Energy-saving hybrid processes combining pressure-swing reactive distillation and pervaporation membrane for n-propyl acetate production

Abstract

The production of n-propyl acetate by transesterification is an environmentally and economically beneficial option for handling a huge amount of methyl acetate from the polyvinyl alcohol industry. This article proposes several energy-saving transesterification processes by combining pressure-swing reactive distillation with pervaporation for the production of n-propyl acetate. Among these, the combined PV unit with a polyoctylmethylsiloxane-based commercial membrane aims to separate the high purity methanol at the retentate side, and the solution diffusion-based PV model is developed by using Aspen Custom Modeler (ACM). The proposed processes with and without heat integration are optimized based on the minimum total annual cost, along with conventional and divided-wall reactive distillation processes. The results show that the partial heat-integrated pressure-swing reactive distillation assisted with pervaporation process provides a clear competitive advantage over the conventional reactive e distillation process, reducing the total annual cost by 58.15% and CO2 emission by 67.32%.