Highly stable and regenerable Mn-based/SBA-15 sorbents for desulfurization of hot coal gas

Abstract

A series of mesoporous xCuyMn/SBA-15 sorbents with different Cu/Mn atomic ratios were prepared by wet impregnation method and their desulfurization performance in hot coal gas was investigated in a fixed-bed quartz reactor in the range of 700–850°C. The successive nine desulfurization–regeneration cycles at 800°C revealed that 1Cu9Mn/SBA-15 presented high performance with durable regeneration ability due to the high dispersion of Mn2O3 particles incorporated with a certain amount of copper oxides. The breakthrough sulfur capacity of 1Cu9Mn/SBA-15 observed 800°C is 13.8g S/100g sorbents, which is remarkably higher than these of 40wt%LaFeO3/SBA-15 (4.8g S/100g sorbents) and 50wt%LaFe2Ox/MCM-41 (5.58g S/100g sorbents) used only at 500–550°C. This suggested that the loading of Mn2O3 active species with high thermal stability to SBA-15 support significantly increased sulfur capacity at relatively higher sulfidation temperature. The fresh and used xCuyMn/SBA-15 sorbents were characterized by means of BET, XRD, XPS, XAES, TG/DSC and HRTEM techniques, confirmed that the structure of the sorbents remained intact before and after hot coal gas desulfurization.