From
https://en.wikipedia.org/wiki/Plasma_gasification:
Plasma gasification is a process which converts organic matter into synthetic gas, electricity, and slag using plasma. A plasma torch powered by an electric arc, is used to ionize gas and catalyze organic matter into synthetic gas and solid waste (slag). It is used commercially as a form of waste treatment and has been tested for the gasification of biomass and solid hydrocarbons, such as coal, oil sands, and oil shale.
From
https://www.wired.com/2012/01/ff_trashblaster/:
There is, in fact, value in trash—if you can unlock it. That’s what this facility in northern Oregon is designed to do. Run by a startup called S4 Energy Solutions, it’s the first commercial plant in the US to use plasma gasification to convert municipal household garbage into gas products like hydrogen and carbon monoxide, which can in turn be burned as fuel or sold to industry for other applications. (Hydrogen, for example, is used to make ammonia and fertilizers.)
From
http://www.explainthatstuff.com/plasma-arc-recycling.html:
The plasma arc in a waste plant heats the waste to temperatures anywhere from about 1000–15,000°C (1800–27,000°F), but typically in the middle of that range, melting the waste and then turning it into vapor. Simple organic (carbon-based) materials cool back down into relatively clean gases; metals and other inorganic wastes fuse together and cool back into solids. In theory, you end up with two products: syngas (an energy-rich mixture of carbon monoxide and hydrogen) and a kind of rocky solid waste not unlike chunks of broken glass. The syngas can be piped away and burned to make energy (some of which can be used to fuel the plasma arc equipment), while the "vitrified" (glass-like) rocky solid can be used as aggregate (for roadbuilding and other construction). In practice, the syngas may be contaminated with toxic gases such as dioxins that have to be scrubbed out and disposed of somehow, while the rocky solid may also contain some contaminated material.