The University of South Carolina will install scrubbers on its new biomass steam- and electricity- generating plant to ensure it satisfies federal clean air rules -- and to address community concerns about air pollutants.
The $1.2 million modification to the original design will boost the cost to $18.2 million for the plant, which is under construction at Sumter and Whaley streets.
USC spokesman Russ McKinney said the plant received permits from the state Department of Health and Environmental Control without the scrubbers.
But neighborhood groups had urged the university to add the scrubbers. Meanwhile, the Environmental Protection Agency toughened its rules for particle emissions, McKinney said.
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Granby neighborhood leader Bob Guild said he is pleased with USC's decision to add the pollution controls.
"It's good news," he said. "This is a lesson in learning how to do it right."
Sometime next year, USC will fire up the generator. It is expected to slash polluting emissions from campus generators, save the university $2 million a year in fuel costs, and use fuels grown
in South Carolina rather than imported from elsewhere.
The biomass plant, in the most simplistic terms, is a giant wood heater. But its high-tech chambers will not directly burn the wood chips as they would in your grandmother's heater.
Instead, the chips will be "cooked," or heated, to just below the point of combustion. The heated material will give off combustible gases that will be siphoned away and burned in much the same way natural gas is burned.
The huge chambers in which the wood chips will cook are in place, and steel girders at the site are awaiting assembly into a 250- by-200-foot building. A 70-foot-tall stack will vent the plant.
The plant will recycle about 57,000 tons of wood chips into 60,000 pounds of steam per hour -- about 85 percent of USC's needs -- and 1.3 megawatts of electricity. By comparison, the V.C. Summer Nuclear Station, 22 miles north of Columbia, generates 900 megawatts of power.
South Carolina's forest products industry can produce 10 million to 20 million tons of wood chips a year for fuel.
USC's $18.2 million plant is the first of its kind in the United States. It is modeled on a facility in western Canada.
The woody residue from the biomass generators probably will be recycled into some type of composted fertilizer.
"It's modern, up-to-date stuff," said Richard Horton, program manager for sustainable energy at the S.C. Energy Office. "Direct combustion of wood chips would put a lot of ash into the air. In this process, the wood does not combust into a flame. The gas coming off is cleaner. You should not see or smell anything."
Staff writer Sammy Fretwell contributed to this story.