1

Biofuels: A High-Beam Perspective

Lee R. LyndThayer School of Engineering & Department of Biology, Dartmouth

Mascoma Corporation

October 10, 2007

2

SustainableResources

Sunlight

Wind

Ocean/hydro

Geothermal

Nuclear

Minerals

Food

HumanNeeds

EnergyMotors/LightsHeat

Transport.

Materials

Organic

Inorganic

Sole Supply

PrimaryIntermediates

Biomass

Electricity

Secondary Intermediates

Hydrogen

Animals

OrganicFuels

Batteries

Choices

Imagining a Sustainable World

3

•Air •Water •Soil •Nutrient cycles •Climate •Habitat/Biodiversity

Sustainability

•Oil: Magnetfor conflict•PolicycompromisesDemocratizeenergy supply

•Rural/farm

•Balanceof payments•Technologyexport

•Poverty

Prosperity

Dimensions of well being for human society…

PeaceSustainableResources

Sunlight

Wind

Ocean/hydro

Geotherm.

Nuclear

Minerals

Food

HumanNeeds

EnergyMotors/LightsHeat

Transport.

Materials

Organic

Inorganic

PrimaryIntermediates

Biomass

Electricity

Secondary Intermediates

Hydrogen

Animals

OrganicFuels

Batteries

… determined to a large extent by resource access & utilization -today & alwaysConvergence of factors makes this critical now - defining challenge of our time

4

Biomass Energy:Dimensions of Evaluation, Inquiry & Envisioning

End-Uses & FeedstocksWhat roles should biomass play in a sustainable world?What forms of biomass are most promising?

What are the options for producing energy from cellulosic biomass ?

Technology

How do these compare - to each other, current energy supply technologies?

Could enough biomass be produced to meaningfully address sustainability& security challenges without compromising other important objectives?

Resource & Environmental Are there environmental benefits that might be realized?

5

End-Uses & Feedstocks What roles should biomass play in a sustainable world?What forms of biomass are most promising?

6

Hierarchy of Biomass End-Uses

NoYesYesNon-liquid

LargeYesNoNoFood (& Feed)

Size of Demand (relative)

Biomass Uniquely Suited?

SustainableNon-SustainableEnd Use

Availability of Alternatives

SmallYes among sustainableNoYesOrganic

Materials

Large

Yes among sustainableNoYesLiquid @

1atm

Transportation Energy Storage

LargeNoYesYesElectricity

LargeNoYesYesHeat

7

Starch-rich (grains)• (e.g.) corn

Ethanol, or other alcohols & CO2Animal feedCoproducts

Oil Seeds• soy (US) • rapeseed (EU)

Biodiesel

GlycerinAnimal feed{

Biofuel Feedstock & Product Options

Sugar-rich• cane (Brazil) • sugar beets (EU)

Ethanol, or other alcohols & CO2

Lignocellulose residueProcess energy (Electricity &/orother coproducts){Coproducts{

{

{CellulosicResidues

• stalks, cobs, husks

Crops• switchgrass• short rotation trees

• paper sludge

Ethanol, or other alcohols, fuels & CO2Coproducts Lignin-rich residues

Process energy Electricity &/orother coproducts{

Aquatic• Not sufficiently defined to allow evaluation • Worthy of investigation

8

Energy Carrier Price Common

FossilPetroleum $65/bblNatural gas $7.50/scfCoal $20/ton

w/ carbon capture @ $100/ton C

BiomassSoy oil $0.23/lbCorn kernels $2.30/buCellulosic cropsa $50/tonneCellulosic residues

Electricity $0.045/kWh

a e.g. switchgrass, short rotation poplar

Biomass Feedstocks, Especially Cellulosic, are Cost Competitive with Conventional Energy Sources

$11.3$7.9$0.9$3.5

$/GJ

$11.3

$13.8$6.6$3.0

Some < 0

At $3/GJ, the purchase price of cellulosic biomass is competitive with oil at $17/bbl.

