Heat-Integrated Pervaporation–Distillation Hybrid System for the Separation of Methyl Acetate–Methanol Azeotropes
Chuanxin Zong, Qingkai Guo, Bowen Shen, Xiaoquan Yang, Haoli Zhou, Wanqin Jin
Abstract
Pervaporation is typically considered an energy-efficient technology for the separation of azeotropic mixtures. However, the vaporization of the permeate leads to a temperature drop in the residual stream, and a supply of external energy is required to maintain a constant residual stream temperature in traditional pervaporation processes, which lowers their energy efficiency. Therefore, in this study, a heat-integrated pervaporation–distillation hybrid system was designed and investigated for the separation of an azeotropic MeAc–MeOH mixture using a low-temperature residual stream to cool the top vapor of the column. The temperature drop in the residual stream during pervaporation was studied using simulations and experiments. Pervaporation–distillation hybrid processes with and without heat integration were simulated and compared with special distillation under various operating parameters; their energy efficiencies were also compared. The results indicated that pervaporation–distillation with heat integration can lower the energy consumption by 24% compared to that via pressurized distillation with heat integration. Additionally, the energy efficiency increased by 31.7% compared to that by pressurized distillation with heat integration at a MeAc feed concentration of 50 wt %. The system proposed in this study is simple and practical for the energy-efficient design of pervaporation setups in industrial settings.