Isothermal vapor–liquid equilibrium at 333.15 K and excess molar volumes and refractive indices at 298.15 K for the mixtures of di-methyl carbonate,ethanol and 2,2,4-trimethylpentane

Isothermal vapor–liquid equilibrium data at 333.15 K are measured for the binary system ethanol + 2,2,4-trimethylpentane and for ternary system di-methyl carbonate (DMC) + ethanol + 2,2,4-trimethylpentane by using headspace gas chromatography. The experimental binary and ternary vapor–liquid equilibrium data were correlated with different activity coefficient models. Excess volume and deviations in molar refractivity data are also reported for the binary systems DMC + ethanol and DMC + 2,2,4-trimethylpentane and the ternary system DMC + ethanol + 2,2,4-trimethylpentane at 298.15 K. These data were correlated with the Redlich-Kister equation for the binary systems and the Cibulka equation for the ternary system, respectively. The ternary excess volume and deviations in molar refractivity data were also compared with estimated values from the binary contribution models of Tsao–Smith, Kohler, Rastogi and Radojkovi?.     

Study of the behaviour of the azeotropic mixture ethanol–water with imidazolium-based ionic liquids

In this work, experimental data of isobaric vapour–liquid equilibria for the ternary system ethanol + water + 1-hexyl-3-methylimidazolium chloride ([C₆mim][Cl]) and for the corresponding binary systems containing the ionic liquid (ethanol + [C₆mim][Cl], water + [C₆mim][Cl]) were carried out at 101.300 kPa. VLE experimental data of binary and ternary systems were correlated using the NRTL equation. In a previous work [N. Calvar, B. González, E. Gómez, A. Domínguez, J. Chem. Eng. Data 51 (2006) 2178–2181], the VLE of the ternary system ethanol + water + [C₄mim][Cl] was determined and correlated, so we can study the influence of different ionic liquids in the behaviour of the azeotropic mixture ethanol–water.     

Isobaric vapor–liquid equilibria of 1,1-dimethylethoxy-butane + methanol or ethanol + water at 101.32 kPa

Isobaric vapor–liquid equilibrium data (VLE) at 101.325 kPa have been determined in the miscible region for 1,1-dimethylethoxy-butane (BTBE) + methanol + water and 1,1-dimethylethoxy-butane (BTBE) + ethanol + water ternary systems, and for their constituent binary systems, methanol + BTBE and ethanol + BTBE. Both binary systems show an azeotrope at the minimum boiling point. In the ternary system BTBE + methanol + water no azeotrope has been found, however, the system BTBE + ethanol + water might form a ternary azeotrope near the top of the binodal. Thermodynamically consistent VLE data have been satisfactorily correlated using the UNIQUAC, NRTL and Wilson equations for the activity coefficient of the liquid phase. Temperature and vapor phase compositions have been compared with those calculated by the group-contribution methods of prediction ASOG, and the original and modified UNIFAC. Predicted values are not in good agreement with experimental values.     

Physical and excess properties of binary and ternary mixtures of 1,1-dimethylethoxy-butane, methanol, ethanol and water at 298.15 K

The ternary systems 1,1-dimethylethoxy-butane (BTBE) + methanol + water and BTBE + ethanol + water have large heterogeneous zones. Experimental densities, refractive indices and speeds of sound have been measured at 298.15 K for mixtures of these systems within the homogeneous zone, and also for methanol + BTBE and ethanol + BTBE binary systems over the entire range of compositions. Excess molar volumes and molar refraction and isentropic compressibility changes of mixing were calculated from the experimental physical properties and were satisfactorily correlated with the corresponding composition data using the Redlich-Kister polynomial. Fitted coefficients and mean standard deviations of correlations have been reported.     

Isothermal vapor-liquid equilibrium at T = 333.15 K and excess volumes and molar refractivity deviation at T = 298.15 K for the ternary mixtures {di-methyl carbonate (DMC) + ethanol + benzene} and {DMC + ethanol + toluene}

Isothermal vapor-liquid equilibrium data at 333.15 K are reported for the ternary systems {di-methyl carbonate (DMC) + ethanol + benzene} and {DMC + ethanol + toluene} as determined with headspace gas chromatography. The experimental ternary vapor-liquid equilibrium (VLE) data were correlated with different activity coefficient models. The excess volume (V^E) and deviations in molar refractivity (ΔR) data are reported for the binary systems {DMC + benzene} and {DMC + toluene} and also for the ternary systems {DMC + ethanol + benzene} and {DMC + ethanol + toluene} at 298.15 K. These V^E and ΔR data were correlated with the Redlich-Kister equation for binary systems and the Cibulka equation for ternary systems.     

