(Liquid + liquid) equilibria for mixtures of (ethylene glycol + benzene + cyclohexane) at temperatures (298.15, 308.15, and 318.15) K

Experimental (liquid + liquid) equilibrium (LLE) data for a ternary system containing (ethylene glycol + benzene + cyclohexane) were determined at temperatures (298.15, 308.15, and 318.15) K and at atmospheric pressure. The experimental distribution coefficients and selectivity factors are presented to evaluate the efficiency of the solvent for extraction of benzene from cyclohexane. The effect of temperature in extraction of benzene from the (benzene + cyclohexane) mixture indicated that at lower temperatures the selectivity (S) is higher, but the distribution coefficient (K) is rather lower. The LLE results for the system studied were used to obtain binary interaction parameters in the UNIQUAC and NRTL models by minimizing the root mean square deviations (RMSD) between the experimental results and calculated results. Using the interaction parameters obtained, the phase equilibria in the systems were calculated and plotted. The NRTL model fits the (liquid + liquid) equilibrium data of the mixture studied slightly better. The root mean square deviations (RMSDs) obtained comparing calculated and experimental two-phase compositions are 0.92% for the NRTL model and 0.95% for the UNIQUAC model.     

Isobaric (vapour + liquid + liquid) equilibrium data for (di-n-propyl ether + n-propyl alcohol + water) and (diisopropyl ether + isopropyl alcohol + water) systems at 100 kPa

Isobaric (vapour + liquid + liquid) equilibria were measured for the (di-n-propyl ether + n-propyl alcohol + water) and (diisopropyl ether + isopropyl alcohol + water) system at 100 kPa.The apparatus used for the determination of (vapour + liquid + liquid) equilibrium data was an all-glass dynamic recirculating still with an ultrasonic homogenizer couple to the boiling flask.The experimental data demonstrated the existence of a heterogeneous ternary azeotrope for both ternary systems. The (vapour + liquid + liquid) equilibria data were found to be thermodynamically consistent for both systems.The experimental data were compared with the estimation using UNIQUAC and NRTL models and the prediction of UNIFAC model.     

Isobaric vapor–liquid equilibria for 1-propanol + water + copper(II) chloride at 100 kPa

Isobaric vapor–liquid equilibria for the ternary system 1-propanol + water + copper(II) chloride has been measured at 100 kPa using a recirculating still. The addition of copper(II) chloride to the solvent mixture produced a salting-out effect of the alcohol, but the azeotrope did not tend to be eliminated when the salt content increased. The experimental data sets were fitted with the electrolyte NRTL model and the parameters of Mock's model were estimated. This model has proved to be suitable to represent experimental data in the entire range of compositions. The effect of copper(II) chloride on the vapor–liquid equilibrium of the 1-propanol + water system has been compared with that produced by other salts.     

(Liquid + liquid) equilibrium for the system {ethyl stearate(1) + ethanol(2) + glycerol(3)}

This paper reports the results of a new experimental study on the (liquid + liquid) equilibrium of the system {ethyl stearate(1) + ethanol(2) + glycerol(3)} at atmospheric pressure and at T = (313.15 and 323.15) K. The equilibrium compositions were measured by gas chromatography. Ternary diagrams were obtained for each temperature and the equilibrium data were compared to the system in the presence of salt (NaCl) at T = 323.15 K. The experimentally determined (liquid + liquid) equilibrium data were satisfactorily correlated with NRTL and UNIQUAC equations. A comparative analysis was performed using the UNIFAC-LLE group contribution method. From the results presented herein good predictions were obtained for this ternary system.     

Experimental and theoretical study of quaternary (liquid + liquid) equilibria for mixtures of (methanol or water + ethanol + toluene + n-decane)

Experimental (liquid + liquid) equilibrium data were obtained for the extraction of toluene from n-decane by mixed-solvents (ethanol + water) and (ethanol + methanol) at three temperatures (298.15, 303.15, and 313.15) K and ambient pressure.The measured tie-line data for two quaternary mixtures of {(ethanol +  water) + toluene + n-decane} and {(ethanol + methanol) + toluene + n-decane} are presented. The experimental quaternary (liquid + liquid) equilibrium data have been correlated using the NRTL activity coefficient model to obtain the binary interaction parameters of these components. The NRTL models predict the equilibrium compositions of the quaternary mixtures with small deviations. The partition coefficients and the selectivity factor of the mixed-solvents used were calculated and presented. From our experimental and calculated results, we conclude that for the extraction of toluene from n-decane mixtures the mixed-solvent (ethanol + methanol) has a higher selectivity factor than the other mixed-solvent at the three temperatures studied.     

