Cassava bioethanol production

Transcription

1 Cassava bioethanol production by Dr. Kuakoon Piyachomkwan Cassava and Starch Technology Research Unit (CSTRU) National Center for Genetic Engineering and Biotechnology (BIOTEC) National Science and Technology Development Agency (NSTDA) South - South Technology Transfer: Ethanol Production from Cassava Siam City Hotel, Bangkok June 2011

2 World Ethanol Production by continent in % South America 35.1% N&C America 45.9% Asia 10.5% Europe 7.6% Africa 0.9% Total production 77,000 mln litres (2008)

3 World Ethanol Consumption Industrial 8.8% (5,643 mln litres) Potable 11.5% (7,375 mln litres) Fuel 79.6% (51,044 mln litres) Total 64,126 million litres (2007)

4 Fuel Ethanol Market China 2.9% Canada 1.4% India 0.6% Thailand 0.5% EU 4% Others 1.6% Brazil 38% USA 51% 63,421 million litres (2008)

5 World Ethanol Production by Feedstock Synthetic 6% Sugar crops 55% Grains 37% Others 2%

6 C H 12 O 6 + Yeast 2CO C 2C H 5 OH Glucose Carbon dioxide Ethanol grams grams grams The Gay-Lussac equation for ethanol production from glucose by fermentation

7 Feedstock for ethanol production Sugar crops Sugar cane Molasses Sugar beets Cellulose Rice straws Bagasse Corn cops Sawdust Starch crops Corn Cassava Rice Wheat Potato

8 Sugar crops Starch crops Cellulose Juice Extraction Liquefaction Saccharification Pretreatment Enzyme Hydrolysis Diluted Molasses Sugar syrup Fermentation Distillation & Dehydration Anhydrous ethanol

9 Ethanol yields from various feed stocks To produce 100 litres of ethanol* it takes: 4,000 l of cheese whey 1,400 kg of sweet sorghum 1,270 kg of sugar cane 1,250 kg of Jerusalem artichoke 1,030 kg of sugar beet 850 kg of potatoes 545 kg of cassava 385 kg of wood 360 kg of molasses 368 kg of maize (wet milling) 258 kg of maize (dry milling) 260 kg of wheat 230 kg of millet 225 kg of paddy rice *) average values actual yields may vary depending on

10 Industrial production of ethanol Brazil USA Europe Russia - Sugarcane - Cereal grains (mostly corn) - Cereal grains, beets - Cereal grains, beets

11 Cassava: The winner

12 The Key of Success

13 -All year round planting- The Key of Success Growth tolerance to poor environmental condition

14 The Key of Success All year round planting/harvesting

15 The Key of Success High root productivity Thai average = T/ha World = T/ha Reported ~ 90 T/ha

16 The Key of Success Continuous development of high yield-improved improved varieties

17 Cassava Varieties Rayong5 Rayong90

18 KU50 Huaybong 60

19 The Key of Success Less input in planting and harvesting

20 The Key of Success High-quantity/quality carbohydrate source

21 The Key of Success Well developed technology for raw material preparation

22 Simple conversion to dried chips for effective storage and transportation Dried Chips

23

24 Chemical composition of cassava chips and corn grain Composition Content Corn grain* Cassava chips Moisture (% wet basis) Starch (% dry basis) Protein (% dry basis) Fat (% dry basis) Ash (% dry basis) Crude fiber (% dry basis) *Source: Watson, 1984

25 Protein / Fiber Raw materials Steeping with water Grinding Starch Separation Raw materials Grinding Liquefaction Saccharification Starch hydrolysis (Liquefaction and Saccharification) Fermentation Fermentation Ethanol (a) Yeast 368 kg of corn /100 liters of ethanol DDGS Ethanol (b) 258 kg of corn /100 liters of ethanol Ethanol production from corn by (a) Wet milling and (b) Dry grinding process

26 Raw material preparation in ethanol production process

27 Air bag filter Hopper 1 st milling Bucket elevator Metal and stone detector 2 nd Milling Sifter Chip grinding and slurry preparation Mixing tank To Liquefaction

28 Root Hopper Root Peeler Root Washer Root Chopper Root Rasper 2 nd coarse extractor 1 st fine extractor (vertical type) De-sand cyclone 1 st coarse extractor (Horizontal type) Screener Starch milk tank 2 nd fine extractor (vertical type) 3 th coarse extractor M Agitator tank Separator Hydrocyclone M Starch slurry (without fiber) prepared from fresh root To liquefaction section Concentrate Starch milk tank