9

Crop Yields (U.S.) Fuel YieldsNear-term celllulosic: 5 dry ton/acre Cellulosic ethanol from RBAEFLong-term cellulosic: 15 dton/acre Corn ethanol: 2.8 gal/bushelCorn yield: 160 bushel/acre Soy oil: 18% of bean (dry basis)Soy yield: 42 bushel/acre Biodiesel yield: 0.95 kg/kg soy oil

Comparative Land Productivity of Biofuel Options

Bio

fuel

Yie

ld (G

J fu

el/h

a)

0

50

100

150

200

250

300

350

400

89

Ethanol fromCorn/Maize(kernels)

16

Biodiesel(soy)

134

CellulosicEthanol

Near-term productivity

402

Long-term productivity

10

Different Plant Feedstocks are Responsive to Different Objectives

Soil Fertility & Ag.

EcologyFutureNow

Low Cost Fuels(feedstock & conversion)

TotalPer unitTotalPer unitFutureNowTotalPer unit

Fossil Fuel Displacement/

GHG Reductions

PetroleumDisplacement

(Security)

Rural Economic

Development

Large Scale Production

Ratings:excellentvery goodgoodfairpoor

Cellulosic biomass is the focus of all studies foreseeing(very) large-scale widespread energy supply from plants.

• Environmentally benign/beneficial production• Low purchase cost• Large potential scale of production

Cellulosic

Oil seed

Sugar-rich

Starch-rich

11

Structural part of plant matter - not seeds, not edible

Cellulosic Biomass

12

What are the options for producing energy from cellulosic biomass ?

Technology

How do these compare - to each other, current energy supply technologies?

13

Liquid Biofuels

PretreatmentEnzymatic/MicrobialHydrolysis

Acid Hydrolysis

Sugars

OrFermentation

Distillation

Utilities &ResidueProcessing

EthanolButanol

Biotech.fuels

Biomass(solid)

DedicatedElectrictyGeneration Combined Cycle Gas Turbine

Fuel Cell

Or

OrTreatedEffluents

Electricity

OrSteam (Rankine) Cycle

Combustion

TreatedEffluents

Biomass Energy Process Families

ThermochemicalFuels

Gasification

PyrolysisOr

Small Molecules(reactive, fluid phase)Biomass

(solid)Catalyticsynthesis

Separation

Utilities &ResidueProcessing

HydrogenFT FuelsDMEAlcohols

TreatedEffluents

14

Thermochemical Fuelswith Electricity

Energy Coproduction Strategies

Thermochemical FuelsTC FuelProduction

ElectricityElectricityGeneration

Heat

Heat

Biofuels with Power BiofuelProduction

Residues

ElectricityGeneration Electricity

Biofuels

TC FuelProduction

Heat

Biofuels withThermochemicalFuels

BiofuelProduction

Residues

Thermochemical Fuels

Biofuels

15

Sources:External energy inputs/efficiencies: GREETRefinery outputs: EIA

100%

Cru

de R

ecov

ery,

TS&

D

Ref

inin

g

TS&

D

100% 96%

0.4%2.2% 9.5%

Input MixCrude 1%Residual oil 1%Diesel 15%Gasoline 2%Natural gas 62%Electricity 19%

Input MixCoal 19%Residual oil 4%Natural gas 71%Electricity 6%

Input MixDiesel 100%

FuelsGasoline (42.0%)Diesel (23.8%)Jet fuel (8.9%)LPG (2.6%)

Petrochemicals (3%)

77%

15%OtherCoke (5.2%)Residual oil (4.5%)Asphalt (3.6%)Lubricants (1.0%)Other (1.0%)

4.4%(Still gas)

2.9% (FFE) 10.1% (FFE)

Oil Refining (Numbers Denote Energy Flows)

16

Biomass Refining

Bio

mas

s Pro

duct

ion,

TS&

D

Ref

inin

g

TS&

D

What will we make

?

