Effect of Ce modification on desulfurization performance of regenerated sorbent for high temperature H2S removal from coal gas

Ce modified Mn x O y /Al 2 O 3 -La have been prepared to investigate the effect of Ce loadings on pre-breakthrough H 2 S removal efficiency, breakthrough sulfur capacity (BSC) and BSC durability of the sorbents during desulfurization-regeneration cycles. The results showed Ce modification could improve the pre-breakthrough H 2 S removal efficiency of regenerated sorbents during desulfurization-regeneration cycles. The XPS characterization showed that the Ce can promote the binding energy of Mn ion to shift to lower energy, which enhanced H 2 S adsorption on the regenerated sorbent. However, the Ce loading sequence had effect on BSC durability of sorbent during desulfurization-regeneration cycles. The Ce-Mn x O y /Al 2 O 3 -La with co-impregnation of Mn and Ce oxides had higher BSC than Mn x O y /Al 2 O 3 -La, while the Ce/Mn x O y /Al 2 O 3 -La with Ce loading on the surface of Mn x O y /Al 2 O 3 -La had lower BSC and worse BSC durability than Mn x O y /Al 2 O 3 -La. The characterization results showed Ce-Mn x O y /Al 2 O 3 -La obtained better surface area and pore structure than Mn x O y /Al 2 O 3 -La, and Ce ion can promote the increasing of the around electron density of Mn ion, which was beneficial for H 2 S adsorption of Ce-Mn x O y /Al 2 O 3 -La. The poor surface area and pore structure would cause the low BSC of Ce/Mn x O y /Al 2 O 3 -La, and less stability of pore structure might lead to poorer BSC durability of Ce/Mn x O y /Al 2 O 3 -La than Mn x O y /Al 2 O 3 -La during desulfurization-regeneration cycles.