Every year 130 million tons of America’s trash ends up in landfills. Together the dumps emit more of the greenhouse gas methane than any other human-related source. But thanks to plasma technology, one city’s rotting rubbish will soon release far less methane—and provide power for 50,000 homes—because of an innovation in plasma technology backed by Atlanta-based Geoplasma.
Engineers have developed an efficient torch for blasting garbage with a stream of
superheated gas, known as plasma. When trash is dropped into a chamber and heated
to 10,000 degrees Fahrenheit, its organic components—food, fluids, paper—vaporize into a hot, pressurized gas, which turns a turbine to generate electricity. Steam, a by-product, can generate more. Inorganic refuse such as metals condense at the bottom and can be used in roadbeds and heavy construction.
Several small plasma plants exist around the world for industrial processes, but Geoplasma is constructing the first U.S. plasma refuse plant in St. Lucie County, Florida. The plant is scheduled to go online by 2011; it will process 1,500 tons of garbage a day, sending 60 megawatts of electricity to the power grid (after using some to power itself).
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Emissions are far lower than in standard incineration, and the process reduces landfill volume and methane release. Power prices are projected to be on par with electricity from natural gas. The difference, says Ron Roberts, St. Lucie County’s assistant director of solid waste, is that “you’re getting rid of a problem and making it a positive.”
Note: This article was originally printed with the title, "Florida's Garbage Vaporized".