Effect of H2S on carbon-catalyzed methane decomposition and CO2 reforming reactions

The effect of H2S on catalytic processing of methane is of a great practical importance. In this work, the effect of small quantities (0.5–1.0 vol.%) of H2S present in the feedstock on the methane decomposition and CO2 reforming reactions over carbon and metal based catalysts was investigated. Activated carbon (FY5), an in-house prepared alumina-supported Ni catalyst (NiA) and the mixture of both (FY5 + NiA) were used as catalysts in this study. It was found that CH4 and CO2 conversions were noticeably increased when H2S was added to the reacting mixture, which points to (i) the tolerance of carbon catalyst to H2S and (ii) the catalytic effect of H2S on carbon-catalyzed decomposition and dry reforming of methane. In contrast, NiA catalyst and the mixture FY5 + NiA were deactivated in the presence of H2S in both reactions. The effect of the heating system (i.e., conventional electric resistance vs microwave heating) on the products yield of the dry reforming reaction in the presence of H2S is also discussed in this paper.

► Effect of H2S on methane decomposition and CO2 reforming reactions is examined.
► Carbon catalyst exhibits tolerance to H2S in CH4 decomposition and dry reforming.
► H2S exerts catalytic effect on carbon-catalyzed CH4 and CO2 conversions.
► Ni/Al2O3 and its mixture with carbon catalyst are deactivated in H2S presence.
► H2S effect is similar in case of conventional and microwave heating conditions.