REMOVAL OF H2S FROM FUEL GASES AT HIGH-TEMPERATURES USING MNO/GAMMA-AL2O3

High temperature desulfurization of gases from coal gasification processes has important aspects for many industrial applications and electrical power generation plants. MnO, supported by gamma-Al2O3 (MnO/gamma-Al2O3), was used as a regenerable sorbent for high temperature removal of H2S from gases. The sorbent was prepared by wet impregnation and tested for successive sulfidation-regeneration cycles. Sulfidation was carried out at 600 degrees C with an N-2/H-2/H2S mixture containing 1.41-4.48% H2S. Regeneration of the sorbent was performed with both N-2/H-2 and N-2/H-2/steam mixtures at the same temperature. The sorbent can be completely regenerated with a gas-steam mixture, while only 25-20% of the sulfur can be removed by physical (N-2/H-2) regeneration. The breakthrough and total capacities of the sorbent were found to be affected by the flow rate and the H2S concentration of the gas. Consumption of steam for regeneration increased slowly until 60-70% of the regeneration was completed, and then rose rapidly. The manganese conversion ranged from 15-19% at the breakthrough point, to 32-35% at the end of sulfidation (acceptation).