Argonne National Laboratory is managed by The University of Chicago for the U.S. Department of Energy

Energy and Greenhouse Gas Emissions Results of Fuel Ethanol

Michael WangCenter for Transportation ResearchArgonne National Laboratory

2

U.S. Fuel Ethanol Production Has Experienced Large Increases, and the Trend Will Continue

Source: Renewable Fuels Association

0

1000

2000

3000

4000

5000

6000

7000

8000

1980

1981

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2010

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2012

Mill

ion

s o

f g

allo

ns

/Ye

ar

Actual ProductionEnergy Bill Requirement

3

Comparative Results Between Ethanol and Gasoline Are More Relevant to Policy Debate

4

Even Though Electricity Has a Large Negative Net Energy Balance, There Is No Substitute for Its Main Uses

Coal Mining

CoalTransportation

NGProcessing

NGTransmission

NGRecovery

Coal NG

Diesel FuelElectricity

NG

Diesel Fuel

NGElectricity

LPG, NGLs

NGElectricity

Electricity Generation

Electricity Transmissionand Distribution (8% loss)

1 mm Btu of Electricityat Wall Outlets

Uranium Ore Recovery

Petroleum Recovery

Uranium Petroleum

Uranium OreTransportation

PetroleumTransportation

OtherPetroleumProducts

Residual Oil

Electricity

Diesel Fuel

NG

Uranium Enrichment

Petroleum Refinery

Electricity

Refinery Gas

CoalNG

Uranium Fuel Transportation

Residual Oil TransportationDiesel Fuel

Residual Oil

ElectricityNG

Diesel FuelElectricity

NG

U.S. Electricity Generation:2.34 mm Btu Fossil Energy Input

for each 1.00 mm Btu Electricity Output

5

Energy in Different Fuels Can Have Very Different Qualities

Increase in Energy Quality

Fossil Energy Ratio (FER) = energy in fuel/fossil energy input

10.31

1.36

0.980.81

0.45

0.0

0.5

1.0

1.5

2.0

Cell. EtOH Corn EtOH Coal Gasoline Electricity

6

Accurate Ethanol Energy Analysis Must Account for Increased Productivity in Farming Over Time

Based on historical USDA data; results are 3-year moving averages

0.30

0.35

0.40

0.45

0.50

0.55

0.60

0.65

1965 1970 1975 1980 1985 1990 1995 2000 2005

Bu

shel

s/lb

. Fer

tiliz

er

?

Precision farming, etc.?

U.S. Corn Output Per Pound of Fertilizer Has Risen by 70% in The Past 35 Years

7

Improved Technology Has Reduced Energy Use and Operating Costs in Corn Ethanol Plants

Source: from Argonne’s discussions with ethanol plant designers, recent USDA data, and other reported data.

0

10,000

20,000

30,000

40,000

50,000

60,000

70,000

Btu

/Ga

llon

Wet Mill Dry Mill

1980s

2000s

8

One-Third of Corn Kernel Mass Ends as Animal Feed (a Co-Product) in Ethanol Plants

Protein

Dis

till

ers

Dry

G

rain

s an

d

So

lub

les

(DD

GS

)

EthanolStarch

Carbon Dioxide

Dairy: 46%

Beef: 39%

Poultry: 4%

Swine: 11%

2003 North American DDGS Consumption

Source: Commodity Specialist Co. (in RFA, 2005)

9

Accounting for Animal Feed Is a Critical Factor in Ethanol’s Lifecycle Analysis

Allocation Method Wet milling Dry milling Weight 52% 51%

Energy content 43% 39%

Process energy 36% 41%

Market value 30% 24%

Displacement ~16% ~20%

• Weight and energy methods are no longer used• Argonne uses the displacement method, the most conservative approach

• Some studies do not consider co-products at all

10

Cellulosic Ethanol Plants Will Be Significantly More Efficient than Corn Ethanol Plants

Steam

Biomass Feedstock Pretreatment Fermentation Separation

Power Plant: Gas and/or Steam Turbine Electricity Effluent

Discharge

Emissions

Fuel Ethanol

Wastewater

Emissions Emissions

Emissions

Solid Residue and Methane Wastewater

Treatment

Plants under intensive R&D efforts are designed to use the unfermentable portion of biomass to generate steam and electricity.

11

0.0

0.5

1.0

1.5

2.0

2.5

RFG CornEtOH:

DM

CornEtOH:

WM

Cell.EtOH

RFG CornEtOH:

DM

CornEtOH:

WM

Cell.EtOH

RFG CornEtOH:

DM

CornEtOH:

WM

Cell.EtOH

Btu for Fuel Production

Btu in Fuel

Energy Effects of Fuel Ethanol Depend on the Type of Energy Being Analyzed

Total Btu Spent for One Btu of Gasoline and Ethanol Available at Fuel Pumps

Total Energy

Fossil Energy

Petroleum Energy

12

Use of Ethanol to Replace Gasoline Results in Fossil Energy and Petroleum Reduction Benefits

2.1% 4.7%

24.3%

52.3%

-3.2% -6.5%

-32.9%

-69.1%

-6.3% -6.3%

-69.5% -70.0%

-80%

-60%

-40%

-20%

0%

20%

40%

60%

E10 GV:CornEtOH

E10 GV:Cell.EtOH

E85FFV:CornEtOH

E85FFV:Cell.EtOH

E10 GV:CornEtOH

E10 GV:Cell.EtOH

E85FFV:CornEtOH

E85FFV:Cell.EtOH

E10 GV:CornEtOH

E10 GV:Cell.EtOH

E85FFV:CornEtOH

E85FFV:Cell.EtOH

Total Energy

Fossil Energy Petroleum Energy

Change in Per-Mile Energy Use by Ethanol Blend to Displace Gasoline

13

Ethanol Blends, Especially E85 Made from Cellulosic Ethanol, Can Significantly Reduce GHG Emissions

