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Coal GasificationCoal Gasification
Robert NagaiRobert Nagai
AP Environmental ScienceAP Environmental Science
Period 3Period 3
Uses of Coal GasificationUses of Coal Gasification Clean way to convert coal (or any carbon based Clean way to convert coal (or any carbon based
material) into energymaterial) into energy Electricity ProductionElectricity Production Lighting, Heating, and Cooking FuelsLighting, Heating, and Cooking Fuels Energy-Efficient Fuel Cell TechnologyEnergy-Efficient Fuel Cell Technology Ammonia and Hydrogen ProductionAmmonia and Hydrogen Production Transportation Fuel (gasoline, diesel, methanol, Transportation Fuel (gasoline, diesel, methanol,
liquefied natural gas)liquefied natural gas) Road Tar, Creosote (wood preservative), phenol Road Tar, Creosote (wood preservative), phenol
(plastics), cresols (disinfectants), dyes, and (plastics), cresols (disinfectants), dyes, and medicinesmedicines
EfficiencyEfficiency
Combined cycleCombined cycle Coal gases are fired into a gas turbine and creates Coal gases are fired into a gas turbine and creates
electricityelectricity Steam is produced from the gasification process Steam is produced from the gasification process
and the heat made by the gas turbineand the heat made by the gas turbine Gross power generation is 50% efficiencyGross power generation is 50% efficiency Net generation is 40% efficientNet generation is 40% efficient With improvements in high pressure solid fuel cell With improvements in high pressure solid fuel cell
technology, efficiency is expected to rise to 60%technology, efficiency is expected to rise to 60%
Cost of Coal GasificationCost of Coal Gasification
Costs vary widely depending on plant Costs vary widely depending on plant design and type as well as quality of coaldesign and type as well as quality of coal
Capital costs: $13-17.2/GigaJoule (GJ)*Capital costs: $13-17.2/GigaJoule (GJ)* Synthesis Gas (Syngas) production: Synthesis Gas (Syngas) production:
$15.6-19.3/GJ*$15.6-19.3/GJ*
*based on data from US based plants in 2005*based on data from US based plants in 2005
Gasification Extraction Gasification Extraction and Usageand Usage
Coal (or other bio mass) is broken down Coal (or other bio mass) is broken down into its basic chemical constituents by:into its basic chemical constituents by: Exposure to steamExposure to steam Controlled amounts of oxygenControlled amounts of oxygen High temperature and pressureHigh temperature and pressure
ProcessProcess yields carbon monoxide, yields carbon monoxide, hydrogen, and other fuel gaseshydrogen, and other fuel gases
Gasification Extraction Gasification Extraction and Usageand Usage
Gasification Extraction Gasification Extraction and Usage (continued)and Usage (continued)
Underground Coal Gasification (UCG) gasifies Underground Coal Gasification (UCG) gasifies un-mined coal deposits while still undergroundun-mined coal deposits while still underground
UCG technology was first proposed by Sir UCG technology was first proposed by Sir William Siemens in 1868 and developed William Siemens in 1868 and developed extensively by the USSR under Lenin and extensively by the USSR under Lenin and StalinStalin
The US conducted UCG research form 1974 to The US conducted UCG research form 1974 to 1989, but abandoned development due to a 1989, but abandoned development due to a drop in oil pricesdrop in oil prices
China, Australia, and South Africa continue to China, Australia, and South Africa continue to develop UCG technologydevelop UCG technology
Gasification Extraction Gasification Extraction and Usage (continued)and Usage (continued)
China has the largest China has the largest UCG program with more UCG program with more than 16 plants built since than 16 plants built since 19911991
Gasification Gasification Consumption/UsageConsumption/Usage
The United States started using modern The United States started using modern gasification in 1984gasification in 1984
20 plants are in operation in the US as of 2002 20 plants are in operation in the US as of 2002 with 10 more scheduled to be builtwith 10 more scheduled to be built
Worldwide, there are 117 plants in operation Worldwide, there are 117 plants in operation with 35 additional plants in developmentwith 35 additional plants in development
36% of these plants generate fuels, 19% 36% of these plants generate fuels, 19% generate electricity, and 42% generate generate electricity, and 42% generate chemical feedstock.chemical feedstock.
These plants account for 24,000 megawatts of These plants account for 24,000 megawatts of electricity with an annual growth rate of 10%electricity with an annual growth rate of 10%
Gasification AdvantagesGasification Advantages
Gasification yields a wide variety of Gasification yields a wide variety of useful products beyond electricity such useful products beyond electricity such as sulfur and ammoniaas sulfur and ammonia
The process is 17% more efficient than The process is 17% more efficient than conventional coal burning plantsconventional coal burning plants
Converting coal into a gaseous state Converting coal into a gaseous state allows easier removal of polluting allows easier removal of polluting compoundscompounds
Gasification Gasification DisadvantagesDisadvantages
Installation and maintenance costs are Installation and maintenance costs are higher than conventional coal burning higher than conventional coal burning plantsplants
Process produces more greenhouse Process produces more greenhouse gases than petroleumgases than petroleum
The environmental impact of coal mining The environmental impact of coal mining is not reduced by gasificationis not reduced by gasification
Gasification—Ecological Gasification—Ecological ProblemsProblems
Gasification waste products may pollute Gasification waste products may pollute the groundwater surrounding the plantthe groundwater surrounding the plant
Gasification products are highly toxic and Gasification products are highly toxic and pose a health and environment threat pose a health and environment threat should a leak occurshould a leak occur
Gasification does not reduce the demand Gasification does not reduce the demand for coal, nor does it make coal mining for coal, nor does it make coal mining more environmentally friendlymore environmentally friendly
Gasification InstallationsGasification Installations
The first modern coal gasification plant in the The first modern coal gasification plant in the US was built in 1984 in Beulah, North DakotaUS was built in 1984 in Beulah, North Dakota
Facilities in Barstow, California; West Terre Facilities in Barstow, California; West Terre Haute, Indiana; and Lakeland, Florida are Haute, Indiana; and Lakeland, Florida are among the more than 20 active plants in the among the more than 20 active plants in the USUS
China is building more than 50 gasification China is building more than 50 gasification plants in its northwestern region in order to plants in its northwestern region in order to reduce smog (despite the large amount of reduce smog (despite the large amount of greenhouse gases produced by gasification)greenhouse gases produced by gasification)
SourcesSources
http://energy.gov/fe/how-coal-gasification-power-plants-workhttp://energy.gov/fe/how-coal-gasification-power-plants-work http://energy.gov/fe/science-innovation/clean-coal-research/http://energy.gov/fe/science-innovation/clean-coal-research/
gasificationgasification http://www.worldcoal.org/coal/uses-of-coal/underground-coal-http://www.worldcoal.org/coal/uses-of-coal/underground-coal-
gasification/gasification/ http://www.kbr.com/Technologies/Coal-Gasification/http://www.kbr.com/Technologies/Coal-Gasification/ http://www.reuters.com/article/2013/07/01/utilities-southern-http://www.reuters.com/article/2013/07/01/utilities-southern-
kemper-idUSL2N0F723N20130701kemper-idUSL2N0F723N20130701 Bell, D. A., Brian F. Towler, and Maohong Fan. "Chapter 7." Bell, D. A., Brian F. Towler, and Maohong Fan. "Chapter 7." Coal Coal
Gasification and Its ApplicationsGasification and Its Applications. Oxford, U.K.: William . Oxford, U.K.: William Andrew/Elsevier, 2011, pages 139-142.Andrew/Elsevier, 2011, pages 139-142.