Regeneration of zinc titanate H2S sorbents

Zinc titanate is one of the leading regenerable sorbent candidates for high-temperature hydrogen sulfide (H2S) removal from coal gasifier gas. Temperatures in excess of 625 degrees C are required for regeneration of sulfided zinc titanate using air. However, hot-gas desulfurization processes require initiation of regeneration at temperatures below 550 degrees C. Modified zinc titanate sorbents were prepared by coprecipitation with Cu, Ni, Co, Fe, and Mo at levels up to 10 wt % to reduce the regeneration temperature. The maximum reduction in regeneration temperature was achieved for a zinc titanate sorbent with 5 wt % Co and 5 wt % Ni, which could be regenerated at temperatures as low as 475 degrees C.