Main point: many of these technologies are at an early stage of development and, so far, they have mostly been investigated for larger-scale industrial use. Starch ethanol and biodiesel processes are widely used already, but cellulosic ethanol remains at a pre-commercial stage thus far and will probably not have major impact on the next 5-10 years. For example: At present, the initial capital investment cost to build a corn-grain ethanol plant in the U.S. is about $1 per gallon of ethanol production capacity. The capital cost for a cellulosic ethanol plant is, at present, estimated to be 10 times as much, i.e., $10 per gallon capacity.
Trendline yield in 2007 is 9300 kg/ha, on 34.6 Mha, tottal production in 2007 = 322 Mt. yield increase is 112 kg/ha-yr, and estimated maize area in future years is 34 Mha, and probably less due to balance needed for soybean area.
There are other examples for such closed cycles at pilot stage: Oilseed biodiesel + high protein animal feed after oil extraction with wheat straw used to provide heat and power the process New Zealand (R. Sims): Fractionate biomass into various components, washing, pre-heating, hydrolysis of hemicellulose to chemicals such as furfural, lignin, and dried cellulose
Biofuels - what is in it for rice farmers?
Biofuel – what’s in it for rice farmers? Achim Dobermann
<ul><li>Some trends </li></ul><ul><li>The maize – ethanol system </li></ul><ul><li>Options for rice </li></ul>
Terminology <ul><li>Bioenergy = Renewable energy produced from organic matter, i.e., solar-derived energy contained in biomass of living or recently living biological material. </li></ul><ul><li>Biofuel = Liquid, solid, or gaseous fuel produced by conversion of biomass. </li></ul><ul><li>Biopower = Direct use of biomass to generate electricity, heat or steam. </li></ul>http://bioenergy.ornl.gov/faqs/glossary.html
Biofuel categories <ul><li>Produced from feedstocks contained within the food cycle: </li></ul><ul><ul><li>Biodiesel: transesterification of plant-based oils </li></ul></ul><ul><ul><ul><li>Canola, soybean, oil palm, coconut, jatropha </li></ul></ul></ul><ul><ul><li>Bioethanol: sugar or starch conversion by fermentation </li></ul></ul><ul><ul><ul><li>Sugarcane, sugar beet, sweet sorghum, maize, wheat, sorghum, cassava </li></ul></ul></ul><ul><li>Produced from non-food biomass: </li></ul><ul><ul><li>Combustion (wood, crop residues, waste) </li></ul></ul><ul><ul><li>Gasification </li></ul></ul><ul><ul><li>Biomass to liquid (gasification/pyrolysis – liquefaction) </li></ul></ul><ul><ul><li>Biogas (anaerobic digestion) </li></ul></ul><ul><ul><li>Ligno-cellulosic ethanol </li></ul></ul><ul><ul><li>Ligno-cellulosic butanol </li></ul></ul>
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 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 costs Ethanol: 50-70%; Biodiesel: 70-80%
Not a new idea <ul><li>“ 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.” </li></ul><ul><li>Henry Ford, 1925 </li></ul>First corn-ethanol blended gasoline station, Lincoln, Nebraska, 1933
Gross energy yield of various biofuel crops 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 39 1863 14 Brazil Cassava-E 18 552 3 USA Soybean-BD 21 641 2 Canada Rapeseed-BD 79 3751 9 USA Maize-E 124 5865 74 Brazil Sugarcane-E 195 5920 21 Malaysia Oil Palm-BD GJ/ha L/ha Mg/ha Energy Biofuel Yield Country Crop-biofuel*
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 world Net GHG gas reductions: literature summary Gross energy yield (GJ/ha)