?Requiredinputs?

? What will it cost?

Role of Biomass in America’s Energy Future ProjectCo-led with Nathanael Greene (NRDC), 11 institutions

Sponsors: DOE, National Commission on Energy Policy, Energy Foundation

Examined resource and environmental issues

Forecast mature biomass processing technologies

17

Ag Inputs (Farming, feedstock transport) ~ 7 %

Feed

Han

dlin

g

Pret

reat

men

t

CB

P

Dis

tilla

tion

WW

T Dri

er

Coo

ling/

Hea

t Los

s

Oth

er U

tiliti

es

100% 100% 97% 96%54%

Feedstock Ethanol

NH31%

Solids26%Liquid

16%

Residue

Biogas 13%

WWTSludge

1%

3%

2%

3%

6% 2% 9%

4%21%

BIOLOGICAL

26%

1.6%0.9%0.2%0.1%

0.6% 0.3%

27%

5% Steam 10%

Power 3.7%

Steam 10%

Power 3.6%

Mature Biomass Refining Energy Flows (one of 24 scenarios)

Gas

ifica

tion

22%

Gas

Cle

anup

35%

POX

FT S

ynth

esis 19%

GT

FT Diesel 10%

FT Gasoline 6%

HR

SG

Stea

m T

urbi

ne

0.1%

17%1%

0.1%

1%

THERMOCHEMICAL

Power 1%

Steam 10%

Power 3.7%

27%

Energy out/Ag inputs in:

71/7 ≈ 10

18

-10 0 10 20 30 40 50 60 70 80 90

EtOHFT dieselFT gasolineDMEH2CH4PowerProtein

Efficiency of Mature RBAEF Process Scenarios

FT/GTCC powerDME/GTCC power

H2/GTCC power

Energy out as a % of feedstock LHV (bars starting below zero indicate a power requirement for the process)

FT fuels + Power

64.254.957.7

EtOH/Rankine

EtOH/FT/GTCC po

EtOH/FT (recy

EtOH/protEtOH/prot

powerEtOH/GTCC power

werEtOH/FT (1X)/CH4

cle)/CH4EtOH/H2

ein/Rankine powerein/GTCC power

EtOH/protein/FT

Bioethanol + Coproducts

73.369.461.276.579.676.570.468.161.4

Rankine powerGTCC power Power49.1

32.8

Total Efficiency

19

RankineGTCC

2002($26/bbl)($0.83/gal)

2003($31/bbl)($1.00/gal)

2004($42/bbl)($1.29/gal)

2005($57/bbl)($1.68/gal)

2006($66/bbl)($1.97/gal)

($75/bbl)($2.20/gal)

Crude :

Gasoline:

$0.05/kWh$0.20/lb protein35/65 D/E7.0% loan rate$44/dry ton

0%

5%

10%

15%

20%

25%

30%

35%

40%

45%

50%

$5 $10 $15 $20Fuel Price ($/GJ gasoline equiv.)

Inte

rnal

Rat

e of

Ret

urn

(%)

EtOH-FT-GTCCEtOH-FT(1X)CH4EtOH-FT(recycle)CH4Ethanol-H2EtOHl-Prtn.-RankinEtOH-Protein-GTCCEtOH-Protein-FT

EtOH-GTCCEtOH-Rankine

FT-GTCCDME-GTCCH2-GTCC

Scenario Comparison: Fuel price variable, power price constant, 5,000 tpd

20

2002($26/bbl)($0.83/gal)

2003($31/bbl)($1.00/gal)($1.29/

2004($42/bbl)

gal)

2005($57/bbl)($1.68/gal)

2006($66/bbl)($1.97/gal)

($75/bbl)($2.20/gal)

Crude:

Gasoline:

EtOH-FT-GTCCEtOH-FT(1X)CH4EtOH-FT(recycle)CH4EtOH-H2EtOH-Prtn.-RankineEtOH-Protein-GTCCEtOH-Protein-FT

EtOH-GTCCEtOH-Rankine

FT-GTCCDME-GTCCH2-GTCCRankineGTCC

$0.05/kWh$0.20/lb protein35/65 D/E7.0% loan rate$44/dry ton

0%

5%

10%

15%

20%

25%

30%

35%

40%

45%

50%

$5 $10 $15 $20Fuel Price ($/GJ gasoline equiv.)

