PHASE EQUILIBRIA OF THE CYCLOHEXANE-TOLUENE-SULFOLANE AND HEXANE-TOLUENE-SULFOLANE TERNARY SYSTEMS

Liquid-liquid equilibrium data for two ternary systems were obtained. The experimental data were measured for cyclohexane-toluene-sulfolane at 17, 25 and 50°C, and for hexane-toluene-sulfolane at 18 and 25°C. The NTRL and UNIQUAC models were used to correlate the experimental results and to calculate the phase compositions of the ternary systems. The agreement between the experimental results and the fitted values was equally good with both of the models.     

SOLUBILITIES,DENSITIES, AND REFRACTIVE INDICES FOR THE TERNARY SYSTEMS 1,2-PROPYLENE GLYCOL + MNO3 + H2O (M = Na,K, Rb,Cs) AT 25° AND 35°C

The solubilities, densities, and refractive index data for the 1,2-propylene glycol + MNO₃ + H₂O (M = Na, K, Rb, Cs) ternary systems at 25° and 35°C were measured with mass fractions of 1,2-propylene glycol ranging from 0 to 1.0. In all cases, the presence of 1,2-propylene glycol significantly reduces the solubility of the salts in aqueous solution. The experimental data of density, refractive index, and solubility of saturated solutions for these systems were correlated using polynomial equations. Furthermore, the refractive index and density of unsaturated ternary solutions were also determined and correlated with the salt concentrations and proportions of 1,2-propylene glycol in the systems.     

Prediction of heats of mixing of liquid mixtures containing alkane,chloroalkane and alcohol by an analytical group solution model

An analytical group solution model (AGSM) previously developed for the prediction of heats of mixing has been applied to ternary group, ternary component mixtures. A simple temperature dependence is proposed for the group interaction parameters. Temperature independent coefficients were obtained in the temperature range 15 to 35°C for mixtures containing CH₂, OH and Cl groups. These coefficients allow the prediction of heat of mixing for binary or ternary mixtures containing alcohols, chloroalkanes and alkanes. Heats of mixing for the following systems are reported: 1-chlorobutane and 2-chlorobutane with both n-hexane and n-octanol at 35°C; n-octanol — n-hexane at 25 and 35°C; and three chords of the ternary system 1-chlorobutane — n-octanol — n-hexane at 25 and 35°C.     

Solid–Liquid Equilibrium (SLE) for Polyhydric Alcohol + Cs2SO4 + H2O Ternary Systems at Different Temperatures

The solubility, density, and refractive index data for 1,2-propanediol + Cs₂SO₄ + H₂O, ethylene glycol + Cs₂SO₄ + H₂O, and glycerin + Cs₂SO₄ + H₂O ternary systems were determined at 15°C, 25°C, and 35°C. In all cases, the solubility of Cs₂SO₄ in aqueous solutions decreased significantly due to the presence of the polyhydric alcohol. The experimental density, refractive index, and solubility data of saturated solutions for these systems were correlated using polynomial equations. Furthermore, the refractive index and density of unsaturated ternary solutions were also determined and correlated with salt concentrations and proportions of polyhydric alcohol in these systems.     

Liquid-liquid equilibria of the system water + acetic acid + methyl propyl ketone

This article reports equilibrium data for the binary liquid-liquid system water + methyl propyl ketone at temperatures in the range 20-55°C, together with solubilities and equilibrium compositions of the ternary system water + acetic acid + methyl propyl ketone at 25, 35, 45 and 55°C. NRTL and UNIQUAC equations have been fitted to the experimental data for the ternary system, which are likewise compared with the values predicted by the group contribution method UNIFAC.     

LIQUID-LIQUID EQUILIBRIUM OF THE SYSTEM WATER-PHOSPHORIC ACID-DI-N-PROPYL ETHER AT 25 AND 40°C. INFLUENCE OF THE ISOMER PROPYL-ISOPROPYL ETHER ON THE APPEARANCE OF THREE LIQUID PHASES AT EQUILIBRIUM.

Solubility and liquid-liquid phase equilibrium data have been determined for the ternary systems Water-Phosphoric Acid-Di-n-propyl Ether as supplied by Merck (with about 6.4% of the isomer propyl-isopropyl ether), and Water-Phosphoric Acid-Di-n-propyl Ether (rectified up to less than 1% of propyl-isopropyl ether), at 25 and 40^°C The temperatures at which three liquid phases at equilibrium appeared were 28.0-28.2^°C and 49.0-50.0^°C, respectively. The presence of the isomer propyl-isopropyl ether causes these systems to split into three liquid phases at equilibrium     

Heats of mixing for ternary systems: n-Alkanes + Two n-Alcohols

Heats of mixing for 21 ternary systems of one n-alkane + two n-alcohols are reported at 25°C. Evaluation of four equations permitting the prediction of heats of mixing of ternary systems from binary data is made. Scatchard's modified equation for systems containing a polar component was found to be the most accurate.     

