Achim DobermannAchim Dobermann

Biofuel – what’s Biofuel – what’s in it for rice in it for rice

farmers?farmers?

• Some trends

• The maize – ethanol system

• Options for rice

Terminology• Bioenergy = Renewable energy produced from

organic matter, i.e., solar-derived energy contained in biomass of living or recently living biological material.

• Biofuel = Liquid, solid, or gaseous fuel produced by conversion of biomass.

• Biopower = Direct use of biomass to generate electricity, heat or steam.

http://bioenergy.ornl.gov/faqs/glossary.html

Biofuel categories• Produced from feedstocks contained within the food

cycle: – Biodiesel: transesterification of plant-based oils

• Canola, soybean, oil palm, coconut, jatropha

– Bioethanol: sugar or starch conversion by fermentation• Sugarcane, sugar beet, sweet sorghum, maize, wheat, sorghum,

cassava

• Produced from non-food biomass: – Combustion (wood, crop residues, waste)– Gasification – Biomass to liquid (gasification/pyrolysis – liquefaction) – Biogas (anaerobic digestion)– Ligno-cellulosic ethanol – Ligno-cellulosic butanol

World Energy 1850-2000

050

100150200250300350400450500

1850 1875 1900 1925 1950 1975 2000

Year

EJ/

year

Gas

Oil

Coal

Nuclear

Hydro +

Biomass

20-fold increase from 1850 to 2000. Fossil fuels supplied 80% of the world’s energy in 2000 (Holdren 2007)

Oil consumption in selected countries

Country 2003 total 10-yr change Per capita1000 barrels/d % barrels/yr

USA 20034 16 25.6Canada 2079 25 24.5Australia 876 15 16.8Japan 5578 4 16.0France 2060 10 12.5Germany 2677 -8 11.9U.K. 1722 -6 10.5Brazil 2132 31 4.5Indonesia 1155 51 2.0China 5550 88 1.6India 2320 77 0.8

World energy demand is projected to increase

by 50% by 2030.

Biofuel production is viable if crude oil prices stay above $55/barrel.Global vegetable oil production (150 Mt) = 10 d global fossil fuel consumption.

Plans for annual growth in biofuel production…2010/12

Joachim von Braun, IFPRI, August 2007

Costs of feedstock dominate costsEthanol: 50-70%; Biodiesel: 70-80%

Not a new idea“We can get fuel from fruit, from that shrub by the roadside, or from apples, weeds, saw-dust—almost anything! There is fuel in every bit of vegetable matter that can be fermented … And it remains for someone to find out how this fuel can be produced commercially—better fuel at a cheaper price than we know now.”

Henry Ford, 1925

First corn-ethanol blended gasolinestation, Lincoln, Nebraska, 1933

Gross energy yield of various biofuel crops

Crop-biofuel* Country Yield Biofuel Energy

    Mg/ha L/ha GJ/ha

Oil Palm-BD Malaysia 21 5920 195

Sugarcane-E Brazil 74 5865 124

Maize-E USA 9 3751 79

Cassava-E Brazil 14 1863 39

Rapeseed-BD Canada 2 641 21

Soybean-BD USA 3 552 18

Liska and Cassman. 2007. J. Biobased Materials and Bioenergy

* BD – biodiesel; E – Ethanol

Crop yields: 2003-2005 average (FAOSTAT)Conversion yields: corn,0.399 L/kg; cassava, 0.137 L/kg; soybean 0.205 L/kg; rapeseed, 0.427 L/kg

Gross energy yield and net GHG reduction estimates for food-crop biofuel systems

Liska and Cassman. 2007. J. Biobased Materials and Bioenergy

Gross energy values: two largest producers in the worldNet GHG gas reductions: literature summary

GHG reduction (%)

0 20 40 60 80 100

Gro

ss energ

y yield (G

J ha

-1)

0

50

100

150

200

rapeseed-biodieselsoybean-

biodiesel

cassava-ethanol

corn-ethanol

sugarcane-ethanol

oil palm-biodiesel

Gro

ss e

ner

gy

yiel

d (

GJ/

ha)

Impact on food prices• December 2006 – demonstrations in Mexico: rising

tortilla prices due to rising corn prices• April 2007 - consumer food prices in the USA have

increased 3-4% compared to one year ago• May 2007 – globally, milk powder price has risen 60%

in 6 months; fluid milk 63% in one year• May 2007 – Indofood Sukses Makmut raises prices of

instant noodles in Indonesia by 5% • September 2007 – rising food prices are a major

cause of rising inflation in China• September 2007 - beer prices rise 5.5% at the

Oktoberfest in Munich

Two examples

• Technology options for optimizing maize-ethanol systems in North America

• Biofuel options for rice systems in Asia

Year

1980 1985 1990 1995 2000 2005 2010

Eth

ano

l P

rod

uct

ion

(10

6 L

/yr)

0

10

20

30

40

50

60

Maize requirement (MMt)

70

110

140 42%

34%

% of maize production, assuming 34 Mha area harvested and trend- line yield increase

Expansion of USA maize-ethanol production

22%

K. Cassman, Univ. of Nebraska

http://www.ethanolrfa.org

U.S. maize yields

USA corn yield and irrigation (red hatched) by county (2004-2006 average). Source: National Agricultural Statistics Service, USDA.

