Liquid–liquid equilibria for the ternary system water + tetradecane + 2-butyloxyethanol

Liquid–liquid equilibria of the ternary system water + tetradecane + 2-butyloxyethanol in the temperature range from 298.15 to 338.15 K were investigated at atmospheric pressure. The experimental data correlated well with the UNIQUAC model. For the system with a three-liquid-phase-coexisting region, all the six UNIQUAC interaction parameters can be determined numerically by minimizing the deviation of the compositions of three coexisting liquid phases only.     

Vapor–liquid equilibrium of binary mixtures of trichloroethylene with 1-pentanol, 2-methyl-1-butanol and 3-methyl-1-butanol at 100 kPa

Isobaric vapor–liquid equilibria (VLE) have been obtained for the systems trichloroethylene+1-pentanol, trichloroethylene+2-methyl-1-butanol and trichloroethylene+3-methyl-1-butanol at 100 kPa using a dynamic still. The experimental error in temperature is ±0.1 K, in pressure ±0.1 kPa, and in the liquid and vapor mole fraction ±0.001. The three systems satisfy the point-to-point thermodynamic consistency test. All the systems show positive deviations from ideality. The data have been correlated with the Margules, van Laar, Wilson, NRTL and UNIQUAC equations.     

High-pressure phase equilibria for the carbon dioxide–2-methyl-1-butanol,carbon dioxide–2-methyl-2-butanol,carbon dioxide–2-methyl-1-butanol–water,and carbon dioxide–2-methyl-2-butanol–water systems

High-pressure vapor–liquid equilibria for the binary carbon dioxide–2-methyl-1-butanol and carbon dioxide–2-methyl-2-butanol systems were measured at 313.2 K. The phase equilibrium apparatus used in this work is of the circulation type in which the coexisting phases are recirculated, on-line sampled, and analyzed. The critical pressure and corresponding mole fraction of carbon dioxide for the binary carbon dioxide–2-methyl-1-butanol system at 313.2 K were found to be 8.36 MPa and 0.980, respectively. The critical point of the binary carbon dioxide–2-methyl-2-butanol was also found 8.15 MPa and 0.970 mole fraction of carbon dioxide. In addition, the phase equilibria of the ternary carbon dioxide–2-methyl-1-butanol–water and carbon dioxide–2-methyl-2-butanol–water systems were measured at 313.2 K and several pressures. These ternary systems showed the liquid–liquid–vapor phase behavior over the range of pressure up to their critical point. The binary equilibrium data were all reasonably well correlated with the Redlich–Kwong (RK), Soave–Redlich–Kwong (SRK), Peng–Robinson (PR), and Patel–Teja (PT) equations of state with eight different mixing rules the van der Waals, Panagiotopoulos–Reid (P&R), and six Huron–Vidal type mixing rules with UNIQUAC parameters.     

Liquid–liquid equilibria in ternary systems of linear and cross-linked water-soluble polymers

In this study, ternary liquid–liquid equilibrium data of structurally similar linear and cross-linked polymers have been measured in order to elucidate the significance of mixing and elastic effects in sorption of binary liquid mixtures by cross-linked polymers. Dextran, sodium poly(styrene sulfonate), and sodium poly(acrylate) were used as the linear analogues for Sephadex gels and for strong and weak cation exchange resins. Cloud-point and co-existence curves were measured in water/ethanol and water/2-propanol mixtures at 283–343 K and the results were correlated by using a generalized Flory–Huggins model. The mixing parameters of the linear polymers were used to simulate the sorption data in the cross-linked materials and the effect of cross-links was accounted for by a non-ideal elastic model. Good agreement between the simulated and experimental values is obtained, when the chemical heterogeneity and the incomplete functionalization of the cross-linked materials are taken into account. The influence of temperature on the sorption equilibria in cross-linked polymers is also discussed on the basis of the temperature dependence of the cloud-point data.     

Liquid—liquid equilibria of ternary systems of 1-hexene/hexane and extraction solvents

Olefins and paraffins are important basic chemical raw materials with so similar molecular structure and volatility that their separation is a difficult and energy-consuming process. Liquid—liquid equilibrium (LLE) data were determined for ternary systems of: 1-hexene + hexane + solvent at 25°C, 30°C, and 35°C, and N-formylmorpholine (NFM), N-methyl-2-pyrrolidone (NMP), γ-butyrolactone (GBL), and 1-methylimidazole (1-MEI) as the solvents studied. Liquid—liquid equilibrium data for each system were correlated to the NRTL (Non-Random Two Liquid) equation and the interaction parameters presented. The calculated results agree well with the experimental data.     