Liquid-liquid equilibria of (MTBE or TAME) + ethanol + water mixtures

Experimental liquid-liquid equilibrium data obtained at 25 and 35°C for ternary mixtures of MTBE + ethanol + water, and at 25, 35 and 45°C for ternary mixtures of TAME + ethanol + water, were satisfactorily fitted with NRTL and UNI-QUAC equations using the correlation program developed by Sørensen (1980).     

Extrapolation of ternary excess thermodynamic properties

A method, based on the Gibbs-Duhem equation, is proposed for extrapolating ternary excess thermodynamic properties over the complete concentration range. For those thermodynamic properties whose three excess partial molal quantities at a given composition can be directly evaluated from a single measurement, such as excess Gibbs free energy of mixing, 4 ternary experimental points are required. For those thermodynamic properties whose three excess partial mólal quantities at a given composition cannot be directly evaluated from a single measurement, such as excess enthalpy of mixing, 7 ternary experimental points are required. In both cases necessary binary data are assumed to be available. Experimental heat of mixing data for the systems ethanol-n-heptane, n-heptane-benzene and ethanol-n-heptane-benzene at 25°C. are also reported.     

Prediction of heats of mixing by a group solution model with application to alkane/alcohol mixtures

Group solution models of liquid mixtures have been used previously to predict excess free energies of non-ideal systems. With increasing experimental data available on heats of mixing, the application of a similar model to excess enthalpies has been investigated. The model allows for both structural and group contributions to excess enthalpies. The former contribution is determined from experimental data on mixtures of alkanes. The group contribution has been determined at 25°C and 45°C for systems containing alkanes and alcohols. Predictions require no experimental data on the system in question, and are in good agreement with experiment. Limited extrapolation to other temperatures and group compositions should be satisfactory.     

Thermodynamic assessments of ZrO2-YO1.5-TiO2 system

The ZrO₂–TiO₂ and ZrO₂-YO_1.5 binary systems have been reassessed based on the latest literature information, then the thermodynamic parameters of the two systems combine with that of the YO_1.5-TiO₂ system have been used to extrapolate the thermodynamic database of ZrO₂-YO_1.5-TiO₂ ternary system. Based on the available experimental information, the ternary interaction parameters of liquid, F (fluorite), and P (pyrochlore) phases are introduced to fix this ternary system. Especially, the calculated solid solubility limit of Tss (tetragonal) and F phases are first considered in this work, which are consistent with the reported experiments. Finally, the isothermal sections calculated at 1573 K, 1773 K, 1823K 1873K and 1923K (1300 °C, 1500 °C, 1550 °C, 1600 °C and 1650 °C) are plotted, which are more consistent with the experimental results than other calculations.     

Analysis of several methods to determine the activity of water in solutions of strong electrolytes

The methods of Zdanovskii-Stokes-Robinson (ZSR), Reilly-Wood-Robinson (RWR), Pitzer and Correa, to determine water activity in ternary solutions of electrolytes from data for water activity in binary solutions, were analysed. In addition, the first two methods were used to estimate the activity of water in supersaturated binary solutions using data from ternary solutions. Also, the equation of Correa for binary solutions was extrapolated to calculate the activity of water at supersaturation. The methods were tested using the experimental data (at 25°C) for nine ternary systems, with a common ion, involving the following ions: Li⁺, Na⁺, K⁺, Ca⁺⁺, Mg⁺⁺, Cl^? and NO₃^?. Zdanovskii's method gave the best estimations of water activity in ternary systems. The method of Correa gave smaller standard deviations than the methods of Pitzer and RWR with the advantage that its application is simpler. For binary solutions at supersaturation, Correa's method gave better results than the method of ZSR and this, in turn, yielded smaller deviations than the RWR method.     

Prediction of ternary liquid-liquid equilibria using the NRTL and the UNIQUAC models

The Experimental binodal curve, tie line data, plait point data and the tie lines and plit point, calculated by liquid models for foil wing six ternary liquid liquid equilibria systems: monochlorobenzene-water-acetone, cyclohexane-water-acetone, cyclohexane-water-acetone. chlorform-water-acetone. methylisobutylketone-water-acetone, and n-hexane-water-acetone were reported at 10°C Experimental tie line data were correlated to test consistency with Othmer-Tobias equation [15] And those data were also correlated with the NRTL the UNIQUAC, and the modified UNIQLAC models respectively and the parameters in each model were estimated to predict the value of tie lines by least squares methods.     

Purification of wet process phosphoric acid by solvent extraction liquid-liquid equilibrium at 25 and 40°C of the system water-phosphoric acid-methylisobutylketone

Solubility and liquid-liquid phase equilibrium data are presented for the ternary system water-phosphoric acid-methyl isobutyl ketone at 25 and 40°C. Binodal curves, tie lines and distribution curves have been determined. Hand's method has been used to correlate tie lines and to calculate coordinates of plait points. The heterogeneous region at 40°C appeared to be slightly broader than that at 25°C, and the slopes of tie lines somewhat higher: the solubility of this system increases with decreasing temperature. The distribution curves indicated that methyl isobutyl ketone was an effective extractant for concentrated phosphoric acid solutions only.     

