Design and Optimization of Sustainable Pressure Swing Distillation for Minimum-Boiling Azeotrope Separation

Abstract

A systematic approach for designing an energy-saving and environmentally friendly pressure swing distillation (PSD) process for separating binary azeotropes is proposed and involves the initial determination of the operating pressure and separating sequence based on the temperature–composition (T–xy) diagram, optimization by the two-step optimization procedure via minimizing the lifetime total cost (LTC), heat integration (HI), and a heat pump to achieve further energy savings and increase the process sustainability. The Eco-indicator 99 (EI99) is first introduced as an assessment criterion to evaluate the damage to the environment and sustainability of the PSD process. The partial and full HI-PSD processes are studied, and their corresponding T–H diagrams are provided to evaluate the feasibility and degree of heat integration. Three HP-PSD processes are investigated and optimized by minimizing the LTC. The results show that compared with the literature design, our conventional PSD process reduces the LTC and EI99 by 43.42% and 47.86%. The partial HI-PSD processes could further decrease the LTC and EI99 by 20.71% and 27.19% compared with the conventional PSD process. Meanwhile, the full HP-PSD process could reduce the LTC and EI99 by 14.12% and 68.77% compared to the partial HI-PSD process. Hence, the full HP-PSD process is the most favorable from both economic and sustainability perspectives.

Eco-Efficient Self-Heat Recuperative Vapor Recompression-Assisted Side-Stream Pressure-Swing Distillation Arrangement for Separating a Minimum-Boiling Azeotrope

“…The complex heat exchanger network configuration, proposed by Xia et al, was simplified and reoptimized by Luyben, which can further generate 31 and 16% decreased compressor power requirements and energy costs, respectively. As concluded in the works of Mangili, You et al, and Li et al, the same remarkable economic and ecological results were obtained, and the performance of the VRC-PSD arrangement was perceptibly superior to the thermal integration case. The use of the vapor recompression-assisted PSD process to separate the maximum-boiling azeotrope was also investigated.…”

Determination of the optimal distillation sequence of a ternary mixture incorporating heat integration by means of Microsoft Excel Solver

“…Again, the MS Excel Solver tool was applied to solve the resulting optimization problem. This is an important field for optimization since the energy cost of distillation constitutes a very important share of the total operational expenditures of a chemical process [2,16,23,25]. Thus, the heat integration of the distillation unit operations sequence results in a significant abatement of the total cost of the process, increasing its profitability.…”

Economic and Environmental Evaluation of Heat-Integrated Pressure-Swing Distillation by Multiobjective Optimization

“…In addition, an intermediate connection in PSD was developed for methanol/chloroform with the aim of energy savings . Eco-indicator 99 was introduced for separating isopropyl alcohol/diisopropyl ether mixture to evaluate the sustainability of the HIPSD process . Chen et al studied the HI PSD process for a methanol/methyl acetate mixture with acetaldehyde as an impurity, and four control structures were employed for comparison.…”