Vapor-liquid equilibria at 333.15 K and excess molar volumes and deviations in molar refractivity at 298.15 K for mixtures of diisopropyl ether, ethanol and ionic liquids

In this work, we have studied influence of ionic liquids (ILs) on the azeotrope composition for the system {diisopropyl ether (DIPE) + ethanol} using trihexyltetradecylphosphonium chloride ([P_666,14][Cl]) and trihexyltetradecylphosphonium bis(2,2,4-trimethylpentyl) phosphinate ([P_666,14][TMPP]). Isothermal vapor-liquid equilibrium data at 333.15 K are reported for the ternary systems {DIPE + ethanol + [P_666,14][Cl]} and {DIPE + ethanol + [P_666,14][TMPP]} with varying the mole fraction of ILs from 0.05 to 0.10. The experimental ternary VLE data were correlated using the Wilson equation. In addition, excess molar volumes (V^E) and deviations in molar refractivity (ΔR) data at 298.15 K are reported for the binary systems {DIPE + [P_666,14][Cl]} and {ethanol + [P_666,14][Cl]} by a digital vibrating tube densimeter and a precision digital refractometer. The V^E and ΔR were correlated by the Redlich-Kister equation.     

Volumetric properties of the ternary system ethanol + chloroform + benzene at temperature range (288.15–313.15) K: Experimental data,correlation and prediction by cubic EOS

Densities ρ of the ternary system (ethanol + chloroform + benzene) and binaries (ethanol + chloroform) and (chloroform + benzene), have been measured at six temperatures (288.15, 293.15, 298.15, 303.15, 308.15, 313.15) K and pressure 101.33 kPa with an Anton Paar DMA 5000 digital vibrating tube densimeter. Excess molar volumes V^E were calculated from these densities data and fitted by the polynomial Redlich–Kister (for binary data) and Nagata and Tamura (for ternary data) equations. Radojkovi? et al. equation was used for the prediction of the V^E of ternary data. The obtained results have been explained in terms of different effects between molecules of present species, taking into consideration influence of temperature on them.     

(Liquid + liquid) equilibria of the quaternary system methanol + isooctane + cyclohexane + benzene at T = 303.15 K

Tie line data of the ternary system {methanol + isooctane + cyclohexane} were obtained at T = 303.15 K. A quaternary system containing these three compounds and benzene was also studied at the same temperature, while data for {methanol + benzene + cyclohexane} and {methanol + benzene + isooctane} were taken from literature. In order to obtain the binodal surface of the quaternary system, four quaternary sectional planes with several cyclohexane/isooctane ratios were studied. The distribution of benzene between both phases was also analysed. Ternary experimental results were correlated with the UNIQUAC and NRTL equations and compared with predictions using the UNIFAC group contribution method.     

Excess Gibbs energies and volumes of the ternary system chloroform + tetrahydrofuran + cyclohexane at 298.15 K

Vapour–liquid equilibria and densities for the ternary system chloroform + tetrahydrofuran + cyclohexane and for the binary mixtures containing chloroform have been determined at 298.15 K. Vapour–liquid equilibrium data have been collected by head-space gas-chromatographic analysis of the vapour phase directly withdrawn from an equilibration apparatus. Density measurements have been carried out by means of a vibrating tube densimeter. Molar excess Gibbs energies G^E and volumes V^E, as well as activity coefficients and apparent molar volumes of the components, have been obtained from the measured quantities and discussed. The binary chloroform + tetrahydrofuran displays negative deviations from ideality, while chloroform + cyclohexane positive deviations, for both volume and Gibbs energy. The G^E's and V^E's for the ternary system are positive in the region rich in cyclohexane while negative in the region rich in chloroform + tetrahydrofuran. This indicates that hydrogen bonding between chloroform and tetrahydrofuran molecules produces negative values of G^E and V^E and strongly influences the behaviour of the ternary system.     

Isobaric vapor–liquid equilibria of 1,1-dimethylethoxy-butane + methanol or ethanol + water at 101.32 kPa

Isobaric vapor–liquid equilibrium data (VLE) at 101.325 kPa have been determined in the miscible region for 1,1-dimethylethoxy-butane (BTBE) + methanol + water and 1,1-dimethylethoxy-butane (BTBE) + ethanol + water ternary systems, and for their constituent binary systems, methanol + BTBE and ethanol + BTBE. Both binary systems show an azeotrope at the minimum boiling point. In the ternary system BTBE + methanol + water no azeotrope has been found, however, the system BTBE + ethanol + water might form a ternary azeotrope near the top of the binodal. Thermodynamically consistent VLE data have been satisfactorily correlated using the UNIQUAC, NRTL and Wilson equations for the activity coefficient of the liquid phase. Temperature and vapor phase compositions have been compared with those calculated by the group-contribution methods of prediction ASOG, and the original and modified UNIFAC. Predicted values are not in good agreement with experimental values.     

