(Vapor + liquid) equilibria of binary mixtures formed by iso-octane with a variety of compounds at 95.8 kPa

(Vapor + liquid) equilibria were evaluated from the measured bubble temperatures at 95.8 kPa, over the entire composition range for the binary mixtures of iso-octane with ethanol, tert-butanol, m- and p-xylenes, n-hexane and chlorobenzene, making use of a Swietoslawski type ebulliometer. Wilson model, representing the liquid phase mole fraction versus temperature measurements well was used for the computations.     

Bubble point measurements of binary mixtures formed by ethyl benzene with selected compounds at 95.35 kPa

Bubble point temperatures (at 95.35 kPa) over the entire composition range were measured for the binary mixtures formed by ethyl benzene with: acetyl acetone, o-, and p-cresols, 1-hexanol, and tetraethoxysilane, employing a Swietoslawski type ebulliometer. Wilson equation was used to represent the measured liquid phase composition versus bubble point temperature data, and the computed values of the vapor phase mole fractions, activity coefficients, and excess Gibbs free energy were tabulated and briefly discussed.     

(Vapor + liquid) equilibria of binary mixtures containing light alcohols and ionic liquids

This work presents (vapor + liquid) equilibrium (VLE) of binary mixtures containing methanol or ethanol and three imidazolium based ionic liquids: 1-butyl-3-methylimidazolium tetrafluoroborate, 1-butyl-3-methylimidazolium acetate, and 1-butyl-3-methylimidazolium hydrogen sulfate. VLE measurements were carried out over the whole range of composition between (283.15 and 298.15) K using a static apparatus. Activity coefficients γ_i of these solvents in the ionic liquids have been determined from the VLE data and correlated using the NRTL model. The results show that the NRTL model can be applied successfully with systems containing ionic liquids.     

Quaternary isobaric (vapor + liquid + liquid) equilibrium and (vapor + liquid) equilibrium for the system (water + ethanol + cyclohexane + heptane) at 101.3 kPa

Experimental isobaric (vapor + liquid + liquid) and (vapor + liquid) equilibrium data for the ternary system {water (1) + cyclohexane (2) + heptane (3)} and the quaternary system {water (1) + ethanol (2) + cyclohexane (3) + heptane (4)} were measured at 101.3 kPa. An all-glass, dynamic recirculating still equipped with an ultrasonic homogenizer was used to determine the VLLE. The results obtained show that the system does not present quaternary azeotropes. The point-by-point method by Wisniak for testing the thermodynamic consistency of isobaric measurements was used to test the equilibrium data.     

Bubble temperature measurements on the binary mixtures formed by decane with a variety of compounds at 95.8 kPa

Bubble temperatures at 95.8 kPa, over the entire composition range are measured for the binary mixtures formed by decane with cyclohexanone, 1,2-dimethoxyethane, tetrahydrofuran and ortho-, meta- and para-xylenes, making use of a Swietoslawski type ebulliometer. The liquid phase composition versus temperature measurements is found to be well represented by the Wilson model.     

Bubble points of some binary mixtures formed by o-cresol at 95.75 kPa

Bubble points at 95.75 kPa, over the entire composition range were measured for the binary mixtures formed by o-cresol with 1,2-dichloroethane, 1,1,2,2-tetrachloroethane, trichloroethylene, tetrachloroethylene, o-, m-, p-xylenes and n-heptane, making use of a Swietoslawski type ebulliometer. The liquid phase composition versus temperature measurements was found to be well represented by the Wilson model.     

(Vapor + liquid) equilibrium properties of (ethane + ethanol) system at (295, 303, and 313) K

The (vapor + liquid) equilibrium data for binary system of (ethane + ethanol) at three temperatures (295, 303, and 313) K were measured using a designed pressure–volume–temperature (PVT) apparatus. A wide range of pressures, (1 to 5) MPa, were considered for the measurements. The phase composition, saturated density, and viscosity of liquid phase were measured for each pressure and temperature. The experimental (vapor + liquid) equilibrium data were compared with the modeling results obtained using the Peng–Robinson and Soave–Redlich–Kwong equations of state.     

Isothermal (vapour + liquid) equilibrium for binary mixtures of (tetrahydrofuran + 1,1,2,2-tetrachloroethane or tetrachloroethene) at nine temperatures

Vapour pressures of (tetrahydrofuran + 1,1,2,2-tetrachloroethane, or tetrachloroethene) at nine temperatures between T = 283.15 K and T = 323.15 K were measured by a static method. The reduction of the vapour pressures data to obtain activity coefficients and excess molar Gibbs energies was carried out by fitting the vapour pressure data to the Redlich–Kister polynomial according to Barker’s method. Excess molar volumes were also measured at T = 298.15 K. A comparative analysis about the thermodynamic behaviour of both systems is performed, in terms of hydrogen bonding and electron-donor–acceptor interactions, as well as the resonance effect in tetrachloroethene.     

