Liquid–Liquid Equilibrium of Isobutyl Acetate + Isobutyl Alcohol + Imidazolium-Based Ionic Liquids at 298.15 and 308.15 K (original) (raw)
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The Journal of Chemical Thermodynamics, 2018
The present work was focused on the study of two imidazolium-based ionic liquids (ILs) as solvents in liquid-liquid extraction of ethanol from aqueous mixtures. With this aim, the experimental liquid-liquid equilibria (LLE) data of water (1) + ethanol (2) + 1ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([emim][Tf 2 N]) (3) and water (1) + ethanol (2) + 1-hexyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([hmim][Tf N]) (4) systems were obtained at different temperatures: 283.2, 303.2, and 323.2 K, in order to check the influence of temperature. The results were correlated by non-random two-liquid (NRTL) and universal quasichemical (UNIQUAC) models with good concordance in both cases. Finally, the ability of the two ILs to act as solvents was studied by evaluating the coefficient distribution and the selectivity of ternary systems and compared with another IL from the literature.
The Journal of Chemical Thermodynamics, 2012
(Liquid + liquid) equilibrium data for the ionic liquids 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, [EMim][NTf 2 ], 1-propyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, [PMim] [NTf 2 ], 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, [BMim][NTf 2 ], and 1-hexyl-3methylimidazolium bis(trifluoromethylsulfonyl)imide, [HMim][NTf 2 ], mixed with ethanol and heptane were studied at T = 298.15 K and atmospheric pressure. The ability of these ionic liquids as solvents for the extraction of ethanol from heptane was evaluated in terms of selectivity and solute distribution ratio. Moreover, density and refractive index values over the miscible region for the ternary mixtures were also measured at T = 313.15 K. Finally, the experimental data were correlated with the Non Random Two Liquids (NRTL) and UNIversal QUAsi Chemical (UNIQUAC) thermodynamic models, and an exhaustive comparison with available literature data of the studied systems was carried out.
The Journal of Chemical Thermodynamics, 2012
In this work, the ionic liquids 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, [EMim] [NTf 2 ], 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, [BMim][NTf 2 ], 1-butyl-3-methylpyridinium bis(trifluoromethylsulfonyl)imide, [BMpy][NTf 2 ], 1-butyl-3-methylpyridinium trifluoromethanesulfonate, [BMpy][TfO], have been investigated for their use as solvents in extraction processes for the ethanol removal from its azeotropic mixture with hexane. Therefore, the experimental determination of the liquid + liquid equilibrium for the ternary systems {hexane (1) + ethanol (2) + [EMim][NTf 2 ] (3)}, {hexane (1) + ethanol (2) + [BMim][NTf 2 ] (3)}, {hexane (1) + ethanol (2) + [BMpy][NTf 2 ] (3)} and {hexane (1) + ethanol (2) + [BMpy][TfO] (3)} was carried out at T = 298.15 K and atmospheric pressure. Classical parameters such as selectivity and solute distribution ratio, derived from the tie-line data, were calculated and afterwards, the structural influence of the ionic liquids on the extraction process was analyzed. Finally, the experimental LLE data were correlated by means of the NRTL and UNIQUAC models.
The present work focussed on application of the environmental friendly 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl) imide ([BMIM] + [Tf 2 N] − ) ionic liquid for the separations of (alkane/aromatic), (alkane/alk-1-ene), (cycloalkane/aromatic) and (water/alkan-1-ol) using gas-liquid chromatography (GLC) technique. In this reason the activity coefficients at infinite dilution, γ 13 ∞ , for 31 organic solutes (alkanes, cycloalkanes, alkenes, alkynes, aromatics, alkanol and ketones) and water in ionic liquid were measured at temperatures of (323.15, 333.15, 343.15, 353.15 and 363.15) K. Stationary phase loadings of (42.83 and 68.66) % by mass were used to ensure repeatability of measurements. Density and viscosity values were measured to confirm the purity of ionic liquid. Partial molar excess enthalpies at infinite dilution, ΔH 1 E,∞
The Journal of Chemical Thermodynamics, 2018
The separation of olefins/paraffins is a challenge for the petrochemical industry due to the close boiling points of these hydrocarbons. In this work we have studied the feasibility of different imidazolium and pyridinium-based ionic liquids (ILs) as alternative solvents in the cyclohexane/cyclohexene separation. Five ILs have been studied, namely 1-butyl-4methylpyridinium tricyanomethanide ([4bmpy][TCM]), bis(1-ethyl-3-methylimidazolium) tetrathiocyanatocobaltate ([emim] 2 [Co(SCN) 4 ]), bis(1-butyl-3-methylimidazolium) tetrathiocyanatocobaltate ([bmim] 2 [Co(SCN) 4 ]), 1-ethyl-4-methylpyridinium bis(trifluoromethylsulfonyl)imide ([4empy][Tf 2 N]), and 1-butyl-4-methylpyridinium bis(trifluoromethylsulfonyl)imide ([4bmpy][Tf 2 N]). Experimental liquid-liquid equilibrium (LLE) data were obtained for the equimolar ternary mixtures {cyclohexane (1) + cyclohexene (2) + IL (3)} at T = (298.2, 313.2 and 328.2) K and atmospheric pressure in order to study the effect of the temperature on the extractive properties. Afterwards, LLE data for every ternary system was determined at the best temperature and for the whole cyclohexane/cyclohexene composition range. These ILs have shown promising results in terms of distribution ratio and selectivity, showing the [4bmpy][TCM] IL the best extractive properties at 298.2 K and atmospheric pressure. The Non-Random Two Liquids (NRTL) model was used to successfully correlate the experimental LLE data.
