Production of methane from carbon monoxide and carbon dioxide in a plasma-catalytic combined reactor system

Abstract

Plasma-catalytic hydrogenation of CO and CO 2 for producing methane was investigated with a catalyst-packed dielectric barrier discharge reactor. The characteristics of methane production from CO/H 2 or CO 2 /H 2 gas mixture were examined with bare alumina, TiO 2 /alumina, Ni/alumina, and Ni-TiO 2 /alumina under plasma and non-plasma conditions. The results obtained with bare alumina and TiO 2 /alumina suggest that either plasmainduced gas-phase reactions or photocatalytic reactions hardly contribute to the conversion of CO and CO 2 . The nonthermal plasma was found to have a promotive effect on the conversion of CO and CO 2 only when nickel-loaded catalysts such as Ni/alumina and Ni-TiO 2 /alumina were used, implying that the nonthermal plasma serves to promote the dissociation of carbon-oxygen bonds of CO and CO 2 adsorbed on the active sites of the catalysts, known as the slowest step of the reaction.