Conversion of natural gas to C2 hydrocarbons via cold plasma technology

The plasma technology served as a tool in unconventional catalysis has been used in natural gas conversion, because the traditional catalytic methane oxidative coupling reaction must be performed at high temperature on account of the stability of methane molecule. The focus of this research is to develop a process of converting methane to C-2 hydrocarbons with non-equilibrium plasma technology at room temperature and atmospheric pressure. It was found that methane conversion increased and the selectivity of C-2 hydrocarbons decreased with the voltage. The optimum input voltage range was 40-80 V corresponding to high yield of C-2 hydrocarbons. Methane conversion decreased and the selectivity of C-2 hydrocarbons increased with the inlet flow rate of methane. The proper methane flow rate was 20-40 ml/min (corresponding residence time 10-20 s). The experimental results show that methane conversion was 47% and the selectivity of C-2 hydrocarbons was 40% under the proper condition using atmospheric DBD cold plasma technology. It was found that the breakdown voltage of methane V-B was determined by the type of electrode and the discharge gap width in this glow discharge reactor. The breakdown voltage of methane V-B,(min) derived from the Paschen law equation was established.