Ethanol-Gasoline Fuels: Ethanol-Gasoline Fuels: Are they Effective?Are they Effective?

Presented by Steve Presented by Steve CavadeasCavadeas

OutlineOutline

BackgroundBackground Ethanol production processEthanol production process Pros and ConsPros and Cons ConclusionsConclusions

1990 Ammendment to 1990 Ammendment to Clean Air ActClean Air Act

An attempt to reduce severe smog areasAn attempt to reduce severe smog areas Reduce CO emissions in winterReduce CO emissions in winter

– Requires an oxygenateRequires an oxygenateAllows more complete combustionAllows more complete combustionEthanol, MTBEEthanol, MTBE

The federal RFG program was introduced in 1995The federal RFG program was introduced in 1995 RFG is currently used in 17 states RFG is currently used in 17 states About 30 percent of gasoline sold in the U.S. is About 30 percent of gasoline sold in the U.S. is

reformulated. reformulated. Each oil company prepares its own formula. Each oil company prepares its own formula.

OptionsOptions

MTBE vs. EthanolMTBE vs. Ethanol Corn vs. BiomassCorn vs. Biomass Dry milling vs. Dry milling vs.

Wet millingWet milling

Dry Milling ProcessDry Milling Process

Wet Milling ProcessWet Milling Process

Biomass ProcessBiomass Process

Wet Milling DetailsWet Milling Details

SteepingSteeping– Grain is soaked in sulfurous acid for 24 to 48 hoursGrain is soaked in sulfurous acid for 24 to 48 hours

Grinding and SeparationGrinding and Separation– Grain is separated into gluten, fiber, starch, and germGrain is separated into gluten, fiber, starch, and germ– Oil is extracted from germ using benzeneOil is extracted from germ using benzene

By-ProductsBy-Products

Feed productFeed product– Fiber is extruded and heavy Fiber is extruded and heavy

steep water is added, then steep water is added, then dried.dried.

– Sold as feed for livestockSold as feed for livestock

Gluten MealGluten Meal– Gluten is filtered and driedGluten is filtered and dried– Sold as feed ingredient to Sold as feed ingredient to

poultry boiler operationspoultry boiler operations

ProductsProducts

StarchStarch– Can be processed Can be processed

further to producefurther to produce1.1. Modified or dried Modified or dried

corn starchcorn starch

2.2. Corn syrup Corn syrup (dextrose, (dextrose, fructose)fructose)

3.3. EthanolEthanol

Ethanol from Corn StarchEthanol from Corn Starch

LiquificationLiquification -amylase added to -amylase added to

cleave random cleave random -1,4 -1,4 and and -1,6-glucosidic -1,6-glucosidic bondsbonds

– Gluco-amylase added to Gluco-amylase added to digest digest -1,4-glucosidic -1,4-glucosidic bond from non-reducing bond from non-reducing endend

Ethanol from Corn StarchEthanol from Corn Starch

Yeast then added to resulting sugar for Yeast then added to resulting sugar for fermentation (40-50 hours).fermentation (40-50 hours).

CC66HH1212OO66 + 6 O + 6 O22 2 C 2 C22HH66O + 2 COO + 2 CO22

(6 separate reactions, (6 separate reactions, ∆G = -41.1 kcal/mol)∆G = -41.1 kcal/mol)

however, there is a problem… however, there is a problem…

Ethanol from Corn StarchEthanol from Corn Starch

Respiration can occur!Respiration can occur!

CC66HH1212OO66 + 6 O + 6 O22 6 CO 6 CO2 2 + 6 H+ 6 H22OO

((G = -686 kcal/mol)G = -686 kcal/mol)

Solution?Solution?– Get rid of OGet rid of O22

– Use organisms that preferentially fermentUse organisms that preferentially ferment

Ethanol from Corn StarchEthanol from Corn Starch

After fermentation, 8-10% EtOH in waterAfter fermentation, 8-10% EtOH in water– Distilled to approximately 190 proofDistilled to approximately 190 proof– Dehydrated to 200 proof using molecular Dehydrated to 200 proof using molecular

sievessieves Finally, 5% denaturant is added to render Finally, 5% denaturant is added to render

undrinkable (usually gasoline)undrinkable (usually gasoline)– Avoid beverage alcohol taxAvoid beverage alcohol tax

Product is sent to be mixed as 10 vol% Product is sent to be mixed as 10 vol% gasolinegasoline