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.     

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.     

Excess molar volumes of N,N-dimethylformamide + 2-pentanone + alkan-1-ols mixed solvent systems at 303.15 K

Accurate excess molar volumes (V^E), at ambient pressure and 303.15 K, have been determined in the ternary liquid mixtures of N,N-dimethylformamide (DMF) + 2-pentanone (PE) + 1-alkan-1-ols (C₃-C₆) and in the binary mixtures of PE + alkan-1-ols (C₃-C₆) as a function of composition. The alkanols include 1-propanol, 1-butanol, 1-pentanol and 1-hexanol. The intermolecular interactions and structural effects were analyzed on the basis of the measured and derived properties. Excess molar volumes increase in magnitude with increase in chain length of alcohol. Valuable information on the behavior and governing factors of the liquid structure of the strongly associated solvents studied were inferred from the parameters deduced. The V^E results were correlated and fitted by the Redlich-Kister equation for binary mixtures and by the Cibulka equation for ternary mixtures, as a function of mole fraction. Several predictive empirical relations were applied to predict the excess volumes of ternary mixtures from the binary mixing data. An analysis of the data indicates a good agreement between experimental results and predicted values in all ternary systems. A discussion is presented and deviations are interpreted in terms of size, shape, the position of ketone group, the chain length of alkanol and hydrogen bond effects in the liquid mixtures studied to explain chemical and thermophysical behavior.     

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?.     

Liquid phase equilibria of (water + phosphoric acid + 1-butanol or butyl acetate) ternary systems at T = 308.2 K

(Liquid + liquid) equilibria and tie lines for the ternary systems of (water + phosphoric acid + 1-butanol) and (water + phosphoric acid + butyl acetate) were measured at T = 308.2 K. The experimental ternary (liquid + liquid) equilibrium data were correlated with the UNIQUAC model. The reliability of the experimental tie lines was confirmed using Othmer-Tobias correlation. The average root-mean-square deviation (RMSD) values of (water + phosphoric acid + 1-butanol) and (water + phosphoric acid + butyl acetate) systems were 2.17% and 2.16%, respectively. Distribution coefficients and separation factors were measured to evaluate the extracting capability of the solvents. The results show that butyl acetate may be considered as a reliable organic solvent for the extraction of phosphoric acid from aqueous solutions.     

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.     

Vapour pressure and excess Gibbs free energy of the ternary system {x1CH3F + x2HCl + x3N2O} at temperature of 182.33 K

The equilibrium pressure of ternary mixtures of {x₁CH₃F + x₂HCl + x₃N₂O} covering the entire composition range has been measured at temperature of 182.33 K by the static method. The system exhibits a minimum pressure for the binary {x₁CH₃F + x₂HCl}. The molar excess Gibbs free energy has been calculated from the experimental equilibrium pressure. For the equimolar mixture . The (p, x, y) surface for the ternary system and the corresponding curves for the three constituent binary mixtures obtained from the Peng-Robinson equation of state are in agreement with the experimental data.     

Densities, refractive indices and speeds of sound of the ternary mixtures (dimethyl carbonate + methanol + ethanol) and (dimethyl carbonate + methanol + 1-propanol) at T=298.15 K

Density, refractive index and speed of sound at T=298.15 K and atmospheric pressure have been measured over the entire composition range for (dimethyl carbonate (DMC) + methanol + ethanol) and (DMC + methanol + 1-propanol). Excess molar volumes, changes of refractive index on mixing and deviations in isentropic compressibility for the above systems have been calculated. The calculated quantities are further fitted to the Cibulka equation to estimate the ternary fitting parameters. Standard deviations from the regression lines are shown.     

Volumetric, ultrasonic and viscometric studies of binary mixtures of dimethyl sulphoxide with chloro and nitro substituted aromatic hydrocarbons at T = 303.15 K

Excess volumes (V^E) ultrasonic sound velocities (u), isentropic compressibilities (K_s) and viscosities (η) have been measured for the binary mixtures of dimethylsulphoxide (DMSO) with 1,2-dichlorobenzene, 1,3-dichlorobenzene, 1,2,4-trichlorobenzene, o-chlorotoluene, m-chlorotoluene, p-chlorotoluene, o-nitrotoluene and m-nitrotoluene at T = 303.15 K. The measured V^E values were positive over the entire composition range in all the binary mixtures. Isentropic compressibilities (K_s) have been computed for the same systems from precise sound velocity and density data. Further, deviation in isentropic compressibility (ΔK_s) from ideal behaviour was also calculated. The viscosity data are analysed on the basis of corresponding states approach. Deviation in viscosities are positive over the entire composition range. The measured data is explained on the basis of intermolecular interactions between unlike molecules.     

