Decomposition of Chlorinated Aromatics by Microwave-induced Ar Plasma Generated using SiC Ceramic Trigger under Atmospheric Pressure

Abstract

Decomposition behavior of chlorinated aromatics, such as monochlorobenzene, o-dichlorobenzene, and o- chlorophenol by microwave-induced (MI) Ar plasma generated from SiC ceramics has been investigated under atmospheric pressure, and was compared with that of benzene under the same decomposition conditions. Benzene was decomposed and oxidized almost completely by the MI Ar plasma in the Ar-based feed gas containing 3.0% O₂ and 0.46% H₂O with a maximum CO concentration of 22 ppm. Much larger quantities of CO tended to be produced by the decomposition of other chlorinated aromatics under the almost the same feed gas composition. However, co-addition of H₂O in the feed gas was useful for reducing the CO concentration for the decomposition of all the chlorinated aromatics. Therefore, H₂O was considered to act as a weak oxidant under the MI Ar plasma decomposition. In addition, it was revealed that an increase in the O₂ content to a level of 10% resulted in a decrease of CO concentration in the effluent gas and then promoted complete oxidation of all the chlorinated aromatics, whereas the minimum microwave power to generated MI Ar plasma tended to increase with the O₂ content.