Design and energy intensification of an ionic-liquid-assisted reactive extractive distillation process for tert-Amyl ethyl ether production

Abstract

The production of tert -amyl ethyl ether (TAEE) involves a quaternary azeotropic system consisting of ethyl alcohol (EtOH)/ tert -amyl alcohol (TAA)/TAEE/Water, making conventional distillation highly energy intensive. This study proposed an ionic liquid(ILs) based reactive extractive distillation strategy through kinetic modeling, computational screening, and process simulation optimization. Five intensified process schemes were also developed to improve separation performance. First, 100 candidate ILs were systematically screened using COSMOtherm, followed by the evaluation of nine organic solvents based on relative volatility analysis. According to selectivity and viscosity criteria, four high performance ILs were identified. Quantum chemical analysis further revealed the separation mechanism and confirmed that ILs perform better than organic solvents as entrainers. Accordingly, 1-butyl-3-methylimidazolium acetate([BMIM][Ac]), was selected as the entrainers. Compared with conventional distillation, the process using [BMIM][Ac] reduced the total annual cost(TAC) by 38.06%. Furthermore, Heat-integration and Intermediate heat exchange reaction extractive distillation (HI-IHE-RED) process was developed. Compared with the process using [BMIM][Ac], this intensified scheme reduced the TAC by 21.38% and gaseous emissions by 32.36%. Overall, this study establishes an integrated research framework involving reaction kinetic modeling, computational screening, mechanistic validation, and process intensification, providing a promising industrial solution for the efficient and low carbon separation of complex etherification azeotropic systems.