Liquid–liquid phase equilibria of the ternary system of water/TBA/2-ethyl-1-hexanol

Liquid–liquid phase equilibria (LLE) for the system of water/tert-butyl alcohol (TBA)/2-ethyl-1-hexanol were investigated experimentally at different temperatures of 298.15, 303.15, 308.15, and 313.15 K. A type 1 liquid–liquid phase diagram was obtained for this ternary system. These results were correlated simultaneously by the UNIQUAC model. The values of the interaction parameters between each pair of components in the system were obtained for the UNIQUAC model using the experimental results. The root mean square deviation (RMSD) between the observed and calculated mole percents was 2.58%. The mutual solubility of 2-ethyl-1-hexanol and water was also investigated by the addition of TBA at different temperatures.     

Liquid–liquid equilibria for the ternary system water+n-dodecane+2-(2-n-hexyloxyethoxy)ethanol

Experiments of the fish-shaped phase diagram for the ternary system water+n-dodecane+2-(2-n-hexyloxyethoxy)ethanol (abbreviated by C₆E₂ hereafter) under atmospheric pressure were performed at constant water/n-dodecane weight ratio (1/1) to locate the critical end points. The upper and lower critical consolute temperatures for the system of interest are 307.80 K and 282.30 K, respectively. Compositions of two- and three-phase liquid–liquid equilibrium for the ternary system water+n-dodecane+C₆E₂ at 293.15 K and 303.15 K under atmospheric pressure are presented in this paper.     

Binary,ternary and quaternary liquid–liquid equilibria in 1-butanol,oleic acid,water and n-heptane mixtures

This work reports on liquid–liquid equilibria in the system 1-butanol, oleic acid, water and n-heptane used for biphasic, lipase catalysed esterifications. The literature was studied on the mutual solubility in binary systems of water and each of the organic components. Experimental results were obtained on the composition of the coexisting phases of a series of ternary and quaternary mixtures of the components at 301, 308 and 313 K. The data were correlated successfully with the UNIQUAC model that was extended with ternary interaction parameters.     

Liquid–liquid–solid equilibria for the quaternary system water+ethanol+1-pentanol+sodium chloride at 25°C

Salting-out effect can be used to improve the extraction of some solutes by modifying the solute distribution between two liquid phases. In this work we report the results obtained for the quaternary system water+ethanol+1-pentanol+sodium chloride at 25°C. All equilibrium regions (one liquid, two liquids, one liquid+one solid and two liquids+one solid zones) have been systematically studied. Tie lines and tie-triangles data were measured, after separating the conjugated phases, determining the liquid components by Chromatography, and sodium chloride by gravimetrical methods and titration with AgNO₃ depending on its concentration. Distribution and selectivity curves are represented to analyse the sodium chloride salt effect. Tie-lines and tie-triangles data have been correlated using a modification of the Eisen–Joffe equation.     

Isothermal vapour–liquid equilibria in the binary and ternary systems consisting of an ionic liquid, 1-propanol and CO2

Vapour–liquid equilibrium measurements for binary and ternary systems containing carbon dioxide, 1-propanol, and 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide or 1-decyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide or 1-ethyl-3-methylimidazolium trifluoromethanesulfonate ionic liquids are presented in this work. The binary CO₂ + 1-decyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide system at 313.15 K at pressure range from 2 to 14.4 MPa was examined. The obtained phase envelop shows that even at low pressure of CO₂ the solubility of the gas in the ionic liquid is high. The ternary phase equilibria were studied at 313.15 K and pressures in the range from 9 to 12 MPa. The ternary phase diagrams show that higher CO₂ pressure diminishes the miscibility gap.     

Vapour—liquid equilibria in the heptane - 1-pentanol and heptane - 3-methyl-1-butanol systems at 75, 85 and 95 °C

Vapour—liquid equilibria in the title systems were measured isothermally at 75, 85 and 95 °C. Both the systems exhibit azeotropic behaviour in region of high concentration of alcohol. The densities of liquid mixtures were determined at 25 °C. Only the non-classical equations (Wilson, NRTL) correlate the data within the accuracy of experimental errors.     

Solid–liquid equilibria for binary and ternary systems with the Cubic-Plus-Association (CPA) equation of state

A systematic investigation of the CPA model’s performance within solid–liquid equilibria (SLE) in binary mixtures (methane + ethane, methane + heptane, methane + benzene, methane + CO₂, ethane + heptane, ethane + CO₂, 1-propanol + 1,4-dioxane, ethanol + water, 2-propanol + water) is presented. The results from the binary mixtures are used to predict SLE behaviour in ternary mixtures (methane + ethane + heptane, methane + ethane + CO₂). Our results are compared with experimental data found in the literature.     

Liquid–liquid equilibria of polydisperse polymer systems: applicability of continuous thermodynamics

Continuous thermodynamics is a suitable tool for describing the thermodynamic properties of solutions of polydisperse polymers. To represent liquid–liquid equilibria of polydisperse polymer/solvent systems, a continuous distribution function to represent the composition of polydisperse polymers has to be considered. In this study, we calculate the molar mass distributions of both principal phases and conjugate phases, using the extended Flory–Huggins model. The results for various polydisperse polymer systems are compared with experimental data.     

