations, especially for the controlled scenario.  Figure 14: Complete life cycle emissions for all three scenariosTable 6 below summarizes the environmental impacts of all three wood pellets definitely mitigate a significant amount of GHG emissions but this comes with a price of higher ARP and SFP as well.    27%16%33%12%7%0%10%20%30%40%50%60%70%80%90%100%GWPHarvestingGasification (controlled)Transportation C050,000100,000150,000200,000250,000300,000CO₂  (MT/yr)CH₄kg emitted/year (MT emitted/year for CO2)Current4 emission as the transmission and prcontribution from harvesting operations. The PM emissions in   scenarios, and it is obvious that using 41%57%4%8%7%15%36%3%11% 15%ARF SFPSawmill Pellet MillTransportation A Transportation BTransportation DN₂O CO NMVOC NOxpellets (uncontrolled) pellet (controlled)  oduction of NG x emission   SOx PM14 | P a g e   Table 6:  Summary of environmental impacts for all three scenariosLife cycle/year  GWP (kg CO2-eqv/yr) Percent differences from current case ARP (kg SO2-eqv/yr) Percent differences from current case SFP  (kg base organic compound-eqv/yr) Percent differences from current case  As UBC boiler house operates on campus where theduring the end stage usage cause concern. they still produce emission at the point of emitted from UBC boiler house alone for all pellets are used. This indicates that NG isThe NOx emissions for the pellet scenarios are also significantly high. The current oil combustion only as wood pellet and NG contains no sulfur. With controlling uvalues can be lower than the current scenario but Nemission after controlling unit will still be 10 times higher than the current situation.  Figure On top of GWP, ARP and SFP, health impact indices are also calculated for end stage emissions. The health impact index is calculated by the emissions, from The TLV values are obtained from Canada’s National Occupational Health & Safety Resource’s (CCOHS) website and are presented in Table risk.     51,288104 1,660104,65311,270104,65311,270020000400006000080000100000120000CO₂  (MT/yr) CH₄kg pollutant emittied/year (MT/year for CO2)CurrentCurrent  Pellets (no control)  P59,761,746 17,776,278 17,734,652 -70% -46,971 182,108 184,362 288% 293%6,945 22,200 17,370 220% 150%re is higher population density, the Even though biomass fuels are “carbon-neutral” during usage, utilization. Figure 15 below shows the amount of scenarios. The actual CO2 emission is much greater if wood  actually fairly clean and emits less CO2 than biomass gasification. SOxnit, the CO and NMVOCs 2O and PM values will still be higher 15: Actual emissions during end usage   Figure 15, over TLV in the unit of mg per cubic meter. 7.  Higher the health impact index indicates higher potential health 3,441 3,22013,6911,7476,977 18,2475,36791,2366,977 2,14753794,456N₂O CO NMVOC NOx SOxpellets (uncontrolled) pellet (controlled) ellets (control)   70%     actual emissions pollutants  emissions are from . Note that PM  119049,9110 1,073PM15 | P a g e   Table 7: Threshold limit value (TLV) of pollutants  Pollutants TLV (mg/m3) CO2 8980 CH4 655 N2O 90 CO 28.5 NMVOC (assume all toluene) 20 NOx 5.64 SO2 5.22 PM 10   Table 8 below summarizes the environmental impacts for the end stage operation for all scenarios. If CO2 is considered neutral, then a 95% reduction in GWP is achievable. But if CO2 emission is not considered neutral, the actual GHG emission will see a 107% increase. For ARP, there is an approximately 470% increase if wood pellets are used and the SFP may be 68% higher if no cleaning unit is included but may be 11% lower otherwise.   Table 8 also includes health impact index for each scenario.   Table 8: Summary of environmental impacts for all three scenarios during end stage usage End usage/year  Current  Pellets (no control)  Pellets (control)  GWP (carbon-neutral) (kg CO2-eqv/yr) 51,801,943  2,407,668 2,366,042  Percent differences from current case  -95% -95% GWP (actual emissions) (kg CO2-eqv/yr) 51,801,943   107,060,234  107,018,608  Percent differences from current case  107% 107% ARP (kg SO2-eqv/yr) 11,330.59  63,864.90  66,118.95  Percent differences from current case  464% 484% SFP  (kg base organic compound-eqv/yr) 3,220.66  5,421.33   2,870.49  Percent differences from current case   68% -11% Health Impact Index (actual emissions) (kg/day)(m3/mg) 24.07   92.67   78.65  Percent differences from current case  285% 227%  It is obvious that by using wood pellets instead of natural gas, the air quality on campus will be compromised. The health impact indices quantify the health risk linked to air quality, which can be affected by pellet utilization on campus. The increases in health impact indices are 285% and 227% for uncontrolled and controlled system, respectively.  