The vapour-liquid equilibrium of ternary systems with limited miscibility at atmospheric pressure

The complete study of the vapour-liquid equilibrium of ternary systems with limited miscibility requires vapour-liquid equilibrium determinations and liquid-liquid equilibrium determinations at boiling point. The vapour-liquid equilibrium was determined by means of an equilibrium still based on the principle of Giilespie but modified in such a way that an accurate boiling point measurement, even for systems with heterogeneous liquid was possible and that the vapour phase was analysed without previous condensation. Two ternary systems have been studied: the system methanol-ethylacetate-water and the system ethanol-ethylacetate-water. The ternary data have been predicted by means of the equation of Renon and Prausnitz. The parameters are determined by correlating the binary data. The ternary vapour-liquid equilibrium are predicted within 1-2. 10 ^?2 mol fraction for the vapour composition and 1°C for the boiling point. The position of the predicted tielines of the liquid-liquid equilibrium at boiling point was almost coinciding with the position of the experimental tielines. There was a slight deviation of the predicted and experimental binodal.     

Measurement and prediction of the density of aqueous ternary mixtures of methyldiethanolamine and diethanolamine at temperatures from 25°c to 80°c

Densities have been measured for mixed aqueous solutions of N-methyldiethanolamine (MDEA) and diethanolamine (DEA) at 25, 30,40,50, 60,70, and 80°C. The compositions of the ternary solutions are near 30 mass% solute, because of industrial applications for the absorption of acid gases. The isopycnotic (same density) method, for predicting densities of multicomponent aqueous systems at 25°C has been used to predict the densities of the present non-electrolyte mixed solutions at other temperatures. Predicted and observed density values are in good agreement (<0.06% error). The method has also been used to predict densities of some aqueous sea salt mixtures at temperatures ranging from 5 to 95°C. Again the predicted and observed values are in good agreement (generally <0.1% error).     

Solubility of methane in glycols at elevated pressures

The solubility of methane in ethylene glycol and in diethylene glycol has been determined at temperatures in the range 25 to 125 °C at pressures up to 20.4 MPa. The experimental results were correlated by the Peng-Robinson (1976) equation of state, and interaction parameters have been obtained for these systems. Henry's constants were derived for comparison with data from the literature.     

Effective separation of aromatic hydrocarbons by pyridine‐based deep eutectic solvents

Many promising qualities of deep‐eutectic solvents made them suitable solvents in separation process. In this work, the pyridine‐based deep eutectic solvents were designed and synthesized with N‐ethylpyridinium bromide and two HBDs (N‐formyl morpholine and levulinic acid). Two ternary systems, benzene + cyclohexane + DES and toluene + n‐heptane + DES, were studied by the liquid‐liquid extraction. The effect of different HBDs, extraction time, volume ratio of DES to system solution, and the initial concentration of aromatic were studied. The DES with N‐formyl morpholine showed better separation performance than that with levulinic acid. The liquid‐liquid extraction equilibrium could be obtained in 10 minutes. The volume ratio of DES to system solution was set as 1:1. Both DESs showed their best separation performance at low temperatures (20°C) and low aromatic concentration system. For the benzene + cyclohexane system, the distribution coefficient of benzene was 1.733 and the selectivity was 23.8 at 20°C. For the toluene + n‐heptane system, the distribution coefficient of toluene was 0.853 and the selectivity was 40.7. Tie‐lines for two ternary systems were obtained, and the Othmer‐Tobias correlation was used to check the reliability of the obtained liquid‐liquid extraction experimental data. The experimental LLE data were correlated using the NRTL model and the calculated data correlated significantly with the experimental data.     

Organotin polymers—XVII. Azeotropy in terpolymerization reactions of tri-n-butyltin 4-acryloyloxybenzoate wit alkyl acrylates or styrene and acrylonitrile

Ternary copolymerizations of tri-n-butyltin 4-acryloyloxybenzoate (ABTB) with acrylonitrile (AN) and alkyl acrylates [methyl (MA), ethyl (EA) or butyl acrylate (BA)], methyl methacrylate (MMA) or styrene (ST) were carried out in solution at 70°C in the presence of free radical initiator. Experimental terpolymerization data agreed well with calculations based on the Alfrey-Goldfinger equation. The determination of unitary, binary and ternary azeotropies of various systems studied was easily handled by a computer program. The results obtained show that there is no ternary azeotropic composition for any terpolymer, system studied. Selective unitary and binary azeotropic compositions were polymerized and the results obtained show good agreement between the theoretical and experimental terpolymer composition for each case.     

On the thermodynamics of concentrated strong electrolytes aqueous solutions the system NaNO3—NaCl—H2O

A simple analytical function is proposed for the calculation of molar excess Gibbs energy of binary solutions of strong electrolytes in water. Empirical parameters can be easily determined from experimental data reported in the literature. The treatment is extended to ternary solutions and to solid liquid equilibria using an empirical equation. Absence of solid solutions is assumed. The correlations are applied to the common ion ternary system NaNO₃-NaCl-H₂O in the temperature range from 0 to 100°C. Predictions of activity coefficients of the binary systems and saturation curves of the ternary system are in good agreement with experimental data.