Liquid–liquid equilibria for ternary systems of {cyclohexane + aromatic compounds + 1-ethyl-3-methylpyridinium ethylsulfate}

Liquid–liquid equilibrium (LLE) data for the ternary systems {cyclohexane + benzene + 1-ethyl-3-methylpyridinium ethylsulfate}, {cyclohexane + toluene + 1-ethyl-3-methylpyridinium ethylsulfate}, and {cyclohexane + ethylbenzene + 1-ethyl-3-methylpyridinium ethylsulfate} were determined at T = 298.15 K and atmospheric pressure. Selectivity, percent removal of aromatic, and solute distribution ratio, derived from the equilibrium data, were used to determine if this ionic liquid can be used as a potential solvent for the separation of aromatic compounds from cyclohexane. The phase diagrams for the ternary systems are shown, and the tie-lines correlated with NRTL model have been compared with the experimental data.     

Measurement and correlation of liquid–liquid equilibria for ternary systems {cyclooctane + aromatic hydrocarbon + 1-ethyl-3-methylpyridinium ethylsulfate} at T = 298.15 K and atmospheric pressure

This work reports liquid–liquid equilibrium (LLE) results for the ternary systems {cyclooctane + benzene + 1-ethyl-3-methylpyridinium ethylsulfate}, {cyclooctane + toluene + 1-ethyl-3-methylpyridinium ethylsulfate}, and {cyclooctane + ethylbenzene + 1-ethyl-3-methylpyridinium ethylsulfate} at T = 298.15 K and under atmospheric pressure. The selectivity, percent removal of aromatic, and distribution coefficient ratio, derived from the tie-line data, were calculated to determine if this ionic liquid is a good solvent for the extraction of aromatics from cyclooctane. The phase diagrams for the ternary systems are shown, and the tie-lines correlated with the NRTL model have been compared with the experimental data. The consistency of the experimental LLE data was ascertained using the Othmer–Tobias and Hand equations. No data for mixtures presented here have been found in the literature.     

Study of [EMim][ESO4] ionic liquid as solvent in the liquid-liquid extraction of xylenes from their mixtures with hexane

The aim of this work is to determine if the ionic liquid 1-ethyl-3-methylimidazolium ethylsulfate is a good solvent for the separation of xylenes and hexane by liquid extraction. With this purpose, liquid-liquid equilibrium (LLE) data for the ternary systems {hexane + o-xylene, or m-xylene, or p-xylene + 1-ethyl-3-methylimidazolium ethylsulfate} were determined at T = 298.15 K and atmospheric pressure. Selectivity and solute distribution ratio, derived from the experimental equilibrium data, were calculated and used to determine if this ionic liquid can be used as a potential solvent for the extraction of xylenes from their mixtures with hexane. The experimental LLE data for the ternary systems were correlated using the NRTL and UNIQUAC models.     

Separation of aromatic hydrocarbons from alkanes using ammonium ionic liquid C2NTf2 at T = 298.15 K

(Liquid + liquid) equilibrium data are presented for four ternary systems of an alkane, or aromatic compound and ethyl(2-hydroxyethyl)dimethylammonium bis{(trifluomethyl)sulfonyl}imide (C₂NTf₂) at 298.15 K: [hexane + benzene + C₂NTf₂], [hexane + p-xylene + C₂NTf₂], and [hexane, or octane + m-xylene + C₂NTf₂]. The separation of aromatic hydrocarbons (benzene, or p-xylene, or m-xylene) from aliphatic hydrocarbons (hexane, or octane) is investigated by extraction with the ammonium ionic liquid. Selectivities and distribution ratios are discussed for these mixtures at constant temperature. The data were analysed and compared to those previously reported for other ionic liquids and especially for the system {hexane + benzene + [EMIM][NTf₂]}. The nonrandom two liquid NRTL model was successfully used to correlate the experimental tie-lines and to calculate the phase compositions of the ternary systems.     

Liquid–liquid equilibria for {hexane + benzene + 1-ethyl-3-methylimidazolium ethylsulfate} at (298.2, 313.2 and 328.2) K

Liquid–liquid equilibria (LLE) for the ternary system {hexane + benzene + 1-ethyl-3-methylimidazolium ethylsulfate ([emim]C₂H₅SO₄)} have been measured at the temperatures (298.2, 313.2 and 328.2) K and atmospheric pressure. The reliability of the experimental data was tested using the Othmer–Tobias correlation. For the extractive effectiveness of the solvent, the distribution ratio and separation factor curves were plotted and compared with those of sulfolane. In addition, the LLE data were also correlated with UNIQUAC and NRTL models in a satisfactory manner.     