Inte

rnal

Rat

e of

Ret

urn

(%)

Bioethanol (max fuels) and coproducts

Bioethanol and coproducts

TC Fuels and power

Power

Scenario Comparison: Fuel price variable, power price constant, 5,000 tpd

21

-0.5

1.5

3.5

5.5

7.5

9.5

11.5

13.5

15.5

17.5

EtO

H/R

anki

ne

EtO

H/G

TCC

EtO

H/F

T/G

TCC

EtO

H/F

T (1

X)/C

H4

EtO

H/F

T (r

ecyc

le)/C

H4

EtO

H/H

2

EtO

H/P

rote

in/R

anki

ne

EtO

H/P

rote

in/G

TCC

EtO

H/P

rote

in/F

T

FT/G

TCC

DM

E/G

TCC H2

Ran

kine

GTC

C

Oil

Dis

plac

emen

t (G

J/dr

y to

n)

Comparative Petroleum Displacement

Dedicated Power

TC fuels and PowerBioethanol and

TC Coproducts

Bioethanol(max fuels) and TC Coproducts

Current US Power MixFuture US Power Mix

22

Comparative Greenhouse Gas Displacement(Ignoring soil carbon & point source carbon capture for the moment)

0

200

400

600

800

1,000

1,200

1,400

EtO

H/R

anki

ne

EtO

H/G

TCC

EtO

H/F

T/G

TCC

EtO

H/F

T (1

X)/C

H4

EtO

H/F

T (r

ecyc

le)/C

H4

EtO

H/H

2

EtO

H/P

rote

in/R

anki

ne

EtO

H/P

rote

in/G

TCC

EtO

H/P

rote

in/F

T

FT/G

TCC

DM

E/G

TCC H2

Ran

kine

GTC

C

GH

G D

ispl

acem

ent (

kg/d

ry to

n)

Current US Power MixFuture US Power Mix

Dedicated Power

TC fuels and PowerBioethanol and

TC Coproducts

Bioethanol(max fuels) and TC Coproducts

23

Results from ~ two dozen biomass mature technology processing scenariossupport the following working hypotheses

All the most cost-effective scenarios feature biological processing - expected tobe the cheapest way to process the carbohydrate fraction of biomass

However, post biological thermochemical processing is very important• Responsible for processing ~ 40% of the energy in the original feedstock• Adds substantially to efficiency, revenues, greenhouse gas displacement

• Strong thermodynamic synergies with biological processing

Production of ethanol in combination with several coproduct combinations is cost-competitive with gasoline at oil prices > $30/barrel

GHG emission reductions** +++ +++ +++

Biofuels & TF fuels &Metric coproducts* power Power

Relative cost effectiveness +++ ++ + Petroleum displacement +++ ++ -

*Thermochemical fuels (TF) and/or power and in some cases protein**Greenhouse gas emission reductions, per ton (or per acre) basis

24

Could enough biomass be produced to meaningfully address sustainability& security challenges without compromising other important objectives?

Resource & Environmental

Are there environmental benefits that might be realized?

