Decomposition of Dichlorodifluoromethane by Adding Hydrogen in a Cold Plasma System

Abstract

The destruction of chlorofluorocarbons (CFCs) has drawn great attention because of its well-known depletion of the ozone layer at the stratosphere. Application of RF plasma for the decomposition and conversion of dichlorodifluoromethane (CFC-12 or CCl2F2) is demonstrated. The decomposition efficiency (ηCFC-12) and the fraction of total carbon input converted into CH4 and C2H2 (FCH4+C2H2) in H2 and Ar mixtures have been investigated as a function of input power wattage, H2/CFC-12 ratio, operational pressure, and CFC-12 feeding concentration by using response surface methodology and model sensitivity analysis. The results showed that the ηCFC-12 is over 94% and the FCH4+C2H2 is over 80% under the condition of 100 W of input power wattage, 7.0 of H2/CFC-12 ratio, 15 Torr of operational pressure, and 7.6% of CFC-12 feeding concentration. In addition, the result of sensitivity analysis indicated that both the ηCFC-12 and the FCH4+C2H2 are more sensitive to CFC-12 feeding concentration and input power wattage. Experimental results showed that CFC-12 could be converted into CH4 and C2H2 up to 80% of conversion in a hydrogen-based RF plasma system.