CO2-assisted hydration of propylene oxide to produce propylene glycol: Accessing high selectivity using a jet loop reactor

Abstract

The synthesis of glycols from the CO2-assisted hydration of epoxides is highly significant in terms of both CO2 utilization and the production of fine chemicals. Significant effort has been devoted to designing effective catalysts. However, the gas–liquid mass transfer of this process, which is critical for the efficiency of the transformation, has received less attention. In this study, propylene glycol (PG) was synthesized with high efficiency through the CO2-assisted hydration of propylene oxide (PO) using a jet loop reactor (JLR). A systemic investigation of the influence of the reaction conditions was carried out with respect to reaction temperature, CO2 pressure, and catalyst concentration. Under optimal reaction conditions, the CO2-assisted hydration of PO proceeded efficiently with a low H2O:PO molar ratio of 1:1, producing PG with a high selectivity of 99% and full conversion of PO. Notably, the JLR exhibited higher efficiency and product selectivity than a stirred-tank reactor, demonstrating its superior advantage in facilitating gas–liquid mass transfer.

Keywords

• Epoxides
• 1
• 2-propylene glycol
• CO2-assisted hydration
• Jet loop reactor