Design of novel side-stream hybrid reactive-extractive distillation for sustainable ternary separation of THF/ethanol/water using mixed entrainer

Abstract

This work explored the possibility of using mixed entrainer in a hybrid reactive-extractive distillation to improve the sustainability of the recovery process for the ternary azeotropic mixture containing THF/ethanol/water. A double column reactive-extractive distillation (DCRED) using mixed entrainer (i.e. dimethyl sulfoxide (DMSO) + ethylene glycol (EG)) is initially proposed and intensified to a side-stream DCRED (SS-DCRED). Both the initial DCRED and SS-DCRED designs are optimised using particle swarm optimisation (PSO) to obtained optimum column configurations. The sustainability of the proposed processes using mixed entrainer are compared against pure EG as entrainer based on five different indicators, i.e. economic, environmental, safety, operational controllability, and thermodynamic efficiency. Generally, it was demonstrated that using mixed entrainer provides significant improvement in all sustainability indicators. Although there may be some trade-offs in the controllability and economic, such drawbacks are consistent with previous publications where the improvement in sustainability are always achieved at an expense of an increase in the economics. Overall, it was revealed that the optimised SS-DCRED using mixed entrainer provides the best improvement to the economic, controllability, safety, environmental, and thermodynamic efficiency by 21 %, 97 %, 19 %, 29 %, and 100 %, with respect to using pure entrainer, which reflects the sustainability of the proposed process.