Liska and Cassman. 2007. J. Biobased Materials and Bioenergy

GRAIN FERMENTATION DISTILLATION

ETHANOL

DISTILLERS GRAINS

Maize-ethanol production life-cycle

CROP PRODUCTION

drywet

Thermal energy

CH4

Methane biodigestor(6) Closed-loop system (-

56% energy)

Biofertilizer

CO2

Maize & soybean production

(1) Improve management(2) Increase NUE (10%)

Grain

Stillage

CO2

Ethanol

Distillers grain

Ethanol plant(3) Starch content 7275%(4) Conversion efficiency 91

97% (enzymes, microbes)

N2O CH4

Manure, urine

Meat Cattle feedlot(5) Directly use wet distillers

grain (-26% energy)

NO3 leaching

CH4

Grain

NO3 leaching

N2OCO2

A. Liska et al., UNL, 2007

Technologies to improve maize-ethanol systems

Technological improvements

Yield NUE Genetics Engineering ALL

CORN YIELD

Ethanol yield: crop management vs. other technological improvements

Black: National average yields and technology (Farrrell et al., 2006)Blue: High-yield irrigated corn-soybean system, CT

A. Liska et al., UNL, 2007

0 1 2 3 4 5 6 7 8

3000

4000

5000

6000

7000

Eth

ano

l yi

eld

(L

/ha)

15.3 Mg/ha

8.7 Mg/ha

Technological improvements

Ethanol biorefinery integration with livestock to avoid drying distiller’s grains and producing methane can DOUBLE corn-ethanol’s net energy efficiency.

Energy Ratio:

1.3-1.6 1.6 1.6 1.6 1.9 2.6 2.8

Black: National average yields and technologyBlue: High-yield irrigated corn-soybean system, CT

A. Liska et al., UNL, 2007

0 1 2 3 4 5 6 7 86

8

10

12

14

16

18

Net

En

erg

y V

alu

e (M

J/L

)

Yield NUE Genetics Engineering ALL

GHG emissions reduction (% and t CO2eq*)

USA average

Advanced Irrigated

coal26%

198000 t39%

294000 t

natural gas51%

38100063%,

478000 t

natural gas, wet DG

60%447000 t

73%544000 t

closed-loop facility

67%504000 t

80%601000 t

Maize production system

Eth

ano

l b

iore

fin

erie

s

*Based on a 100 million gal/yr production capacity

A. Liska et al., UNL, 2007

First Commercial-Scale Closed Loop Biofuel Refinery, Mead, Nebraska

www.e3biofuels.com

Ethanol: 24 M gallons/yrCattle: 28,000 head/yr

R. Perrin, Univ. of Nebraska, Feb. 2007

Feb. 2007

Feb. 2006

Petrol @ $50/barrel: - to be competitive with gasoline ethanol needs to sell for $1.55/gal (incl. $0.51/gal subsidy) - Plant operating costs $0.55/gal + $0.30/gal capital cost - $0.10/gal federal subsidy- max. corn price to break even: $1.55 – 0.85 + 0.10 = 0.80/gal = $3.20/bushel

Oct. 2007

Breakeven price for ethanol in the USA to compete with petroleum, given current subsidies

1960 1970 1980 1990 2000 2010

Wo

rld

ric

e ar

ea (

Mh

a)

100

110

120

130

140

150

160

Wo

rld

ric

e p

rod

uct

ion

(M

t)

100

200

300

400

500

600

700

800

Slope: 9.46 Mt/year 1.47% of current annual production

Includes forecast for 2007 (FAO Rice Market Monitor, Sep. 2007)

Rice area

Rice production

FAO Rice Market Monitor, Sep. 2007

Rice grain should not be used for biofuelsRiceland should not be converted to biofuel crops

Rice hulls• 100 kg of paddy rice 20 kg of hulls during milling• >110 million tons annually collected at rice mills• ~10% moisture• Bulk density 100 to 150 kg/m3

• Energy content: 14-16 MJ/kg (dry wood: 18-20 MJ/kg)• Main carbohydrates: cellulose and lignin• 16 to 22% ash, 90-96% of the ash is silica• Higher ash melting point than ash from rice straw -

less slag deposits when burned for fuel

• 580 million tons of rice straw per year• 35-40% C, 0.5-0.8% N, 1.2-2.0% K, 4-7% Si• Current use: burning, removal (fuel for cooking),

some incorporation, some for other uses• Energy content: 14 MJ/kg at 10% moisture

Straw as a new income source for rice farmers?

System Residue Potential for removal

Portion for removal

Triple rice Rice Yes All

Double rice Rice Yes All

Rice–wheat, rice-maize Maize or wheat Yes All

Rice Limited Partial

Sole upland crop(s) Wheat & maize Limited Partial

In what systems can crop residues be removed without threatening

long-term sustainability?

R. Buresh (IRRI) & K. Sayre (CIMMYT)

In irrigated rice monoculture systems, removal of straw does not cause a decline in soil organic matter.

