INDIANA PLANT `DESULFURIZES' COAL POLLUTION

Under the 1990 Clean Air Act Amendments, 110 of the nation's dirtiest power plants must cut their emissions by 1995 to 2.5 pounds of sulfur dioxide per million British thermal units of energy generated.

Last week, with the dedication of a "flue gas desulfurization" system in Gary, Ind., the Northern Indiana Public Service Company became the first of those 110 utilities to meet the 1995 standard, according to Pure Air, the company contracted to install and operate the system.

The desulfurization technology will allow the plant to continue to use high-sulfur coal mined in Illinois and Indiana; 95 percent of the sulfur dioxide is expected to be captured. The process uses wet limestone to absorb the pollutant and oxidize it to form gypsum.

US Gypsum, an East Chicago company, will buy the gypsum and use it to make wallboard.

Although many utilities may meet the new standards by switching to low-sulfur coal, Robert Conley, president of Pure Air, says he hopes the Allentown, Pa., company can win contracts with more utilities.

"We're convinced that it's a cost-effective product," he says. The Gary system was funded by a $150-million cooperative agreement between Pure Air and the US Department of Energy, which provided $63 million through its "clean-coal" program. The Indiana utility will pay a monthly fee to Pure Air to run the system.

Mr. Conley says that in future contracts, Pure Air would try to get more revenue by selling "pollution permits," as provided for in the new clean-air rules. Utilities that beat the pollution standards can sell emissions permits to other plants.