May 7 2008
Dominion today dedicated a new pollution-control system at its Chesterfield Power Station that will help continue Virginia's move toward cleaner air. The equipment, called a "scrubber," removes more than 95 percent of sulfur dioxide emissions and more than 90 percent of mercury emissions from the company's largest coal- fired generating unit.
"This scrubber demonstrates a thoughtful, economically attractive approach to cleaning Virginia's air," said Preston Bryant, Virginia Secretary of Natural Resources, who took a tour of the new scrubber today. "Potentially harmful material is captured by this scrubber and processed into a useful building product. That's an effective process."
The system -- formally known as "flue gas desulfurization" -- combines pulverized limestone with water and sprays the mixture into the exhaust gas. The mixture removes acid-rain-causing sulfur dioxide and toxic mercury from the flue gas.
The byproducts are gypsum, which can be turned into drywall, and water vapor, which billows out a tall stack as a white plume. The gypsum will be barged to a company in Norfolk, which will use it to manufacture drywall.
"This scrubber is the latest chapter in Dominion's long history of environmental stewardship," said Bob McKinley, vice president-Generation Construction for Dominion. "The new scrubber, along with equipment to reduce particulate emissions and a new chimney, will bring the total investment in air-emissions control equipment for Chesterfield to more than $650 million by the end of the year."
The Chesterfield Power Station is Dominion's largest fossil-fueled power station in Virginia. It has a generating capacity of 1,660 megawatts, or enough to power more than 400,000 homes at peak demand. The scrubber dedicated today is installed on the station's Unit 6, which generates 680 megawatts of electricity.
The water vapor plume from the new scrubber is visible from downtown Richmond's high-rise office buildings about 15 miles away.
Dominion plans to build scrubbers on the other three coal units at Chesterfield to be operational in 2011. Units 4, 5 and 6 are already equipped with selective catalytic reduction equipment, more commonly known as SCRs, which remove nitrogen oxide, a leading cause of ozone and unhealthy air. Dominion is extending the operation of the SCRs from the five-month summer ozone season (May-September) to year-round operation beginning in 2009.
Chesterfield's other two generating units are fueled by natural gas.
By 2015, Dominion will have spent $2.6 billion on environmental projects at power stations generating electricity for Virginia. The result will be an 86 percent reduction in mercury, an 80 percent reduction in sulfur dioxide and a 74 percent reduction in nitrogen oxide from 1998 levels.