The precise measurement of the (vapour + liquid) equilibrium properties for (CO2 + isobutane) binary mixtures

Recently, it has been suggested that natural working fluids, such as CO₂, hydrocarbons, and their mixtures, could provide a long-term alternative to fluorocarbon refrigerants. (Vapour + liquid) equilibrium (VLE) data for these fluids are essential for the development of equations of state, and for industrial process such as separation and refinement. However, there are large inconsistencies among the available literature data for (CO₂ + isobutane) binary mixtures, and therefore provision of reliable and new measurements with expanded uncertainties is required. In this study, we determined precise VLE data using a new re-circulating type apparatus, which was mainly designed by Akico Co., Japan. An equilibrium cell with an inner volume of about 380 cm³ and two optical windows was used to observe the phase behaviour. The cell had re-circulating loops and expansion loops that were immersed in a thermostatted liquid bath and air bath, respectively. After establishment of a steady state in these loops, the compositions of the samples were measured by a gas chromatograph (GL Science, GC-3200). The VLE data were measured for CO₂/propane and CO₂/isobutane binary mixtures within the temperature range from 300 K to 330 K and at pressures up to 7 MPa. These data were compared with the available literature data and with values predicted by thermodynamic property models.     

Excess Gibbs free energies of the binary mixtures of acetonitrile with butanols at 94.83 kPa

Bubble point temperatures at 94.83 kPa, over the entire composition range, are measured for the binary mixtures of acetonitrile with: n-, iso-, sec- and tert-butanols – using a Swietoslawski type ebulliometer. The liquid phase composition versus bubble point temperature measurements are found to be well represented by the Wilson model. Measured values of the liquid phase mole fraction versus bubble point temperature data are presented along with the computed values of the vapor phase mole fractions, activity coefficients and excess Gibbs free energies and discussed.     

Isobaric (vapour + liquid) equilibria for the (1-propanol + 1-butanol) binary mixture at (53.3 and 91.3) kPa

In this work, isobaric (vapour + liquid) equilibrium data have been determined at (53.3 and 91.3) kPa for the binary mixtures of (1-propanol + 1-butanol). The thermodynamic consistency of the experimental values was checked by means the traditional area test and the direct test methods. According to the criteria for the test methods, the (vapour + liquid) equilibrium results were found to be thermodynamically consistent. The experimental values obtained were correlated by using the van Laar, Margules, Wilson, NRTL, and UNIQUAC activity-coefficient models. The binary interaction parameters of the activity-coefficient models have been determined and reported. They have been compared with those calculated by the activity-coefficient models. The average absolute deviation in boiling point and vapour-phase composition were determined. The calculated maximum average absolute deviations were 0.86 K and 0.0151 for the boiling point and vapour-phase composition, respectively. Therefore, it was shown that the activity-coefficient models used satisfactorily correlate the (vapour + liquid) equilibrium results of the mixture studied. However, the performance of the UNIQUAC model was superior to all other models mentioned.     

Experimental (solid + liquid) or (liquid + liquid) phase equilibria of (amine + nitrile) binary mixtures

(Solid + liquid) phase diagrams have been determined for (hexylamine, or octylamine, or 1,3-diaminopropane + acetonitrile) mixtures. Simple eutectic systems have been observed in these mixtures. (Liquid + liquid) phase diagrams have been determined for (octylamine, or decylamine + propanenitrile, or + butanenitrile) mixtures. Mixtures with propanenitrile and butanenitrile show immiscibility in the liquid phase with an upper critical solution temperature, UCST. (Solid + liquid) phase diagrams have been correlated using NRTL, NRTL 1, Wilson and UNIQUAC equations. (Liquid + liquid) phase diagrams have been correlated using NRTL equation.     

Isobaric (vapour + liquid) equilibria for the (1-pentanol + propionic acid) binary mixture at (53.3 and 91.3) kPa

Isobaric (vapour + liquid) equilibrium measurements have been reported for the binary mixture of (1-pentanol + propionic acid) at (53.3 and 91.3) kPa. Liquid phase activity coefficients were calculated from the equilibrium data. The thermodynamic consistency of the experimental results was checked using the area test and direct test methods. According to these criteria, the measured (vapour + liquid) equilibrium results were found to be consistent thermodynamically. The obtained results showed a maximum boiling temperature azeotrope at both pressures studied. The measured equilibrium results were satisfactorily correlated by the models of Wilson, UNIQUAC, and NRTL activity coefficients. The results obtained indicate that the performance of the NRTL model is superior to the Wilson and UNIQUAC models for correlating the measured isobaric (vapour + liquid) equilibrium data.     

