Environmental and Economic Implications of Phasing Out Solid Fuels Used for Cooking in China Eric D. Larson Research Engineer/Associated Faculty Princeton Environmental Institute Princeton University, USA Mitigation of Air Pollution and Climate Change in China 17-19 October 2004 Oslo: Norwegian Academy of Science and Letters Outline • • • • • Indoor air pollution Global warming Challenge of replacing solid cooking fuels Prospects for increasing LPG use Prospects for dimethyl ether (DME) Pollution from Cooking Stoves/Fuels (measured emissions to room air from flue-less stoves in China) 50.0 45.0 PIC = Products of Incomplete Combustion PIC to air (grams/MJ of heat to pot) 40.0 35.0 30.0 25.0 20.0 15.0 10.0 5.0 0.0 Town gas Natural gas LPG Kerosene (wick stove) Coal Honeycomb briquettes coal (metal, (metal stove) improved) Honeycomb Coal powder Fuelwood Brushwood coal (metal (metal stove) (Indian metal (Indian metal stove) stove) stove) Source: Zhang, J., Smith, K.R., et al., 2000, “Greenhouse gases and other airborne pollutants from household stoves in China: a database for emission factors,” Atmos. Environ. 34: 4537-4549. Approximate Total Global Human Exposure to Particulate Air Pollution As cited by Reddy, Williams, Johansson, 1997, Energy After Rio, UNDP, New York. Global Warming Potentials of Combustion Products (relative to CO2) Source: Bond, Venkataraman, and Masera, 2004, “Global atmospheric impacts of residential fuels,” Energy for Sustainable Development, VIII(3): 115-126 Global Warming Commitment of Cooking Fuels/Technologies (estimates) 20-year GWP 100-year GWP (cooling impact) (from biomass, if biomass obtained by deforestation) global warming commitment, kg CO2-equivalent per GJ delivered to pot Source: Bond, Venkataraman, and Masera, 2004, “Global atmospheric impacts of residential fuels,” Energy for Sustainable Development, VIII(3): 115-126 Indicative Change in Radiative Impact Compared with Traditional Fuels Averages taken from previous GWC estimates: Traditional stoves = average of 3 “traditional” cases; Improved stoves = average of 3 “improved” cases; Charcoal = average of 2 “charcoal” cases; Clean fossil fuels = average of kerosene, LPG, and natural gas. Source: Bond, Venkataraman, and Masera, 2004, “Global atmospheric impacts of residential fuels,” Energy for Sustainable Development, VIII(3): 115-126 “Solving” the Problem Pollution from Cooking Stoves/Fuels (measured emissions to room air from flue-less stoves in China) 50.0 45.0 PIC = Products of Incomplete Combustion PIC to air (grams/MJ of heat to pot) 40.0 35.0 30.0 25.0 20.0 15.0 10.0 5.0 0.0 Town gas Natural gas LPG Kerosene (wick stove) Coal Honeycomb briquettes coal (metal, (metal stove) improved) Honeycomb Coal powder Fuelwood Brushwood coal (metal (metal stove) (Indian metal (Indian metal stove) stove) stove) Source: Zhang, J., Smith, K.R., et al., 2000, “Greenhouse gases and other airborne pollutants from household stoves in China: a database for emission factors,” Atmos. Environ. 34: 4537-4549. Efficiencies of Cooking Stoves/Fuels (from standardized meal cooking tests) Source: Dutt, G. S., and N. H. Ravindranath, 1993, “Bioenergy: direct applications in cooking,” Renewable Energy, H. Kelly, T.B. Johansson, A.K.N. Reddy, and R.H. Williams (eds.), Island Press, Washington, DC, pp. 653-697. How “easily” can the dirty cooking problem be solved? • Goldemberg et al. (2004) indicate that 2.6 billion people cook with solid fuels today worldwide. They estimate 35 kg/capita/year of LPG (liquefied petroleum gas) could meet basic cooking needs. • 35 kg LPG x 46 MJ/kg = 1.61 GJ/year/cap. • 1.61 GJ/yr/cap x 2.6 billion = 4.2 billion GJ/year (or 100 million toe, 143 million tce). • This is 1% of global commercial energy use in 2003. • The corresponding figure for China is 2.6%. What is the value of clean cooking fuel? Coal, Biomass WB* has estimated rural indoor air pollution costs $4 - $11 billion/year. This is $22 - $63/GJ of fuel required. Retail price of LPG in rural China is 50-60 Yuan RMB for a 15 