A biofuels developer is building a plant in Westmoreland County to demonstrate a process for producing ethanol from biomass and waste products.

Executives from Coskata, based in Warrenville, Ill., are joining Gov. Ed Rendell; Sen. Robert P. Casey Jr., D-Pa.; and Rep. Tim Murphy, R-Upper St. Clair, at the David L. Lawrence Convention Center this morning to announce the $25 million project in Madison.

The plant, which will be on the grounds of the Westinghouse Plasma Center, will employ about 20 to produce ethanol from a variety of materials, including municipal waste, more cheaply and efficiently than producing it from corn, said Bill Roe, Coskata's president and chief executive officer, in an interview with the Post-Gazette.

"It's not necessary for us to remove food from the food chain," he said.

The plant will employ the Plasma Center's gasifier to superheat raw materials at temperatures up to 1700 degrees Fahrenheit, then release the resulting synthetic gas, or "syngas," into a bioreactor, where it will become food for microorganisms that convert it into ethanol.

Coskata expects to produce 40,000 gallons of ethanol annually at the facility. General Motors, which has an equity stake in Coskata, will use the fuel for testing its growing line of flex-fuel vehicles. Those vehicles are built to run on E85, a blend of 85 percent ethanol and 15 percent gasoline, as well as regular unleaded.

The demonstration plant, expected to be fully operational in a year, will pave the way for construction of full-scale plants that can produce 40 million to 400 million gallons of ethanol annually, Mr. Roe said. Those plants are expected to employ 100 to 150 workers each. Sites have yet to be selected for those facilities.

Mr. Roe said Coskata's process will produce 100 gallons of ethanol from a ton of feedstock, compared with 67 gallons produced from the same amount of corn, and that the fuel will cost less than $1 a gallon to produce.

GM spokesman Alan Adler said the company partnered with Coskata because "when there's a disruption in the supply of fuel … it changes the way people use their vehicles.

"Ethanol is the only play we can make in the near term that will make a difference."