Multi-objective optimization and comparison of the entrainer-assisted pressure-swing distillation and extractive distillation separation sequences for separating a pressure-insensitive binary azeotrope

Abstract

Pressure-insensitive azeotropes are often encountered in chemical production. Entrainer-assisted pressure-swing distillation (EAPSD) is a special pressure-swing distillation showing promising performance in separating pressure-insensitive azeotropes. However, few studies have been reported on this method. In this work, the comparison between the EAPSD with tetrahydrofuran as pressure-sensitive entrainer and extractive distillation (ED) with dimethyl sulfoxide as solvent in separating water/isopropanol azeotrope is performed to explore the performance of EAPSD. Different EAPSD sequences, low-high sequence (LHS) and high-low sequence (HLS), are designed with different product sequences. A strategy considering the possibility of both partial and full heat integration is used to reduce capital cost and energy consumption. Multi-objective genetic algorithm is applied to achieve the optimal performance. The results show that the heat-integrated HLS sequence has lower total annual cost (TAC) by 7.04% and lower CO2 emission (CDE) by 4.27% than LHS, while ED process has lower TAC and CDE by 51.80% and 36.96% than the optimal EAPSD process.