Corn Based Ethanol

By David Acselrod4/12/07

Overview

• Process

• History

• Viable Source of Energy

• Emissions

• Conclusion

Process

• Cultivation of Corn

• Fermentation

• Distillation (95% Water Free)

• Dehydration (99.9% Water Free)

• Denaturing

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History• Used as Fuel Since 1908• Gasoline Found to be Cheaper (debatable)• Used as Knock Suppressive 1920s,1930s• Lead Found to be Cheaper (debatable)• 1973 Oil Embargo Renews Interests• Energy Tax Act of 1978, Reformations• Accounts Presently for 3% of US Fuel Use

Viable Source of Energy

• Net Energy Value (NEV)• Inputs

– -Farm Energy– -Corn Transport– -Ethanol Conversion– -Distribution– +Coproducts (primarily animal feed)

• Output– +Combustible Fuel (HHV≈84,000Btu/gal)

Farm Energy Expended

Energy Balance Before Coproducts

Various Energy Balance Calculations

Pimentel’s Calculations

• Corn Yields Date from pre 1992

• Values for Energy to Create Fertilizer Come from 1990 Worldwide Values

• Value for Energy Needed to Convert Corn to Ethanol (within plant) date pre 1980

• Assumes all Corn is Irrigated (only 16% is)

• Low Energy Credits for Co-products

Yield of Corn with Time

Corn Yield per lb of Fertilizer

Energy Use of Ethanol Plants

Emissions

• EPA Concludes that E-85 Reduces GHG Emissions by 20-25%

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Conclusion

• Viable Source of Energy

• Helps to Reduce GHGs

• Helps to Reduce Dependency on Foreign Oil