CO selective methanation in H2-rich gas for fuel cell application: Microchannel reactor performance with Ru-based catalysts

Abstract

The present paper deals with the study on complete removal of CO in H2-rich gas stream through CO-SMET over Ru-based catalysts supported on γ-Al2O3 and CeO2 carriers. All the catalysts, loaded with 3% Ru, were prepared by a conventional impregnation method and their CO removal performance was determined at the powder level in a fixed bed micro reactor. The 3% Ru–γAl2O3 catalyst showed the best performance; consequently, it was deposited on microchannel metal plates reactor. With a catalyst load on the microchannel plates of 5mgcm−2 the performance was poor as complete CO conversion was not reached and also CO2 methanation was present. Increasing Ru load to 5%, the performance further worsened, the CO conversion decreased and higher amount of methane was produced.The catalytic activity on microchannel metal plates reactor was improved with the 3% Ru–γAl2O3 catalyst by doubling the its load on the surface (10mgcm−2): the residual CO concentration decreased to about 100–150ppmv at 310°C, but a large amount of methane was formed also by the CO2 methanation, thus reducing catalyst selectivity.