Impact on food prices <ul><li>December 2006 – demonstrations in Mexico: rising tortilla prices due to rising corn prices </li></ul><ul><li>April 2007 - consumer food prices in the USA have increased 3-4% compared to one year ago </li></ul><ul><li>May 2007 – globally, milk powder price has risen 60% in 6 months; fluid milk 63% in one year </li></ul><ul><li>May 2007 – Indofood Sukses Makmut raises prices of instant noodles in Indonesia by 5% </li></ul><ul><li>September 2007 – rising food prices are a major cause of rising inflation in China </li></ul><ul><li>September 2007 - beer prices rise 5.5% at the Oktoberfest in Munich </li></ul>
Two examples <ul><li>Technology options for optimizing maize-ethanol systems in North America </li></ul><ul><li>Biofuel options for rice systems in Asia </li></ul>
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
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 dry wet
CH 4 Grain NO 3 leaching N 2 O CO 2 A. Liska et al., UNL, 2007 Technologies to improve maize-ethanol systems Thermal energy CH 4 Methane biodigestor (6) Closed-loop system (-56% energy) Biofertilizer CO 2 Maize & soybean production (1) Improve management (2) Increase NUE (10%) Grain Stillage CO 2 Ethanol Distillers grain Ethanol plant (3) Starch content 72 75% (4) Conversion efficiency 91 97% (enzymes, microbes) N 2 O CH 4 Manure, urine Meat Cattle feedlot (5) Directly use wet distillers grain (-26% energy) NO 3 leaching
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 Ethanol yield (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 technology Blue : High-yield irrigated corn-soybean system, CT A. Liska et al., UNL, 2007 0 1 2 3 4 5 6 7 8 6 8 10 12 14 16 18 Net Energy Value (MJ/L) Yield NUE Genetics Engineering ALL
GHG emissions reduction (% and t CO 2 eq*) Maize production system Ethanol biorefineries *Based on a 100 million gal/yr production capacity A. Liska et al., UNL, 2007 80% 601000 t 67% 504000 t closed-loop facility 73% 544000 t 60% 447000 t natural gas, wet DG 63%, 478000 t 51% 381000 natural gas 39% 294000 t 26% 198000 t coal Advanced Irrigated USA average
First Commercial-Scale Closed Loop Biofuel Refinery, Mead, Nebraska www.e3biofuels.com Ethanol: 24 M gallons/yr Cattle: 28,000 head/yr
R. Perrin, Univ. of Nebraska, Feb. 2007 Feb. 2007 Feb. 2006 <ul><li>Petrol @ $50/barrel: </li></ul><ul><li>- to be competitive with gasoline ethanol needs to sell for $1.55/gal (incl. $0.51/gal subsidy) </li></ul><ul><li>Plant operating costs $0.55/gal + $0.30/gal capital cost - $0.10/gal federal subsidy </li></ul><ul><li>max. corn price to break even: $1.55 – 0.85 + 0.10 = 0.80/gal = $3.20/bushel </li></ul>Oct. 2007 Breakeven price for ethanol in the USA to compete with petroleum, given current subsidies
Includes forecast for 2007 (FAO Rice Market Monitor, Sep. 2007) Rice area Rice production
<ul><li>Rice grain should not be used for biofuels </li></ul><ul><li>Riceland should not be converted to biofuel crops </li></ul>
Rice hulls <ul><li>100 kg of paddy rice 20 kg of hulls during milling </li></ul><ul><li>>110 million tons annually collected at rice mills </li></ul><ul><li>~10% moisture </li></ul><ul><li>Bulk density 100 to 150 kg/m 3 </li></ul><ul><li>Energy content: 14-16 MJ/kg (dry wood: 18-20 MJ/kg) </li></ul><ul><li>Main carbohydrates: cellulose and lignin </li></ul><ul><li>16 to 22% ash, 90-96% of the ash is silica </li></ul><ul><li>Higher ash melting point than ash from rice straw - less slag deposits when burned for fuel </li></ul>
<ul><li>580 million tons of rice straw per year </li></ul><ul><li>35-40% C , 0.5-0.8% N, 1.2-2.0% K, 4-7% Si </li></ul><ul><li>Current use: burning, removal (fuel for cooking), some incorporation, some for other uses </li></ul><ul><li>Energy content: 14 MJ/kg at 10% moisture </li></ul>Straw as a new income source for rice farmers?
