The selective oxidation of H2S on V2O5/zeolite-X catalysts in an IGCC system

Zeolite-KX, which showed high activity for the selective oxidation of H2S under water-free condition, was deactivated by the strong adsorption of water vapor. Among the transition metal oxides tested for the selective oxidation of H2S in the presence of water vapor at 275 degrees C, V2O5 showed the highest conversion of H2S and selectivity of elemental sulfur. The conversion of H,S on V2O5 in the presence of water vapor at 200 degrees C was 75 %, 17 % lower than that under water-free conditions because of the degraded reduction Of V2O5. The degraded reduction of V2O5 could be alleviated by mechanically mixing with zeolite-NaX or KX. The conversion of H2S on V2O5 that had been mechanically mixed with zeolite-NaX or KX was about 85 %, which was 10 % higher than that on unmixed V2O5 under the same reaction conditions. The conversion could be maintained very well when using a coal-derived synthesis gas. It can be concluded that the selective oxidation of H2S can be applied to the hot gas cleanup in IGCC system.