Cerium–manganese mixed oxides for high temperature H2S removal and activity comparisons with V–Mn, Zn–Mn, Fe–Mn sorbents

High temperature H2S sorption activities of cerium–manganese mixed oxide sorbents containing different molar ratios of Ce/Mn and pure CeO2, prepared by the complexation technique, were investigated in a fixed bed flow reactor. Sulfur retention capacity and the H2S sorption rate of CeO2 were significantly enhanced by the incorporation of Mn into the sorbent. Cerium–manganese mixed oxide having a Ce/Mn ratio of 1/3 showed very high sorption rate. Another advantageous feature of this sorbent was its excellent regeneration properties. No deactivation of this sorbent was observed after 10 successive sulfidation–regeneration cycles. Also about 90% of the retained sulfur was converted to elemental sulfur instead of SO2, during regeneration step. The H2S sorption rate constant observed at 600 °C with the Ce1–Mn3 mixed oxide sorbent was also found to be much higher than the corresponding values for Zn–Mn, V–Mn and Fe–Mn mixed oxide sorbents prepared in this study.