The Mobil Oil SOx treatment process (MOST). Catalytic removal of SOx and H2S from refinery tailgas

Growing concerns about the environmental impact of sulfur emissions from st ationary sources, as well as recent regulatory initiatives, have prompted i nvestigations for advanced sulfur reduction strategies. Herein, we present a novel process/catalyst combination for reducing tailgas SOx and H2S emiss ions to very low levels (1-5 ppmw). The Mobil Oil SOx Treatment Process (MO ST) consists of the following steps: (1) combustion of tailgas sulfur speci es to convert all sulfur species to SO2/SO3; (2) adsorption of SOx onto a h igh-capacity sorbent; and (3) in a separate step, reductive desorption of t he sulfur as a concentrated stream of mainly SO2 and H2S. The MOST Process utilizes a regenerable promoted spinel-based sorbent with very high SOx upt ake capacities (>50 wt%), and is both, robust and operationally simple. Cat alyst selection, process scoping studies, and characterization to help unde rstand the nature of the oxidative sorption and reductive regeneration step s, as well as the state of the sorbent during these steps, are described. ( C)2000 Elsevier Science B.V. All rights reserved.