Application of [EMim][ESO4] ionic liquid as solvent in the extraction of toluene from cycloalkanes: Study of liquid-liquid equilibria at T = 298.15 K

In this paper, the separation of toluene from cycloalkanes by liquid extraction using the ionic liquid 1-ethyl-3-methylimidazolium ethylsulfate, [EMim][ESO₄], as solvent was studied. Liquid-liquid equilibrium (LLE) data for ternary systems {cyclohexane, or cyclooctane, or methylcyclohexane + toluene + [EMim][ESO₄]} were determined at T = 298.15 K and atmospheric pressure. Selectivity and solute distribution ratio, derived from the tie-lines, were used to determine the ability of this ionic liquid as solvent for the separation of toluene from its mixtures with cycloalkanes. The degree of consistency of the tie-lines was tested using the Othmer-Tobias equation, and the experimental LLE data were correlated using the non-random two-liquid (NRTL) and the UNIversal QUAsi-Chemical (UNIQUAC) models.     

(Liquid + liquid) equilibrium for ternary mixtures of {heptane + aromatic compounds + [EMpy][ESO4]} at T = 298.15 K

(Liquid + liquid) equilibrium (LLE) data for the ternary systems (heptane + toluene + 1-ethyl-3-methylpyridinium ethylsulfate) and (heptane  + benzene + 1-ethyl-3-methylpyridinium ethylsulfate) were measured at T = 298.15 K and atmospheric pressure. The selectivity and aromatic distribution coefficients, calculated from the equilibrium data, were used to determine if this ionic liquid can be used as a potential extracting solvent for the separation of aromatic compounds from heptane. The consistency of tie-line data was ascertained by applying the Othmer–Tobias and Hand equations.     

Quinary liquid–liquid equilibria for mixtures of nonane + undecane + two pairs of aromatics (benzene/toluene/m-xylene) + sulfolane at 298.15 and 313.15 K

In this work, liquid–liquid equilibrium data were measured for three quinary mixtures (nonane + undecane + benzene + toluene + sulfolane), (nonane + undecane + benzene + m-xylene + sulfolane) and (nonane + undecane + toluene + m-xylene + sulfolane) at 298.15 and 313.15 K and ambient pressure. The experimental LLE data were determined by using a jacketed glass cell with temperature controlled. The quantitative analysis was performed by using a Varian gas chromatograph equipped with a flame ionization detector and a SPB™-1 column. The experimental quinary liquid–liquid equilibrium data have been satisfactorily correlated by using NRTL and UNIFAC-LLE models. The calculated values based on the NRTL model were found to be in a better agreement with the experiment than those based on the UNIFAC-LLE model.     

Liquid–liquid equilibrium for binary and ternary systems containing di-isopropyl ether (DIPE) and an imidazolium-based ionic liquid at different temperatures

Liquid–liquid equilibrium (LLE) data were determined for two binary systems {di-isopropyl ether (DIPE) + 1-ethyl-3-methylimidazolium-ethylsulfate (EMISE)} and {DIPE + 1-butyl-3-methylimidazolium-tetrafluoroborate([Bmim][BF₄])}at temperatures between 293.15 K and 313.15 K. LLE data for six ternary systems {DIPE + water + EMISE} and {DIPE + water + [Bmim][BF₄]} at 293.15 K, 303.15 K, and 313.15 K were also reported. Experiments were carried out at atmospheric pressure using stirred and thermo-regulated cells. The experimental data were correlated with the well-known NRTL and UNIQUAC activity coefficient models. In addition, distribution coefficients and selectivities of the ionic liquids EMISE and [Bmim][BF₄] for water in the DIPE phase were measured.     

Isothermal vapor–liquid equilibrium at 303.15 K and excess molar volumes at 298.15 K for the ternary system of propyl vinyl ether + 1-propanol + 2,2,4-trimethyl-pentane and its binary sub-systems

Isothermal vapor–liquid equilibrium data determined by the static method at 303.15 K are reported for the binary systems propyl vinyl ether + 1-propanol, 1-propanol + 2,2,4-trimethylpentane and propyl vinyl ether + 2,2,4-trimethylpentane and also for the ternary system propyl vinyl ether + 1-propanol + 2,2,4-trimethyl-pentane. Additionally, new excess volume data are reported for the same systems at 298.15 K. The experimental binary and ternary vapor–liquid equilibrium data were correlated with different G^E models and excess molar volume data were correlated with the Redlich–Kister equation for the binary systems and the Cibulka equation for the ternary system, respectively.     

