An improvement scheme for pressure-swing distillation with and without heat integration through an intermediate connection to achieve energy savings

Abstract

Pressure-swing distillation is widely studied in academia and industry. Energy consumption is a key criterion for judging whether a pressure-swing distillation is better than other distillation methods. An improved process with an intermediate connection was developed based on the two-column pressure-swing distillation for separating a binary azeotropic mixture to save energy and reduce the total annual cost. The proposed pressure-swing distillation was applied to three case systems, two minimum-boiling azeotropic mixtures of ethyl acetate/ethanol and methanol/chloroform and one maximum-boiling azeotropic mixture of ethylenediamine/water. According to our analysis, the proposed pressure-swing distillation and heat-integrated scheme can reduce energy consumption and total annual cost. The pressure-swing distillation with the intermediate connection is promising for saving energy. This advantage assists in promoting the application of pressure-swing distillation and overall energy savings in the chemical process industry.