Phase equilibria of ternary systems (water + pyruvic acid + high boiling alcohol). Thermodynamic modeling and optimization of extraction

Phase equilibria of the systems (water + pyruvic acid + high boiling alcohol) have been determined at T = 298.2 K. Among the heavy alcohol solvents studied, 1-decanol gives the largest distribution ratio and separation factors for extraction of pyruvic acid. The distribution data of pyruvic acid are used to establish the basis for an analytical structure to provide optimum extraction. Some aspects of selection of an appropriate criterion for designing optimum extraction of acid are discussed. The solvation energy relation (SERLAS) with 5- and 10-parameters has been performed to correlate the (liquid + liquid) equilibria (LLE) of associated systems containing a protic alcohol solvent capable of hydrogen bonding. The extraction equilibria were also predicted through the UNIFAC-original model. The reliability of both models has been analyzed against the LLE data with respect to the distribution ratio and separation factor.     

Ternary (liquid + liquid) equilibria of {trifluorotris(perfluoroethyl)phosphate based ionic liquids + thiophene + heptane}

Ternary (liquid + liquid) equilibria for three systems containing ionic liquids {(4-(2-methoxyethyl)-4-methylmorpholinium trifluorotris(perfluoroethyl)phosphate, 1-(2-methoxyethyl)-1-methylpiperidinium trifluorotris(perfluoroethyl)phosphate, 1-(2-methoxyethyl)-1-methylpyrrolidinium trifluorotris(perfluoroethyl)phosphate) + thiophene + heptane} have been determined at T = 298.15 K. All systems showed high solubility of thiophene in the ionic liquid and low solubility of heptane. The solute distribution coefficient and the selectivity were calculated for all systems. High values of selectivity were obtained. The experimental results have been correlated using NRTL model. The influence of ionic liquid structure on phase equilibria is discussed.     

Ternary and quaternary (liquid + liquid) equilibria for (water + ethanol + α-pinene, +β-pinene,or +limonene) and (water + ethanol + α-pinene + limonene) at the temperature 298.15 K

(Liquid + liquid) equilibria and tie-lines for the ternary (water + ethanol + α-pinene, or β-pinene or limonene) and quaternary (water + ethanol + α-pinene + limonene) mixtures have been measured at T = 298.15 K. The experimental multicomponent (liquid + liquid) equilibrium data have been successfully represented in terms of the modified UNIQUAC model with binary parameters.     

Temperature dependence on mutual solubility of binary (methanol + limonene) mixture and (liquid + liquid) equilibria of ternary (methanol + ethanol + limonene) mixture

Mutual solubility data of the binary (methanol + limonene) mixture at the temperatures ranging from 288.15 K close to upper critical solution temperature, and ternary (liquid + liquid) equilibrium (tie-lines) of the (methanol + ethanol + limonene) mixture at the temperatures (288.15, 298.15, and 308.15) K have been obtained. The experimental results have been represented accurately in terms of the extended and modified UNIQUAC models with binary parameters, compared with the UNIQUAC model. The temperature dependence of binary and ternary (liquid + liquid) equilibrium for the binary (methanol + limonene) and ternary (methanol + ethanol + limonene) mixtures could be calculated successfully using the extended and modified UNIQUAC model.     

Influence of temperature on the (liquid + liquid) equilibria of {3-methyl pentane + cyclopentane + methanol} ternary system at T = (293.15, 297.15, and 299.15) K

In order to show the influence of temperature on the (liquid + liquid) equilibria (LLE) of the {3-methyl pentane (1) + cyclopentane (2) + methanol (3)} ternary system, equilibrium results at T = (293.15, 297.15, and 299.15) K are reported. The effect of the temperature on the (liquid + liquid) equilibrium is determined and discussed. Experimental results show that this ternary system is completely homogeneous beyond T = 300 K. All chemicals were quantified by gas chromatography using a thermal conductivity detector. The tie line results were satisfactorily correlated by the Othmer and Tobias method, and the plait point coordinates for the three temperatures were estimated. Experimental values 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 solubility curve at these three temperatures. Finally, the UNIFAC model predicts binodal band type curves in the range of temperatures studied here, similar to those observed for systems classified by Treybal as type 2, instead of type 1 as experimentally observed. Distribution coefficients were also analysed through distribution curves.     