Reductions in Per-Mile GHG Emissions by Ethanol Blend to Displace Gasoline

-2% -2%-6%

-23%

-17%

-64%

-80%

-60%

-40%

-20%

0%

E10 GV: DMCorn EtOH

E10 GV: WMCorn EtOH

E10 GV: Cell.EtOH

E85 FFV: DMCorn EtOH

E85 FFV: WMCorn EtOH

E85 FFV:Cell. EtOH

14

Corn EtOH Reduces GHGs by 18-29% While Cellulosic EtOH Yields 85-86% Reduction, on Per Gallon Basis of EtOH Used

GHG Emission Reductions Per Gallon of Ethanol to Displace An Energy-Equivalent Amount of Gasoline

-26%

-18%

-85%

-29%

-21%

-86%

-100%

-80%

-60%

-40%

-20%

0%

E10 GV: DMCorn EtOH

E10 GV: WMCorn EtOH

E10 GV: Cell.EtOH

E85 FFV: DMCorn EtOH

E85 FFV: WMCorn EtOH

E85 FFV: Cell.EtOH

15

Most of the Recent Corn EtOH Studies Show a Positive Net Energy Balance

-120,000

-100,000

-80,000

-60,000

-40,000

-20,000

0

20,000

40,000

60,000

1978 1980 1982 1984 1986 1988 1990 1992 1994 1996 1998 2000 2002 2004 2006

Net

En

erg

y V

alu

e (B

tu/g

allo

n)

Ho

Marland&Turhollow

Pim ente l

Pim ente lKeeney&DeLuca

Lorenz&Morris

Shapouri e t al.

Wang et al.

Agri. Canada

Kim &DaleGraboski

Wang

Pim ente l

Shapouri e t al.

Pim ente l&Patzek

Weinblatt e t al.

NR Canada

Cham bers et al.

Patzek

DelucchiKim &Dale

Wan

g

GR

EE

T

w/P

imen

tel

Ass

um

pti

on

s

Energy balance here is defined as Btu content a gallon of ethanol minus fossil energy used to produce a gallon of ethanol

16

Energy Balance Results of Ethanol Depend Heavily on System Boundary Choices

Operation-Related Activities:Fertilizer, Farming,

Corn Transportation, EthanolProduction, Ethanol Transportation,

Energy Use for Producing Process Fuels

Farming Equipment Materials

and Manufacture

Ethanol Plant Materials

and Construction

Food Intake by Farmers

Solar Energy Embedded

in Biomass

17

The Debate on Energy Balance Itself May Have Little Practical Meaning

Though self evaluation of a fuel’s energy balance is easy to understand, to do so for a fuel in isolation could be arbitrary

All Btus are not created equal. The energy sector has been converting low-value Btus into high-value Btus, with energy losses

Society has not made energy choice decisions on the basis of energy balance values of individual energy products

Issues of concern, such as petroleum consumption and GHG emissions, should be analyzed directly for fuel alternatives

A complete, robust way of evaluating a fuel’s effects is to compare the fuel (e.g., ethanol) with those to be displaced (e.g., gasoline)

18

Most Studies on GHG Emissions Show GHG Emission Reduction by Corn EtOH as Compared to Gasoline

-80%

-60%

-40%

-20%

0%

20%

40%

60%

80%

100%

GH

G C

han

ges

19

A Recent Article by UC Berkeley Questioned the Analyses by Piemntel and Patzek (Science, Jan. 27, 2006)

Examined six representative analyses Used GREET for many parameters in authors’ own calculations Included the following additional items:

Energy and emissions embedded in farming equipments and ethanol plants for corn ethanol; energy and emissions embedded in oil field equipment and petroleum refineries seem not to be included; but the contributions are small

Energy and emissions of water use and water treatment in ethanol plants; potential double-counting with ethanol plant energy use already considered?

Lime application: 988 lbs/acre/yr vs. 16 lbs/acre/yr by USDA; the single most important factor determining difference between UC Berkeley and ANL

The study concluded GHG emission reductions by corn ethanol of 13% for today’s technology Significant petroleum reductions by corn ethanol Much greater energy and GHG benefits by cellulosic ethanol Studies by Pimentel and Patzek incorrectly ignored coproducts and used some

obsolete data

20

Looking into Future: Opportunities and Risks of Corn Ethanol Energy and Emission Effects

Factors with positive effects Corn yield per acre will continue to increase, together with stabilized or

reduced N fertilizer application Ethanol yield per bushel will continue to increase Energy use in ethanol plants may be reduced further through better

engineering, integration of ethanol production and animal feedlots Gasification of biomass to provide process energy for ethanol plants

Factors with negative effects Switch from natural gas to coal for process energy in ethanol plants Use of marginal land for additional corn production

Has the debate of food vs. fuel been dead? Potential use of DGS as a process fuel could renew this debate

21

Conclusions

Energy balance value for a given energy product alone is not meaningful in evaluating its benefit

Any type of fuel ethanol helps substantially reduce fossil energy and petroleum use, relative to petroleum gasoline

Corn-based fuel ethanol achieves moderate reductions in GHG emissions

Cellulosic ethanol can achieve much greater energy and GHG benefits