25

• Perennial grasses accumulate organic matter at substantial rates(~1 tonne C/ha/yr) over timeframes from many decades to a few centuries• Occurs faster with harvest than without - surprising but true

Soil carbon accumulation

When soil fertility and rural ecology advocates consider replacing rowcrops with cellulosic perennials & covercrops, they like what they see

Much lower use of herbicide, pesticides

Much higher nutrient capture and reduced surface water eutrophication

Enhanced wildlife habitat and biodiversity

Radically reduced erosion

Strong potential for recycling mineral nutrients from the processingfacility to the field

Environmental Benefits?

Marked potential to couple and drive these benefits with revitalizationof rural economies

26

Primary Cycle 0 0

CO2 Equivalent Emission(% Gasoline base case, per mile, not cumulative) EtOH & Power EtOH & FT Fuels & Power

Inputs +10 +8

InputsLiquid fuelFertilizerOther

Coproducts -56 -4

Coproducts(e.g. power, feed)

Soil carbon accumulation -43 to -159 -33 to -122

Soil CarbonAccumulation

Conversion

End use

CO2

BiofuelBiomass

PhotosynthesisNutrientrecycle

N recycle -3 -2

CO2point

source

CO2 capture, sequestration -128 -98

Geo/OceanReservoirs CO2 point source

• Two possibilities for removing carbon from the atmosphere, each withcarbon flows comparable to avoided emissions from fuel substitution

• Soil carbon accumulation could potentially be coupled with fertilityenhancement, reclamation of degraded lands

• Neither is infinite, both buy us time and “lower the hump”of GHG levels

Biofuel GHG Accounting Revisited

27Soil carbon

29.8% remaining

6.5%

23.3%

Total CO2 EmissionsTransport & Power Generation

An Illustrative Example

Point source

21.1%

Biofuels as Part of a Broader Greenhouse Gas Mitigation Strategy

A. 1/3 current transport fuel from cellulosic biofuels, coproduce power

A24.5%

CO2 Emission Reduction Strategies

B. 40% electrical power from carbon-neutral sources

B21.2%

29.8% remaining

C24.5%C. Triple transportation sector efficiency

Biofuels C Sequestration Opportunities

27.7%

45.2%

Combined

28

Life Cycle IssuesUsually considered on a per unit basis

e.g. Per ton, per gallon, per mile, per acre

In general, production & utilization of cellulosic biomass score very well

• Spectacular greenhouse gas emission benefits -from near-zero to potential “GHG sponge”• Substantial soil fertility, water quality, &biodiversity benefits when cellulosic perennials,cover crops are incorporated into ag. systems

NRDC: Several important potential benefits,no show-stoppers

Life Cycle & Resource Issues

Resource IssuesEven with positive effectsper acre, an acre devotedto bioenergy production isnot available exclusively for

Food productionWildlife habitat/biodiversityRecreation

A greater challenge

Benefits (+or−) = BenefitsUnit Utilized

⎛

⎝

⎜ ⎜

⎞

⎠

⎟ ⎟ × Units Utilized⎛

⎝ ⎜ ⎞

⎠

29

Resource Sufficiency: Radically Different Conclusions

Large contribution possible & desirable

Biomass will eventually provide over 90% of U.S. chemical and over 50% of U.S. fuel production (NRC, 1999, Biobased Industrial Products,).

1.3 billion tons of biomass could be available in the mid 21st century - 1/3 of current transport fuel demand (Perlack et al., 2005, “Billion Tons Study”).

20% of petroleum demand in 2025 (Lovins et al., 2004, Winning the Oil End Game).

50 % current transportation sector energy use, and potentially nearly all gasoline, by 2050 (Greene et al., 2004, Growing Energy)

Goal of 100 billion gallons of ethanol by 2025 (Ewing & Woolsey, 2006, A High Growth Strategy for Ethanol)

United States

Biomass becomes the largest energy source supporting humankind by a factor of 2 (Johanssen et al., 1993, Renewables-Intensive Global Energy Scenario).