(Liquid + liquid) equilibria of {heptane + xylene + N-formylmorpholine} ternary system

(Liquid + liquid) equilibrium (LLE) data for ternary system {heptane (1) + m-xylene (2) + N-formylmorpholine (3)} have been determined experimentally at temperatures ranging from 298.15 K to 353.15 K. Complete phase diagrams were obtained by determining solubility and tie-line data. Tie-line compositions were correlated by Othmer-Tobias and Bachman methods. The universal quasichemical activity coefficient (UNIQUAC) and The non-random two liquids equation (NRTL) were used to correlate the phase equilibrium in the system using the interaction parameters determined from experimental data. It is found that UNIQUAC and NRTL used for LLE could provide a good correlation. Distribution coefficients, separation factors, and selectivity were evaluated for the immiscibility region.     

Molecular interactions in (2,4,6-trimethyl-1,3,5-trioxane + n-alkyl acetates) at T = (298.15, 303.15, and 308.15) K

Densities and viscosities of the binary mixtures of 2,4,6-trimethyl-1,3,5-trioxane with methyl acetate, ethyl acetate, and 1-butyl acetate were measured over the entire mole fractions at (298.15, 303.15, and 308.15) K. Using the experimental values of densities ρ and viscosities η, excess molar volumes V^E, viscosity deviations δη were calculated. The values of excess molar volumes V^E and viscosity deviations δη were fitted to the Redlich-Kister polynomial.     

Physical properties of 3-methyl-N-butylpyridinium tricyanomethanide and ternary LLE data with an aromatic and an aliphatic hydrocarbon at T = (303.2 and 328.2) K and p = 0.1 MPa

Several physical properties were determined for the ionic liquid 3-methyl-N-butylpyridinium tricyanomethanide ([3-mebupy]C(CN)₃): liquid density, viscosity, surface tension, thermal stability and heat capacity in the temperature range from (283.2 to 363.2) K and at 0.1 MPa. The density and the surface tension could well be correlated with linear equations and the viscosity with a Vogel-Fulcher-Tamman equation. The IL is stable up to a temperature of 420 K.Ternary data for the systems {benzene + n-hexane, toluene + n-heptane, and p-xylene + n-octane + [3-mebupy]C(CN)₃} were determined at T = (303.2 and 328.2) K and p = 0.1 MPa. All experimental data were well correlated with the NRTL model. The experimental and calculated aromatic/aliphatic selectivities are in good agreement with each other.     

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.     

Liquid-liquid equilibria of ternary mixtures of dimethyl carbonate, diphenyl carbonate, phenol and water at 358.15 K

The ternary liquid-liquid equilibria (LLE) of the following systems were analytically determined at 358.15 K at atmospheric pressure using stirred and thermo-regulated cells: {dimethyl carbonate (DMC) + diphenyl carbonate (DPC) + water}, {DMC + phenol + water} and {DPC + phenol + water}. The experimental ternary LLE data were correlated with the NRTL and UNIQUAC activity coefficient models. Additionally, the Bachman-Brown correlation was used to ascertain the reliability of the experimental data for each system.     

Vapour pressure and excess Gibbs energy of binary 1,2-dichloroethane + cyclohexanone,chloroform + cyclopentanone and chloroform + cyclohexanone mixtures at temperatures from 298.15 to 318.15 K

The vapour pressures of the binary systems 1,2-dichloroethane + cyclohexanone, chloroform + cyclopentanone and chloroform + cyclohexanone mixtures were measured at temperatures between 298.15 and 318.15 K. The vapour pressures vs. liquid phase composition data for three isotherms have been used to calculate the activity coefficients of the two components and the excess molar Gibbs energies, G^E, for these mixtures, using Barker's method. Redlich–Kister, Wilson, NRTL and UNIQUAC equations, taking into account the vapour phase imperfection in terms of the 2-nd virial coefficient, have represented the G^E values. No significant difference between G^E values obtained with these equations has been observed. Our data on vapour–liquid equilibria (VLE) and excess properties of the studied systems are examined in terms of the DISQUAC and modified UNIFAC (Dortmund) predictive group contributions models.