Direct synthesis of glycidol from glycerol and propylene carbonate by vacuum reactive distillation (VRD) without any catalyst or solvent: Experiment study and process simulation

A new method for direct synthesis of glycidol from glycerol and propylene carbonate is reported that may be promising and economically valuable. In traditional reactors, under atmospheric pressure and without catalyst, the reaction between glycerol and propylene carbonate can only produce small amount of glycerol carbonate, but almost no glycidol is produced. Here, it is surprisingly found that under vacuum condition, glycidol can be obtained directly from glycerol and propylene carbonate by vacuum reaction distillation (VRD). Based on the above findings, the direct synthesis of glycidol from glycerol and propylene carbonate by VRD without any catalyst or solvent is investigated by the systematic experiment and process simulation. The experiment results indicate that at reflux ratio of about 1, molar ratio of propylene carbonate to glycerol of 2, bottom temperature of 190 °C, and column height of 400 mm, the glycerol conversion and glycidol yield can reach 98.9% and 61.5%, respectively. After purification, the mass fraction of glycidol in distillate can reach 98.9%. Furthermore, based on the study on reaction kinetics and residual curve analysis for the reaction system, the above VRD process is further simulated and optimized by using Aspen plus software and the optimized process flowsheet is obtained. Finally, a technical and economic analysis of the entire process is carried out.