Conversion of Methane to Ethylene and Oxygen-free Hydrogen in a Plasma-catalytic Reactor

Conversion of methane to ethylene and oxygen-free hydrogen has been investigated in a plasma-catalytic reactor. In the absence of catalyst, dielectric barrier discharges(DBD), pulsed spark discharges (PSD), pulsed corona discharges (PCD) and stable kilohertz spark discharges(KSD) were compared for conversion of methane. The results showed that PSD and KSD exhibited distinct advantages over the PCD and DBD for methane conversion, and KSD gave the highest methane conversion and the lowest energy cost. Compared with one-stage reactor after introducing Pd-Ag/SiO(2) catalyst, the plasma-followed-by-catalyst (PFC) reactor was more effective for conversion of methane to ethylene and oxygen-free hydrogen. In PFC reactor with Pd-Ag/SiO(2) catalyst using KSD, about 80% methane conversion was achieved, and the concentrations of ethylene and hydrogen were as high as 17% and 62.6% respectively.