Worldwide

Biomass potential comparable to total worldwide energy demand (Woods & Hall,1994; Yamamoto, 1999; Fischer & Schrattenholzer, 2001; Hoogwijk et al., 2005)

30

Resource Sufficiency: Radically Different Conclusions

Large contribution not possible and/or not desirable

“Use of biomass energy as a primary fuel in the United States would be impossiblewhile maintaining a high standard of living”

“Large-scale biofuel production is not an alternative to the current use of oil andis not even an advisable option to cover a significant fraction of it.”

Power density of photosynthesis is too low for biofuels to have an impact on greenhouse gas reduction (Hoffert et al., 2002)

Impractically large land requirements for biomass energy production on a scalecomparable to energy/petroleum use (Trainer, 1995; Kheshgi, 2000; Avery, 2006)

David Pimentel’s group (8 papers, 1979 to 2002)

Others

2030: Ethanol (corn and cellulose) 2.5% of transportation energy - 2% of this cellulosic (EIA, 2006)

Any substantial increase in biomass harvesting for the purpose of energy generation would deprive other species of their food sources and could causecollapse of ecosystems worldwide (Huesemann, 2004)

Because of large land requirements, biofuels are not a long-term practical solutionto our need for transportation fuels (Jordan and Powell, July 2006, Washington Post)

31

{NNLFP: Net new land, ignoring changed land for food production (acres)VMT: Vehicle miles traveled (miles/yr)MPG: Miles/gallon gasoline equivalentYP/F: Process yield (gallons gasoline equivalent/ton dry biomass)I: Feedstock produced from currently-managed lands (ton dry biomass)P: Productivity of biomass production (tons/acre/year)

NNLFP = VMTMPG • YP/F

- I

{

1P

The math is not the problem

Biomass resource sufficiency: The world is confused & uncertain

32

0

5

10

15

20

25

30Pr

oduc

tivity

(ton

s/ac

re/y

r)

1.3

Pimentel et al. (2002)

5

Current SG(McLaughlin)

16.5

Miscanthus(Heaton &

Long)

Heaton and Long: 3 site average in Illinois over 2 years, direct comparison with switchgrass(Cave-in-Rock), which averaged 4.6 tons/acre/yr

Factors Impacting Biomass Feedstock Availability: Feedstock Productivity (P)

7.5

CornWhole plantU.S. Ave.

Current

15

Richard Hamilton (Ceres) “[Available information]…strongly suggest[s] that over the next decade or so the deployment of modern breeding technologies will result in average energy yields of at least 15 tons per acre, and that these averages can be sustained across a broad range of geographic and environmental conditions, including the approximately 75 million acres of crop and pasture land in the United States that

could easily be converted to their cultivation without impacting domestic food production.”

Energy CropsU.S., 10 years(R. Hamilton)

12.5

SG, 2050(McLaughlin)

25

Energy cane,projected

(Botha, Reinach)

24

Energy CropsU.S., Mature

(V. Khosla)

Projected

33

0

20

40

60

80

100

120

140

160

1 2 3 4 5 6

Lan

d A

rea

(Mill

ions

of A

cres

)

Without Residue Utilization

With Residue Utilization

Idled by federal programs, mid 80s-mid 90s

CRP

Land used for animal feed

Vehicle Efficiency Multiplier

•LDV VMT = 2.5 trillion vehicle miles traveled•Waste availability: 200 million dry tons •Switchgrass productivity: 10 dry tonss/acre/year (20 to 30 year projected average, tentative)•Fuel yield: 100 gallons/dry ton

Land Area Required for Current U.S. Light Duty Mobility in Relation to Vehicle Efficiency

High Vehicle Efficiency A central feature of all sustainabletransportation scenariosBattery/EV; H2/fuel cell:

Avoids otherwise small travel radius

Cellulosic biofuelsAvoids otherwise large footprint

34

Farmers would rethink what they grow and how they grow it.Feed protein/feedstock coproduction

Feedlot pretreatment to make calories more accessible

New crop varieties with higher fiber yieldsBioenergy cover crops

Agricultural residue recovery, enhanced by appropriate crop rotationsIncrease production on under-utilized land (e.g. hay, pasture)

Yet new demand for non-nutritive cellulosic biomass due to cost-competitive processing technology would very likely result in large changes.