Alkylsulfate-based ionic liquids to separate azeotropic mixtures

The knowledge of liquid–liquid equilibria (LLE) of the ternary systems (hexane or heptane + ethanol + 1-ethyl-3-methylimidazolium ethylsulfate (EMIM EtSO₄)) is essential for the separation of alkanes from their azeotropic mixtures with ethanol. The experimental LLE have been determined at 298.15 K and atmospheric pressure. Experimental LLE are correlated using NRTL equation. The solvent capacity of the IL is compared with others aiming to analyze the efficiency of these molten salts used as entrainers. The extraction processes with this IL are simulated using conventional software. A comparison of the alkylsulfate-based IL's ability for the extraction process, determined from the simulation results, is enclosed.     

Liquid–liquid equilibria for quaternary mixtures of nonane + undecane + (benzene or toluene or m-xylene) + sulfolane at 298.15 and 313.15 K

Liquid–liquid equilibrium (LLE) data were measured for three quaternary systems containing sulfolane, nonane + undecane + benzene + sulfolane, nonane + undecane + toluene + sulfolane and nonane + undecane + m-xylene + sulfolane, at T = 298.15 and 313.15 K and ambient pressure. The experimental quaternary liquid–liquid equilibrium data have been satisfactorily represented by using NRTL and UNIFAC-LLE models for the activity coefficient. The calculated compositions based on the NRTL model were found to in a better agreement with the experiment than those based on the UNIFAC-LLE model.     

The phase envelopes of alternative solvents (ionic liquid,CO2) and building blocks of biomass origin (lactic acid,propionic acid)

Solid–liquid, liquid–liquid and vapour–liquid equilibrium measurements for binary and ternary systems containing building blocks of biomass origin such as propionic acid, lactic acid and alternative solvents like carbon dioxide and 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ionic liquid have been carried out at 313.15 K. The binary solid–liquid and liquid–liquid equilibrium measurements were performed at ambient pressure. The vapour–liquid equilibrium was studied in the range of pressure from 3.54 to 12 MPa while ternary systems were examined at 9, 10 and 12 MPa. The samples from the coexisting phases were taken and the compositions of both liquid and vapour phases were determined experimentally. The three-phase system was observed for lactic acid + ionic liquid + CO₂ as well. The achieved results were correlated using the Peng–Robinson equation of state with the Mathias–Klotz–Prausnitz mixing rule. The set of interaction parameters for the employed equations of state and the mixing rule for the investigated systems were obtained.     

Thiophene separation from aliphatic hydrocarbons using the 1-ethyl-3-methylimidazolium ethylsulfate ionic liquid

The ionic liquid 1-ethyl-3-methylimidazolium ethylsulfate has been tested as solvent for the separation of thiophene from aliphatic hydrocarbons. Liquid–liquid equilibrium data have been determined for ternary systems containing the ionic liquid, thiophene and C₆, C₇, C₁₂ or C₁₆ alkanes at T = 298.15 K. The performance of the ionic liquid as solvent in such systems has been evaluated. The experimental data were correlated using the NRTL and UNIQUAC equations, and the binary interaction parameters have been reported. The phase diagrams for the ternary mixtures including both the experimental and calculated tie-lines have been presented.     

Essential oil deterpenation by solvent extraction using 1-ethyl-3-methylimidazolium 2-(2-methoxyethoxy) ethylsulfate ionic liquid

Taking into account that heat application can have undesirable effects in essential oil properties, liquid extraction comes up as a promising process instead of distillation for citrus oil deterpenation. In this work the suitability of using the ionic liquid 1-ethyl-3-methylimidazolium 2-(2-methoxyethoxy) ethylsulfate as a solvent for the extraction of linalool from citrus essential oil (which has been simulated as a mixture of limonene and linalool) has been analyzed. Liquid–liquid equilibrium data at three different temperatures (298.15 K, 308.15 K and 318.15 K) have been reported and successfully correlated using NRTL model. The best results were achieved using α = 0.1 for the systems at 298.15 K and 308.15 K and α = 0.2 at 318.15 K. The solute distribution ratio has showed values close to one and high values of selectivity have been achieved.     