29 The Key of Success Improved technology for ethanol production

30 6 kg Root Chopping Drying 2.5 kg Chips Grinding Slurry & Cooking Liquefaction 105 O C Saccharification 55 O C Fermentation 30 O C Conventional process of ethanol production from cassava Distillation Dehydration 1 L 99.5%Ethanol

31 Cooking Liquefaction Ethanol Fermentation Saccharification

32 Cassava Chips α-amylase glucoamylase yeast Milling Distillation &Dehydration Cooking & Liquefaction Saccharification Fermentation

33 A pilot plant of ethanol production located at The Thai Liquor Distillery Org, Chachengsao province

34 Raw material preparation Cooking Process of ethanol production from cassava chips located at The Thai Liquor Distillery Org, Chachengsao province

35 Saccharification and Fermentation Distillation and Dehydration Process of ethanol production from cassava chips located at The Thai Liquor Distillery Org, Chachengsao province

36 - Conventional process - ph glucose and ethanol (%w/v) active cell ethanol ph TSS glucose Total Soluble Solid ( O Brix) Active Cellx10 7 (cells/ml) เวลา (ช วโมง) Time (hr) glucose ethanol TSS ph Active cell Ethanol production from cassava chips by conventional process (CF) Conditions: Ground cassava chips (25% DS); Liquefaction by 0.1% α-amylase at 95 C, 2 hrs; Saccharification by 0.1% glucoamylase at 55 C, 15 hrs; Fermentation by yeast, Saccharomyces cerevisiae SC90, at 32 C )

37 Ethanol Production Process from cassava by (a) Normal Process and (b) Simultaneous Sacharification and Fermentation (SSF) Cassava Cassava Rough Grinding Rough Grinding Sand Separation Liquefaction (100 o c) Hours Sand Separation Liquefaction (100 o c) 72 Hours Saccharification Fermentation (60 o c) (30 o c) Hours Simultaneous Saccharification & Fermentation, SSF (30 o c) Distillation Distillation (a) (b)

38 Simultaneous Saccharification and Fermentation, SSF Milling Cassava Chips α-amylase glucoamylase yeast Distillation &Dehydration Cooking & Liquefaction SSF

39 ethanol and glucose (% w/v) glu-cf active cell-cf active cell-ssf eth-ssf eth-cf active cell x10 7 (cells/ml) 0 glu-ssf time (hrs.) Ethanol production from cassava chips by conventional (CF) and SSF process glu-cf glu-ssf eth-cf eth-ssf act-cell-cf act-cell-ssf 5 0 Conditions: Ground cassava chips (25% DS); Liquefaction by 0.1% α-amylase at 95 C, 2 hrs; Saccharification by 0.1% glucoamylase at 55 C, 15 hrs; Fermentation by yeast, Saccharomyces cerevisiae SC90, at 32 C. For SSF process, glucoamylase was added with yeast.

40 Production of ethanol from cassava chips by CF and SSF process Parameter CF Process SSF Ethanol concentration (%w/v) Yield (g ethanol / g cassava chip) Yield (g ethanol / g starch) % Fermentation Efficiency 89 89

41 Simultaneous Saccharification and Fermentation, SSF Cassava Chip - Moisture 15 % - Starch content 65% (wet basis) T/D 85.00% TS Milling 1, T/D Water Mixing Steam 120 T/D Spent wash recycle T/D Spent wash recycle 6.23 T/D Liquefaction SSF Fermentation Distillation Molecular Sieve Dehydration Fuel Ethanol T/D or 150,000 L/D 1, T/D 17.16% TS 1, T/D 16.08% TS CO 2 1, T/D 7.42%(w/w) Alcohol T/D 95% Alcohol Fusel oil T/D Thick Slop 0.50 T/D 1, T/D 6.5% TS Mass Balance of Ethanol Production from Cassava Chip by SSF process T/D = Ton/Day, TS = Total Solid,L/D =Liter/day Fermentation efficiency 90%, Distillation efficiency 98.5%

42 Cassava Chips Milling Simultaneous Liquefaction, Saccharification and Fermentation, SLSF Raw-starch digesting enzyme yeast Distillation &Dehydration SINGLE STEP & UNCOOKED process SLSF

43 Cooking Liquefaction /Saccharification + Ethanol Fermentation

44 Cereal starches Corn (55%hydrolysis) Root & tuber starches Rice (65%hydrolysis) Wheat (40%hydrolysis) Cassava (50%hydrolysis) Potato (20%hydrolysis) SEMs of various starches treated with granular starch hydrolyzing enzymes (GSHE)

