Vapor–Liquid Equilibrium Experiment and Thermodynamic Model Correlation for Ethanol + Isopropyl Acetate with Ionic Liquid at 101.3 kPa

Abstract

Due to the azeotrope between ethanol and isopropyl acetate, separating them and meeting the separation requirements is challenging. In this study, ethylene glycol (EG), dimethyl sulfoxide (DMSO), and 1-butyl-3-methyl-imidazole acetate ([BMIM][OAC]) were selected as entrainers, and the vapor−liquid equilibrium data of ethanol−isopropyl acetate, ethanol + isopropyl acetate + EG, ethanol + isopropyl acetate + DMSO, and ethanol-isopropyl acetate + [BMIM][OAC] were measured at atmospheric pressure. The thermodynamic NRTL model was able to fit these experimental results. It showed that the model could correctly describe the influence of these entrainers on this azeotropic system. According to the VLE data, three entrainers caused different effects on the relative volatility of ethanol−isopropyl acetate. The azeotropic point would be completely eliminated, while the mole fraction of [BMIM][OAC] added is 0.1, which performs better than EG and DMSO.

Vapor–Liquid Equilibrium for Acetonitrile + Ethanol with Imidazole-Based Ionic Liquids as Entrainers at 101.3 kPa

“…Acetonitrile, ethanol, and ILs were weighed with an analytic balance (Sartorius, Germany), and the standard uncertainty was 0.1 mg. The mole fraction of acetonitrile and ethanol was measured by GC (HF-901A, China) with a thermal conductivity detector, and detailed information on GC is listed in Table S1 in the Supporting Information . The carrier gas was supplied by a hydrogen generator in GC, and the temperatures of the injector, column, and detector were 423.15, 393.15, and 423.15 K, respectively.…”

“…Therefore, ILs are safe, environmentally friendly, weakly corrosive, and easy to recover as entrainers. In addition, there are significant differences in the intermolecular forces between ILs and different molecules of organic solvents, and ILs have an apparent effect on the relative volatility of different organic solvents and vapor–liquid equilibrium (VLE) . VLE data containing ILs are particularly important to figure out the effect of ILs in extractive distillation, which can contribute to exploring the separation method of the azeotropic system in depth. − …”

Vapor–Liquid Equilibrium for Ethyl Acetate + Acetonitrile with Acetate-Based Ionic Liquids as Entrainers at 101.3 kPa and Analysis of the Separation Mechanism

“…Ethyl acetate and acetonitrile are extremely important organic solvents and additives for synthetic. , A mixture of ethyl acetate and acetonitrile often appears in the pharmaceutical industry, and it is necessary to separate and recover them . However, ethyl acetate–acetonitrile is an azeotrope system, which is difficult to be effectively separated by conventional distillation. , Traditional extractive distillation can be qualified to separate ethyl acetate and acetonitrile, and the key lies in the selection of the solvent. − Traditional volatile organic solvents and inorganic salts are widely used as solvents, but they bring up a series of problems such as low recovery of entrainers, corrosion of equipment, and high energy consumption. , …”