Development of CellulosicBiofuels

Chris SomervilleEnergy Biosciences Institute

UC Berkeley, LBL, University of Illinois

37%

23%

27%

5%

2%6%

39%

25%

23%

7%

2% 4%

* - excludes traditional biomassSource: IEA 2004 & Jim Breson

2002 2030

Current and predicted energy useCurrent use 13 TW

Key:

- oil - coal - gas - nuclear - hydro - modern renewables

Global Primary Energy Supply by Fuel*:

Potential of carbon-free energy sources

Hydro Tides & currents

Wind Geothermal Solar Current use0.1

1

10

100

1000

10000

100000

1000000

TW

?

Nuclear

From: Basic Research Needs for Solar Energy Utilization, DOE 2005

~26,000 km2 of photovoltaicdevices would meet US energy

needs

Turner, Science 285,687

3.3Tw

3.3 TW

Total shipped 1982-98 = 3 km2

Combustion of biomass providescarbon neutral energy

CO2

Polysaccharides

Photosynthesis “Combustion”

Work

Sunlight

(Storage)

Overview of Brazil sugarcane

• 2007-08 harvest 528 MMT• ~8 M Ha planted by 2008• ~20 B liters ethanol, 2007• ~80-120 T/Ha• ~6400 L ethanol/Ha• ~333 mills, 200 planned• Plantings last 5 y, cut one per

year• Large mill

– 22,000 tons/day– 1500 truck loads/day

AS OF: March 2006

In operation

Under construction

Proposed

US Biofuel Production has Expanded Rapidly

Fermentation of glucose to ethanol

Jeffries & Shi Adv Bioch Eng 65,118

2-P-glycerate

www.biocarta.com/pathfiles/h_glycolysisPathway.asp

Cellulosic fuels are expected to become thedominant source of biofuels

Grain

Cellulose

0

10

20

30

40

50

60

70

2000 2005 2010 2015 2020 2025

Year

Eth

an

ol

(Bil

lio

ns

of

gal/

yr)

EXISTING EMERGING

SugarPlatform-New Enzymes-Pretreatment-Fermentation

ADVANCED

FundamentalAdvances inLignocelluloseProcessingand fermentation

Modified from Richard Bain, NREL

90,000 TW of energy arrives on the earthssurface from the sun

5% of land650 MHa

Land29.0%

Water70.9%

Amount of land needed for 13 TW at 1% efficiency

Land Usage

AMBIO 23,198 (Total Land surface 13,000 M Ha)

Forest &Savannah

Cereal4.6% Pasture & Range

23.7%

30.5%

Other crops6.9%

Nonarable

34.4%

>2% yield is feasibleYield of 26.5 tons/acre observed by Young &

colleagues in Illinois, without irrigationCo

urte

sy o

f St

eve

Long

et

al

Switchgrass and Miscanthus at Illinois

Julian day 1993

100 150 200 250 300 350

PA

R in

terceptio

n (%

)

0

20

40

60

80

100

Miscanthus x giganteus

Spartinacynosuroides

Zea mays

Courtesy of Steve Long, University of Illinois

Perennials have more photosynthesis

Harvesting Miscanthus

http://bioenergy.ornl.gov/gallery/index.html

Annual precipitation

Limiting factors for global NPP

Baldocchi et al. 2004 SCOPE 62

Steps in cellulosic ethanol production

From: Breaking the Biological Barriers to Cellulosic Ethanol

Plants are mostly composed of sugars

Section of a pine board

3 nm

Polymerized glucose

Possible routes to improved catalysts

• Explore the enzyme systemsused by termites (andruminants) for digestinglignocellulosic material

• Compost heaps and forestfloors are poorly explored

• In vitro protein engineering ofpromising enzymes

• Develop synthetic organiccatalysts (for polysaccharidesand lignin)

Dissolution of cellulose in an ionic liquid(novel pretreatment methods may create fundamental changes)

Swatloski, Spear, Holbrey, Rogers J. Am. Chem. Soc., 124 (18), 4974 -4975, 2002

Untreated

Treated

Fermentation of all sugars is essential

Jeffries & Shi Adv Bioch Eng 65,118

Lignin

Typical grasscomposition

cellulose

Hemi cellulose

Saccharification & Fermentation

Fermentation Yield Cost Impact

$1.23$1.28$1.3395%

92%

70%

$1.20

$1.50

$1.80

$2.10

$2.40

glucose only add 85% xylose add 85% arabinose all other sugars85%

Min

imum

Eth

anol

Sel

ling

Pric

e ($

/gal

)

NREL

Steps in cellulosic ethanol production

From: Breaking the Biological Barriers to Cellulosic Ethanol

Nature offers many alternatives toethanol

• Plants, algae, and bacteriasynthesize alkanes,alcohols, waxes

• Production of hydrophobiccompounds would reducetoxicity and decrease theenergy required fordehydration

Conversion of sugar to alkanes

Huber et al., (2005) Science 308,1446

The “hydrogen economy”

Justin Adams, BP

The Sleipner Experiment1 million tons/y; capacity 600 B tons

7000 such sites needed

www.agiweb.org/geotimes

1000

M

Summary of priorities

• Develop energy crops and associatedagronomic practices

• Identify or create more active catalystsfor conversion of biomass to sugars

• Develop industrial microorganisms thatferment all sugars

• Develop new types of microorganisms thatproduce and secrete hydrophobiccompounds

A vision of the Future

http://genomicsgtl.energy.gov/biofuels/index.shtml

Global grain production with andwithout yield enhancements

Data from worldwatch

1964 1974 1984 1994 2004Year

0

500

1000

1500

2000

Mill

ion

Hec

tare

s

Economics of Perennials are Favorable

612138**75015 tonsMiscanthus($50/t)

362138**50010 tonsSwitchgrass($50/t)

479193*672160 buCorn ($4.2/bu)($150/t)

Profit$

Cost$

Value$

Yieldper Acre

CROP

*USDA economic research service 2004**50% as much fertilizer, no chemicals

Risks: Historical Price of Oil

Some plants accumulate oil

Biodiesel has been expanding rapidly

Worldwatch 2006 & Louise Fresco

Limited potential of biodiesel

Current biodiesel Capacity US Diesel US Fuel0

20

40

60

80

100

120

140

160

Billi

on g

allo

ns

65 biodiesel companies in operation, 50 in construction 2006

OO BiodieselCH3

Use of algae could enable saline cultivationGreenfuel bioreactor

http://news.com.com/Photos+Betting+big+on+biodiesel/2009-1043_3-5714336.html?tag=st.prev

How Much Ethanol Could the Municipal SolidWaste from a City With 1 Million People Produce?

The average person in the United States generates approximately 1.8 kilogramsof municipal solid waste (MSW) every day. Of this, typically about 75 percent ispredominantly cellulosic organic material, including waste paper, wood wastes,cardboard, and waste food scraps. Thus, a city with 1 million people producesaround 1,800 tonnes of MSW in total, or about 1,300 tonnes per day of organicmaterial. Using technology that could convert organic waste to ethanol, roughly330 liters of ethanol could be produced per tonne of organic waste. Thus,organic waste from a city with 1 million people would be enough feedstock toproduce about 150 million liters per year. This is enough fuel to meet the needsof more than 58,000 people in the United States; 360,000 people in France; ornearly 2.6 million people in China at current rates of per capita fuel use.

Worldwatch, 2006