May 14, 2008

Air Pollution

Controlling Mercury Emissions

Cost down, effectiveness up, Senate panel told

Cheryl Hogue

Technology to capture mercury from coal-fired power plants has grown more effective and less expensive in the past five years, experts said at a Senate hearing on May 13.

Those controls, involving mainly the injection of activated carbon into smoke stacks, can curb mercury emissions by some 90% at many power plants, experts in air pollution controls told the Senate Environment & Public Works Committee. A facility's configuration and the type of coal it burns influence the controls' efficiency, the experts noted.

Lisa P. Jackson, New Jersey commissioner of environmental protection, told the committee that activated carbon injection "has proven to be very low-cost" for coal-fired facilities, which must comply with a state regulation requiring them to cut mercury emissions by 90%. She added that the state also has an alternative standard of 3 mg of mercury per megawatt-hour for plants that already had lower emissions of the neurotoxic metal.

The testimony came as part of a hearing on S. 2643, a bill that would require an EPA regulation to cut mercury emissions from power plants by 90% from their current level. Earlier this year, a federal court threw out EPA's cap-and-trade rule on mercury that would have cut mercury emissions from power plants by 69% (C&EN, Feb. 18, page 6), but that could have created mercury hot spots around the country.

Chemical & Engineering News

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