“Hot Coal Gas” Desulfurization by Perovskite-type Sorbents

We have evaluated the performance of perovskite-based sorbents for hot coal gas desulfurization. These sorbents (LaMnO 3, LaCoO 3, LaFeO 3, and La 2 CuO 4 ) were tested in a fixed-bed reactor and characterized by X-ray diffraction studies and BET surface area measurements. The results indicate a high initial sulfur removal capacity for the perovskites (0.15−0.34 g of H 2 S/g of sorbent) but poor regenerability. The analysis of spent and regenerated sorbents has revealed complete segregation of the A-site and B-site elements following sulfidation in the case of LaMnO 3 and LaCoO 3 . No such segregation was observed in the case of LaFeO 3, while an intermediate behavior was exhibited by La 2 CuO 4 . The BET measurements indicate a substantial loss of surface area following the first cycle of sulfidation and regeneration, which is in part responsible for the poor performance of the sorbents in successive cycles.