Rising costs of energy and other commodities have silenced erstwhile critics of municipal collection of plastic, paper and glass for recycling. Critics of converting trash into energy may be the next to go, if developments in Ottawa are any guide. Last week Ottawa’s city council unanimously approved a proposal by local technology developer PlascoEnergy to build an innovative 400-m.t./day waste-to-energy facility within city limits. If built, it would be the first such plant in North America in over a decade.
PlascoEnergy CEO Rod Bryden says the plant’s technology is key to public acceptance. “There wasn’t a single person who attended the council meeting to object. There’s no chance that would happen with a landfill or an incinerator,” says Bryden.
Rather than simply tossing trash into a giant furnace, PlascoEnergy’s design employs superhot electric plasma torches to first gasify municipal waste. Gasification eases the subsequent removal of contaminants such as mercury and produces a clean-burning ‘synthesis gas’ amenable to combustion in high-efficiency engine generators; net power exports to the grid will be about 21 megawatts. At the same time the plant will cut the equivalent of 2.1 m.t. of CO2 for every tonne of waste, thanks largely to avoided methane emissions from Ottawa’s landfill.
More gasification-based waste treatment is on the way, and not just to generate electricity. In April General Motors-based cellulosic ethanol firm Coskata, which plans to make ethanol from syngas, announced plans to integrate its first demonstration plant with an existing waste gasification pilot plant in Pennsylvania.
For more on the trash gas trend, see “Garbage In, Megawatts Out” on MIT’s TechnologyReview.com.