Separation of Ethanol−Heptane Azeotropic Mixtures by Solvent Extraction with an Ionic Liquid
Industrial & Engineering Chemistry Research, 2009
Ionic liquids (ILs) are gaining attention as potential substitutes for classical organic solvents in extraction processes. This article reports the results of a study on the use of the IL 1,3-dimethylimidazolium methyl sulfate ([MMIM][MeSO 4 ]) as an extraction solvent in petrochemical processes for the removal of heptane from its mixtures with ethanol. The separation of heptane and ethanol is valuable but difficult because of the formation of an azeotropic mixture. Knowledge of the liquid-liquid equilibria (LLE) of this mixture is essential for the design of separation techniques. For this reason, the experimental LLE for the ternary system heptane + ethanol + [MMIM][MeSO 4 ] were investigated at 298.15 K. The solvent capacity of [MMIM][MeSO 4 ] was compared with those of other ILs. The extraction process derived from the use of this solvent was simulated using conventional software, and the obtained results are reported. Experimental data were obtained in a laboratory-scale packed-column extraction system for the separation of this azeotropic mixture using [MMIM][MeSO 4 ]. A comparison with the experimental column data for other ILs is included. Moreover, it is concluded that [MMIM] [MeSO 4 ] has the highest extraction efficiency. Also, this IL can be recycled, meaning that the separation process results in a vast reduction of energy consumption.
Fluid Phase Equilibria, 2015
The separation of azeotropic mixtures, so that their components can be reused in productions cycles, is of particular interest in modern sustainable chemical plants. In the last decade, ionic liquids have shown to possess the ability to act as extraction solvents and have been emerging as a greener alternative to organic solvents in the separation of azeotropes. Recently, high ionicity ionic liquids (HIILs) have been developed through the addition of inorganic salts to an ionic liquid, as well as by mixing two or more ionic liquids. In this work, a high ionicity ionic liquid, prepared by mixing 0.1 of 1-ethyl-3-methylimidazolium thiocyanate ([C 2 MIM][SCN]) and 0.9 of [C 2 MIM][C 2 SO 4 ] was used to separate the azeotrope ethanol + heptane. Liquid[ 1 0 _ T D $ D I F F ]-liquid equilibria for the two ternary systems: ethanol + heptane + [C 2 MIM][SCN] and ethanol + heptane + HIIL was measured at 298.15 K and 0.1 MPa. Both the selectivity and the distribution coefficient were used in the assessment of the extraction solvent feasibility and a correlation of these parameters with the ionicity of the solvent was established. 2015 Elsevier B.V. All rights reserved.
Analytical and Bioanalytical Chemistry, 2005
Owing to their favorable properties, ionic liquids have recently gained recognition as possibly environmentally benign solvents. Now among the most promising industrial chemicals, they have already been labeled ''green'', but this appellation seems due entirely to their very low vapor pressure. This growing interest in the various applications of ionic liquids will soon result in their presence in the environment. Therefore, reliable analytical tools for the environmental analysis of ionic liquids need to be developed urgently. This paper presents a newly developed analytical procedure for the enrichment of 1-alkyl-and 1-aryl-3-methylimidazolium ionic liquids from water samples. The method is based on cation exchange solid-phase extraction followed by selective elution. Pre-concentrated samples are subjected to high-performance liquid chromatography (HPLC) with an advanced methodology for qualitative and quantitative analysis. The overall procedure was verified by using standard spiked samples of tap water, seawater, and freshwater.
Separation of azeotropic mixtures using protic ionic liquids as extraction solvents
Journal of Molecular Liquids, 2019
The aim of this work is to evaluate the separation of hydrocarbons (hexane and heptane) from their azeotropic mixtures with ethanol using protic ionic liquid (PIL) as extraction solvents. With this goal in mind, PILs were synthesized and their thermal and physical characterization were carried out. Experimental determination of the phase equilibrium for the ternary systems hydrocarbons + ethanol + PIL at 298.15 K and 101.2 kPa were also carried out in order to evaluate the feasibility of this application. The solute distribution ratio and the selectivity were also determined to compare the solvent capacity of these PILs. The NRTL equation was used to correlate the experimental data. Furthermore, this paper provides a comparison of the solvent capacity of these PILs with different extraction solvents (ionic liquids (ILs), ILs mixtures and deep eutectic solvents) available in the literature. Then, a critical review for the separation of these azeotropic mixtures was carried out using the extraction processes data obtained through the simulation using a conventional software.