Pressure-swing heterogeneous azeotropic distillation for energy-efficient recovery of ethyl acetate and methanol from wastewater with expanded feed composition range

This article tends to address the limitations of heterogeneous azeotropic distillation (HAD) for separating Serafimov's class 2.0-2b mixtures, such as ethyl acetate/methanol/water. The feasibility of proposed HAD is constrained by a narrow feed composition range, as thoroughly analyzed through thermodynamic insights in this work. To address these limitations, we propose pressure-swing heterogeneous azeotropic distillation (PSHAD), which allows for a broader application range in feed composition and facilitates heat integration for enhanced economic performance. Thermodynamic insights explore the economic viability and feasibility of PSHAD as feed composition and operating pressure vary. The applicable feed concentration range for PSHAD is determined by liquid-liquid region area and maximum allowable pressure. A parallel genetic algorithm optimizes the processes to minimize total annual cost (TAC). Both PSHAD and the heat-integrated configuration demonstrate superior performance compared to the best process in published literature (i.e., intensified extractive distillation), achieving TAC reductions of 26.46 % and 46.22 %, respectively.