David Robau tours the country promoting a system that sounds too good to be true: It devours municipal garbage, recycles metals, blasts toxic contaminants and produces electricity and usable byproducts — all with drastic reductions in emissions.

Mr. Robau, an environmental scientist for the Air Force, has been promoting a method that was developed with the Air Force to dispose of garbage with neither the harmful byproducts of conventional incineration nor the environmental impact of transporting and burying waste. It is one of several innovative techniques that the United States military has been researching to provide alternatives to the open-pit burns that some veterans of the Iraq and Afghanistan wars say have made them ill.

Already some waste companies and cities like New York have shown an interest in technology similar to what Mr. Robau has been promoting, known as plasma arc gasification. Proponents say the process can break chemical bonds and destroy medical waste, PCBs (polychlorinated biphenyls), asbestos and hydrocarbons, some of which can be hazardous if disposed of in landfills or traditional mass-burn incinerators.

Still, some environmentalists are leery. They say the ability to fully dispose of waste will discourage recycling and the development of renewable products, and the gasification will still result in toxic substances like dioxins.