Isobaric (vapour + liquid) equilibrium of (1,3-dioxolane,or 1,4-dioxane + 1-butanol,or 2-butanol) at 40.0 kPa and 101.3 kPa

Isobaric (vapour  +  liquid) equilibrium (v.l.e.) of (1,3-dioxolane, or 1,4-dioxane  +  1-butanol, or 2-butanol) at 40.0 kPa and 101.3 kPa have been studied with a dynamic recirculating still. The experimental data for all mixtures were checked for thermodynamic consistency using the method of Van Ness. Activity coefficients calculated from (v.l.e.) data have been correlated with different equations (Wilson, Van Laar, Margulles, NRTL, and UNIQUAC), giving satisfactory results. Predictions with the group contribution methods ASOG and UNIFAC were also obtained.     

Activity coefficients and excess Gibbs’ energies of the binary mixtures formed by 2-cyanopyrazine with some chloroaliphatics at 95.5 kPa

Bubble points at a pressure of 95.5?kPa, over the entire composition range are measured for the binary mixtures formed by 2-cyanopyrazine with: 1,2-dichloroethane, 1,1,2,2-tetrachloroethane, trichloroethylene and tetrachloroethylene making use of a Swietoslawski type ebulliometer. The liquid phase composition versus temperature measurements are found to be well represented by the Wilson model. Computed values of the activity coefficients and excess Gibbs’ energies are also presented along with the phase equilibrium data.     

Boiling temperature measurements on the binary mixtures formed by acetonitrile with some chloroethanes and chloroethylenes at 94.6 kPa

Boiling temperatures at 94.6 kPa, over the entire composition range are measured for the binary mixtures, formed by acetonitrile with 1,2,-dichloroethane, 1,1,1-trichloroethane, 1,1,2,2-tetrachloroethane, trichloroethylene and tetrachloroethylene, making use of a Swietoslawski type ebulliometer. The liquid phase composition versus temperature measurements are found to be well represented by the Wilson 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.     

Vapor–liquid equilibria of some binary mixtures formed by methylethylketone at 94.7 kPa

Bubble temperatures at 94.7?kPa, for the binary mixtures formed by methylethylketone (MEK) with cyclo-hexanone, tetrahydrofuran, ortho- and meta-xylenes, bromobenzene, chlorobenzene, epichlorohydrin, nitrobenzene, and iso- and tert-butanols have been measured by means of a Swietoslawski-type ebulliometer. The data could be represented well by the Wilson model.     

(Liquid + liquid) equilibrium for binary systems of N-formylmorpholine with alkanes

(Liquid + liquid) equilibrium (LLE) data were determined for four binary systems containing N-formylmorpholine (NFM) and alkanes (3-methylpentane, heptane, nonane, and 2,2,4-trimethylpentane) over the temperature range from around 300 K to near 420 K using a set of newly designed equilibrium equipment. The compositions of both light and heavy phases were analyzed by gas chromatography. The mutual solubility increased as the temperature increased for all these systems. The binary (liquid + liquid) equilibrium data were correlated by the NRTL and UNIQUAC equations with temperature-dependent parameters. Both models correlate the experimental results well. Furthermore, the UNIFAC (Do) group contribution model was used to correlate and estimate the LLE data for NFM containing systems. Two methods of group division for NFM were used. NFM is treated as a single group: NFM group (method I) or divided into two groups: CHO and C₄H₈NO (method II), respectively. The group interaction parameters for CH₂–NFM, or CH₂–CHO and CH₂–C₄H₈NO were fitted from the experimental LLE data. The UNIFAC (Do) model correlates the experimental data well. In addition, in order to develop UNIFAC (Do) group contribution model to estimate the LLE data of (NFM + cycloalkane) systems, some literature LLE data were used. The group interaction parameters for c-CH₂–NFM, c-CH₂–CHO and c-CH₂–C₄H₈NO were correlated. Then these group interaction parameters were used to estimate the phase equilibrium data of binary systems in the literature by the UNIFAC (Do) model. The results showed that the estimated values are in good agreement with the literature data. In contrast, the method I is better than the method II. This shows that treating NFM as a single NFM group is more reasonable, and the fitted parameters are satisfactory for designing the aromatic recovery process with NFM as solvent.