Experimental measurements of vapor–liquid equilibria at low pressure: Systems containing alcohols,esters and organic acids

In this work the vapor–liquid equilibria for nine binary mixtures (methanol + acetic acid, methanol + methyl acetate, methanol + water, methyl acetate + acetic acid, water + acetic acid, ethyl acetate + acetic acid, ethanol + acetic acid, ethanol + ethyl acetate and ethanol + water) at subatmospherical pressure (580 mmHg) is presented. Peng–Robinson Stryjek–Vera equation of state coupled with the Wong–Sandler mixing rules were used for predicting phase equilibria of these mixtures. The measurements were developed using an apparatus with recirculation that can also be employed for liquid–vapor equilibrium with chemical reaction.     

Vapor–liquid equilibria for binary and ternary mixtures of ethanol, 2-butanone,and 2,2,4-trimethylpentane at 101.3 kPa

Vapor–liquid equilibrium (VLE) at 101.3 kPa have been determined for the ternary system ethanol + 2-butanone + 2,2,4-trimethylpentane (isooctane) and its constituent binary systems: ethanol + 2,2,4-trimethylpentane, ethanol + 2-butanone, and 2-butanone + 2,2,4-trimethylpentane. Minimum boiling azeotropes were observed for all these binary systems. No azeotropic behavior was found for the ternary system. Thermodynamic consistency tests were performed for all VLE data. The activity coefficients of the binary mixtures were satisfactorily correlated with the Wilson, NRTL, and UNIQUAC models. The models with their best-fitted binary parameters were used to predict the ternary vapor–liquid equilibrium.     

Measurement and calculation of vapor–liquid equilibria for methanol + glycerol and ethanol + glycerol systems at 493–573 K

The vapor–liquid equilibria for methanol + glycerol and ethanol + glycerol systems were measured by a flow method at 493–573 K. The pressure conditions focused in this work were 3.03–11.02 MPa for methanol + glycerol system and 2.27–8.78 MPa for ethanol + glycerol system. The mole fractions of alcohol in vapor phase are close to unity at the pressures below 7.0 MPa for both systems. The pressures of liquid saturated lines of the liquid phase for methanol + glycerol and ethanol + glycerol systems are higher than that for the mixtures containing alcohol and biodiesel compound, methyl laurate or ethyl laurate.     

Vapor-liquid equilibria at 333.15 K and excess molar volumes and deviations in molar refractivity at 298.15 K for mixtures of diisopropyl ether, ethanol and ionic liquids

In this work, we have studied influence of ionic liquids (ILs) on the azeotrope composition for the system {diisopropyl ether (DIPE) + ethanol} using trihexyltetradecylphosphonium chloride ([P_666,14][Cl]) and trihexyltetradecylphosphonium bis(2,2,4-trimethylpentyl) phosphinate ([P_666,14][TMPP]). Isothermal vapor-liquid equilibrium data at 333.15 K are reported for the ternary systems {DIPE + ethanol + [P_666,14][Cl]} and {DIPE + ethanol + [P_666,14][TMPP]} with varying the mole fraction of ILs from 0.05 to 0.10. The experimental ternary VLE data were correlated using the Wilson equation. In addition, excess molar volumes (V^E) and deviations in molar refractivity (ΔR) data at 298.15 K are reported for the binary systems {DIPE + [P_666,14][Cl]} and {ethanol + [P_666,14][Cl]} by a digital vibrating tube densimeter and a precision digital refractometer. The V^E and ΔR were correlated by the Redlich-Kister equation.     

Study on the effect of increasing the chain length of the alkanol in excess molar enthalpies of mixtures containing 2-methoxy-2-methylpropane, 1-alkanol,decane

Excess molar enthalpies for the ternary system {x₁ 2-methoxy-2-methylpropane + x₂ ethanol + (1 − x₁ − x₂) decane} and the involved binary mixture {x ethanol + (1 − x) decane} have been measured at the temperature of 298.15 K and atmospheric pressure, over the whole composition range. No experimental excess enthalpy values were found in the currently available literature for the ternary mixture under study. The results were fitted by means of different variable-degree polynomials. Smooth representations of the results are presented and used to construct constant excess molar enthalpy contours on Roozeboom diagrams. The excess molar enthalpies for the binary and ternary system are positive over the whole range of composition. The binary mixture {x ethanol + (1 − x) decane} is asymmetric, with its maximum displace toward a high mole fraction of decane. The ternary contribution is also positive, and the representation is asymmetric.     