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. Partial Limited Wheat & maize Sole upland crop(s) Partial Limited Rice All Yes Maize or wheat Rice – wheat, rice-maize All Yes Rice Double rice All Yes Rice Triple rice Portion for removal Potential for removal Residue System
Dry Season 2006 (kt straw) Wet Season 2006 (kt straw) Seasonal rice straw availability in 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 step Harvest Collection Transport Baling Combustion Pyrolysis Biomethanation Gasification Fermentation Raw material processing Shredded Briquetting Form as received Heat Gaseous fuel Liquid fuel Hydrolysis As intermediate steps increase – efficiency goes down Thermal conversion
<ul><li>Local electricity generation as the major target </li></ul><ul><li>Applicable across a wide-range of sizes: 5 kW to >5 MW </li></ul><ul><li>Centralized or decentralized </li></ul><ul><li>Can use a wide range of biomass feedstocks </li></ul><ul><li>Moderate to high savings in net GHG equivalents </li></ul>Thermal conversion technologies Combustion Gasification Pyrolysis Heat Syngas Bio-oil Gases Charcoal Excess air and heat Partial air, ~700 °C No air, 200-500 °C Liquid fuels Electricity Ash Steam
Biopower from thermal straw combustion <ul><li>Denmark: 75 straw-fired plants (11 heat + power) </li></ul><ul><li>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) </li></ul><ul><li>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. </li></ul><ul><li>Technical problems: high alkali content of straw </li></ul><ul><ul><li>High Si content of rice ash leads to a low melting point and formation of alkali deposits </li></ul></ul><ul><ul><li>Corrosion and fouling problems in the superheater </li></ul></ul><ul><li>Logistics of feedstock supply and storage (safety) </li></ul>Gadde et al., 2007
China’s first biopower plant using 100 % crop straw Prof. Cheng Xu, CAU
Gasification and pyrolysis <ul><li>Well known technologies </li></ul><ul><li>Rice hulls and rice straw are suitable (>20% lignin) </li></ul><ul><li>Little work on low density feedstock such as straw </li></ul><ul><li>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 </li></ul><ul><li>Technical problems: </li></ul><ul><ul><li>Size reduction, drying & compaction </li></ul></ul><ul><ul><li>Alkali deposits and ash melting (straw gasification) </li></ul></ul><ul><ul><li>Gas cleaning (tar and particle removal) and conditioning </li></ul></ul><ul><li>Mostly for energy needs of a small industry or few hundred homes; charcoal production </li></ul>Gadde et al., 2007
Small scale rice hull furnaces, gasifiers, pyrolysis units
What’s in it for rice farmers? <ul><li>Indirectly: increased income through stable or rising grain prices (pressure on land) </li></ul><ul><li>Income from selling rice hulls and straw </li></ul><ul><li>Shareholder arrangements (ownership in village-level biopower plants) </li></ul><ul><li>Payments for carbon credits through Clean Development Mechanisms </li></ul>
Research needs for utilizing rice straw <ul><li>Short-term: </li></ul><ul><ul><li>Adapt thermal conversion technologies: reduce ash melting in combustion/gasification, tar removal from Syngas, gas conditioning, co-firing of rice hulls + straw </li></ul></ul><ul><ul><li>Fully operational village scale solutions </li></ul></ul><ul><ul><li>Biomass supply and processing chains </li></ul></ul><ul><ul><li>LCA of thermal conversion solutions </li></ul></ul><ul><ul><li>Payment schemes, including payments for C credits </li></ul></ul><ul><li>Long-term: </li></ul><ul><ul><li>BTL process </li></ul></ul><ul><ul><li>Ligno-cellulosic conversion to ethanol or butanol </li></ul></ul><ul><ul><li>Physical and chemical straw characterization & breeding for straw conversion traits (Si, Cl, K, lignin, brittle straw) </li></ul></ul>
Summary <ul><li>Biofuels will stay, accelerate globalization of ag, increase crop prizes, and raise land values. </li></ul><ul><li>Technology advances made in developed countries may not benefit the developing world. </li></ul><ul><li>Key risks: food price increases and instability & wrong policies. </li></ul><ul><li>Subsidies for biofuels are anti-poor. Need to establish a transparent global market and trade regime. </li></ul><ul><li>Rice farmers may benefit, but policy makers need to protect the poor from rising commodity prices. </li></ul><ul><li>Decide based on unbiased information on life cycle performance and impact of crop-biofuel systems. </li></ul><ul><li>Asia: utilize crop residues that can be safely removed, especially rice straw. </li></ul>
Acknowledgements <ul><li>Adam Liska and Ken Cassman, Univ. of Nebraska </li></ul><ul><li>Butch Gadde and Christoph Menke, Joint Graduate School for Energy and Environment, King Mongkut’s University of Technology, Bangkok </li></ul><ul><li>Professor Cheng Xu, China Agric. Univ., Beijing </li></ul><ul><li>IRRI: Martin Gummert, Stephan Haefele, Reiner Wassmann </li></ul>
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