关键词: 高温脱硫, 锰系脱硫剂, 共沉淀法

Abstract: High temperature desulfurization of coal gas is a key step of integrated gasification combined cycle (IGCC)and direct reduced iron (DRI)production,which directly influences the global thermal efficiency.Manganese-based sorbents with different Mn-contents were prepared by coprecipitation method for the high temperature sulfur removal.Precipitation was conducted by neutralizing the mixed solution of manganese nitrate and alumina nitrate with 10% NH₃·H₂O at 50℃.And the pH value in precipitation was kept around 9.The sorbents prepared were tested in a fixed-bed reactor by sulfidation-regeneration cycles.XRD,SEM and BET were used to characterise the structural change of the sorbents during the cycles.The sorbents made by coprecipitation method have good Mn/Al dispersibility.The desulfurization reaction at 850℃ was rapid and quantitative.The sulfur capacity increased linearly with increase of manganese content in the sorbents.The S/Mn atomic ratio was within 0.90—0.95 after sulfurization.The sulfur capacity was not influenced by space velocity and H₂S content in feed gas.The sulfided sorbent was regenerated using diluted air containing 3% O₂ at 850℃.The sulfur capacity was stable after many cycles.So,the sorbents could be used as regenerable sulfur sorbents for high temperature H₂S removal.

Key words: high temperature H₂S removal, manganese-based regenerable sorbents, coprecipitation