Phase equilibria in binary mixtures with monoethyl succinate

Monoethyl succinate was produced by partial esterification of succinic anhydride with ethanol using Amberlyst 15^® as catalyst. After separation and purification, the purity of monoethyl succinate was confirmed by nuclear magnetic resonance (NMR). Vapor pressure of monoethyl succinate was measured and correlated with Antoine equation. Vapor-liquid equilibria at constant temperature were measured for the binary systems ethyl acetate + monoethyl succinate, acetic acid + monoethyl succinate, and water + monoethyl succinate at 323.15 K, and ethanol + monoethyl succinate at 313.15 K. Binary parameters for the NRTL equations were obtained by fitting experimental data using the regression tool in ASPEN Plus^® using the Hayden-O’Connell method for vapor phase fugacities. The model agrees reasonably well with the experimental data.     

Bubble-point measurements for the system CO2 + aqueous ethanol solutions of boldo leaf antioxidant components (boldine and catechin) at high pressures

The bubble-points pressures of solute(s) + ethanol + water + CO₂ mixtures were determined visually using a synthetic method in an experimental apparatus that included a variable-volume equilibrium cell. Tested solutes included boldo leaf tincture, a boldine + catechin mixture, pure boldine, and pure catechin. Uncertainties in bubble-point pressures were estimated to be <5%, based on comparisons with literature values and replicate measurements. The largest effect we observed was an average increase of 205% in the bubble-point pressure when decreasing the ethanol-to-water ratio from 63:37 to 37:63 (w/w). The bubble-point pressure increased 11% when increasing the temperature from 313 to 343 K, and decreased 8.2% when increasing the concentration of solids from 400 to 1500 ppm. The bubble-point pressure was higher for boldo leaf tincture than for a boldine + catechin mixture having the same boldine-to-catechin weight ratio, but this was partially due to a lower content of solids in the tincture. On the other hand, bubble-point pressures of the boldine + catechin mixture were marginally (0.33%) higher than the weighed average of the bubble-point pressures for pure boldine and pure catechin.     

Isothermal vapor–liquid equilibrium at 333.15 K,excess molar volumes and refractive indices at 298.15 K for mixtures of tert-amyl methyl ether + ethanol + 2,2,4-trimethylpentane

Isothermal vapor–liquid equilibrium data at 333.15 K are measured for the binary system tert-amyl methyl ether + ethanol and tert-amyl methyl ether + 2,2,4-trimethylpentane and for ternary system tert-amyl methyl ether + ethanol + 2,2,4-trimethylpentane by using headspace gas chromatography. The experimental vapor–liquid equilibrium data were correlated with G^E models (Margules, van Laar, Wilson, NRTL, UNIQUAC) equations. The excess volume and deviations in molar refractivity data are also reported for the same binary and ternary systems at 298.15 K. These data were correlated with the Redlich–Kister equation for the binary systems and the Cibulka equation for the ternary system, respectively. The experimental ternary excess volume and deviations in molar refractivity data, were also compared with the estimated values from the binary contribution models of Tsao–Smith, Kohler, Rastogi and Radojkovi?.     

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.     

Densities and derived thermodynamic properties of ternary mixtures 1-butyl-3-methyl-imidazolium tetrafluoroborate + ethanol + water at seven pressures and two temperatures

This work is a continuation of our studies on experimental measurements of physical properties on binary mixtures of the ionic liquid (IL) family 1-alkyl-3-methyl imidazolium tetrafluoroborate (CnMIM-BF₄) with water and ethanol. Here, we present density for the ternary system Butyl-MIM-BF₄ + ethanol + water at two temperatures (298.15 K and 323.15 K) and seven pressures (from 0.1 to 30 MPa). It should be noted that BMIM-BF₄ is the only IL of the family CnMIM-BF₄ that can be mixed with water and ethanol in all range of concentrations at room conditions. From the density data measured in function of pressure and temperature other important derived thermodynamic properties can be calculated, such us excess molar volumes, isothermal compressibility, isobaric expansion and the thermal pressure coefficients. These properties for selected ternary mixtures will be discussed and compared with data from the scarce number of published results for similar ternary mixtures with this same IL.     

