Extractive distillation for ethanol dehydration using imidazolium-based ionic liquids as solvents

摘要

An extractive distillation process was investigated, comparing the imidazolium-based ionic liquids [EMIM][BF4] and [BMIM][BF4] as solvents for ethanol dehydration. An Aspen Plus process simulator was used to simulate the feasibility of the ionic liquid-based extractive distillation (ILED) process and determine the main operating conditions of anhydrous ethanol production. User-defined ionic liquid components were created in Aspen Plus, with the required thermodynamic and physical property parameters. The NRTL model was used to calculate the thermodynamic properties. The proposed process and methodology using [EMIM][BF4] as the solvent was applied to evaluate the potential of extractive distillation for ethanol dehydration. The results show that the distillate purity of ethanol was higher than 99.9 mol% and revealed the advantage of decreased energy requirements compared with the extractive distillation process using conventional solvents. The ILED process design obtained from the sensitivity analysis for minimum energy consumption presented a lower total annual cost (TAC). (C) 2016 Elsevier B.V. All rights reserved.