Vapor-liquid equilibrium experiment and extractive distillation process design for the azeotrope ethyl propionate n-propanol using ionic liquid

Ionic liquid 1-ethyl-3-methylimidazolium acetate ([Emim][OAC]) and organic solvent ethylene glycol (EG) were evaluated for their performance to disrupt the ethyl propionate and n-propanol azeotrope through the phase equilibrium experiment. Isobaric vapor-liquid equilibrium (VLE) data of ethyl propionate + n-propanol, ethyl propionate + n-propanol + [Emim][OAC] and ethyl propionate + n-propa nol + EG was measured at atmospheric pressure. The experimental apparatus and procedure were confirmed for reliability by comparing the binary experimental VLE data to published data. The NRTL model was employed to correlate the VLE data and predict the phase equilibrium behavior of systems. The results demonstrated that the separation performance of [Emim][OAC] is more excellent than EG, and the more ionic liquid is added, the better the separation performance. The simulation of the extractive distillation process using [Emim][OAC] as entrainer was developed via Aspen Plus software. The optimal operating variables were determined by reducing the total annual cost (TAC) to a minimum. Finally, the economic assessment analysis indicated that the TAC of optimal operating conditions is 803.39 k$ and the feasibility of the extractive distillation scheme to separate azeotropic systems. (C) 2022 Elsevier B.V. All rights reserved.