Comparative Assessment of Steam Processed pellets produced from - PowerPoint PPT Presentation

Comparative Assessment of Steam Processed pellets produced from wood, straw and switchgrass S M H ASSAN S HAHRUKH , A DETOYESE O YEDUN , A MIT K UMAR 1 , L INOJ K UMAR , B AHMAN G HIASI , S HAHAB S OKHANSANJ 2 1 Department of Mechanical Engineering, University of Alberta Edmonton, AB, Canada 2 Department of Chemical and Biological Engineering, Vancouver, BC, Canada A DVANCED B IOFUELS S YMPOSIUM July 22 - 24, 2015, Montreal, Canada

Presentation Outline  Background and Objective  Pellet Production Supply Chain  Model Development and Validation  Mass and Heat Balance of Steam Pretreatment  Techno-Economic Result  Summary of Result Presentation at BFN, 2 2 -2 4 July, 2 0 1 5

Background • High transportation • Need for higher cost of regular utilization of Biom ass biom ass and pellets Low Cost I ssues Utilization Low Bulk and Energy density of Pretreatm ent regular pellets • Energy density of • Pretreatm ent helps regular pellets is producing high 1 / 8 th of coal quality pellets Presentation at BFN, 2 2 -2 4 July, 2 0 1 5

Objectives Develop process model for steam pretreatment of wood, straw and switchgrass Data intensive modeling Heat and mass balance Conduct Energy Analysis Net energy ratio (NER) Sensitivity & uncertainty Conduct Techno-Economic Assessment Cost curves Sensitivity & uncertainty Presentation at BFN, 2 2 -2 4 July, 2 0 1 5

Pellet Supply Chain Bale le Trans nspo portation n Biomass ss Trans nspo portation n Pelle llet Used i in n for ormation on/ of of p pellet t to o collection to p pelle llet pla lant prod oduction on biorefine bi nery chi hippi pping ng bi biorefine nery Suppl pply cha hain o n of pelle llet to a o a b bior orefinery (Con onvention onal method od) Bale le Trans nspo portation n Biomass ss Trans nspo portation n Steam Pelle llet Used i in n Steam for ormation on of of p pellet t to o collection to p pelle llet pla lant pretreatment Prod oduction on biorefine bi nery Pretreatment /chi hippi pping ng biorefine bi nery Supply chain o of p pellet ( (produced from pretreated biomass) t to a a b biorefinery Presentation at BFN, 2 2 -2 4 July, 2 0 1 5

Experimental Material and Method Material Method Pretreatm ent carried in 2 .6 L StakeTech W ood, Straw Steam gun w ith 4 0 0 g ,Sw itchgrass of biom ass treated at different tem perature and tim e Moisture content ~ Steam treated 1 0 % -5 0 % biom ass pelletized Presentation at BFN, 2 2 -2 4 July, 2 0 1 5

Model Input and Validation logR = log � exp(T − 100 Governing Source: Lam et al. 14.75 )dt 2 0 1 3 Equation: 2 . Steam Pretreatm ent Unit: Biom ass is treated w ith high pressure steam in batch reactor ( Yield reactor considered) 1 . Boiler unit: Supply of steam at different tim e and tem perature 2 . Tim e: 1 0 m in 3 . Tem perature: 1 8 0 -2 1 0 ⁰C Presentation at BFN, 2 2 -2 4 July, 2 0 1 5

Model Input and Validation 3 . Pellet m ill: produces pellet of 2 0 -3 0 m m long, 6 m m in diam eter, has a heating elem ent operating at 7 0 -1 0 0 C. 2 . Grinder: Kicks energy constant 1 0 0 KJ/ kg, solid recovery 9 5 % No grinder is required for 1 . Dryer: operating pellet production of straw and tem perature at sw itchgrass 8 0 C. Presentation at ASABE, 2 6 -2 9 July,2 0 1 5

Model Validation Result Experimental Energy ASPEN model Predicted Energy Consumption (kJ) Consumption (kJ) Operation Wood Straw SG Wood Straw SG Steam 2097 749 678 2095 760 710 Pretreatment Drying 6162 6731 8979 6156 6951 9045 Size reduction 15 0 0 17 0 0 Pelletization 492 330 318 500 352 325 Presentation at BFN, 2 2 -2 4 July,2 0 1 5

Comparative Heat and Mass Balance W ood 1.3 MJ 0.2 MJ 0.5 MJ 1 kg 0.7 kg 0.65 kg 0.61 kg Hammer Mill Dryer Pellet Mill 18 MJ A. Regular Pellet 0.45 MJ 2.1 MJ 0. 01 MJ 6.2 MJ 1 kg 2.4 kg 0.63 kg 0.58 kg 0.54 kg Hammer Pellet Dryer Mill Mill 19.6 MJ B. Steam Pretreated Pellet Presentation at BFN, 2 2 -2 4 July,2 0 1 5

Comparative Heat and Mass Balance (Cont’d) Straw Sw itchgrass 0 MJ 0.3MJ 0.8 MJ 0.3MJ 0.8 MJ 0 MJ 1kg 0.95 kg 0.92kg 0.88 kg 1kg 0.95 kg 0.92kg 0.85 kg Hammer Mill Dryer Pellet Mill Hammer Mill Dryer Pellet Mill 17 MJ 17 MJ A. Regular Pellet A. Regular Pellet 0 MJ 0.42 MJ 0.4 MJ 0.8MJ 6.7 MJ 0.7MJ 0 MJ 8.9 MJ 1kg 3.0 kg 0.8 kg 0.8kg 0.72 kg Hammer 1kg 3.4 kg 0.8 kg 0.8kg 0.71 kg Pellet Dryer Hammer Mill Dryer Pellet Mill Mill Mill 19 MJ 19.1 MJ B. Steam Pretreated Pellet B. Steam Pretreated Pellet Presentation at BFN, 2 2 -2 4 July,2 0 1 5

