Abstract
In Japan, there is a large amount of insulating oil that contains traces of polychlorinated biphenyls (PCBs) in transformers, capacitors and other electrical equipment, and these PCBs need to be destroyed appropriately and economically. In this study, we conducted experiments on destroying trace PCBs in oil through incineration in a small furnace at relatively low temperatures between 700 and 950 degrees Celsius in order to examine the possibility of destroying them at ordinary industrial waste incineration facilities.
As a result, we found that the presence of hydrocarbons affects the destruction of trace PCBs much more than the temperature or gas residence time in the furnace. Incinerating with hydrocarbons at a temperature of over 800 degrees Celsius and a residence time of over 2 seconds, traces of PCBs contained in oil can be destroyed with a very high destruction efficiency of over 99.9999%, reducing the concentration in the incineration gas to much lower than the threshold values for industrial hygiene and environmental air quality in Japan. From these results, we believe that traces of PCBs contained in oil can be adequately destroyed by incineration in ordinary industrial waste incineration facilities because a large amount of hydrocarbons surely coexist (in the form of oil) with the traces of PCBs.
