CFC-11 destruction by microwave torch generated atmospheric-pressure nitrogen discharge

A novel plasma method and its application for destruction of Freons using a moderate-power (several hundred watts) microwave torch discharge (MTD) in atmospheric-pressure flowing nitrogen are presented. The capability of the MTD to decompose Freons is demonstrated using a chlorofluorocarbon CCl3F (Freon CFC-11) as an example. The gas flow rate and microwave power (2.45 GHz) delivered to the MTD were 1-3 litre min(-1) and 200-400 W, respectively. Concentration of the CFC-11 in the nitrogen was up to 50%. The results show that the decomposition efficiency of CFC-11 is up to 100% with the removal rate of several hundred h(-1) and energy efficiency of about 1 kg kWh(-1). This impressive performance, superior to that of other methods, is achieved without generating any significant unwanted by-products. As a result of this investigation, a relatively low-cost prototype system for Freon destruction based on a moderate-power MTD and a scrubber is proposed.