Catalytic conversion of CO2 by supported ionic liquid prepared with supercritical fluid deposition in a continuous fixed-bed reactor

Abstract

The capture and fixation of CO2 can effectively alleviate greenhouse effect. Propylene carbonate is a highly efficient solvent, which can be used as an excellent medium for lithium battery. It is of great significance to convert CO2 into propylene carbonate. In this paper, ionic liquid BMImBr was immobilized into the pores of SBA-15 by supercritical deposition, and BMImBr@SBA-15 was obtained for catalytic conversion of CO2. The catalytic properties of BMImBr and BMImBr@SBA-15 were investigated by batch method. Then the catalytic performance of supported catalyst BMImBr@SBA-15 was investigated by continuous method, which was carried out in a fixed-bed reactor. The continuous experiments controlled the CO2 pressure change (0.5–2.0 MPa) when the inlet liquid flow rate was 0.02 mL/min and 0.04 mL/min. Under the conditions of 0.04 mL/min and 1.0 MPa, the yield was the highest (66.14 %). In this paper, through the calculation of the reaction rate constant, it can be concluded that the continuous method can avoid the repeated packing of the catalyst and obtain a higher yield in a short time. It has a broad prospect of industrialization.