SO2 Adsorption and Kinetics Analysis during Supported Triethanolamine Acetate Ionic Liquid Desulfurization

Ionic liquid desulfurization is an effective method for achieving green and circulating desulfurization. To overcome the negative impact of the high viscosity of ionic liquids on the desulfurization process, an economical and efficient supported ionic liquid-triethanolamine acetate ionic liquid/silica (TAIL/SiO2) was prepared in this study. TAIL is synthesized using triethanolamine and acetic acid and subsequently loaded onto silica gel particles. The effects of the reaction temperature, humidity, silica particle size, and loading ratio on SO2 adsorption are investigated using a fixed-bed reactor. The results indicate that the surface of the silica gel loaded with ionic liquid formed uneven spherical clusters, and the aggregate volume increased with an increase in the loading ratio. The TAIL/SiO2 sulfur capacity could be effectively increased by increasing the loading ratio (exceeding 0.74 is unfavorable), decreasing the silica particle size, and reducing the reaction temperature and moisture content. The maximum sulfur capacity can reach 124.98 mg SO2/(g TAIL/SiO2) under experimental conditions, which is higher than that of activated carbon. The Bangham rate model effectively predicts the kinetics of the adsorption process of SO2.