Multi-objective Optimization and Control of Self-Heat Recuperative Azeoropic Distillation for Separating an Ethanol/Water Mixture

Abstract

Azeotropic distillation is an important method for the separation of an ethanol/water mixture, while the main disadvantage of azeotropic distillation is its high energy consumption. Since the self-heat recuperation technology can effectively recover and utilize the heat of effluent stream in thermal processes, it is introduced into the ethanol dehydration process. The conventional azeotropic distillation and self-heat recuperative azeotropic distillation (SHRAD) are simulated and optimized with multiple objectives. There exists a design point in the Pareto solution set for which the total annual cost is the lowest, the thermodynamic efficiency is the highest, and the CO 2 emission is the least. Based on the specified design, the dynamic characteristics of the SHRAD configuration are studied, and two control structures are proposed. The improved control structure of the SHRAD process works well under the feed flowrate and composition disturbance, and the SHRAD system can obtain a high-purity ethanol product. The results show that the SHRAD process has significant advantages over conventional azeotropic distillation in terms of economic and environmental benefits. In addition, an effective control structure can ensure the stable operation of the SHRAD process.

Improved Harmony Search Algorithm for Enhancing Efficiency and Quality in Optimization of the Distillation Process

“…Acetonitrile (MeCN)/N-propanol (N-Pro) is an azeotropic system. Tian 41 has designed a dividing-wall extractive distillation process by using N-methyl pyrrolidone (NMP) as an extractant and employing the Wilson-RK thermodynamic method. There are two columns shown in Figure 12; one is the main column (T1) and the other is the auxiliary column (T2).…”

Design of Reaction Region of Reactive Dividing Wall Column Based on Cross-Wall Heat Transfer

“…Various high-efficiency thermally coupled distillation columns and new distillation technologies have also been developed. The development of distillation technology is mainly in terms of the following categories: (1) coupling of reactive distillation, adsorption distillation, extractive distillation, and other processes, (2) heat-integrated columns, such as dividing wall distillation columns (DWCs), and (3) use of heat pump distillation, pressure swing distillation, molecular distillation, and other technologies. The reactive dividing wall column (RDWC) is an application that couples dividing wall distillation technology with reactive distillation technology.…”