Have you ever seen a garbage landfill? We have one 5 km from here, at the periphery of our town (about 200,000 inhabitants). It’s huge and incredibly smelly. It really stinks! And let’s not talk about the gaseous mess it does by producing methane and releasing it into the atmosphere.
In America, about 130 million tons end up in landfills. If a town of 200,000 people produces so much trash, imagine Los Angeles, San Francisco, or New York.
Plasma technology is being used to heat large amounts of trash to about 10,000 degrees Fahrenheit, and thus create a very hot, pressurized gas, spinning a turbine to generate electricity. It also creates steam, that is also being used to this. Metals condense and the bottom and can be recycled.
Unlike incinerators, which use combustion to break down garbage, there is no burning, or oxidation, in this process. The heat from plasma converters causes pyrolysis, a process in which organic matter breaks down and decomposes. Plasma torches can operate in airtight vessels. Combustion requires oxidization; pyrolysis does not.
The first US-based plasma station is being built in St. Lucie County, Florida. They plan to go online by 2011, being able to process 1,500 tons of garbage daily, and producing 60 megawatts of electricity for the grid.
The emissions generated from this plant are far lower than in standard incineration. The process will reduce the landfill volume and the release of methane gas, one of the most active in greenhouse effects. The price of the electricity generated this way is comparable to that of the electricity generated by using 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.”
[thanks to cleantechnica]