(Liquid + liquid) equilibria for ternary mixtures of (polyvinylpyrrolidone + MgSO4 + water) at different temperatures

Experimental (liquid + liquid) equilibrium (LLE) data were determined for a ternary system (polyvinylpyrrolidone + MgSO₄ + water) at various temperatures of (298.15, 303.15, and 308.15) K. The UNIQAC, modified regular solution, modified Wilson and Chen-NRTL models were used to correlate the experimental tie-line data. The results show that at each temperature, the quality of fitting is better with the Chen-NRTL model.     

Measurements and modeling of quaternary (liquid + liquid) equilibria for mixtures of (methanol or ethanol + water + toluene + n-dodecane)

The extraction of aromatic compound toluene from alkane, dodecane, by mixed solvents (water + methanol), (water + ethanol) and (methanol + ethanol) have been studied by (liquid + liquid) equilibrium (LLE) measurements at three temperatures (298.15, 303.15, and 313.15) K and ambient pressure. The compositions of liquid phases at equilibrium were determined by gas liquid chromatography.The experimental tie-line data for three quaternary mixtures of {(water + methanol) + toluene + dodecane}, {(water + ethanol) + toluene + dodecane}, and {(methanol + ethanol) + toluene + dodecane} are presented. The experimental quaternary LLE data have been satisfactorily correlated by using the UNIQUAC and NRTL activity coefficient models. The parameters of the models have been evaluated and presented. The tie-line data of the studied quaternary mixtures also were correlated using the Hand method. The partition coefficients and the selectivity factor of solvent are calculated and compared for the three mixed solvents.The comparisons indicate that the selectivity factor for mixed solvent (methanol + ethanol) is higher than the other two mixed solvents at the three studied temperatures. However, considering the temperature variations of partition coefficients of toluene in two liquid phases at equilibrium, an optimum temperature may be obtained for an efficient extraction of toluene from dodecane by the mixed solvents.     

Measurement of (liquid + liquid) equilibria for ternary systems of (N-formylmorpholine + benzene + cyclohexane) at temperatures (303.15, 308.15, and 313.15) K

This work demonstrates the ability of N-formylmorpholine (NFM) to act as an extraction solvent for the removal of benzene from its mixture with cyclohexane. The (liquid + liquid) equilibria (LLE) were measured for a ternary system of {N-formylmorpholine (NFM) + benzene + cyclohexane} under atmospheric pressure and at temperatures (303.15, 308.15, and 313.15) K. The experimental distribution coefficients (K) and selectivity factors (S) were obtained to reveal the extractive effectiveness of the solvent for separation of benzene from cyclohexane. The LLE results for the system studied indicate that increasing temperature decreases selectivity of the solvent. The reliability of the experimental results was tested by applying the Othmer–Tobias correlation. In addition, the universal quasichemical activity coefficient (UNIQUAC) and the non-random two liquids equation (NRTL) were used to correlate the LLE data using the interaction parameters determined from the experimental data. The root mean square deviations (RMSDs) obtained comparing calculated and experimental two-phase compositions are 0.0367 for the NRTL model and 0.0539 for the UNIQUAC model.     

(Liquid + liquid), (solid + liquid), and (solid + liquid + liquid) equilibria of systems containing cyclic ether (tetrahydrofuran or 1,3-dioxolane), water,and a biological buffer MOPS

Two liquid phases were formed as the addition of a certain amount of biological buffer 3-(N-morpholino)propane sulfonic acid (MOPS) in the aqueous solutions of tetrahydrofuran (THF) or 1,3-dioxolane. To evaluate the feasibility of recovering the cyclic ethers from their aqueous solutions with the aid of MOPS, we determined experimentally the phase diagrams of the ternary systems of {cyclic ether (THF or 1,3-dioxolane) + water + MOPS} at T = 298.15 K under atmospheric pressure. In this study, the solubility data of MOPS in water and in the mixed solvents of water/cyclic ethers were obtained from the results of a series of density measurements, while the (liquid + liquid) and the (solid + liquid + liquid) phase boundaries were determined by visually inspection. Additionally, the tie-line results for (liquid + liquid) equilibrium (LLE) and for (solid + liquid + liquid) equilibrium (SLLE) were measured using an analytical method. The reliability of the experimental LLE tie-line results data was validated by using the Othmer–Tobias correlation. These LLE tie-line values were correlated well with the NRTL model. The phase diagrams obtained from this study reveal that MOPS is a feasible green auxiliary agent to recover the cyclic ethers from their aqueous solutions, especially for 1,3-dioxolane.     