kg bottle. (US$8.8 to $10.6/GJ). * Johnson, Liu, Newfarmer, Clear Water, Blue Skies, China’s Environment in the New Century, World Bank, 1997. LPG Producer Gas Barriers to Cleaner Cooking • • • • • • • “Natural” progression up the “energy ladder” (dung/crop residues Æ fuelwood Æ charcoal Æ kerosene Æ LPG Æ NG/electricity) follows increasing incomes – very slow process. Low/zero private cost for biomass/coal use. External costs (e.g., health damages) not reflected in private price of solid fuels, so difficult to compete with cleaner fuels that carry higher private cost. Cooking is women’s domain, but women are not generally the decision makers regarding cooking fuels. Dirty fuels are not politically consequential. (In recent Indian elections, roads, water, and electricity were swing issues. Cooking fuel was not.) Governments of industrialized countries may not appreciate the links between dirty fuels in developing countries and impacts on their own countries. Most energy-related development assistance over the past 30 years has focused on electrification, and this continues to be the case. Where heating is done with solid fuels, adopting clean cooking fuel will only partially improve the situation. Fuel Options for Cleaner Cooking in China • Fossil-derived fuels – – – – – – Liquefied petroleum gas, LPG Town gas (gasified coal) Natural gas Kerosene Dimethyl ether (from coal) Electricity • Biomass-derived fuels – – – – – Producer gas Biogas Dimethyl ether Ethanol/ethanol gel Electricity LPG Use in Developing Countries 14000 LPG CONSUMPTION IN 1999 (Top 20 Developing Country Consumers) 12000 1000 t kg per capita 8000 6000 4000 2000 Source: Annual Statistical Review of LP Gas, LP Gas Association, Paris. a om bi ia es on In d C ol hi le C s pi ne lip Ph i cc o M or o Ta iw an q Ira en tin a Ar g ys ia M al a ia er Al g Th ai la nd n Ira zu ne Ve Ar di Eg yp t el a ia ab ia Sa u Ko r ut h So In d ea il Br az M ex ic o hi na 0 C Total Consumption (1000 t) 10000 China’s LPG Sources 16000 CHINA LPG SOURCES Average annual consumption growth of 15.7% per year, 1995-2001 14000 Imported Domestic Production 12000 (including some from imported crude oil) 1000 t 10000 8000 Supplying 800 million people with 35 kg/cap/yr of LPG would require 28 million tons of LPG (double current consumption). Much of the additional supply would need to be imported. 6000 4000 2000 0 1990 1991 1992 1993 1994 Source: Annual Statistical Review of LP Gas, LP Gas Association, Paris. 1995 1996 1997 1998 1999 2000 2001 中国原油和油品进口增长情况 Chinese Oil Imports since 1988 100 80 百 万 吨 M ln t 70 60 50 40 30 前苏联 FSU 苏丹 Sudan Crude oil 原油 安哥拉 Angola 越南 Vietnam 印度尼西亚 Indonesia 百 万 吨 Mln t 90 其它国家 Others 40 苏丹 Yemen 阿曼 Oman 沙特阿拉伯 Saudi Arabia 伊朗 Iran Refined products/LPG 油品和液化气 LPG 35 液化气 其它 Other Products 30 石脑油 Naphtha 汽油 Gasoline 25 20 航空煤油 Jet 柴油 Gas oil 燃料油 Fuel oil 15 10 20 5 10 0 1988 0 1993 1998 Source: Tony Cui (BP China), personal communication, July 2004. 2003 1988 1993 1998 2003 液化气与原油价格比较 LPG and Crude Oil Prices 350 原油 Crude oil 30 300 沙特丙烷 Saudi CP 25 250 预计 Proj 20 200 15 150 10 100 5 50 1988 1990 1992 1994 Source: Tony Cui (BP China), personal communication, July 2004. 1996 1998 2000 2002 2004 丙 烷 , 美 元 / 吨 Propane, USD/t 油 价 , 美 元 / 桶 Oil, USD/bbl 35 DME (CH3OCH3) is Similar to LPG • • • DME used today as ozone-safe aerosol propellant. Current global production is ~150,000 tons/year (from methanol). DME is also a good diesel-engine fuel: high cetane #, no sulfur, no C-C bonds so no soot, lower NOx emissions. New DME manufacturing capacity under construction/planned: – From nat. gas: 110,000 t/y (Sichuan, China, 2005 on-line); 800,000 t/y (Iran, 2006 on-line) – From coal: 840,000 t/y project approved (Ningxia, China, construction not yet started) Making DME from Coal • • • • • • Gasify coal in O2/H2O to produce synthesis gas “syngas” (mostly CO, H2). Increase H/C ratio (from ~0.8 for coal to ~ 3 for DME) via water gas shift reaction (CO + H2O Æ H2 + CO2). Remove acid gases (H2S and CO2) from syngas. Convert