Vitrification

Vitrification is the process by which minerals are melted into glass. After the feedstock is dried to 10 percent moisture content, it is heated in a furnace at very high temperatures, around 2800 degrees Fahrenheit, to destroy harmful organic compounds and trap trace metals in the resulting liquid mixture. This mixture is then quickly cooled to form a solid sheet of glass that is crushed into aggregates of various size, dependent upon the intended use. The organic compounds that are burned off can be captured and become a significant part of the fuel needed to run the system, thus making it nearly self-sustaining. Feedstocks that are high in ash content, such as paper mill residues, require supplemental heating to vitrify the ash but this exothermic process still results in net energy production (Mauro 1996).

Vitrification plants have been operating in the United States since the early 1990s. Minergy, based in Wisconsin, even offers modular vitrifacation units that can be incorporated into existing biomass-fed processes.

Minergy Vitrification Process