The Synthesis of Magnesium-aluminium Spinel for Catalytic Hydrolysis of Carbonyl Sulphur at the Middle Temperature

Abstract The influences of the physical and chemical properties for the catalyst materials on the hydrolysis catalytic activity of carbonyl sulphur (COS) and the anti-oxygen property will be crucial to removing COS from gas at moderate temperature. The magnesium-aluminium spinel for catalytic hydrolysis of COS was synthesized by the dry mixing of pseudo boehmite with MgO. The performances of the prepared catalyst were characterized by XRD, nitrogen isothermal adsorption (BET), CO2-TPD, and the COS hydrolysis activities were measured in fix-bed reactor with the change of space velocity, temperature, COS concentration and O2. The results showed that the MgAl2O4 synthesized by mixing of pseudo boehmite with MgO and then calcining at 873K is feasible. By comparison with γ-Al2O3 catalyst, the synthesized MgAl2O4 catalyst possesses more pore volume and diameter so as to improve the diffusion rate of reactant and product of COS hydrolysis. MgAl2O4 spinel catalyst showed the better catalytic activity of COS hydrolysis, combining the advantages of γ-Al2O3 and MgO. As a result, MgAl2O4 catalyst in itself not only helps to improve the catalytic activity of COS, but also helps to enhance the anti-oxygen poisoning property.