Isobaric Vapor–Liquid Equilibrium of the Acetonitrile + 1-Propanol + Ionic Liquids at an Atmospheric Pressure

Abstract

The mixture of acetonitrile (1) + n-propanol (2) forms a binary azeotropic mixture at atmospheric pressure, which cannot be separated by common distillation. In this paper, the ionic liquids ( ILs) 1,3-dimethylimidazolium dimethylphosphate ([MMIM][DMP]) and 1-ethyl-3-methylimidazolium diethylphosphate ([EMIM][DEP]) were used as solvents for separating the binary azeotropic mixture. The ternary isobaric vapor−liquid equilibrium data of acetonitrile (1) + n-propanol (2) + ILs (3) at atmospheric pressure in three IL mole fractions of 0.048, 0.091, and 0.131 were obtained. The results showed that the addition of [MMIM][DMP] or [EMIM]-[DEP] could enhance the relative volatility of acetonitrile to npropanol, and the azeotropic point of the binary azeotropic system could disappear at the mole fractions of ILs abovementioned. The effect of separation of ILs was in the order of [EMIM][DEP] > [MMIM][DMP]. The interaction parameters were obtained by fitting the nonrandom two-liquid (NRTL) model to the binary vapor−liquid equilibrium experimental data.The predicted results obtained using the NRTL model were in good agreement with the experimental data. In addition, a quantum chemical calculation based on Gaussian 09 at the B3LYP/6-311++G** level was also conducted. The calculated results indicated that the molecules of ILs had a stronger interaction with the n-propanol molecule than with the acetonitrile one.

Vapor–Liquid Equilibrium Experiment and Process Simulation for Methanol and Ethyl Formate at 101.3 kPa

“…Among them, the NRTL model has a simple structure and the application scope is wide. Also, the NRTL model has been used many times in other literature studies − for alcohol and ester systems, and the deviation value between experimental data and calculated data by the NRTL model is the smallest. Therefore, we selected the NRTL model in this study.…”

UNIFAC Model for Ionic Liquids: 3. Revision and Extension

“…Figure directly compares the experimental and predicted VLE data for ethanol (1) + [EMIM]­[Ac] (2) (a), CH 3 CN (1) + [MMIM]­[DMP] (2) (b), toluene (1) + [EMIM]­[TCM] (2) (c), and methyl acetate (1) + [EMIM]­[MeSO 4 ] (2) (d) systems, where good agreement is found for UNIFAC model predicted values and experimental data − over a wide concentration range. Considering that the COSMO-UNIFAC model is a purely predictive model, its accuracy is lower than that of the UNIFAC model.…”

“…This work calculates a nm and a mn in the UNIFAC and COSMO-UNIFAC methods. Researchers measured some newly experimental data, − and this part of the data was collected and regressed to obtain the a nm and a mn . However, the other a nm and a mn values were obtained by the COSMO-UNIFAC model because of the need for more experimental data.…”

Isobaric Vapor–Liquid Equilibrium Experiment of Methyl Acetate + Ethanol Containing Different Ionic Liquids at 101.3 kPa

“…At present, the research on an azeotropic system + IL is very extensive. The main azeotropic system includes the ketone + ester system, ketone + alcohol − system, alcohol+ester − system, alcohol+benzene − system, alcohol+ether system, alcohol+furan − system, nitrile+alcohol − system, nitrile+furan system, nitril+ester system, and so on. Methyl acetate + ethanol belongs to the alcohol + ester azeotropic system, and representative studies such as Shi selected [OMIM]­[BF 4 ] as the entrainer for separating ethyl acetate and isopropanol.…”