Effect of MnSO 4 on the Removal of SO 2 by Manganese-Modified Activated Coke

In this study, the effect of manganese sulfate (MnSO 4 ) on desulfurization capacity was investigated through carrying out consecutive desulfurization–regeneration cycles of MnO 2 -blended activated coke (Mn/AC). It was observed that MnSO 4 was produced on the surface of Mn/AC during the desulfurization process, and the amount of MnSO 4 accumulated on Mn/AC first increased significantly and then became relatively stable. In addition, the desulfurization results of MnSO 4 -impregnated Mn/AC indicate that Mn 2+ from MnSO 4 could form new liquid-phase catalysis, which existed with the solid-phase catalysis (blended MnO 2 ) simultaneously in the desulfurization system. However, an excessive amount of MnSO 4 over the surface of activated coke can block the access of SO 2 to the pore network, hampering the activity of the solid-phase catalyst and, consequently, resulting in a decrease of desulfurization capacity.