[EMIM][DCA] as an entrainer for the extractive distillation of methanol-ethanol-water system

• 作者: Shengli Liu Zhenhang Wang Ruisong Zhu Zhigang Lei Jiqin Zhu
• 来源期刊: 绿色能源与环境（英文版）
• 年，卷（期）: 2021,（3）
• 所属期刊栏目: Research papers
• 页码范围: 363-370
• 页数: 8页
• 语种: 英文

摘要

The ionic liquid (IL) 1-ethyl-3-methylimidazolium dicyanamide ([EMIM][DCA]) was selected as an appropriate entrainer for the extractive distillation of the methanol-ethanol-water mixture.The COSMO-RS model was applied to screen out the appropriate solvents considering selectivity and solvent capacity together.Isobaric vapor-liquid equilibrium (VLE) experiments for the two systems of methanol-water and ethanol-water with different amounts of[EMIM][DCA]added were conducted at 101.3 kPa.The experimental data showed that[EMIM][DCA]exhibits an obvious salting effect for the methanol (or ethanol)-water mixture and eliminates the azeotropic point of ethanol-water.Moreover,the predicted values by UNIFAC-Lei model coincide well with experimental data.The separation mechanism was further explained in com-bination with surface charge density distribution (a-profiles),excess enthalpy (HE),and binding energy.In addition,the flow charts were designed to evaluate the improvement of energy consumption with[EMIM][DCA]as the entrainer when compared to ethylene glycol (EG).The simulation results demonstrated that[EMIM][DCA]is more energy efficient than EG.