Separation of toluene from alkanes using 1-ethyl-3-methylpyridinium ethylsulfate ionic liquid at T = 298.15 K and atmospheric pressure

In this paper, the separation of toluene from aliphatic hydrocarbons (heptane, or octane, or nonane) was analyzed by solvent extraction with 1-ethyl-3-methylpyridinium ethylsulfate ionic liquid, [EMpy][ESO₄]. Liquid?liquid equilibrium (LLE) data for the ternary systems {heptane (1) + toluene (2) + [EMpy][ESO₄] (3)}, {octane (1) + toluene (2) + [EMpy][ESO₄] (3)}, and {nonane (1) + toluene (2) + [EMpy][ESO₄] (3)} were obtained by measurements at T = 298.15 K and atmospheric pressure. The selectivity, % removal of aromatic, and solute distribution ratio, obtained from experimental equilibrium results, were used to determine the ability of [EMpy][ESO₄] as a solvent. The degree of consistency of the experimental LLE values was ascertained using the Othmer–Tobias and Hand equations. The experimental results for the ternary systems were correlated with the NRTL model. Finally, the results obtained were compared with other ionic liquids and other solvents.     

Isothermal vapor–liquid equilibrium at 333.15 K,excess molar volumes and refractive indices at 298.15 K for mixtures of tert-amyl methyl ether + ethanol + 2,2,4-trimethylpentane

Isothermal vapor–liquid equilibrium data at 333.15 K are measured for the binary system tert-amyl methyl ether + ethanol and tert-amyl methyl ether + 2,2,4-trimethylpentane and for ternary system tert-amyl methyl ether + ethanol + 2,2,4-trimethylpentane by using headspace gas chromatography. The experimental vapor–liquid equilibrium data were correlated with G^E models (Margules, van Laar, Wilson, NRTL, UNIQUAC) equations. The excess volume and deviations in molar refractivity data are also reported for the same binary and ternary systems at 298.15 K. These data were correlated with the Redlich–Kister equation for the binary systems and the Cibulka equation for the ternary system, respectively. The experimental ternary excess volume and deviations in molar refractivity data, were also compared with the estimated values from the binary contribution models of Tsao–Smith, Kohler, Rastogi and Radojkovi?.     

Influence of temperature on the (liquid + liquid) equilibria of {methanol + benzene + hexane} ternary system

In order to show the influence of temperature on the liquid-liquid equilibria (LLE) of {methanol (1) + benzene (2) + hexane (3)} ternary system, equilibrium data at T = (278.15, 283.15, and 293.15) K are reported. The effect of the temperature on liquid-liquid equilibrium is determined and discussed. Ternary system is available from the literature at T = 298 K. All chemicals were quantified by gas chromatography using a thermal conductivity detector. The solubility data for methanol + hexane and the upper critical temperature (UCST) at 308.3 K was reported. The tie line data for the ternary system were satisfactorily correlated by the Othmer and Tobias method, and the plait point coordinates for the three temperatures were estimated. Experimental data for the ternary system are compared with values calculated by the NRTL and UNIQUAC equations, and predicted by means of the UNIFAC group contribution method. It is found that the UNIQUAC and NRTL models provide similar good correlations of the equilibrium data at these three temperatures. Finally, the UNIFAC model predicts an immiscibility region larger than the experimental observed. Distribution coefficients were also analysed through distribution curves.     

Reliable evaluation of temperature-independent parameters in correlation of vapour–liquid equilibrium data

A new algorithm/program has been elaborated for simultaneous processing of different sets of vapour–liquid equilibrium data. The program was tested with six binary hexane + isomeric pentanol systems, each of them measured at three different isobaric conditions and one isothermal system of tert-butyl-methyl-ether + 2-methyl-2-propanol measured at three different temperatures. The correlation uses the maximum likelihood method, taking into account real behaviour of vapour phase. The parameters obtained are valid within the whole temperature range of the data, and are consistent in comparison with those obtained from individual correlations of isobars or isotherms. Results are presented for the Wilson and NRTL equations.     

Isothermal vapor–liquid equilibrium at 333.15 K and excess molar volumes and refractive indices at 298.15 K for the mixtures of di-methyl carbonate,ethanol and 2,2,4-trimethylpentane

Isothermal vapor–liquid equilibrium data at 333.15 K are measured for the binary system ethanol + 2,2,4-trimethylpentane and for ternary system di-methyl carbonate (DMC) + ethanol + 2,2,4-trimethylpentane by using headspace gas chromatography. The experimental binary and ternary vapor–liquid equilibrium data were correlated with different activity coefficient models. Excess volume and deviations in molar refractivity data are also reported for the binary systems DMC + ethanol and DMC + 2,2,4-trimethylpentane and the ternary system DMC + ethanol + 2,2,4-trimethylpentane at 298.15 K. These data were correlated with the Redlich-Kister equation for the binary systems and the Cibulka equation for the ternary system, respectively. The ternary excess volume and deviations in molar refractivity data were also compared with estimated values from the binary contribution models of Tsao–Smith, Kohler, Rastogi and Radojkovi?.