In order to clarify the possibility of safe utilization of insulation oil in which contained trace amounts of polychlorinated biphenyls (PCBs)- on the order of 250ppm or less-as fuel, laboratory experiments for evaluation of degradation conditions of PCBs were conducted. Oxidative pyrolysis using a flow reactor and premixed combustion of vaporized oil were performed, and products were analyzed quantitatively for PCBs, polychlorinated dibenzo-p-dioxines (PCDDs) and polychlorinated dibenzofurans (PCDFs).
Pyrolysis experiments at the conditions in which oxygen in excess revealed that the complete degradation of PCBs was attained at 973K or more. This temperature was slightly lower than the case of pure PCBs. At the condition of 923K or less, not a little PCBs were remained and PCDFs were also detected. In combustion experiments, PCBs, PCDDs and PCDFs were not detected at all experimental conditions. Because the hazardous products were not detected at the condition of short residence time after combustion, it is found that the degradation of PCBs were completed in the flame zone.
