Liquid—Liquid Equilibria for the Water-ethanol-methyl Ethyl Ketone Ternary System at 298.15 and 318.15 K

Abstract

Ternary liquid—liquid equilibrium data for the system water-ethanol-methyl ethyl ketone were obtained at 298.15 and 318.15 K. Data for the binodal curves have been determined by the cloud-point method and conjugate points on tie-lines were determined by gas-chromatographic analysis. Tie-line data at each temperature were satisfactorily correlated by the Othmer and Tobias' method and the plait points coordinates were estimated. The experimental data were also fitted with the UNIFAC group contribution method for the activity coefficients using the isoactivity conditions as restraint equations and with the NRTL and UNIQUAC models.     

Liquid–Liquid Equilibria of the Methanol + Ethylbenzene + Methylcyclohexane Ternary System at 278.15, 283.15, and 293.15 K

Liquid–liquid equilibria of the methanol + ethylbenzene + methylcyclohexane ternary system are reported at 278.15, 283.15, and 293.15 K. The effect of the temperature on the liquid–liquid equilibrium is discussed. All chemical concentrations were quantified by gas chromatography using a thermal conductivity detector. Experimental data for the ternary system are compared with values calculated by the NRTL and UNIQUAC equations. It was found that both equations gave comparable quality representations of the experimental data for this ternary system. Distribution curves were also analyzed. Data for the ternary system is available from the literature at 303.15 K.     

Liquid–Liquid Equilibrium of Water + 1-Butanol + Inorganic Salt Systems at 303.15, 313.15 and 323.15 K: Experiments and Correlation

Liquid–liquid equilibria (LLE) and tie-line data of systems containing 1-butanol, water and NaCl, Na₂SO₄, NH₄Cl or (NH₄)₂SO₄ were investigated at 303.15, 313.15 and 323.15 K and atmospheric pressure. The salt decreases mutual solubilities of these two solvents leading to a higher degree of phase separation at equilibrium. The effect is more pronounced at high salt concentration. Temperature in the studied range had a minor effect on LLE behavior of these mixtures. Experimental data were correlated using a modified extended UNIQUAC model. Satisfactory agreement between the calculated and measured mass fractions of the components was achieved.     

Liquid–Liquid Equilibria of Some Aliphatic Alcohols + Disodium Hydrogen Citrate + Water Ternary Systems at 298.15 K

In this paper, the liquid?Cliquid equilibria for 1-propanol, 2-propanol or 2-methyl-2-propanol + disodium hydrogen citrate aqueous two-phase systems at 298.15 K were studied. The experimental binodal curves at 298.15?K are reported, and the parameters of the Merchuk equation, modified as a nonlinear function of mixed solvent properties and used for the simultaneous correlation of the experimental binodal data. Moreover, the salting-out ability of different salts and different alcohols with different anions is discussed. Additionally, experimental tie-line data are reported at 298.15 K. The generalized electrolyte-NRTL model of the mixed solvent electrolyte systems (e-NRTL) satisfactorily used for the correlation of the tie-line compositions; restricted binary interaction parameters were also obtained.     

Liquid–Liquid Equilibria of the Methanol + Toluene + Methylcyclohexane Ternary System at 278.15, 283.15, 288.15, 293.15, 298.15 and 303.15 K

Liquid–liquid equilibria of the methanol + toluene + methylcyclohexane ternary system at 278.15, 283.15, 288.15, 293.15, 298.15 and 303.15 K are reported. The effect of the temperature on liquid–liquid equilibrium is discussed. Data for the ternary system is available from the literature at T = 298 K. All chemicals were quantified by gas chromatography using a thermal conductivity detector. Experimental data for the ternary system are compared with values calculated by the NRTL and UNIQUAC equations. It is found that the UNIQUAC and NRTL models provide similar good correlations of the solubility curve at these six temperatures.     

Chemical Equilibrium for the Reacting System Acetic Acid–Ethanol–Ethyl Acetate–Water at 303.15 K, 313.15 K and 323.15 K

The chemical equilibrium (CE) for the quaternary reacting system ethanol–acetic acid–ethyl acetate–water was studied at 303.15, 313.15 and 323.15 K and atmospheric pressure. The CE compositions were determined by gas chromatography and nuclear magnetic resonance analytical methods. The thermodynamic constants of CE at 303.15, 313.15 and 323.15 K were calculated based on the obtained experimental data with the use of the NRTL model.     

Quaternary Liquid–Liquid Equilibria for Aqueous Systems Containing Dimethyl Carbonate at 298.15 K

Experimental tie-line data for two ternary systems, water + dimethyl carbonate + methanol or ethanol, and two quaternary systems, water + dimethyl carbonate + toluene + methanol or ethanol were investigated at 298.15 K and atmospheric pressure. The experimental liquid–liquid equilibrium data were correlated using a modified UNIQUAC activity coefficient model with binary and ternary as well as quaternary parameters. The calculated results were further compared with those obtained from an extended UNIQUAC model.     

