Ethanol

Solar Energy

Photosynthesis

Biomass

Corn/Cane

Ethanol Bioethanol

Natural Vegetation(grass, foliage, timber)

Energy crops Ag and Urban Wastes

Crops

Avg. 0.3 - Max 6.7% of Incident Sunlight Converted to Biomass1

20 - 40%2,3,4

1 - Kheshgi et al. 2000 2 - Cook et al. 19913 - Lynd et al. 19914 - Wooley et al. 1999

33 - 54%1

Cellulosic Sources

• Bioethanol defined as being derived from cellulose/hemicellulose

• Types of energy crops:– Hybrid Poplars– Cottonwoods– Willows– Switchgrass

Poplars

Poplar Plantation

Poplar Cutting

Switchgrass Stand

Switchgrass

Cellulosic Biomass Composition

Cellulose 45%Hemicellulose 30%Lignin 15%Other 10%

Herbaceous Energy Crops

Cellulose 43%Hemicellulose 27%Lignin 17%Other 13%

Agricultural Residues

Municipal Solid Waste

Ash 15%Lignin 10%Hemicellulose 9%Other carbohydrates 9%Protein 3%Other 9%

Cellulose 45%

Cellulose 45%Hemicellulose 25%Lignin 22%Extractives 5%Ash 3%

Woody Crops

DOE approach

• Use of idle crop land (82 million acres)– 392 million acres are suitable for biomass

• best land is in the north central region

– Short-rotation woody crops expected annual yields of 5 or more dry tons

per acre could be grown on 225 million acres (2423 million tons) – Herbaceous energy crops with similar yields could be grown on 324

million acres (1427 million tons) – It would take 82 million acres (6 dry tons/acre) to produce 492 million tons

of dry biomass. This would yield to produce ~ 40 billion gallons of ethanol - enough to replace 22% of US gasoline consumption on an energy basis.

– If you used all 392 million acres ~ 190 million gallons, slightly more than enough ethanol to replace gasoline consumption.

U.S. Crop Suitability Map

Source: Oak Ridge National Laboratory

Source: ORNL County Level Study

Ethanol production using Switchgrass on Idled Cropland1

Idled

Cropland

(million acres)

Ethanol Produced

(million gallons)

2010 Demand Met using

Optimistic Biomass Yields

(%)

Region Medium2 Optimistic2 Region US

New England >1 22 24 >1 <1

Mid East 1 426 478 1 <1

Southeast 10 4,370 5,492 11 3

Great Lakes 6 2,443 2,896 9 9

Plains 20 7941 9,570 68 5

Southwest 8 3,426 4,175 17 2

Rocky

Mountain

0 0 0 0 0

Pacific 0 0 0 0 0

48 States 56 18,619 22,634 - 11

1 – Numbers may not add due to rounding

2 – Defined in Table 1.

Gasoline requirements per region (% of Total - 1.2 billion gallons)

27%

16%14%15% 8%

5%

3%

12%

5%

> 5 to 10%

> 10 to 20%

> 20%Do to rounding values may not equal 100%

Land Use in the Contiguous 48 States

Use Acreage(Million Acres)

Proportion ofTotal Area

(%)

Grassland Pasture& Range

ForestCroplandSpecial UseOther Use

589

55946019492

31

302410

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48

Sta

tes

0

50

100

150

200

250

300

350

Vol

ume

of E

than

ol (

Bill

ion

Gal

lons

)

US Region

2000 Ethanol Requirements

2010 Ethanol Requirements

Production Capacity

Ethanol Supply & Demand

1997 1998 1999 2000 2001 2002 2003 20040

500

1000

1500

2000

2500

3000

3500

Eth

an

ol A

mo

un

t (m

illio

n g

allo

ns)

Year

Supply

Demand

Projected Demand

Projected with no MTBE

Data from Urbanchik, 2000

Ethanol fuel properties in relation to fuel performance

Energy density

Heat of vaporization

Lower flame temperature

Relative volume ofcombustion products

Octane Number

0.65-0.69

2.3

0.976

1.07

1.15

Lower mpgLarger tank

More air to cylinderIncreased powerDecreased cooling needs

Higher efficiencyin optimized engine

Increases work from gas expansion

Allows increased compression ratio and hence higherPower and efficiency

PropertyEthanol/Gasoline

ValueImpact

From Lynd 1996;Bailey 1996

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are needed to see this picture.

