Removal of H2S from fuel gases at high temperatures using MnO/γ-Al2O3

Abstract

Abstract High temperature desulfurization of gases from coal gasification processes has important aspects for many industrial applications and electrical power generation plants. MnO, supported by γ-Al 2 O 3 (MnO/γ-Al 2 O 3 ), was used as a regenerable sorbent for high temperature removal of H 2 S from gases. The sorbent was prepared by wet impregnation and tested for successive sulfidation-regeneration cycles. Sulfidation was carried out at 600°C with an N 2 /H 2 /H 2 S mixture containing 1.41–4.48% H 2 S. 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 H 2 S 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).