To better present the scale of emission from this project, the emissions change resulting from scenario changes are compared to the annual Lower Fraser Valley emission in 2005 (Metro Vancouver, 2007). Table 9 presents 2005 annual Lower Fraser Valley emissions, current UBC boiler house emissions and the boiler house emissions based on the pellets without control unit and pellets with control unit scenarios. Moreover, Table 9 also includes the percent change in each of the pollutants based on scenario changes. It is obvious that UBC boiler house contribute minimally to the entire Lower Fraser Valley emission profile. The most significant change on the list of pollutant provided is the GHG emission. If the fuel is taken to be carbon-neutral, the overall Lower Fraser Valley GHG emission can be lowered by 0.22%. However, this is 16 | P a g e   accompanied with a 0.13% increase in NOx emissions. Higher NOx is linked to a higher chance of acid rain formation. Nonetheless, there is also a 0.017% decrease in SOx, which indicates a slight decrease in the likelihood of acid rain formation at the same time.  Note that VOC (volatile organic compounds) values for the scenarios are the sums of CH4 and NMVOCs.   Table 9: Possible changes in Lower Fraser Valley’s annual emissions due to fuel change in UBC boiler house Pollutants (all in kt/yr) Lower Fraser Valley annual emission in  2005 Current Pellets without cleaning unit Pellets with cleaning unit End stage emissions End stage emissions Change in LFV emissions due to scenario change End stage emissions Change in LFV emissions due to scenario change NOx 61 0.0137 0.0912 0.127% 0.0945 0.132% SOx 10.3 0.0017 0 -0.017% 0 -0.017% VOC 108 0.0033 0.0167 0.012% 0.0118 -0.008% GHG 22800 51.80 2.126 -0.218% 2.084 -0.218% GHG (actual) 22800 51.80 106.78 0.241% 106.74 0.241%  It is worth noting that if the gasification system is to be installed on campus, ESP will definitely be required (Sparica, 2009). Furthermore, from Figure 15, it is evident that the high NOx emission is the main problem in pellet utilization on campus. High NOx contributes to the dramatic increase in ARP. The NOx emission problem can be dealt with by the installation of a selective catalytic reduction (SCR) unit. Within this unit, NOx is converted to N2 via catalytic reaction and the unit has been shown to reduce NOx from 52 to 92% depending on various factors such as temperature (Baukal, 2003). On the other hand, the emission of CO and VOC from the syngas oxidizer depends on the efficiency of the oxidizer. Higher efficiency would resulting in lower CO and VOC emission thus their rate of release may be improved by optimizing the oxidizer via adjusting operating parameters such as temperature or residence time. Higher temperature and time usually increase the efficiency of the oxidizer but is often linked to more NOx formation.   Lastly, Table 10 compares the energy contents of wood pellets exported to Port Rotterdam and pellets delivered to UBC. The values for pellets arriving at UBC are similar to that of “pellets stored at Vancouver Port” in Table 4 except that the values in Table 4 include energy consumed during storage at port while the values here include energy consumption for trucking these pellets to UBC for the Vancouver port.  Table 10: Energy distribution of pellets delivered to Port Rotterdam and UBC  Energy Consumption  (MJ/MT) Energy Penalty Renewable based energy (MJ/MT) Fossil Fuel Content kg CO2 emitted/MT pellets kg CO2-eqv emitted/MT pellets Pellets delivered to Port Rotterdam 5940 33.0% 1938 22.2% 401 445 Pellets delivered to UBC 3280 18.2% 1928 7.5% 191 222  17 | P a g e   CONCLUSIONS For Part I, the GWP, ARP and SFP for BC-exported pellets arriving in Port Rotterdam, Netherlands are 443 kg CO2-eqv/MT, 6.17 kg SO2-eqv/MT and 0.45 kg base organic compound per MT of pellets, respectively.  Marine transportation alone is responsible for 45% of the energy consumption of the entire life cycle. It is also one of the top contributors to all pollutants investigated. Exported pellets have an energy penalty of 33% while non-exported pellet’s value is only 18.3% Moreover, exported pellets’ energy value contains 22.2% fossil fuels but non-exported only contains 7.5%. From these values, it is evident that by exploring domestic wood pellet markets, wood pellets can be even greener.  Based on the LCAs performed in Part II, it is gathered that the GWP of UBC boiler house operation can be reduced by 70% if pellets are used but ARP will increase by approximately 285% while SFP can increase by 150% to 220%. Pellet utilization is effective in reducing GHG emission but may compromise the air quality on campus. If the actual end usage emission is considered, GWP would double while ARP can increase by 464% to 484% and SFP may increase by 68% if no controlling unit are implemented or decrease by 11% if the flue gas is cleaned.  Health impact index also increases by 285% from 24.07 to 92.67 for switching to pellets without cleaning unit and the increase is 227% to 78.65 when switched to a pellet scenario with cleaning unit. NOx emission can be further reduced by approximately 80% with an additional SCR unit. To decrease CO and VOC emissions from the pellet scenarios, the performance of the oxidizer may need to be further optimized my adjusting temperature and residence time.  