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.

Recent Solutions for Efficient Carbonyl Sulfide Hydrolysis: A Review

“…Shangguan et al studied the performances of a synthesized magnesium−aluminum spinel in the range 150−250 °C and compared the performances with a bare alumina. 61 They observed that, in general, the MgAl 2 O 4 catalyst resulted in better performances in any experimental condition, changing the temperature and the space velocity in the range of 2000− 12 000 h −1 . The greatest difference between the undoped alumina and the magnesium−aluminum spinel was observed in the stability, which was evaluated at 250 °C and 9000 h −1 for almost 30 h. The MgAl 2 O 4 catalyst showed a reduction in conversion from 99% to 97%, while γ-Al 2 O 3 was 100% active at the beginning of the test, but the COS conversion dropped to 87% at the end of the experiment.…”

“…Shangguan et al studied the performances of a synthesized magnesium–aluminum spinel in the range 150–250 °C and compared the performances with a bare alumina . They observed that, in general, the MgAl 2 O 4 catalyst resulted in better performances in any experimental condition, changing the temperature and the space velocity in the range of 2000–12 000 h –1 .…”

Design and Performance Evaluation of Integrating the Waste Heat Recovery System (WHRS) for a Silicon Arc Furnace with Plasma Gasification for Medical Waste

“…The scrubbed syngas needs to be reheated to ~250 °C in view of the efficiency of alumina-based catalysts used in COS hydrolysis [ 53 , 54 ]. The conversion of COS to H 2 S is an exothermic reaction, technically, but the passing of the syngas through COS hydrolysis can be regarded as an isothermal process in heat calculation due to the low concentration of COS.…”