syngas to DME in a slurry-phase synthesis reactor. Separate DME product from unconverted syngas. Produce exportable electricity with unconverted syngas. Source: Larson and Yang, 2004, “Dimethyl Ether (DME) from Coal as a Household Cooking Fuel in China,” Energy for Sustainable Development, VIII(3): 115-126 Growing Global Gasification Capacity Will Reach 61 GWth in 2004 In 2004 By activity: • 24 GWth chemicals • 23 GWth power • 14 GWth synfuels By region: • 9 GWth China • 10 GWth N America • 19 GWth W Europe • 23 GWth Rest of world By feedstock: • 27 GWth pet. residuals • 27 GWth coal • 6 GWth natural gas • 1 GWth biomass Source: Dale Simbeck, SFA Pacific Inc., Mountain View, California. Slurry-Phase Synthesis of Liquids • Basic overall reactions: CO + 2H ⇔ - CH - + H O 2 2 2 3CO + 3H CO + 2 H 2 2 Fischer-Tropsch liquids ⇔ CH OCH + CO 2 3 3 ⇔ CH OH 3 Dimethyl ether Methanol • Commercial status: Fuel product (vapor) + unreacted syngas FischerTropsch MeOH DME Commercial units in operation Steam 3 Demonstrated at commercial scale Disengagement zone 3 Catalyst powder slurried in oil Cooling water Demonstrated at pilot-plant scale China, Japan, USA CO 3 Synthesis gas (CO + H2) H2 Liquid-phase reactors have much higher onepass conversion of CO+H2 to liquids than traditional gas-phase reactors, e.g., liquidphase Fischer-Tropsch synthesis has ~80% one-pass conversion, compared to <40% for traditional technology. TYPICAL CONDITIONS: P = 25-100 atm. T = 200-300oC catalyst CH3OCH3 CH3OH CnH2n+2 (depending on catalyst) Energy Balance for DME from Coal clean syngas water Rectisol Grinding, Slurrying coal synthesis product syngas bypass O2 (95%) vent Recycle Compressor Cooler Gasifier 1390°C 75 bar Oxygen Production Syngas Pre-heater boiler feed water Sour WGS CO2 H2S Cooler Liquid Phase Synthesis Reactor scrubber water quench water air Quench quenched gas Scrubber MP steam steam Bituminous coal typical of Yanzhou area, Shandong Province (dry weight %) C LP Steam unconverted syngas to stack 63.7 H 4.3 O 6.8 S 4.0 N 1.1 Ash 20.2 Moisture (as rec’d) 7.1 HHV (MJ/kg as rec’d) 24.54 LHV (MJ/kg, as rec’d) 23.49 Flash Expander ~ Flash cond. Boiler ~ Gas Turbine air liquid ~ Steam turbine DME Distillation Energy Balance Summary* Coal feed (MW) 2203 DME (MW) 600 Net electricity (MW) 490 methanol * Source: “VENT” case in Celik, F. Larson, E.D., and Williams, R.H., 2004, “Transportation Fuel from Coal with Low CO2 Emissions,” Proceedings of the 7th International Conference on Greenhouse Gas Control Technologies, held Sept. 2004 (proceedings forthcoming). Estimated Retail Cost/Price of DME from Coal in China Source: Larson and Yang, 2004, “Dimethyl Ether (DME) from Coal as a Household Cooking Fuel in China,” Energy for Sustainable Development, VIII(3): 115-126 LPG, DME Retail Price Comparisons Windfall profits potential Source: Larson and Yang, 2004, “Dimethyl Ether (DME) from Coal as a Household Cooking Fuel in China,” Energy for Sustainable Development, VIII(3): 115-126 Summary/Conclusions • Environmental/health problems associated with cooking/heating with solid fuels are significant in China. • From a societal perspective, the cooking problem can be solved cost-effectively and without significant global energy impacts. • Major institutional, financial, political, social, and other barriers exist, however. (I have not addressed these in this talk!) • LPG is attractive for China, but concerns over energy security and crude-oil linked price may limit future expansion potential. • DME from coal (with co-production of electricity) is an attractive additional option. – DME could be made in large quantities in many areas of China, including in some of the poorest Western provinces. – Low costs compared to prospective future LPG prices. – Total coal use for cooking and electricity could be reduced by about 25% compared to cooking directly with solid coal and generating the electricity from a stand-alone coal-IGCC power plant. – CO2 capture and storage during DME production may be long term option.