USA – plasma gasification converts waste to energy in Minnesota

The Minnesota state legislature recently awarded US$400,000 to Koochiching County in the north-central part of the state to fund a feasibility study for a potential facility that would convert municipal solid waste (MSW) into energy.



Biomass magazine reports that the plant, which would be located near International Falls, would use plasma torches to gasify MSW. These torches house electrodes, and when a continuous flow of electricity is applied, an arc forms between them. The air in the torch pushes this extremely hot artificial bolt of lightning into a furnace, where the MSW enters.



The temperatures generated by this process, which can be hotter than the surface of the sun, rip apart compounds and convert inorganic solids into a glassy obsidian-like rock that can be used in road construction. The process also transforms organic materials into syngas that can be used to make electricity and liquid fuels.



"Plasma gasification could revolutionize the whole field of waste management," said Lou Circeo, director of plasma research at Georgia Tech Research Institute. He is considered a pioneer in plasma gasification, and part of the Minnesota feasibility study will involve sending waste samples to the institute in order to test the plasma gasification process. The process has been successfully used to eliminate MSW in two facilities in Japan. Similarly, the first phase of a facility in St. Lucie, Fla.-expected to come on line in 2009-will process up to 3,000 tons of waste per day.