Insights on sustainable separation of ternary azeotropic mixture tetrahydrofuran/ethyl acetate/water using hybrid vapor recompression assisted side-stream extractive distillation

Abstract

The energy-efficiency of the traditional distillation-based processes are low, which results in waste of resources and environmental pollution. Therefore, a sustainable extractive distillation (ED) process should be developed to reduce energy consumption and CO2 emissions while improve the energy efficiency. In this work, a systematic approach is developed for the first time, for the separation of ternary azeotropic mixture containing Tetrahydrofuran (THF)/Ethyl acetate (EtAC)/Water via the combination of side-stream distillation and vapor recompression heat pump techniques. Firstly, the conceptual design of the various intensified schemes such as single (or double) side-stream(s) ED configurations are developed. Subsequently, the developed configurations were optimized using mesh adaptive direct search algorithm to obtain the optimal operating conditions of the established processes. Vapor recompression heat pump technique is used to further reduce the energy consumption. The sustainability of the various established configurations is assessed via the comparison of total annual cost (TAC), CO2 emissions, energy consumption, and thermodynamic efficiency. Overall, it was revealed that the TAC, CO2 emissions, and energy-consumption for the integrated vapor recompression assisted side-stream ED process were reduced by 33%, 49%, and 38%, respectively, relative to the conventional triple column ED. Likewise, the thermodynamic efficiency was improved by 52%.