On Vitrifying Wastes Using a Plasma Arc Torch

This study reviews the state of the art regarding plasma arc torch vitrification of waste. It provides background by describing the history and environmental benefits of vitrification and the history and design of plasma arc torches. It reviews current uses of a plasma torch to heat ex-situ furnaces, and develops a case study showing how such a furnace could be used by the Army to pyrolyze scrap tires. This pyrolysis process would benefit the Army by providing an additional source of revenue and ensuring an environmental solution to the destruction of the 16 million scrap tires the Army collects each year. An immediate research product is a computer model, which allows in-situ heat transfer to be investigated. These model results provide important constraints on in-situ applications of plasma arc technology. Finally, laboratory scale experiments and associated analytical work allowed direct study of in-situ vitrification using a plasma arc torch. These research results fill gaps in theoretical knowledge and inform general understanding of the thermal and geochemical changes caused by vitrification. The United States Army is actively seeking innovative and effective methods of treating the wastes associated with producing and using the technology todays Army requires. Plasma arc torch vitrification offers one potential solution. Before the Army can adapt this solution to its requirements, significant research directed at understanding the vitrification process must still be accomplished.