Technical and Economic Prospects of Rice Residues for Energy in Asia Dipl.-Ing. Werner Siemers Sustainable Bioenergy Symposium at RE Asia Bangkok, June 2, 2011
Contents Introduction Motivation Characteristics for rice husks and rice straw Potentials for energetic use Rice husks Rice straw Economic and institutional implications Conclusion
Motivation Use of biomass for energy production If surplus available Reduction of fossil energy consumption Substitution for electricity, heat and. Reduction of CO2- emissions Net reduction is assured Husk and straw are by-product resp. waste of food production Husks and straw are/had been burnt for waste handling local emissions
Characteristics Straw and husks are totally different Husks Uniform in size Dry At factory level accumulated Market access, traded Price structure available Direct use for energy (power plant, heat) possible Ash content high Straw Bulky Dry, but sometimes wet Field based resource Only local market High variation in prices Needs further processing for efficient energy use Ash content high
Potential for energetic use Desktop studies for four countries India, Thailand, Vietnam, China Additional summary paper Organised by FAO, Rome Executed in 2008 and 2009 References Shijun Ding: Rice Residue Utilization for Bio-fuels Production in China, revised version, 12 October 2009 Phan Hieu Hien: Study on bioenergy production from rice residues in Viet Nam, Final report (revised), August 2009 Werner Siemers: Rice residue utilization for biofuels production Case Study Thailand, Final report (revised edition), May 2009 Werner Siemers: Rice residue utilization for biofuels production Case Study India, Final report (revised edition), July 2009 Werner Siemers: Policy Brief Rice residue Utilization for Biofuels Production, October 2009
India Total rice production of 130 Mt 30 Mt rice husks Rice husk for traditional non-energetic use, 20% to 30% of volume assumed Rice husk for energy, total 11 Mt Rural heat and energy demand, milling, parboiling Open burning for ash production Some modern biomass power plants Apparent surplus of some 10 Mt husk 100 Mt rice straw Animal production: Fodder and bedding material, nearly 50% Domestic purpose, energy and material, nearly 30% Apparent surplus of 22 Mt in the rice producing areas One power plant operated on straw, but technical difficulties
Thailand Total rice production of 30 Mt 6.1 Mt rice husk Negligible traditional non-energetic use, 0.3 Mt Traditional energy use: rice mills and cooking/heating, 1.2 Mt Energy demand in cement and other industries, 1.3 Mt Existing modern biomass power plants (usual 10 MW), 1.7 Mt Apparent surplus of 1.6 Mt, but would be Zero soon, regional shortages occur already, transport over long distances 22 Mt rice straw Animal production: fodder and bedding material Open field burning Apparent surplus: nearly 50% But: present material costs are too high for modern energetic utilization, logistics and markets not developed
Vietnam Total rice production 36 Mt 6.5 Mt rice husk Non-energetic: Fertiliser, fodder Energy use: household cooking, food processing, paddy drying, brick and cement industry Apparent surplus of 1 Mt, mainly in the Mekong Delta, rest of surplus scattered One modern biomass power plant erected (2 MW), more planned 21.5 Mt rice straw Animal production: fodder (regionally 50% to 80%), bedding material (15% to 30%) Organic fertilizer, mushroom production Energetic: cooking and heating (10%, Northern and Central) Apparent surplus: 6 Mt (mainly Mekong Delta) But: traded price for straw is 2 to 5 times higher than husk
China Total rice production 189 Mt 38 Mt rice husk 200 Mt rice straw (no further distinction between husks and straw) Fodder (20%) and organic fertilizer (15%) Household cooking, 47% of all resources Burning without energy recovery, 15% No real visible surplus Apparent surplus: 37 Mt or maximum 150 Mt which is the conversion of the field burning quantity into useful energy, plus a possible shift from the household cooking demand to modern energy Plans for decentralized use (briquetting, pelletizing, gasification) and centralized (cogeneration) power plants
Potentials for energetic use Summary for 4 representative countries China Vietnam Thailand India Theoretical potential Rice husk, Mt 38 6.5 6.1 30 Rice straw, Mt 200 21.5 22.0 100 Estimated surplus Rice husk, Mt See straw 1.0 1.6 10 Rice straw, Mt 37 to 150 6.0 11.0 22 Present Modern use Power Plant, Mt n.a. 0.016 1.7 2.0 to 2.5
Economic implication Husks prices are rising, straw costs are higher because of logistics and processing Examples from Thailand, IRR for biomass power plants Husk Straw
Institutional implication Incentives are necessary Feed-in tariff to cover higher costs Feed-in tariffs for biomass China Vietnam Thailand India USct/kWh 3.7 to 5.2 4.0 8.2 to 8.8 3.0 to 4.7 CDM (Clean Development Mechanism) as additional income for CO2 reduction Framework conditions must be right Independent power production Feed-in law for renewables and/or biomass Reliable policy More efforts for straw utilisation
Conclusion Rice husks and rice straw are one of the major sources for biomass energy in Asia The potential is only used to a certain extent in modern applications There are traditional and modern competing usages (both non-energetic and energetic) Situation for husks is more advanced because of technical and economic advantages For efficient straw utilisation there is still need for improvement in logistics and pre-processing Both can contribute to more renewable energy and less carbon There is limited competition for food and some competition on the fodder situation
Thank you very much for your attention!! Further Contact: werner.siemers@cutec.de