REVERSE-BURN GASIFICATION FOR TREATMENT OF HAZARDOUS WASTES - CONTAMINATED SOIL, MIXED WASTES, AND SPENT ACTIVATED CARBON REGENERATION

A unique reverse-burn gasification process (the ChemChar process) employing secondary combustion of the product gases is described. The process has been applied to a variety of hazardous and nonhazardous wastes. Thermochemical destruction of these wastes is accomplished in a primarily reducing atmosphere induced by reactions of carbon, oxygen, and water. This paper describes the results from selected studies involving application of reverse-burn gasification to soil contaminated with polychlorinated biphenyls (PCBs), activated carbon regeneration, and mixed waste treatment. The process is especially useful in destroying hazardous wastes because of the unique characteristics of reverse-burn gasification, which is particularly effective for dehydrohalogenating organohalide compounds without producing undesirable byproducts, such as dioxins, in retaining acid gases, such as hydrogen chloride produced in the destruction of organohalides, and in retaining radionuclides during the destruction of the organic constituents of mixed waste. With second-stage combustion of the product gas, destruction/removal efficiency of greater than 99.9999% (''six nines'') is readily achieved.