CO2 decomposition using glow discharge plasmas

Carbon dioxide decomposition has been studied using ac glow discharge plasm as at atmospheric pressure. A tubular reactor with a metal rod inside a qua rtz tube was wrapped with aluminum foil. The reaction mixture was analyzed by using a mass spectrometer. No coke deposits or other side reactions were observed. A variety of parameters, such as different metals, CO2 concentra tions, flow rate of the CO2 containing gas, frequency, and power were inves tigated. The effects of these parameters on CO2 conversion, reaction rates, and energy efficiency were examined. The initial excitation voltage to pro duce the plasma is independent of the metal identity on the surface of the rod and the flow rate of CO2 containing gas, but dependent on the CO2 conce ntration and ac frequency used. The maximum energy efficiency was obtained with relatively high CO2 concentration, high flow rate of CO2 containing ga s, high frequency, as well as low input voltage at the expense of conversio n. (C) 1999 Academic Press.