Volumetric properties of the ternary system ethanol + chloroform + benzene at temperature range (288.15–313.15) K: Experimental data,correlation and prediction by cubic EOS

Densities ρ of the ternary system (ethanol + chloroform + benzene) and binaries (ethanol + chloroform) and (chloroform + benzene), have been measured at six temperatures (288.15, 293.15, 298.15, 303.15, 308.15, 313.15) K and pressure 101.33 kPa with an Anton Paar DMA 5000 digital vibrating tube densimeter. Excess molar volumes V^E were calculated from these densities data and fitted by the polynomial Redlich–Kister (for binary data) and Nagata and Tamura (for ternary data) equations. Radojkovi? et al. equation was used for the prediction of the V^E of ternary data. The obtained results have been explained in terms of different effects between molecules of present species, taking into consideration influence of temperature on them.     

Experimental data on binary and ternary mixtures of perfluoro-1,3-dimethylcyclohexane with normal alkanes at 373.15 K

Phase behaviour measurement of binary mixtures of perfluoro-1,3-dimethylcyclohexane with methane and propane, and ternary mixtures of perfluoro-1,3-dimethylcyclohexane with methane + n-hexane and methane + n-decane at 373.15 K and over a wide range of concentration are presented. Measurements are made at the liquid bubble point and retrograde dew point pressures of the mixtures. A constant composition expansion test was carried out on perfluoro-1, 3-dimethylcyclohexane + methane mixture at 373.15 K.     

Equation of state for square-well chain molecules with variable range II. Extension to mixtures

An equation of state (EOS) developed in our previous work for square-well chain molecules with variable range is further extended to the mixtures of non-associating fluids. The volumetric properties of binary mixtures for small molecules as well as polymer blends can well be predicted without using adjustable parameter. With one temperature-independent binary interaction parameter, satisfactory correlations for experimental vapor–liquid equilibria (VLE) data of binary normal fluid mixtures at low and elevated pressures are obtained. In addition, VLE of n-alkane mixtures and nitrogen + n-alkane mixtures at high pressures are well predicted using this EOS. The phase behavior calculations on polymer mixture solutions are also investigated using one-fluid mixing rule. The equilibrium pressure and solubility of gas in polymer are evaluated with a single adjustable parameter and good results are obtained. The calculated results for gas + polymer systems are compared with those from other equations of state.     

Measurement of activity coefficients at infinite dilution for acetonitrile,water, limonene,limonene epoxide and their binary pairs

Activity coefficients at infinite dilution were determined for binary pairs of acetonitrile, water, limonene and limonene epoxide at room temperature using the dilutor technique (inert gas stripping) in a home-made dilutor apparatus. The activity coefficients were predicted with the Aspen Plus software using the Dortmund-modified UNIFAC contribution method. Values predicted by software simulations are in good agreement with experimental data. However, experimental activity coefficients at infinite dilution obtained for limonene + acetonitrile, water + limonene and limonene epoxide + water systems are in disagreement with reported values estimated from LLE or solubility data.     

Study of azeotropic mixtures with the advanced distillation curve approach

Classical methods for the study of complex fluid phase behavior include static and dynamic equilibrium cells that usually require vapor and liquid recirculation. These are sophisticated, costly apparatus that require highly trained operators, usually months of labor-intensive work per mixture, and the data analysis is also rather complex. Simpler approaches to the fundamental study of azeotropes are highly desirable, even if they provide only selected cuts through the phase diagram. Recently, we introduced an advanced distillation curve measurement method featuring: (1) a composition explicit data channel for each distillate fraction (for both qualitative and quantitative analysis), (2) temperature measurements that are true thermodynamic state points that can be modeled with an equation of state, (3) temperature, volume and pressure measurements of low uncertainty suitable for equation of state development, (4) consistency with a century of historical data, (5) an assessment of the energy content of each distillate fraction, (6) trace chemical analysis of each distillate fraction, and (7) corrosivity assessment of each distillate fraction. We have applied this technique to the study of azeotropic mixtures, for which this method provides the bubble point temperature and dew point composition, completely defining the thermodynamic state from the Gibbs phase rule perspective. In this paper, we present the application of the approach to several simple binary azeotropic mixtures: ethanol + benzene, 2-propanol + benzene, and acetone + chloroform.