Continuous flow synthesis of propylene carbonate using DBU-based ionic liquid in a packed bed reactor

Self-synthesis of green and high-efficiency DBU-based ionic liquid catalyst immobilized on SBA-15, conversion of CO2 into PC through the use of packed bed reactors. Tableting and changing the type of filler were adopted to tune the padding pattern of the catalyst in the reactor and improve the flow channel status. The effect of reaction temperature (45 ℃-90 ℃), operating pressure (1 MPa–4 MPa), CO2 flow rate (5 mL/min-100 mL/min), reaction time (2 h–8 h) on the yield of continuous flow synthesis of PC was investigated, and the catalyst activity also was evaluated by continuous use for 30 h. The intimate and direct contact of binary fluids leads to enhanced mass transfer and promoted reactions. Screen the optimal process conditions were 90 °C, 2 MPa, PO flow rate 0.1 mL/min, CO2 flow rate 5 mL/min, after continuous reaction for 2 h, the yield of PC could be achieved the highest, 57.10 %. Compared with the conventional batch reactor, the substrate was consumed immediately in the continuous reaction, and the product was generated in situ, and the reaction was safe and efficient, which provides guidance for industrial scale-up.