1. 1 9/21/2010 Iman Rusmana Department of Biology Bogor Agricultural University What is Ethanol? Ethanol Production From Biomass Ethanol Production From Grains Ethanol Engine Fuel Characteristics Ethanol Strengths & Weaknesses 9/21/2010 1212

2. 2  Ethanol is a clear liquid made from fermenting sugars from:  Grains – grain ethanol Biomass – cellulosic ethanol  Ethanol is an engine fuel that burns to produce carbon dioxide and water 9/21/20103 4 Ethanol Lignin Cellulosic Feedstock 1 st Pretreatment (convert hemi-cellulose into xylose and reduce size and open up structure of cellulose) Fermentation of xylose and other simple sugars from hemi-cellulose 9/21/2010 2 nd Pretreatment (convert cellulose into Glucose) Simultaneous saccharification & fermentation Glucose fermentatio n Distillation to recover ethanol Fuel for heat and electricity

3. 3  Convert hemi-cellulose into pentoses (5 carbon sugars) and partial breakdown of cellulose Each type of cellulosic feedstock requires a unique combination of pretreatments.  Physical methods:  steam explosion  9/21/20105 1 st Pretreatment  Convert cellulose into hexoses (6 carbon sugars)  9/21/2010 The cellulose fraction is hydrolyzed by acids or enzymes to produce glucose  Enzymatic hydrolysis – biological conversion of cellulose to sugars  Acid hydrolysis – acid concentrations to convert cellulose to sugars 6 Chemical methods:  dilute acid, alkaline, organic solvent, ammonia, sulfur dioxide, carbon dioxide Biological methods: 2 nd Pretreatment

4. 4  The solids remaining after the hemi- cellulose and cellulose are converted to sugars are washed, dried and used as fuel source for power production. 9/21/20107 Lignin (By-product)  Hydrolysis breaks down the hydrogen bonds in the hemi-cellulose and cellulose fractions into their sugar components: pentoses and hexoses. The yeast contains an enzyme called invertase, which acts as a catalyst and helps to convert the sucrose sugars into glucose and fructose (both C6H12O6) 9/21/20108 Hydrolysis (saccharification)

5. 5  The fructose and glucose sugars reacts with an enzyme called zymase, which is also contained in the yeast, to produce ethanol and carbon dioxide. The fermented mash, called beer, contains about 10% alcohol plus all the non-fermentable  solids from the corn and yeast cells. The mash and solids are separated 9/21/20109 Fermentation (After fermentation the cellulosic and grain ethanol production processes are similar and will be explained together.) Ethanol Liquify & Cook Grain Grind Fermentation Dehydration Centrification Dryer Distillers Solubles Distillers Grains w/Solubles 10 Dried Distillers Grains Saccharify Enzymes 9/21/2010 Denaturing CO 2 Beer Distillation Whole Stillage Thin Stillage Evaporation 190 Proof Syrup Wet Grains 200 Proof

6. 9/21/2010 6  The grain passes through a hammer mill which grinds it into a fine powder called meal. 9/21/201011  The meal is mixed with water and cooked to liquify the starch. Heat is applied to enhance liquefaction resulting in a mash.  Enzymes are added to facilitate starch breakdown 9/21/201012

7. 9/21/2010 7  An enzyme is added to the mash to convert the liquefied starch to fermentable sugars 13 Yeast is added to the mash to ferment the sugars to ethanol and carbon dioxide. In a batch process, the mash stays in one fermenter for about 48 hours before the distillation process is started. 14

8. 8 9/21/2010 Distillation (Cellulosic or Grain)  9/21/2010 15 16 The distillation involves boiling the water and ethanol mixture. Since ethanol has a lower boiling point (78.3C) than water (100C), ethanol vaporizes before water and can be condensed and separated The distilled alcohol is about 96% strength. Drying & Denaturing (Cellulosic or Grain) Most ethanol plants use a molecular sieve to water from the distilled ethanol. Fuel ethanol must be denatured, or made unfit for human consumption, with a small amount of gasoline (2-5%)

9. 9  DDG is a by-product of grain ethanol production. Drying the distillers grain increases its shelf life and reduces transportation costs A bushel of corn (56 lbs) yields about 2.8 gallons of ethanol and 17 pounds of distillers grain 9/21/201017 9/21/2010 Dried Distillers Grains (DDG)  DDGS is a by-product of grain ethanol production. The liquid that is separated from the mash during the distilling process is partially dehydrated into a syrup, then added back onto the dried distillers grain to create DDGS 9/21/201018 Dried Distillers Grains with Solubles (DDGS)

10. Ethanol E100 E85 85 % Ethanol – 15 % Gasoline Gasohol 10 % Ethanol – 90 % Gasoline Gasoline BTU,s/Gal84,40090,000120,900125,000 Octane Number 100989487 - 93 Equitable Value (BTU) $2.02/gal$2.16/gal$2.90/gal $3.00/gal 9/21/2010 10  CO2 is given off during fermentation Ethanol production plants collect, compress, and sell it for use in other industries 19 ( Cellulosic or Grain) Carbon Dioxide (CO 2 ) 20 9/21/2010

11. 11  Potential Strengths  Fewer air pollutants  Renewable sources  Potential Weaknesses  Fewer BTU’s per gallon  Higher ethanol blends require engine modification 21 22 lig n in o th ers C 5 S ug ar C 6 S ug ar o th ers lig n in *recombinant E. coli "KO11" New technology 9/21/2010 ･ This process can convert C 5 sugars (from hemi-cellulose) to ethanol. ･ Conventional methods can convert only C 6 sugars. ･ Using this technology, lignocellulosic biomass waste can be utilized as a feedstock for ethanol production. Conventional technology Fermentation of C 6 sugars by yeast, etc. Fermentation of C 6 sugars by yeast, etc. C 5 S ug ar New microorganism* can convert C 5 sugars to ethanol

12. 9/21/2010 ProcessingDistillationFeedstock Handling KO11 Ethanol Lignin for boiler C 5 Sugars Yeast C 5 hydrolysi s C 6 Sugars C 6 hydrolysi s C 5 sugar recovery (Stillage) Conventional technology 23 Fermentation New technology Process Flow of New Technology ･ With the added benefit of KO11 bacteria, C 5 sugars are converted into ethanol ･ Lignin, and stillage from the process, are utilized as boiler fuel Biomass Ethanol (Development) Overview of Pilot Plant (1) Biomass Ethanol (Pilot Plant) Location: TSK R&D CENTER Chiba, Japan Capacity: 4T/D of raw materials Raw materials: waste construction wood : bagasse Construction: August 2003 24 12

13. on microbial growth Growth 9/21/2010 RITE Bioprocess Conventional bioprocesses Production accompanied by microbial growth ■ Large reactor space needed because microorganisms need space to grow ■ Production (reaction) time depends No growth No production Rite bioprocess Reactor filled to high density with microbial cells No microbial growth High productivity ■ Corynebacterium Ethanol production without microbial growth Ligno- cellulose RITE Bioprocess Ethanol ■ High production yield ■ Simple system 25 Process requirements for Commercial scale production *Dien 26 BS et al. Appl Microbiol Biotechnol (2003) 63: 258-266 13 Requirements * Ethanol productivity: more than 1 g/L ・ h Ethanol concentration: more than 4% Ethanol production from C5 sugars Tolerance for lignocellulose--derived-inhibitors RITE Bioprocess >20 g/L ・ h Over 7% Yes Virtually no inhibition

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