(Liquid + liquid) equilibrium of (water + 2-propanol + 1-butanol + salt) systems at T = 313.15 K and T = 353.15 K: Experimental data and correlation

(Liquid + liquid) equilibrium data for the quaternary systems (water + 2-propanol + 1-butanol + potassium bromide) and (water + 2-propanol + 1-butanol + magnesium chloride) were measured at T = 313.15 K and T = 353.15 K. The overall salt concentrations were 5 and 10 mass percent. Ternary (liquid + liquid) equilibrium data for the salt-free system (water + 2-propanol + 1-butanol) were also determined and found to be in good agreement with data from the literature. The NRTL model for the activity coefficient was used to correlate the data. New interaction parameters were estimated, using the Simplex minimization method and a concentration-based objective function. The results are very satisfactory, with root mean square deviations between experimental and calculated compositions of both phases being less than 0.5%.     

(Liquid + liquid) equilibria of (sulfolane + benzene + n-hexane), (N-formylmorpholine + benzene + n-hexane), and (sulfolane + N-formylmorpholine + benzene + n-hexane) at temperatures ranging from (298.15 to 318.15) K: Experimental results and correlation

The experimental (liquid + liquid) equilibrium (LLE) properties for two ternary systems containing (N-formylmorpholine + benzene + n-hexane), (sulfolane + benzene + n-hexane) and a quaternary mixed solvent system (sulfolane + N-formylmorpholine + benzene + n-hexane) were measured at temperature ranging from (298.15 to 318.15) K and at an atmospheric pressure. The experimental distribution coefficients and selectivity factors are presented to evaluate the efficiency of the solvents for extraction of benzene from n-hexane. The LLE results obtained indicate that increasing temperature decreases selectivity for all solvents. The LLE results for the systems studied were used to obtain binary interaction parameters in the UNIQUAC model by minimizing the root mean square deviations (RMSD) between the experimental and calculated results. Using the interaction parameters obtained, the phase equilibria in the systems were calculated and plotted. The calculated compositions based on the UNIQUAC model were found to be in good agreement with the experimental values. The result of the RMSD obtained by comparing the calculated and experimental two-phase compositions is 0.0163 for (N-formylmorpholine + benzene + n-hexane) system and is 0.0120 for (sulfolane + benzene + n-hexane) system.     

Measurement and modeling of high-pressure (vapour + liquid) equilibria of (CO2 + alcohol) binary systems

An apparatus based on a static-analytic method assembled in this work was utilized to perform high pressure (vapour + liquid) equilibria measurements with uncertainties estimated at <5%. Complementary isothermal (vapour + liquid) equilibria results are reported for the (CO₂ + 1-propanol), (CO₂ + 2-methyl-1-propanol), (CO₂ + 3-methyl-1-butanol), and (CO₂ + 1-pentanol) binary systems at temperatures of (313, 323, and 333) K, and at pressure range of (2 to 12) MPa. For all the (CO₂ + alcohol) systems, it was visually monitored to insure that there was no liquid immiscibility at the temperatures and pressures studied. The experimental results were correlated with the Peng–Robinson equation of state using the quadratic mixing rules of van der Waals with two adjustable parameters. The calculated (vapour + liquid) equilibria compositions were found to be in good agreement with the experimental values with deviations for the mol fractions <0.12 and <0.05 for the liquid and vapour phase, respectively.     

Thermodynamic evaluation and optimization of the (Ca + C + O + S) system

A critical evaluation of all available thermodynamic and (solid + liquid) phase equilibrium data for the (Ca + C + O + S) system has been performed. The liquid phase was modelled using the Modified Quasichemical Model in the pair approximation. The present database reproduces the (solid + liquid) equilibria of the experimentally studied subsystems of the (Ca + C + O + S) system within the experimental error limits. Estimations of the phase equilibria of systems lacking experimental data were made. The database of thermodynamic data for all phases can be used, along with other databases and Gibbs free energy minimization software, to calculate the phase equilibria and all thermodynamic properties of (Ca + C + O + S) mixtures, which are of great importance for several industrially relevant processes.     

Quaternary liquid–liquid equilibrium for water + 1-propanol + cesium sulfate + cesium chloride at 25 °C

Liquid–liquid equilibria for the quaternary system water + 1-propanol + cesium sulfate + cesium chloride were measured at 25 °C. The binodal curves and tie lines for quaternary system have been determined in order to investigate salting effects. Experimental tie lines were compared with values predicated by a modification of the Eisen–Joffe equation.