Davis considering plasma arc to zap waste

FARMINGTON — Some of the electricity you use could one day come from disintegrated garbage.

Imagine a plasma arc, basically a man-made lightning bolt, that converts solid waste that would normally go to a landfill into gases for generating electricity and an inert obsidian-like substance that could be an ingredient in asphalt.

Currently, the Wasatch Integrated Waste Management District's incinerator converts garbage into electricity, which powers the facility, and steam, which is sold to Hill Air Force Base.

At current rates, the Layton landfill, which accepts most of the waste from Davis County cities, will be full in 14 years. It would have already been closed if not for the nearby incinerator, which burns about half of the garbage that comes to Layton every day. Eventually, the 22-year-old incinerator will need to shut down.

On Tuesday, Davis County commissioners were presented with an option to extend the life of the landfill even further by using plasma-arc technology.

Engineering firm ISES associate vice president Roger Reich and business development vice president David Brown offered to perform a feasibility study for Davis County to see if plasma arcs would be a good fit for the county's solid waste. They said a formal proposal would be forthcoming.

Nathan Rich, the waste district's executive director, said the technology Reich and Brown propose is exciting, but he would really like to "kick the tires" on such a facility before embarking on building one in Davis County.

No such facility has been built in the United States, though some contracts are in place, and parts of Europe and Japan have used plasma arcs for waste management for 10 years.

Plasma torches, which use superheated gases to destroy waste, were first used in the dismantling of ships and engine blocks. Because the torches burn at 10,000 degrees, waste passing through them is disintegrated.

Reich said a 200-ton-per-day facility, which could generate 240 kilowatts of electricity, would cost about $140 million to build, but it would pay for itself in nine years. A 1,500-ton-per-day facility, which could generate 2.1 megawatts of electricity, would cost $450 million, with an eight-year payback.

Ottawa has built a 100-ton facility, and St. Lucie, Fla., is working on the first phase of a 3,000-ton plant.

Rich said Davis County has plenty of time to evaluate the technology as it's deployed in North America. Plasma arcs are still considered to be among a few emerging technologies that deal with turning waste into electricity, he said.

Various questions stick in Rich's mind: Where will tipping fees need to be set? How much electricity is needed to power the plasma arcs? How much revenue would the facility generate?

That's why Davis County needs time, he said, adding that he's a believer in waste-to-energy facilities, which decrease dependence on fossil fuels and cut down on greenhouse gases, such as methane, that are generated in landfills.

E-MAIL: jdougherty@desnews.com