Ethanol Production FacilitiesEthanol Production Facilities

Source: U.S. Energy Information Administration/Renewable Fuels Administrations

U.S. Ethanol ProductionU.S. Ethanol Production

0

500

1000

1500

2000

2500

3000

Mill

ion

s o

f G

allo

ns

1980

1981

1982

1983

1984

1985

1986

1987

1988

1989

1990

1991

1992

1993

1994

1995

1996

1997

1998

1999

2000

2001

2002

2003

Year

Source: U.S. Energy Information Administration/Renewable Fuels Administrations

BenefitsBenefits

Octane BoosterOctane Booster– Raises octane 2.5~3 numbersRaises octane 2.5~3 numbers

Allows for higher combustion ratesAllows for higher combustion rates Reduces harmful emissionsReduces harmful emissions

– CO emissions decrease by 26%CO emissions decrease by 26%– Fewer higher order hydrocarbons emittedFewer higher order hydrocarbons emitted

Large number of jobs for productionLarge number of jobs for production– 32% of corn harvested goes to production of 32% of corn harvested goes to production of

ethanolethanol

DrawbacksDrawbacks

Additional emissionsAdditional emissions– 15% NO15% NOxx

– 65% Organic emissions65% Organic emissions– 46% aldehydes46% aldehydes– 10% PAN, PPN10% PAN, PPN

Potent lachrymators and mutagens

Data from Data from Performance Evaluation of Alcohol-Gasoline Blends in 1980 AutomobilesPerformance Evaluation of Alcohol-Gasoline Blends in 1980 Automobiles. Coordinating Research Council. No 527. July, 1982.. Coordinating Research Council. No 527. July, 1982.

But then again…But then again…

New study from EPA New study from EPA suggests air quality is suggests air quality is highest in three highest in three decadesdecades

Depends on who you Depends on who you askask

Millions of Tons

  1970 2003*  

CO 197.3   93.7

NOx 26.9 20.5

PPN    12.2 2.3

SO2 31.2 15.8

VOC 33.7 15.4

Lead 0.221 0.003

*preliminary data

http://www.epa.gov/air/

Other DrawbacksOther Drawbacks

Energy loss!Energy loss!– 1 acre corn field creates ~ 330 gal EtOH1 acre corn field creates ~ 330 gal EtOH– Planting, growing, harvesting 1 acre requires Planting, growing, harvesting 1 acre requires

~1,000 gal fossil fuels~1,000 gal fossil fuels– 1 gal EtOH = 77,000 Btu1 gal EtOH = 77,000 Btu– 1 gal Gasoline = 114,000 Btu1 gal Gasoline = 114,000 Btu

Possible vapor lock in engines (older cars)Possible vapor lock in engines (older cars)– Not an issue with “forward pumping”Not an issue with “forward pumping”

More DrawbacksMore Drawbacks

Cost of production (2003)Cost of production (2003)– EtOH ~ $1.74 / gallonEtOH ~ $1.74 / gallon– Gasoline ~ $1.14 / gallonGasoline ~ $1.14 / gallon

State and Federal SubsidiesState and Federal Subsidies– ~$1 Billion/year given to ethanol producers~$1 Billion/year given to ethanol producers– This is added cost to consumerThis is added cost to consumer

ConclusionConclusion

Environmental benefits vs. Environmental benefits vs. cost/performancecost/performance

Other oxygenates available?Other oxygenates available?– ETBEETBE (Ethyl Tert-Butyl Ether) (Ethyl Tert-Butyl Ether)– TAME (Tertiary Amyl Methyl Ether)TAME (Tertiary Amyl Methyl Ether)– MTBEMTBE (Methyl Tert-Butyl Ether) (Methyl Tert-Butyl Ether)

What do you think?What do you think?

ReferencesReferences1.1. Performance Evaluation of Alcohol-Gasoline Blends in 1980 Performance Evaluation of Alcohol-Gasoline Blends in 1980

AutomobilesAutomobiles. Coordinating Research Council. No 527. July, . Coordinating Research Council. No 527. July, 1982. 1982.

2.2. Ethanol from Corn Wastes Energy?Ethanol from Corn Wastes Energy? Social Science. October Social Science. October 2001. Pg 6.2001. Pg 6.

3.3. Potential Air Quality Effects of Using Ethanol-Gasoline Fuel Potential Air Quality Effects of Using Ethanol-Gasoline Fuel Blends: A Field Study in Albuquerque, New Mexico. Blends: A Field Study in Albuquerque, New Mexico. Environ. Environ. Sci. Technol. Vol. 31, No. 11. 1997. Pgs. 3053-3061Sci. Technol. Vol. 31, No. 11. 1997. Pgs. 3053-3061

4.4. Renewable Fuels Association. Renewable Fuels Association. www.ethanolrfa.orgwww.ethanolrfa.org

5.5. U.S. Department of Energy. www.doe.govU.S. Department of Energy. www.doe.gov

6.6. American Corn Growers Association. www.acga.orgAmerican Corn Growers Association. www.acga.org