The separation of ternary azeotropic mixtures is a common challenge in the chemical industry due to the unique properties of azeotropes. This phenomenon complicates the separation processes, as traditional distillation methods may not effectively separate the components. The present work introduces a novel pressure-swing distillation (NPSD) process integrated with natural decanting for the effective separation of an n-propanol/benzene/water mixture. By exploiting the liquid–liquid envelope characteristics of the mixture, phase separation prior to distillation significantly enhances the separation efficiency. The NPSD process was optimised using the NSGA-II, addressing economic, environmental, and energetic objectives. Key findings reveal that the implementation of decanting allows the NPSD process to operate without substantial pressure adjustments, thereby facilitating fine separation more efficiently than conventional pressure-swing distillation designs. The proposed NPSD process can achieve up to 25.76 % savings in TAC while reducing CO₂ emissions and improving energy efficiency. Furthermore, the integration of mechanical vapour recompression heat pump and Organic Rankine Cycle systems enhances energy saving, resulting in a TAC reduction of up to 31 % and a decrease in CO₂ emissions of up to 38 % compared to existing energy-efficient designs. These findings highlight the potential of the NPSD-MVR-ORC system for sustainable chemical separation processes.

中文翻译：

---

变压蒸馏结合自然倾析和有机朗肯循环的新型可持续设计，用于分离正丙醇/苯/水混合物


由于共沸物的独特性质，三元共沸混合物的分离是化学工业中的常见挑战。这种现象使分离过程复杂化，因为传统的蒸馏方法可能无法有效地分离成分。本研究介绍了一种新型变压蒸馏 （NPSD） 工艺，与自然倾析相结合，用于有效分离正丙醇/苯/水混合物。通过利用混合物的液-液包络特性，蒸馏前的相分离显著提高了分离效率。NPSD 工艺使用 NSGA-II 进行了优化，解决了经济、环境和能源目标。主要研究结果表明，倾析的实施使 NPSD 工艺无需大量压力调整即可运行，从而比传统的变压蒸馏设计更有效地促进精细分离。拟议的 NPSD 工艺可以节省高达 25.76% 的 TAC，同时减少 CO₂ 排放并提高能源效率。此外，机械蒸汽再压缩热泵和有机朗肯循环系统的集成增强了节能效果，与现有的节能设计相比，总热耗降低了 31%，二氧化碳排放量减少了 38%。这些发现突出了 NPSD-MVR-ORC 系统在可持续化学分离过程中的潜力。