Food production is usually assumed to remain static, or extrapolated,in analyses of biomass supply.

Integrating Feedstock Production Into Currently-Managed Land (I)

Doesn’t increasing biofuel production mean either producing less food orrecruiting new land into growing biomass and hence lost wildlife habitat?Not necessarily!

35

Feed Protein/Feedstock Coproduction

Switchgrass Protein Recovery/

(& Pretreatment)

Fuels/Chemicals

Feed ProteinConcept

0.40 – 0.650.36 - 0.5 (bean only)1.1 – 1.3Soybeans0.4 – 1.2.08 - 0.12 (early cut)5.0 – 10 Switchgrass

Protein Productivity(tons/acre/year)

Protein (Mass Fraction)

Mass Productivity(tons/acre/year)

Crop

Composition & productivity comparison

Processing

• Requires readily foreseeable processing technology to recover feed protein

• Not pursued now because of absence of demand for cellulosic residues

• Many positive indications of feed protein quality, but not fully established

• Cellulosic feedstocks could also be coproduced from large biomass soybeans

• Production of perennial grass could potentially produce the same amount of feed protein per acre while producing a large amount of feedstock for energy production

36

Reimagining Agriculture to Accommodate Large Scale Energy Production

New uses for existing crops(e.g. corn stover)New combinations of existing crops New & improved crops &cropping systems

New demand --> new rewards & opportunities --> new agriculture

This new agriculturehas received only scantinvestigation worldwide

Different solutions willbe most practical indifferent local situations

Bioenergy cover cropping in Iowa,A. Heggenstaller, M. Liebman, R. Anex

37

Returning to that simple equation…

ParameterLeast

EfficientMost

Efficient (High, Low)Ratio

VMT (trillion miles, 2050) “Car Talk” scenarios 6.1 4.5 1.4

MPG (LDV) Current, D. Friedman 21 50 2.4

YP/F (gallons/ton) Recent NREL, RBAEF36 91 2.5

Many, “Billion tons”I (million tons) 0 600 Infinite

P (tons/acre/year) 1.3 24 D. Pimentel, V. Khosla 18

NNLFP (million acres) 5,328 14 381

(Max/Min)Source

{NNLFP = VMTMPG • YP/F

- I

{

1P

38

Category of Change

Primarily technological (process yield, cropproductivity)

Anticipated improvement in process yield & energy cropproductivity together would increase per acre biofuel yieldby ~ 8-fold (1370 gal gasoline equivalent, GE, per acre)

Multiple complimentarychanges

Becomes realistic to consider meeting all U.S. mobility demandfrom biofuels, with some scenarios requiring little if any newland to achieve this

Opportunities to Increase Bioenergy Feedstocks from Managed Lands

Illustrative Large Impacts

Energy crops, 15 dt/yr (Ceres); Cover crops, 5 dt/yr (D. Bransby); 91 gal GE/dry ton (RBAEF)

Both technological &behavioral(MPG, integration offeedstock productioninto managed land)

Technically-possible mileage increases could decrease fueldemand by 2.5-fold

Bioenergy cover crops, feasible on perhaps 1/3 of agriculturalland: ~ 66 billion gal GE1/2 soy replaced by switchgrass with constant feed proteinProduction: ~48 billion gal GE

Primarily behavioral(diet, exports, VMT)

Shifts in meat consumption could make available largeacreages (~50 million acres), with a corresponding biofuel production potential on the order of 80 billion gal GE

80 million acres currently devoted to producing export cropshas a biofuel production potential of 110 billion gal GE

Drive less, mass transport, “smart growth”

