Air Pollution Control Equipment Services, Coal, Emissions

Conemaugh Station adds scrubbers to comply with CAAA mandates

Issue 3 and Volume 99.

Conemaugh Station adds scrubbers to comply with CAAA mandates

Conemaugh Electric Generating Station Unit 1 is on line with a new flue gas desulfurization (FGD) system that is reducing the unit?s SO2 emissions by approximately 95 percent. The FGD went into service on Dec. 15, 1994, and a scrubber for Unit 2 should be complete this fall. Both scrubbers will cost approximately $341 million. The two-scrubber project will enable the 1,700-MW plant to meet the acid rain requirements of the Clean Air Act Amendments (CAAA) of 1990. Conemaugh Station, operated by Penelec, is one of the first power plants in the country to be modified with scrubbers to meet all mandates of the CAAA, according to John Gritzer, station director. Cost of the scrubbers will be divided among the station?s nine owners and customer bills will not be affected, he said.

The scrubbing process begins with a limestone slurry that is sprayed through the hot exhaust gases in an absorber tower. SO2 in the exhaust gas is absorbed into the slurry, resulting in a byproduct that is collected in an igloo-shaped building adjacent to the scrubber unit. The byproduct can be used to produce commercial-grade gypsum or can be safely disposed of in a landfill. The scrubber brings economic benefits to the region as it will allow the station to continue burning coal from the Pennsylvania market, rather than switching to lower-sulfur coal from other areas.