Decomposition of fluorocarbon gaseous contaminants by surface discharge-induced plasma chemical processing

The decomposition performance of surface discharge induced plasma chemical processing (SPCP) with a cylindrical ceramic-based reactor for chlorofluorocarbon gases was measured in atmospheric air, pure oxygen gas, or pure nitrogen gas. In the case of decomposition test for 1000 p.p.m. CFC-22 in air, a maximum decomposition rate of about 90% was recorded. In the case of the decomposition test for 100 p.p.m. CFC-113, more than 99% fluorocarbon could be removed. The decomposition mechanism of fluorocarbon is not yet known exactly but is assumed to be due to the effect of the surface discharge plasma near the discharge electrode. The decomposition rate for fluorocarbon in nitrogen gas was the largest among three gases (air, nitrogen, and oxygen), indicating the strong activity of the nitrogen radicals. A large ceramic reactor was also tested, and the decomposition performance was found to be proportional to the real electric power consumption under best conditions. The reaction products after the SPCP are not yet identified, but phosgene and its derivatives have not yet been found