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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

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Ethanol is a clear liquid made fromfermenting sugars from:

Grains – grain ethanolBiomass – cellulosic ethanol

Ethanol is an engine fuel that burns toproduce carbon dioxide and water

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Ethanol

Lignin

Lignin

CellulosicFeedstock

1st Pretreatment(convert hemi-celluloseinto xylose and reducesize and open upstructure of cellulose)

Fermentation ofxylose andother simplesugars fromhemi-cellulose

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2nd Pretreatment(convert cellulose intoGlucose)

Simultaneoussaccharification& fermentation

Glucosefermentation

Distillationto recoverethanol

Fuel forheat andelectricity

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Convert hemi-cellulose into pentoses (5 carbon sugars)and partial breakdown of cellulose

Each type of cellulosic feedstock requires a uniquecombination of pretreatments.Physical methods:

steam explosion

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1st Pretreatment

Convert cellulose into hexoses (6 carbonsugars)

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The cellulose fraction is hydrolyzed by acidsor enzymes to produce glucoseEnzymatic hydrolysis – biological conversion

of cellulose to sugarsAcid hydrolysis – acid concentrations to

convert cellulose to sugars

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Chemical methods:dilute acid, alkaline, organic solvent, ammonia, sulfur

dioxide, carbon dioxideBiological methods:

2nd Pretreatment

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The solids remaining after the hemi-cellulose and cellulose are converted tosugars are washed, dried and used asfuel source for power production.

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Lignin (By-product)

Hydrolysis breaks down the hydrogenbonds in the hemi-cellulose andcellulose fractions into their sugarcomponents: pentoses and hexoses.The yeast contains an enzyme calledinvertase, which acts as a catalyst andhelps to convert the sucrose sugars intoglucose and fructose (both C6H12O6)

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Hydrolysis (saccharification)

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The fructose and glucose sugars reacts with anenzyme called zymase, which is also containedin the yeast, to produce ethanol and carbondioxide.The fermented mash, called beer, containsabout 10% alcohol plus all the non-fermentable

solids from the corn and yeast cells.The mash and solids are separated

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Fermentation

(After fermentationthe cellulosic andgrain ethanolproductionprocesses are similarand will beexplained together.)

Ethanol

Liquify & Cook

Grain

Grind

Fermentation

Dehydration

Centrification

Dryer

Distillers Solubles DistillersGrainsw/Solubles

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DriedDistillersGrains

Saccharify

Enzymes

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DenaturingCO2

Beer

Distillation

Whole Stillage

Thin Stillage

Evaporation

190

Proof

Syrup

Wet Grains

200

Proof

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The grain passes through a hammer mill whichgrinds it into a fine powder called meal.

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The meal is mixed with water andcooked to liquify the starch. Heat isapplied to enhance liquefactionresulting in a mash.

Enzymes are added to facilitate starchbreakdown

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An enzyme is added to the mash toconvert the liquefied starch tofermentable sugars

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Yeast is added to the mash to fermentthe sugars to ethanol and carbondioxide.

In a batch process, the mash stays in onefermenter for about 48 hours before thedistillation process is started.

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Distillation (Cellulosic or Grain)

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The distillation involves boiling thewater and ethanol mixture. Sinceethanol has a lower boiling point(78.3C) than water (100C), ethanolvaporizes before water and can becondensed and separatedThe distilled alcohol is about 96%strength.

Drying & Denaturing(Cellulosic or Grain)

Most ethanol plants use amolecular sieve to water from thedistilled ethanol.

Fuel ethanol must be denatured, ormade unfit for humanconsumption, with a small amountof gasoline (2-5%)

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DDG is a by-product of grain ethanolproduction.Drying the distillers grain increases itsshelf life and reduces transportationcostsA bushel of corn (56 lbs) yields about 2.8gallons of ethanol and 17 pounds ofdistillers grain

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Dried Distillers Grains (DDG)

DDGS is a by-product of grainethanol production.The liquid that is separated fromthe mash during the distillingprocess is partially dehydrated intoa syrup, then added back onto thedried distillers grain to createDDGS

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Dried Distillers Grains with Solubles (DDGS)

EthanolE100

E8585 % Ethanol –15 % Gasoline

Gasohol10 % Ethanol –90 % Gasoline

Gasoline

BTU,s/Gal 84,400 90,000 120,900 125,000

OctaneNumber

100 98 94 87 - 93

EquitableValue(BTU)

$2.02/gal $2.16/gal $2.90/gal $3.00/gal

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CO2 is given off duringfermentation

Ethanol production plants collect,compress, and sell it for use inother industries

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(Cellulosic or Grain) Carbon Dioxide (CO2)

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Potential StrengthsFewer air pollutants

Renewable sources

Potential WeaknessesFewer BTU’s per gallon

Higher ethanol blends require enginemodification

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lig n in

o th ers

C 5 S ug ar

C 6 S ug ar

C 6 S ug aro th ers

lig n in

*recombinant E. coli "KO11"

New technology

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･ This process can convert C5 sugars (from hemi-cellulose) to ethanol.･ Conventional methods can convert only C6 sugars.･ Using this technology, lignocellulosic biomass waste can be utilized as a feedstock for ethanol production.

Conventional technology

Fermentation of C6 sugars byyeast, etc.

Fermentation of C6 sugars byyeast, etc.

C 5 S ug ar

New microorganism*

can convert C5 sugars to ethanol

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Processing DistillationFeedstock

Handling

KO11

Ethanol

Lignin forboiler

C5 Sugars

Yeast

C5

hydrolysis

C6 SugarsC6

hydrolysis

C5 sugarrecovery

(Stillage)

Conventional

technology

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Fermentation

New technology

Process Flow of New Technology

･ With the added benefit of KO11 bacteria, C5 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 constructionwood

: bagasse

Construction: August 2003

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on microbial growthGrowth

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RITE Bioprocess

Conventional bioprocessesProduction accompanied by microbial growth

■ Large reactor space neededbecause microorganisms needspace to grow

■ Production (reaction) time depends

No growth No production

Rite bioprocessReactor filled to high densitywith microbial cells

No microbial growth

High productivity

■ Corynebacterium

Ethanol production without

microbial growth

Ligno-cellulose

RITEBioprocess Ethanol

■ High production yield

■ Simple system25

Process requirements forCommercial scale production

*Dien26BS et al. Appl Microbiol Biotechnol (2003) 63: 258-266

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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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