A study of deactivation by H2S and regeneration of a Ni catalyst supported on Al2O3, during methanation of CO2. Effect of the promoters Co, Cr, Fe and Mo

Abstract

Energy storage from renewable sources is possible by chemical procedures, power to gas technology being a possible solution for long-term storage. In this work, CO₂ methanation from a sulphur containing gas was studied, taking into account deactivation of the catalysts and a regeneration process. In order to improve the sulphur resistance of a standard nickel (13%) catalyst supported on alumina, transition metals like molybdenum (Mo), iron (Fe), cobalt (Co) or chromium (Cr), in different proportions (from 4 to 8 wt%) were added to the catalyst formulation. The catalyst activity, between 573 and 773 K, at 10 bar, increased when transition metals were added except for Mo in the highest proportion. These bimetallic catalysts presented a similar deactivation resistance than the monometallic catalyst when sulphur was present in the feed. Once H₂S was removed from the feed, and the catalysts regenerated with oxygen, only the catalyst containing cobalt recovered up to a 13% methane yield.