渗透汽化-隔壁塔精馏耦合初步分离费托合成水的过程研究

Fischer-Tropsch synthetic water contains a variety of high value-added oxygen-containing organic compounds such as alcohols, ketones, and acids. However, due to the large amount of water and the complex azeotrope system, it is usually necessary to perform preliminary separation first. In this study, four alternative preliminary separation processes, direct two-column distillation, pervaporation-two-column distillation, direct dividing wall column distillation, and pervaporation-dividing wall column distillation, were designed first. According to the pervaporation experimental data, the pervaporation process model was constructed and simulated in Aspen Plus, and the optimal process parameters and simulation results of the distillation process were obtained through sensitivity analysis. The energy consumption and effective energy loss of the four processes were compared. The results show that the pervaporation-dividing wall column distillation process has obvious energy-saving advantages. Compared with direct two-column distillation, the energy consumption could be reduced by 15.85%, and the effective energy loss could be reduced by 45.74%. After pre-concentration by the pervaporation membrane, the concentration of the solution could enter the appropriate separation concentration range of the dividing wall column, so as to give full play to the advantages of the dividing wall column. Since the energy required for pervaporation could be provided by low-grade heat sources such as waste heat, the loss of effective energy could be significantly reduced in the coal chemical industry with sufficient waste heat. For this process, when the price of pervaporation membrane is lower than 438 CNY/m², the coupled process of pervaporation-dividing wall column distillation would show higher economy.