Chemical Engineering Journal, Vol.372, 638-647, 2019
NTP reactor for a single stage methane conversion to methanol: Influence of catalyst addition and effect of promoters
Partial oxidation of methane to methanol is one of the best routes for liquid oxygenates preparation. The present study describes the application of a non-thermal plasma reactor operated under dielectric barrier discharge mode with/without catalyst addition for a single stage methane conversion to methanol. Air has been chosen as the oxidant for methane partial oxidation. It is found that both the reactant conversion and product distribution are strongly dependent on the reactor configuration, feed gases composition and also catalyst addition. A series of gamma-Al2O3 supported Cu catalyst with metal oxide promoters (ZnO, ZrO2 and MgO) were integrated with plasma zone as to obtain in-plasma catalytic reactor. Typical results show that the synergistic effect due to plasma activation and catalytic action, significantly improves both CH4 conversion and CH3OH selectivity. The best methanol selectivity of similar to 28% is achieved over the CuZrAl catalyst with a CH4 conversion of similar to 11%, while plasma reactor provides only similar to 18% CH3OH selectivity. The possible reaction mechanism of methanol formation inside the plasma reactor has been discussed, which highlights that the catalyst facilitates the adsorption of plasma excited species and improves the performance of the reactor.