LAUSR

Abstract CO 2 hydrogenation to methane (CO 2 methanation) is gaining increasing interest as a major chemical synthesis process for chemical storage of fluctuating renewable energy and producing synthetic natural gas by providing an effective process for biogas upgrading. In this study, a series of 12 and 20 wt% Ni/Al 2 O 3 catalysts, either unpromoted or promoted by 0.5 wt% Ru, were prepared by the incipient wetness method for the CO 2 methanation reaction from a feed of pure CO 2 or biogas. The catalysts were characterized by N 2 physisorption, XRD, TPR and H 2 chemisorption. The activity for the 12 wt% Ni catalyst increased continuously in the temperature range from 250 °C to 400 °C. Increasing the Ni loading and Ru promotion greatly improved the activity of the catalyst. At 350 °C, the highest CO 2 conversion of 82% and CH 4 selectivity of 100% was achieved over the 20Ni0.5Ru/Al 2 O 3 catalyst. Thereafter, methanation of a simulated biogas mixture was investigated over the 20Ni/Al 2 O 3 and 20Ni0.5Ru/Al 2 O 3 catalysts. The results showed that the CO 2 conversion and CH 4 selectivity were only mildly affected by the feed composition. Furthermore, the stability of the catalysts was similar regardless of the feed composition. This study demonstrates that high purity CH 4 can be achieved from a biogas feed over our Ni based catalysts.