Preparation And Performance Of Mesoporous Sorbents For Hot Coal Gas Desulfurization

In recent years, metal oxides as desulfurizer for hot coal gas desulfurization havebeen in depth studied. To solve these technical problems, such as sintering，lowutlization and pulverization, mesoporous metal oxides with large surface area wereprepared and the performance for hot coal gas desulfurization was investigated.A series of mesoporous Cu_xMn_y/SBA-15sorbents with different Cu/Mn atomicratios were prepared by wet impregnation method and their desulfurizationperformance in hot coal gas was investigated in the temperature range of700-850℃.The breakthrough sulfur capacity of Cu₁Mn₉/SBA-15observed at800°C is13.8gS/100g sorbents, which is remarkably higher than these of40wt%LaFeO3/SBA-15（4.8g S/100g sorbents） and50wt%LaFe₂O_x/MCM-41（5.58g S/100g sorbents） usedat500-550°C. This suggested that the loading of Mn₂O₃active species with highthermal stability to SBA-15support significantly increased sulfur capacity atrelatively higher sulfidation temperature. The successive ninedesulfurization-regeneration cycles at800°C revealed that Cu₁Mn₉/SBA-15presentedhigh performance with endurable regeneration ability due to the high dispersion ofMn₂O₃particles incorporated with a certain amount of copper oxides. The fresh andused Cu_xMn_y/SBA-15sorbents were characterized by means of BET, XRD, andHRTEM techniques, confirmed that the structure of the sorbents remained intactbefore and after hot coal gas desulfurization.To enhance the stability of sorbent during continuous desulfurization-regenerationcycles, KIT-6with3-D pore channels was applied as support for desulfurizers. Aseries of mesoporous La_xMn_y/KIT-6sorbents with different La/Mn atomic ratio werefabricated by wet impregnation method and their desulfurization properties for hotcoal gas desulfurization were investigated in the temperature range of700-850℃.La₃Mn₉₇/KIT-6performed the best at800℃with breakthrough sulfur capacity of11.56g sulfur/100g sorbent. The successive eight desulfurization （800℃）-regeneration （600℃） cycles revealed that La₃Mn₉₇/KIT-6performed well withendurable regeneration ability, which obtained80%of its initial sulfur capacity. Thefresh and used La_xMn_y/KIT-6sorbents were characterized by means of BET, XRD,HRTEM and H₂-TPR techniques. The XRD patterns and HRTEM images of fresh andused La₃Mn₉₇/KIT-6confirmed that the utilization of KIT-6suppressed the aggregation of Mn₂O₃particles effectively and improved the stability of sorbent.Some attempts were tried to fabricate mesoporous metal oxides by usingsoft-template method. The performance of sorbents was investigated and the sorbentwas characterized by means of BET and XRD techniques.