Major harvested rice straw production 06 (kt)0 - 63.8863.88 - 145.9145.9 - 253.29253.29 - 534.63534.63 - 913.52

Thailand country boundary

0 200 400 600 Kilometers

N

EW

S

2nd harvested rice straw production 06 (kt)0 - 11.2811.28 - 37.4637.46 - 113.77113.77 - 225.97225.97 - 651.31

Thailand country boundary

0 200 400 600 Kilometers

N

EW

S

Dry Season 2006 (kt straw) Wet Season 2006 (kt straw)

Seasonal rice straw availabilityin Thailand

B. Gadde, JGSEE Bangkok

Straw conversion to biopower or biofuel

Slightly modified from C. Menke, JGSEE Bangkok

Straw

Energy conversion

Electricity

Solid Liquid Gas Intermediate energy form

Form of end use

Mandatory stepHarvest Collection TransportBaling

Combustion Pyrolysis BiomethanationGasification Fermentation

Raw material processingShredded Briquetting

Form asreceived

Heat Gaseous fuelLiquid fuel

Hydrolysis

As intermediate steps increase – efficiency goes down

Thermal conversion

• Local electricity generation as the major target • Applicable across a wide-range of sizes: 5 kW to >5 MW• Centralized or decentralized• Can use a wide range of biomass feedstocks• Moderate to high savings in net GHG equivalents

Thermal conversion technologies

Combustion Gasification Pyrolysis

Heat Syngas Bio-oilGasesCharcoal

Excess air and heat Partial air, ~700 °C No air, 200-500 °C

Liquid fuelsElectricity

Ash

Steam

Biopower from thermal straw combustion• Denmark: 75 straw-fired plants (11 heat + power)• India: First 10 MW straw combustion plant built in

1992 (Punjab); many operational problems; 17 new 12 MW rice straw power plants planned for Punjab and Haryana (first in 2008)

• China: 6 straw power plants in Jiangsu (2 operate), 24-30 MW each; source straw within 25-50 km, need about 150-200,000 t straw/year. More are planned.

• Technical problems: high alkali content of straw – High Si content of rice ash leads to a low melting point and

formation of alkali deposits– Corrosion and fouling problems in the superheater

• Logistics of feedstock supply and storage (safety)

Gadde et al., 2007

China’s first biopower plant using 100 % crop straw

Prof. Cheng Xu, CAU

Prof. Cheng Xu, CAU

Gasification and pyrolysis• Well known technologies• Rice hulls and rice straw are suitable (>20% lignin)• Little work on low density feedstock such as straw• Pyrolysis: T and residence time can be varied to produce

different proportions of end products: 10-85% gas, 5-75% bio-oil, 10-35% bio-char

• Technical problems: – Size reduction, drying & compaction– Alkali deposits and ash melting (straw gasification) – Gas cleaning (tar and particle removal) and

conditioning• Mostly for energy needs of a small industry or few

hundred homes; charcoal production

Gadde et al., 2007

Small scale rice hull furnaces, gasifiers, pyrolysis units

Industrial scale rice hull gasifiers

Cargill Rice MillingGreenville, Mississippi 330 t rice hulls+straw/day 6.5 MW electricity + steamfor parboiling facility

Riceland Foods, Inc., Stuttgart, Arkansas525 t rice hulls/day 15 MW electricity

What’s in it for rice farmers?

• Indirectly: increased income through stable or rising grain prices (pressure on land)

• Income from selling rice hulls and straw • Shareholder arrangements (ownership in

village-level biopower plants)• Payments for carbon credits through Clean

Development Mechanisms

Research needs for utilizing rice straw• Short-term:

– Adapt thermal conversion technologies: reduce ash melting in combustion/gasification, tar removal from Syngas, gas conditioning, co-firing of rice hulls + straw

– Fully operational village scale solutions– Biomass supply and processing chains– LCA of thermal conversion solutions– Payment schemes, including payments for C credits

• Long-term:– BTL process– Ligno-cellulosic conversion to ethanol or butanol– Physical and chemical straw characterization & breeding for straw

conversion traits (Si, Cl, K, lignin, brittle straw)

Summary• Biofuels will stay, accelerate globalization of ag,

increase crop prizes, and raise land values.• Technology advances made in developed countries

may not benefit the developing world.• Key risks: food price increases and instability &

wrong policies.• Subsidies for biofuels are anti-poor. Need to establish

a transparent global market and trade regime.• Rice farmers may benefit, but policy makers need to

protect the poor from rising commodity prices. • Decide based on unbiased information on life cycle

performance and impact of crop-biofuel systems.• Asia: utilize crop residues that can be safely removed,

especially rice straw.

Acknowledgements

• Adam Liska and Ken Cassman, Univ. of Nebraska• Butch Gadde and Christoph Menke, Joint Graduate

School for Energy and Environment, King Mongkut’s University of Technology, Bangkok

• Professor Cheng Xu, China Agric. Univ., Beijing• IRRI: Martin Gummert, Stephan Haefele, Reiner

Wassmann