AbstractThe influence of pressure up to 5600 kPa and temperature up to 175 °C on the oxidation of low concentrations of H2S in natural gas was studied in a fixed bed reactor over an activated carbon catalyst. Operation of this system at 5600 kPa provides higher catalyst activity (virtually 100% H2S conversion) over a longer period of time and with lower selectivity to SO2than when operated at atmospheric pressure. The desorption of sulfur from a loaded catalyst occurs first from the macropores (>100 nm) of the catalyst which contain a substantial portion of the sulfur load and then from the micropores (<100 nm). This study also indicated that the sulfur recovery process is both rapid and effective at 327°