Furthermore, the contribution from UBC boiler house to the total Lower Fraser Valley emission is minimal. The most significant change due to utilization pellet in UBC boiler house would be a 0.24% increase in annual GHG emission in Lower Fraser Valley if the actual emission of CO2 is taken into account. On the other hand, if the CO2 emission is considered to be 0 for the end stage pellet utilization, the change in the Lower Fraser Valley’s GHG emission would be -0.22%.  Comparing pellets delivered to Port Rotterdam and UBC, the latter emits only 191 kg of CO2 per MT of pellets delivered compared to 401 kg for those arriving at Port Rotterdam. The fossil fuel content of the pellets delivered to UBC is approximately one third of those delivered to Port Rotterdam.  Some uncertainties in this study include the efficiency value used for the gasification. This means a possible over-estimation in the amount of pellets required thus resulting in over-estimation in both upstream and end-usage emissions. Furthermore, the emission factors obtained for the gasification systems are for generic wood waste instead of wood pellets. As generic wood waste may contain bark or other contaminants such as soil, the emissions generated may also be different. Pellets are also likely to have a lower VOCs emission during end usage as they were pre-processed and heated in the pellet plants already. Lastly, the N2O emission factor for gasification is not available thus the emission factor for wood waste combustion is used instead and this value may or may not be a reasonable estimate. Lastly, one important future task is to investigate the human toxicity potential or any health effects that may arise from the use of wood pellets on campus.     18 | P a g e   REFERENCES Allen, David T. and David R. Shonnard (2002). Green Engineering: Environmentally conscious design of chemical processes. Upper Saddle River: Prentice Hall PTR.  Baukal, Charles E. (2003). Industrial Combustion Pollution and Control (Environmental Science and Pollution Control Series). Boca Raton: CRC.  Bridgwater, A. V. (2003). Renewable fuels and chemicals by thermal processing of biomass. Chemical Engineering Journal, 91(2-3), 87-102.  Canada’s National Occupational Health & Safety Resource’s (CCOHS) website. < >. Cantas, Jason and Giffin, Jeff (2009). Boiler house contacts, provided boiler emission data and annual report for 2008. Carter, WPL (1994). Development of ozone reactivity scales for volatile organic compounds. J. Air Waste Manage. Assoc., 44(7), 881-889.  Cleveland, Cutler J (2004). Encyclopedia of Energy, Volumes 1 - 6. (pp. 746). Elsevier. <>  Delucchi and Levelton (2004). GHGenius v3.11. < >.  Delucchi and Levelton (2008). GHGenius v3.14b. < >.  Ecoinvent2. Emission factors for steam generated for chemical processes. EMEP CORINAIR Emission Inventory Guidebook. (2007). Chapter 1: Combustion in energy and transformation industries., Forster et al. (2007). Changes in Atmospheric Constituents and in Radiative Forcing. In: Climate Change 2007: The Physical Science Basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change [Solomon, S., D. Qin, M. Manning, Z. Chen, M. Marquis, K.B. Averyt, M.Tignor and H.L. Miller (eds.)]. Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA.  Heijungs and Guinée (1992). Environmental life cycle assessment of products: Guide (Part 1) and Backgrounds (Part 2), 96 + 130 pp, CML, TNO B&B, Leiden  Lau, Anthony (2009). Personal communication. Provided CO2 emission data. Magelli, Francesca et al (2009). An environmental impact assessment of exported wood pellets from Canada to Europe. Biomass Bioenergy. (In press and available on-line).  Melin, Staffan (2008). Wood pellets manufacturing in Canada-- Briefing note. Wood Pellet Association of Canada.  Metro Vancouver (2007). 2005 Lower Fraser Valley Air Emissions Inventory & Forecast and Backcast Executive Summary Nyboer, J. (2007). A review of energy consumption and greenhouse gas emissions in the Canadian wood product industry: 1990 to 2005. Vancouver, BC: Canadian Industrial Energy End-use Data and Analysis Centre, SFU.  OPRF (2000). A report on research concerning the reduction of CO2 emission from vessels.  Pa, Ann et al (2009). Life-Cycle Analysis of Exported Wood Pellets from Canada to Europe. Accepted and to be presented in the 8th World Congress of Chemical Engineering on August 23–27, 2009 in Montréal. Railway Association of Canada (2008). Locomotive emissions monitoring program 2006.  Sambo (2002). Fuel consumption for ground-based harvesting systems in western Canada. Advantage. 3(29). 1-12.  Skreiberg, Ø. (2005). Thermochemical biomass conversion and processes -- (co)-combustion, pyrolysis and gasification  Sparica, Dejan (2009). Personal communication The Chamber of Shipping (2007). 2005 – 2006 BC ocean-going vessel emissions inventory.  Transport Canada (2007). Truck Activity in Canada - A Profile. Retrieved January 7, 2009, from  19 | P a g e   Transport Canada (2003). Transport Canada; Policy; Transportation in Canada 2000. Retrieved January 8, 2009, from  US EPA (1995). AP 42: Compilation of Air Pollutant Emission Factors. 5.1 Office of Air Quality Planning and Standards, Office of Air and Radiation, U. S. Environmental Protection Agency.  


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