Optimization of methanol–vinyl acetate azeotrope separation process based on the pressure swing distillation and energy saving study

This study delves into the optimization of the methanol–vinyl acetate (VAC) azeotrope separation process via pressure swing distillation (PSD), along with an evaluation of its energy-saving potential. The methanol–VAC system, a polar azeotrope highly susceptible to pressure variations, presents notable separation complexities in polyvinyl alcohol production. Aspen Plus simulations were utilized to assess the feasibility of PSD, with particular emphasis on critical process parameters such as the number of theoretical plates, feed position, reflux ratio, and sidestream extraction location. The results indicate that PSD demonstrates remarkable efficacy in separating methanol and VAC, achieving purities of 99.88% and 99.73% respectively. When compared to extractive distillation, PSD achieves a reduction of 9.07 t·h⁻¹ in steam consumption and minimizes wastewater generation by 20.77 t·h⁻¹. Furthermore, the economic assessment reveals a 7.91% decrease in the total annual cost associated with PSD. This study not only provides theoretical insights but also offers practical guidance for the design of energy-efficient and sustainable separation processes. Future research will focus on extending the analysis to encompass multi-pressure scenarios, further enhancing the applicability and robustness of the findings.