Design of Energy-Saving and Environment-Friendly Process via Sustainable Reactive Extraction Distillation with Thermal Integration for Separating the Azeotrope Mixture of Ethyl Acetate/Methanol/Water

The development and design of green, low-energy, and sustainable processes remain core focuses in chemical industrial production. Separating azeotropes is a particularly challenging task, one plagued by significant pollution and high energy consumption, which have long been bottlenecks limiting the progress of the chemical industry. In this study, a novel reactive-extractive distillation (RED) process is proposed for separating the ethyl acetate/methanol/water ternary azeotrope. The process is further improved via thermal integration, achieving substantial reductions in energy consumption and CO2 emissions. In the reactive distillation column, water reacts with ethylene oxide to form ethylene glycol, effectively breaking the azeotropic limitation and removing water from the system. Additionally, dimethyl sulfoxide is used as the extractant to separate methanol and ethyl acetate in subsequent extractive distillation steps, enabling full solvent recycling and reuse. Optimal process parameters are determined using a multiobjective genetic algorithm, and two thermal integration schemes are developed. Results indicate that, compared to the existing three-column extractive distillation process, the thermally integrated RED process reduces the total annual cost by 50.8%, CO2 emissions by 21.1%, and exergy loss by 29.1%. This study provides a sustainable, efficient technical approach for separating industrial multicomponent azeotropes, thus supporting green development in the chemical and pharmaceutical industries.