39

New Land Required to Satisfy Current U.S. Mobility Demand

1,200600200 400 800 1,0000New Land Required (million acres)

CRP Land (30 MM)

LDVHDV

U.S. Cropland (400 MM)

II. Corn stover (72%) -50 Feasibility of stover utilization enhanced by rotation

I. Soy switchgrass or large biomass soy -10

Agricultural integrationEarly-cut switchgrass produces more feed protein/acrethan soy; similar benefits from “large biomass soy”

Vehicle efficiency 2.5X↑ 165

Advanced processing 41091 gal Geq/ton

1,030Status quo 36 gal Geq/ton, current mpg, no ag. integration, 5 tons/acre*yr

Biomass yield 2.5X↑ 65

III. Other Cover crops, other residues, increased productivityof food crops, increased production on under-utilized land…

40

Approaches to Energy Planning & Analysis1. Bury our heads in the sand. Pretend that energy challenges are not real or will go away.

2. Extrapolate current trends.

3. Hope for a miracle (e.g. Hoffert et al., Science, 2002).

• Acknowledge the importance of sustainable and secure energy supplies

• Dismiss foreseeable options as inadequate to provide for the world’s energy needs

• Call for “disruptive” advances in entirely new technologies whose performance cannot be foreseen.

4. Innovate & change.

• Work back from such futures to articulate transition paths beginning where we are now

• Define sustainable futures based on mature but foreseeable technologies in combination with an assumed willingness of society to change in ways that increase resource utilization efficiency

#4 is the most sensible choice if it is assumed that problems associated with sustainability and security are important to solve.

#1 and #2 do not offer solutions to sustainability and security challenges.#3 should be pursued but is too risky to rely on.

41

Environmental “footprint”: Land area required to provide for resource consumption & waste assimilation on a sustainable basis

Wackernagel et al., PNAS (2002)

Cropland

GrazingLandFishing

ForestBuilt-up

Energy

0.0

2.0

4.0

6.0

8.0

10.0

12.0

14.0

61 66 71 76 81 86 91 96Year

Bill

ion

glob

al h

ecta

res

0.00

0.20

0.40

0.60

0.80

1.00

1.20

Num

ber o

f Ear

ths

PopulationAssumedFootprint

Numberof Earths

6 billion World (2003) 1.36 billion India 0.46 billion Denmark 3.26 billion USA 5.2

10 billion Denmark 5.1www.footprintnetwork.org

42

The first industrial revolutionContext: Resources plentiful, people scarce

The second industrial revolutionResources scarce, people plentifulContext:

Response

Dramatic increases in• Resource productivity (service delivered/resource invested)• Reliance on sustainable resources, especially for energy

Population stabilization (appears to be happening)

ResponseDramatic increases in

• Labor productivity (output/person/hour): 100-fold higher• Fraction of energy supply from non-sustainable sources: from 0 to ~80%)• Resource consumption per capita• Population• Level of services (mobility, housing, dietary variety, information) expected

The Next Industrial Revolution?Hawkins, Lovins, and Lovins, “Natural Capitalism”

43

Economic & Process Analysis - Mark Laser, Charles Wyman, Eric Larson, Bruce Dale, RBAEF team

Collaborators

Physiology of microbial cellulose utilization - Percival Zhang, Yanpin Lu,Nicolai Panikov

Cellulolytic yeasts - Emile van Zyl, Riaan Den Haan, John McBride

Metabolic engineering of T. saccharolyticum & thermophilic SSF - Joe ShawKara Podkaminer

Ecology of microbial cellulose utilization - Gideon Wolfaardt, Paul Weimer,Javier Izquierdo

Resource & environmental analysis - Nathanael Greene, John Sheehan,Rob Anex, Tom Richard, RBAEF team, Reimagining Agriculture Team

Science of biomass recalcitrance - Bioenergy Science Center team

Technology development & commercialization - Mascoma Corp. team