Using By-Products Generated From Coal-Fired Power Plants
Eleven organizations, from energy companies to universities to a big box store, received awards from the U.S. Environmental Protection Agency for their achievements in using the by-products generated from burning coal in coal-fired power plants. The organizations are part of EPA's Coal Combustion Products Partnership. In addition, three individuals received recognition for their leadership in increasing the amount of coal combustion products recycled and used. EPA also welcomed the Department of Agriculture as a sponsor of the Coal Combustion Products Partnership (C2P2). Other sponsors include the American Coal Ash Association, the Utility Solid Waste Activities Group, the Federal Highway Administration, and the Department of Energy, as well as EPA.
The Coal Combustion Products Partnership is a voluntary partnership, with more than 150 private and public partners working to increase the beneficial use of coal ash. Currently, there is a 40 percent recycling rate for coal combustion products. Using these by-products safely preserves our natural resources, conserves energy, saves money, and promotes environmental sustainability.
Information on the award winners:http://www.epa.gov/c2p2/news/awards.htm
Information on the Coal Combustion Products Partnership: http://www.epa.gov/c2p2
EPA Examines New Coal Technology
EPA has released a new report that shows how Integrated Gasification Combined Cycle (IGCC) can help provide electricity from coal in an environmentally sustainable way. IGCC partially burns coal to generate gas. EPA examined the environmental impacts of IGCC technology as part of the agency's continued efforts to understand how the latest available science and technology could lead to a cleaner method to generate power from coal. The technical report found that IGCC can lower air emissions, lower water usage and produce less solid waste. The technical report also found that IGCC has the potential to provide a more cost effective approach to capture carbon dioxide, a greenhouse gas, produced during coal combustion. More than 50 percent of electricity in the United States is generated from the burning of coal. Only two coal fired power plants in the country currently use IGCC technology; however, several companies have announced plans to build and operate additional IGCC facilities. On the web: http://www.epa.gov/airmarkets/articles/control.html
Contact: John Millett, (202) 564-4355
Mountaintop Removal Ruling
On July 8, 2004, a federal court in Charleston, West Virginia, struck down a recently-issued Army Corps of Engineers permit -- Nationwide Permit 21 (NWP 21) -- that gave blanket pre-clearance for mountaintop removal mining. The court ruled that the Clean Water Act does not allow the Corps to issue short-cut permits for burying streams -- including prime trout streams -- under tons of spoilage from mountaintop removal mining.
Mining companies will now have to obtain individual permits and the Corps will have to acknowledge, carefully analyze, and rigorously apply the existing scientific studies about the effects of mountaintop removal. The decision probably means that the Corps will have to rewrite its draft environmental impact statement (EIS) on mountaintop mining, since the Corps relied heavily on the availability of NWP 21 when it issued the EIS in 2003. The Corps will have change its entire approach for permits to fill streams and will have to devote more resources to protecting streams.
Integrated Gasification Combined Cycle (IGCC)
If coal is to survive as a viable technology in a global warming world, it will probably be through the development of Integrated Gasification Combined Cycle (IGCC) electric power plants. AEP is planning to build the first commercial-scale plant.
Coal gasification takes place in the presence of a controlled 'shortage' of air/oxygen, thus maintaining reducing conditions. The process is carried out in an enclosed pressurized reactor, and the product is a mixture of CO + H2 (called synthesis gas, syngas or fuel gas). The product gas is cleaned and then burned with either oxygen or air, generating combustion products at high temperature and pressure. The sulphur present mainly forms H2S but there is also a little COS. The H2S can be more readily removed than SO2. Although no NOx is formed during gasification, some is formed when the fuel gas or syngas is subsequently burned.
IGCC uses a combined cycle format with a gas turbine driven by the combusted syngas, while the exhaust gases are heat exchanged with water/steam to generate superheated steam to drive a steam turbine. Using IGCC, more of the power comes from the gas turbine. Typically 60-70% of the power comes from the gas turbine with IGCC, compared with about 20% using PFBC.
Three gasifier formats are possible, with fixed beds (not normally used for power generation), fluidized beds and entrained flow. Fixed bed units use only lump coal, fluidized bed units a feed of 3-6 mm size, and entrained flow gasifiers use a pulverised feed, similar to that used in PCC.
IGCC plants can be configured to facilitate C02 capture. The new gas is quenched and cleaned. The syngas is 'shifted' using steam to convert C0 to C02, which is then separated for possible long-term sequestration.