45 Corn Cassava 6-hr incubation 12 - hr incubation 24 - hr incubation 48 - hr incubation SEMs of corn and cassava starches treated with granular starch hydrolyzing enzymes (GSHE)

46 12 ) Pretreat ( 0.25 Pretreat Pretreat Ethanol concentration (%w/w) Fermentation time (hr) Ethanol concentration produced from cassava chips (25%DS) with and without alkali pretreatment by granular starch hydrolyzing enzymes ( % by wt) in SLSF process

47 ph Glucose and ethanol content (%w/v) TSS Ethanol TS 2 ph 1 Glucose Total soluble solid, TSS ( O Brix) Total solid, TS (%w/w) Time (h) Ethanol production from cassava chips by SLSF process Conditions: Ground cassava chips (25% DS); Liquefaction and Saccharification by 0.25% granular starch hydrolyzing enzymes and Fermentation by yeast, Saccharomyces cerevisiae, at 32 C

48 Conventional process 1. Cassava chips Today s process 1. Cassava chips Future process 1. Cassava chips 2. Milling / Cooking 2. Milling / Cooking 2.Milling / Uncooked 3. Liquefaction (100 o C, 2 hr) 4. Saccharification (60 o C, hr) 5. Fermentation (30 o C, hr) 6. Filtration& Distillation Ethanol 3. Liquefaction (100 o C, 2 hr) 4. Simultaneous Saccharification and Fermentation (SSF) (30 o C, hr) 5. Filtration& Distillation Ethanol 3. Simultaneous Liquefaction Saccharification and Fermentation (30 o C, hr) 4. Filtration & Distillation Ethanol

49 The Key of Success Various forms of cassava can be used

50 The Key of Success 4 million tons/year (12% moisture content) Roots 25 million tons/year (65-70% moisture content) Chips Water 2-3 million tons/year (12% moisture content) Starch Pulp 3 million tons/year (70% moisture content)

51 Composition of cassava feedstock Composition (% dry basis) Roots Chips Starch Fiber content nil Protein Ash Starch content Starch content (wet basis) (%MC) (65) (10) (12)

52 Starch slurry (with fiber) prepared from fresh root

53 PROBLEM: At high total solid content Roots Chips Starch Viscosity Flowability Processing effectiveness

54 Ethanol production from cassava fresh roots Ground fresh roots ( 35-40% DS) Total solid adjustment ( 20% DS) by water addition (feedstock to water ratios 1:0.5 to 1:1) Liquefaction Saccharification and Fermentation Fermented mash with 8% (w/w) or 10% (v/v) ethanol

55 VHG (very high gravity) technology in fuel alcohol production To increase the alcohol concentration to 18% (v/v) or 14.6% (w/w) Increase total solid/starch content (or increase the feedstock to water ratio)

56 VHG (very high gravity) technology in fuel alcohol production 1. Increased plant capacity 2. Increased plant efficiency - reduction in labor costs 3. reduction in energy costs - less heating/cooling of mash, less water to process in the still, optimum ethanol for efficient distillation, lower solids in the still 4. reduction in inputs - decreased water usage Cassava and Starch Technology Research Unit

57 VHG technology development for cassava roots Mash viscosity reduction

58 Ethanol production from cassava fresh roots Ground fresh roots ( 35% DS) (feedstock to water ratios 1 : 0.1) Mash viscosity reduction Liquefaction Saccharification and Fermentation Fermented mash with 16-18% (v/v) ethanol

59 20 18 SSF process VHG - SSF process Ethanol concentration (%v/v) Fermentation time (hr) Ethanol concentration during fermentation of cassava fresh roots by SSF and VHG-SSF process Raw material: moisture content = 65%, starch and sugar contents = 85 and 6.25% dry basis, respectively Condition: SSF: 20% dry solid, VHG-SSF: 35% dry solid

60 Sun Drying Water 59 Tons Cassava Chip (moisture content = 14%) 41 Tons Milling Process water 99 Tons Mixing (total solid = 25%) 140 Tons Fresh Root (moisture content = 60-70%) 100 Tons Process water saving VHG Technology Development Ethanol Fermentation

61 12 Energy Saving 18.5% Energy Consumption (MJ/L ethanol) SSF process VHG/SSF process Dehydration Distillation Fermentation Root Preparation &Liquefaction Estimated reduction on energy consumption of ethanol production by VHG-SSF process

62 H 2 O Water Less by using fresh H 2 roots O H 2 O Energy Energy Less by using fresh roots Energy Less by using SLSF process Energy Less by using VHG process

63 THANK YOU FOR YOUR ATTENTION