Reducing mercury emissions
24 Jul 2002
ADA Environmental Solutions and PG&E Corporation's National Energy Group (NEG) have begun a field test for controlling mercury emissions at the Brayton Point Station in Somerset, MA.
The US Department of Energy (DOE) proposed the joint government-business funded project to offer coal power plant operators better ways to reduce these emissions at much lower costs. The goal is to develop a cost-effective technology that will allow the industry to reduce annual mercury emissions from power plants by 50 to 70% of current levels.
PG&E NEG volunteered and was selected by the DOE's National Energy Technology Laboratory to participate in the initial phase of the Department's advanced mercury control technology field-testing program. This is part of a larger DOE effort to develop and test low-cost mercury controls for the US's fleet of coal-fired electric utility boilers.
Brayton Point Station was selected as a test site because its low-sulphur, eastern bituminous coal, and existing particulate matter control devices are representative of a large number of plants across the US. The test results will provide information on the potential use of this mercury-specific technology at other power plants.
The technology consists of injecting mercury-adsorbing sorbents into the flue gas upstream of the particulate matter control device called an electrostatic precipitator (ESP). The gas phase mercury contacts the sorbent, attaches to its surface and is collected in the precipitator.
During 2001, ADA-ES conducted two other field tests at power plants operated by Alabama Power, a subsidiary of Southern Company, and Wisconsin Energy Corporation. Each plant represents a different mixture of coal types, plant equipment, and operating conditions.
The DOE is funding two-thirds of the overall $6.8 million test program.
PG&E NEG also volunteered for its Salem, MA coal plant to participate in the test this autumn. In 2000, company plants in Massachusetts, Pennsylvania and New Jersey were chosen to participate in EPA's Mercury Information Collection Request program, a national, full scale test program designed to gather detailed information on mercury emissions from coal-fired power plants.