Salt effects on liquid–liquid equilibria in the partially miscible systems water+2-butanone and water+ethyl acetate

Liquid–liquid equilibrium data for the partially miscible systems of water+2-butanone+salt and water+ethyl acetate+salt were measured at 298.15 K. The salts used were potassium iodide, sodium bromide and lithium chloride. The systems were compared in terms of salting effect. The three-contribution electrolyte NRTL model is used to perform the data regression of the experimental data. New binary parameters are obtained. The calculated results are compared with the experimental data.     

Liquid–liquid equilibria of two ternary systems: methanol–cyclohexane including 1,3-dioxolane or 1,4-dioxane in the range of 277.79–308.64 K

Liquid–liquid equilibria (LLE) of the binary system of methanol–cyclohexane were measured in the range of 277.79–317.94 K. LLE of two ternary systems, methanol–cyclohexane including either one of cyclic ethers of 1,3-dioxolane and 1,4-dioxane, were also measured at the temperatures of 277.79, 288.54, 298.63 and 308.64 K. Two liquid phase regions of the ternary systems were found in the range 0.2–0.04 mole fraction of the ethers, which were smaller than those of the ternary systems of methanol–heptane including the ethers of 0.35 to 0.1 mole fraction studied before. The results were successfully correlated with the UNIQUAC equation by minimizing an objective function with weighting factors.     

The influence of the temperature on the liquid–liquid equilibrium of the ternary system 1-pentanol–ethanol–water

Liquid–liquid equilibrium data for the ternary system 1-pentanol–ethanol–water have been determined experimentally at 25, 50, 85 and 95°C. These results have been correlated simultaneously by the uniquac method obtaining two sets of interaction parameters: one of them independent of the temperature and the other with a linear dependence. Both sets of parameters fit the experimental results well.     

Vapor — liquid and vapor — liquid — liquid phase equilibria of binary and ternary systems of nitrogen,ethene and methanol: Experiment and data evaluation

Zeck, S. and Knapp, H., 1986. Vapor—liquid and vapor—liquid—liquid phase equilibria of binary and ternary systems of nitrogen, ethene and methanol: experiment and data evaluation. Fluid Phase Equilibria, 26: 37–58.VLE and VLLE of three binary and one ternary system containing the components N₂, C₂H₄ and CH₃OH are investigated in a high-pressure phase equilibrium apparatus with vapor recirculation at temperatures 240 < T < 298 K and pressures 4 < p < 100 bar. Immiscibilities in the liquid phase are observed in the binary system C₂H₄CH₃OH with a lower critical end point and in the ternary system N₂C₂H₄CH₃OH.The experimental results are reported and compared with the results of other investigators and of available correlations.     

Liquid–liquid equilibria of water/acetic acid/1-butanol system — effects of sodium (potassium) chloride and correlations

Sodium and potassium chloride were experimentally shown to be effective in modifying the liquid–liquid equilibrium (LLE) of water/acetic acid/1-butanol system in favour of the solvent extraction of acetic acid from an aqueous solution with 1-butanol, particularly at high salt concentrations. Both the salts enlarged the area of the two-phase region; decreased the mutual solubilities of water and marginally decreased the concentrations of 1-butanol and acetic acid in the aqueous phase while significantly increased the concentrations of the same components in the organic phase. These effects essentially increased the heterogeneity of the system, which is an important consideration in designing a solvent extraction process. The equilibrium data were well correlated by Eisen–Joffe equation with respect to the overall molar ratio of salt to water in the liquid phases. By expressing the salt–solvent interaction parameters as a third order polynomial of salt concentration in the liquid phase, Tan's modified NRTL model [T.C. Tan, Trans. Inst. Chem. Eng., Part A 68 (1990) 93–103.] for solvent mixtures containing salts or dissolved non-volatile solutes was able to provide good correlation of the present LLE data. Using the regressed salt concentration coefficients for the salt–solvent interaction parameters and the solvent–solvent interaction parameters obtained from the same system without salt, the calculated phase equilibria compared satisfactorily well with the experimental data.     

Isobaric vapor–liquid equilibria of three aromatic hydrocarbon-tetraethylene glycol binary systems

Isobaric vapor–liquid equilibrium data have been determined at 101.33 kPa for the binary mixtures of benzene-tetraethylene glycol (TeEG), toluene-TeEG and o-xylene-TeEG. The vapor-phase fugacity coefficients were calculated from the virial equation. The thermodynamic consistency of the data has been tested via Herington analysis. The binary parameters for four activity coefficient models (van Laar, Wilson, NRTL and UNIQUAC) have been fitted with the experimental data. A comparison of model performances has been made by using the criterion of root mean square deviations in boiling point and vapor-phase composition.