Manganese-based regenerable sorbents for high temperature H2S removal

A series of sorbents with different manganese contents have been prepared by co-precipitation method for 850 °C regenerative H2S removal. The sulfur capacity increased linearly with the increase of manganese content. The performance of sorbents prepared by co-precipitation of Mn nitrate and Al nitrate appears to be stable over five sulfidation–regeneration cycles. Al2O3 plays an important role in the performance of sorbents and the recovery of elemental sulfur in O2 regeneration. With increasing Mn content in the sorbent, increasing O2 concentration in the regeneration gas or increasing total regeneration gas flow rate, the recovery of elemental sulfur decreased. Elemental sulfur is the only product with SO2 regeneration. The sorbents cannot be completely regenerated with SO2 under the conditions used. The sorbents, however, can be completely regenerated by steam. The main product for steam regeneration is H2S. Steam regeneration results in less sintering than O2 regeneration.