Corn Milling Liquefaction Saccharification Fermentation

Distillation Dehydration

Centrifugation

Evaporation

Dry FeedMixing Drying Cooling

Corn

-Amylase Gluco-amylase Yeast

Fuel GradeEthanol

Denaturant

Distillers Dried Grains w/ soluble

Dry Milling Simplified Process

Net Corn Costs

Other Operating Costs

Annualized Capital Costs

Total Production Costs

0.45

0.34-0.45

0.26-0.49

1.05-1.40

0.37

0.31-0.47

0.20-0.44

0.90-1.33

$/gal

Dry Mill Wet Mill

Current Ethanol Costs

How much land for corn ethanol?

• 2.5 gallons of ethanol from a bushel of corn• US average corn yield per acre was 132 bushels

for the period from 1997 to 1999• Thus, a little under 3.9 million acres of corn is

needed to meet the current ethanol demand• 9.6 million acres would be needed to meet the

2004 ethanol demand

Issues

• The projected 2004 demand is essentially equivalent to the ethanol produced from cane sugar in Brazil (3.1 vs 3.4 billion gallons).

• Infrastructure development - mainly dry mills

• Co-products

• Energy Balance

Energy Requirements

• Units of Fossil Energy/Unit of Fuel Energy

– Gasoline 1.29 – Diesel 1.19

– Corn ethanol 0.99

•  Sources: Sheehan [1998], Riley [1995], Shapouri [1995]

Reasons to use Bioethanol

• Energy security

• Petroleum prices rise

• CAFE Increase

• Serious about greenhouse gas emissions

Size ReductionDilute AcidPretreatment

Liquid Solid Separation

DetoxificationVia

Ion Exchange

Enzyme Production SSCF Fermentation

SeparationSolids ProcessingCogen

Biomass

Fuel GradeEthanol

Simplified Bioethanol Process

Energy Requirements

• Units of Fossil Energy/Unit of Fuel Energy

– Gasoline 1.29 – Diesel 1.19

– Corn ethanol 0.99– E95 (lignocell) 0.25

•  Sources: Sheehan [1998], Riley [1995], Shapouri [1995]

Current Ethanol Costs

Net Feedstock Costs

Other Operating Costs

Annualized Capital Costs

Total Production Costs

0.45

0.34

0.26

1.05

0.37

0.31

0.22

0.90

$/gal

Dry Mill Wet Mill

0.37

0.25

0.54

1.16

Cellulosic

Effect of Biomass Cost on Ethanol Production Cost

$ 1.00/gal ethanol

$ 1.20/gal ethanol

E85 Costsvs

Gasoline Costs

Gasoline Cost

Volume Basis

Energy Basis

Dedicated E85 Vehicle

1.0 1.5 2.00.5

0.5

1.0

1.5

2.0

0.5

1.0

1.5

2.0

0.5

1.0

1.5

2.0

Ble

n de d

Fu e

ls C

ost s

($/

g al )

Gasoline Costs ($/gal)

$1.14

$0.94

$1.72

$1.42

$1.53

$1.26

Fuel Economics• Cellulosic ethanol currently costs too much• Gasoline $/gal $/liter

Refinery gate price: 0.80 0.21Transportation, storage, retailing: 0.40 0.11Taxes: 0.30 0.08Total (price at pump) 1.50 0.40

• EthanolProduction cost: 1.20 0.32Assume distribution $/gal as above 0.40 0.11Hold total tax revenue constant 0.20 0.05Total 1.80 0.48Total ($/volume gasoline equivalent) 2.70 0.71

Fuel/Vehicle Issues for Transition

• E10: current gasoline ICE are able to use up to E10• High level blends (up to E85): Flexible fueled ICE

– 2 million current vehicles in U.S.– Requires vehicle modifications– Dedicated vehicles slightly more efficient

• Start by all vehicles using E10 (50 billion liters for U.S., 10 X present production)

• Manufacture flexible fueled vehicles, gradually shifting to dedicated vehicles as ethanol production increases

For lignocellulosic ethanol to penetrate transportation fuel market:

• Technological advances & cost reductions• Infrastructure development• Higher petroleum prices• Stringent GHG emissions legislation• Subsidize production (via lower taxes)• Consumer demand for renewable fuels• Consumer acceptance of land use

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Fuel Cycle

Global Warming Potential for Alternative Fuel Vehicle Options

Ethanol OptionsLave 2000

Environmental Impact

• food vs. energy

• land use competition

• soil quality

• water quality

• chemical inputs

• biodiversity– monoculture

– suitability for wildlife habitat

– landscape effects

– stability

Could the U.S. produce sufficient ethanol from energy crops to fuel its

light-duty fleet? • To replace the 130 billion gallons (490 billion liters) of

gasoline, would require 300-500 million acres (approx. ¼ of land area lower 48 states)

• Investment in infrastructure (production facilities, distribution systems, retail stations) - $900 billion (over a decade)

Does this make sense?