Variation of NER with Pretreatment Temperature and Level 3 7.00 Straw Switchgrass Wood Straw SG 6.00 2.5 5.00 2 4.00 NER NER 1.5 3.00 1 2.00 0.5 1.00 0 - 25% 50% 75% 140 160 180 Pretreatment level Steam Pretreatment Temperature Presentation at BFN, 2 2 -2 4 July,2 0 1 5

Uncertainty Analysis Histogram Plot for NER 055 5% 90% 5% 050 = 1.21) 95%฀(x = 1.49) 045 040 035 030 W ood 025 020 015 010 005 Probability 000 1.2 1.3 1.4 1.5 1.6 1.7 NER .21) 49) Straw Sw itchgrass Presentation at BFN, 2 2 -2 4 July,2 0 1 5

Techno-Economic Snapshot Straw Forest residue Switchgrass Regular Steam Regular Steam Regular Steam pretreated pretreated pretreated Optimum size 190,000 250,000 190,000 290,000 190,000 230,000 (t year -1 ) Pellet cost ($ t -1 ) 122.04 188.34 116.01 183.14 116.20 192.41 -Capital recovery 9.56 15.31 10.83 20.34 13.74 21.53 - Maintenance cost 2.64 3.68 2.34 3.59 2.58 3.76 -Field cost 52.34 58.75 28.19 32.08 25.57 29.39 -Transportation cost 33.89 42.99 37.04 50.24 45.38 57.68 -Premium 0.00 0.00 6.39 5.50 5.34 6.13 -Employee cost 7.27 7.85 6.58 6.76 7.27 8.53 -Energy cost 5.41 48.91 14.74 53.79 5.41 54.50 -Consumable item cost 10.93 10.86 9.90 10.84 10.93 10.88 Pellet transportation 6.30 5.50 6.20 5.45 6.80 6.10 Total pellet delivery 128.34 193.84 122.21 188.59 123.00 198.51 cost Presentation at BFN 2 2 -2 4 July,2 0 1 5

Variation of Transportation Cost Presentation at BFN, 2 2 -2 4 July, 2 0 1 5

Variation of Capital Cost Presentation at BFN, 2 2 -2 4 July, 2 0 1 5

Variation in Production Cost Presentation at BFN, 2 2 -2 4 July,2 0 1 5

Sensitivity Analysis - Wood 194.00 199.00 192.00 194.00 Production Cost, $ \ t 190.00 Production Cost, $\t 189.00 188.00 186.00 184.00 184.00 179.00 182.00 174.00 180.00 -20% -10% 0% 10% 20% -20% -10% 0% 10% 20% capital cost employee cost % change Moisture content Feed stock material loss Energy cost Transportation cost Inflation IRR Field cost consumable cost % area Presentation at BFN, 2 2 -2 4 July,2 0 1 5

Sensitivity Analysis - Straw 200.00 205.00 Total cost of pellet production($(t) -1 ) 198.00 Total cost of pellet ($(t) -1 ) 200.00 196.00 195.00 194.00 190.00 192.00 185.00 190.00 % change 180.00 188.00 -20% -10% 0% 10% 20% -20% -10% 0% 10% 20% % change Moisture content Feed stock material loss Inflation IRR capital cost employee cost % area Energy cost Transportation cost Field cost consumable cost Presentation at BFN, 2 2 -2 4 July,2 0 1 5

Sensitivity Analysis - Switchgrass 203.00 202.00 206.00 Total cost of pellet ($(t) -1 ) Total cost of pellet production($(t) -1 ) 201.00 200.00 201.00 199.00 198.00 196.00 197.00 196.00 191.00 195.00 194.00 % change 186.00 193.00 -20% -10% 0% 10% 20% -20% -10% 0% 10% 20% Moisture content Feed stock material loss % change Inflation IRR capital cost employee cost Energy cost Transportation cost % area Field cost consumable cost Presentation at BFN, 2 2 -2 4 July,2 0 1 5

Uncertainty Analysis Uncertainty Steam Pretreatment Base case-45000 tonne for Forest Residue 050 4.995% 90.00999% 4.995% 045 95.005%฀(x = 247.11) 28.37) 040 035 030 025 W ood 020 015 010 005 Probability 000 220 225 230 235 240 245 250 255 Pellet Cost ($/tonne) 7) ) Histogram Plot for 236.846391740834 0.06 Histogram Plot for 236.862753087947 055 5% 5% 90% 5% 90.005% 4.995% 050 0.05 95%฀(x = 261.8) 95.005%฀(x = 258.65) 236.39) 237.93) 045 040 0.04 035 030 0.03 025 0.02 020 015 0.01 010 005 Probability Probability 0.00 000 230 235 240 245 250 255 260 265 270 275 230 235 240 245 250 255 260 265 270 275 Pellet Cost ($/tonne) Pellet Cost ($/tonne) 1.8) 39) 93) 5) Straw Sw itchgrass Presentation at BFN, 2 2 -2 4 July,2 0 1 5

Summary of Result • Energy ratio of regular pelletization process is higher than steam pretreated pellet due to addition of steam as energy source • Calorific value of pellet increases by 21% due to steam pretreatment Energy • Grinding energy input is zero for straw and switchgrass • $/ tonne cost of production for steam pretreated pellet is higher than regular pellet due to increased capital cost • $/ GJ cost production of pellet for both steam treated pellet and Cost regular pellet is similar with approximately 30 cents difference • Steam pretreatment is more effective over a plant size of 270,000 tonnes/ yr plant capacity due to economy of scale benefits based on $/ GJ Scaling Presentation at BFN 2 2 -2 4 July, 2 0 1 5