Activity Coefficient Determination for the Ternary Systems CsCl in N-Methylformamide or Urea + Water Mixtures at T = 298.15 K

The mean activity coefficients for CsCl in N-methylformamide or urea (w) + H₂O (1 ? w) systems were determined in this work by potentiometry, using ion-selective electrodes at 298.15 K. The value of mass fraction w was varied between 0.00 and 0.40 in five unit-steps and the molality of CsCl was between 0.0020 and 1.4009 mol·kg^?1. The experimental data have been correlated with the Pitzer, modified Pitzer and the extended Debye–Hückel equations. The resulting values of the mean activity coefficients, the osmotic coefficients and the standard Gibbs energy of transfer, together with the Pitzer ion-interaction parameters (β ⁽⁰⁾, β ⁽¹⁾ and C ^φ), extended Debye–Hückel parameters (a, c and d), and modified Pitzer parameters (b, B _MX, C _MX) are reported for the investigated systems.     

Quaternary Liquid–Liquid Equilibria for Fuel Additive Systems Containing Diethyl Carbonate or 1,1-Dimethylethyl Methyl Ether at 298.15 K and Atmospheric Pressure

Liquid–liquid equilibrium tie line data were determined for three quaternary systems water + ethanol + diethyl carbonate+n-heptane, water + ethanol + 1,1-dimethylethyl methyl ether + diethyl carbonate, and water + 1,1-dimethylethyl methyl ether + diethyl carbonate+n-heptane at 298.15 K and atmospheric pressure. The experimental liquid–liquid equilibria results have been correlated using a modified UNIQUAC model and an extended UNIQUAC model, both with multicomponent interaction parameters in addition to the binary ones.     

Solid–Liquid Equilibrium for the Ternary System 2-Methyl-4-Nitroaniline + 2-Methyl-6-Nitroaniline + Ethyl Acetate: Determination and Modelling

The solid–liquid phase equilibria for the ternary system 2-methyl-4-nitroaniline + 2-methyl-6-nitroaniline + ethyl acetate was determined experimentally by the method of isothermal solution saturation at temperatures of (293.15, 303.15 and 313.15) K under the pressure of 101.2 kPa. Based on the obtained solubility data, the isothermal phase diagrams of the system were constructed. At each temperature, there are two pure solid phases formed, which correspond to pure 2-methyl-4-nitroaniline and pure 2-methyl-6-nitroaniline, which was confirmed by Schreinemakers’ wet residue method and X-ray powder diffraction. The crystallization regions of pure 2-methyl-4-nitroaniline and pure 2-methyl-6-nitroaniline increased with decreasing temperature. The crystalline region of 2-methyl-4-nitroaniline was larger than that of 2-methyl-6-nitroaniline at a fixed temperature. The solubility data were correlated with the NRTL and Wilson models. The values of the root-mean-square deviations are 5.01 × 10^?3 for the NRTL model, and 6.43 × 10^?3 for the Wilson model. The solid–liquid equilibria, phase diagrams and the thermodynamic models for the ternary system can provide the foundation for separating 2-methyl-6-nitroaniline or 2-methyl-4-nitroaniline from its mixtures.     

Isothermal Vapor–Liquid Equilibria for the Ternary System 2-Propanol + Tetrahydrofuran + 1-Chlorobutane at 25°C

Isothermal vapor–liquid equilibria (VLE) for mixtures containing 2-propanol + tetrahydrofuran + 1-chlorobutane have been measured using a modified version of a Boublik–Benson still at 25°C. A test of thermodynamic consistency, like the McDermott–Ellis method was applied to the activity coefficients. Excess molar Gibbs free energies were calculated over the entire range composition. Different expressions existing in the literature were used to predict activity coefficients.     

Solubility Data of Diazepam in Binary and Ternary Mixtures of PEGs 200 and 400 with N-Methyl Pyrrolidone and Water at 298.2 K: Experimental Data and Modeling

Experimental solubilities of diazepam in binary and ternary solvents of polyethylene glycols 200 and 400 with N-methyl pyrrolidone and water at T = 298.2 K are reported. The Jouyban–Acree model was used to fit solubility data of diazepam in the binary and ternary solvent mixtures (106 data points) in which the overall mean relative deviations (OMRD %) is 13.1 % and the prediction OMRD % is 31.7 %. The combined version of the Jouyban–Acree model with Hansen solubility parameters was used for fitting and predicting the solubility data and the OMRDs % are 10.0 and 20.8 %, respectively. Also, the previously proposed trained versions of the Jouyban–Acree model were used for predicting the reported data in this work and all results are listed in the tables. The density of the solute-free solvent mixtures were measured and employed to calculate the constants of the Jouyban–Acree model and then the densities of the saturated solutions were predicted.