Fe2O3/β-SiC: A new high efficient catalyst for the selective oxidation of H2S into elemental sulfur

Over the last decades, sulfur recovery from the H₂S-containing acid gases (issued from oil refineries or natural gas plants) has become more and more important due to the ever increasing standards of efficiency required by environmental protection pressures. The H₂S-tail gas was directly oxidized by oxygen to yield elemental sulfur. A significant improvement of the H₂S conversion and selectivity has been developed, however, the support which is the core of the process still needs to be improved. Recently, β-SiC has been reported to be an efficient and selective catalyst support for the H₂S-to-S reaction. One expected reason for this superior yield should be due to the high thermal conductivity of the support. The high thermal conductivity of the silicon carbide plays an important role in the maintenance of the high selectivity by avoiding the formation of hot spots on the catalyst surface which could favor secondary reactions. On the other hand, insulator supports such as alumina exhibit a poor selectivity due to catalyst surface temperature runaway.