The destruction of halogenated organic chemicals by plasma pyrolysis

Abstract

Very high destruction efficiencies for halogenated chemicals have been achieved by plasma pyrolysis. Destruction efficiencies exceeded 99.9999999% for tests with polychlorinated biphenyls (PCBs). Preliminary tests with tetrachloromethane have obtained destruction efficiencies exceeding 99.99%. The plasma pyrolysis process involved the creation of a 250-kW plasma with a temperature in excess of 25 000 °C. The toxic material was injected into the plasma zone at a rate between 1 and 2 L/min. Thermochemical and photochemical dissociation of the toxic materials produced atoms and ions which recombined to form primarily H2, CO, HCl, and particulate carbon. The HCl was neutralized by NaOH. The flaring of the H2 and CO should destroy to a high degree any trace residuals. The application of plasma pyrolysis for the ultimate disposal of toxicological waste was also investigated. Rat carcasses containing mean lethal dosage of PCB were pyrolyzed.