Honeycomb Structured Catalysts for H2 Production via H2S Oxidative Decomposition

Abstract

Cordierite honeycomb structured catalysts were studied for the reaction of H2S decomposition in the presence of oxygen to obtain H2 and sulphur. An Al2O3-based washcoat was deposited on the honeycomb monolith by a dip-coating procedure. In particular, three different washcoat percentages (15, 20 and 30 wt%) were deposited on the structured carrier and the obtained samples were characterized by N2 adsorption and SEM analysis. The evaluation of the catalytic performance of the three samples was carried out at two different temperatures (1000 °C and 1100 °C). The sample with 30 wt% washcoat content showed the lowest SO2 selectivity at 1000 °C (<0.4%), whereas the H2S conversion and H2 yield values were very similar to those achieved for the samples at 15 and 20 wt% washcoat loading. Based on these results, additional tests were carried out on the catalyst with 30 wt% Al2O3-based washcoat loading, varying the contact time and the H2S inlet concentration to identify the operating conditions that minimize the SO2 formation, obtaining good H2S conversion and H2 yield. The comparison of the structured catalyst with the powder alumina sample has shown the same catalytic performance, exhibiting lower SO2 selectivity.