Vapor–liquid equilibrium of octane-enhancing additives in gasolines: 6. Total pressure data and GE for binary and ternary mixtures containing 1,1-dimethylethyl methyl ether (MTBE), methanol and n-hexane at 313.15 K

Experimental isothermal P–x data at T=313.15 K for the binary systems 1,1-dimethylethyl methyl ether (MTBE)+n-hexane and methanol+n-hexane, and the ternary system MTBE+methanol+n-hexane are reported. Data reduction by Barker’s method provides correlations for G^E using the Margules equation for the binary systems and the Wohl expansion for the ternary system. Wilson, NRTL and UNIQUAC models have been applied successfully to both the binary and the ternary systems. Moreover, we compare the experimental results for these binary mixtures to the prediction of the UNIFAC (Dortmund) model. Experimental results have been compared to predictions for the ternary system obtained from the Wilson, NRTL, UNIQUAC and UNIFAC models; for the ternary system, the UNIFAC predictions seem poor. The presence of azeotropes in the binary systems has been studied.     

Experimental investigation of the vapor–liquid equilibrium at 313.15 K of the ternary system tert-amylmethyl ether (TAME)+n-heptane+methanol

Experimental isothermal P–x data at 313.15 K for the ternary system (tert-amylmethyl ether (TAME)+n-heptane+methanol) and for one of the unmeasured constituent binary systems, (tert-amylmethyl ether (TAME)+methanol) are reported. Data reduction by Barker's method provides correlations for g^E using the Margules equation for the binary systems and the Wohl expansion for the ternary system. Wilson, NRTL and UNIQUAC models have been applied successfully to both the binary and the ternary systems. The presence of azeotropes in the ternary system and constituent binaries are studied as well as the presence of immiscible zones.     

Isothermal vapour–liquid equilibrium data for the binary propan-2-one+chloroalkanes mixtures at temperatures from 298.15 K to 313.15 K

Isothermal vapour–liquid equilibrium data are reported for binary mixtures of propan-2-one with 1,1,2,2-tetrachloroethane (I) and 1,4-dichlorobutane (II) within the 298.15–313.15 K temperature range. Total vapour pressures were measured by a static method, the mixtures beeing prepared by weight and degased directly into the working cell. The experimental data were correlated by Barker's method and different expressions for excess Gibbs energy were tested. The results indicate negative deviation from ideality for mixture (I), while mixture (II) behaves almost ideally, with slightly positive deviations.     

Liquid–liquid equilibrium for binary and ternary systems containing di-isopropyl ether (DIPE) and an imidazolium-based ionic liquid at different temperatures

Liquid–liquid equilibrium (LLE) data were determined for two binary systems {di-isopropyl ether (DIPE) + 1-ethyl-3-methylimidazolium-ethylsulfate (EMISE)} and {DIPE + 1-butyl-3-methylimidazolium-tetrafluoroborate([Bmim][BF₄])}at temperatures between 293.15 K and 313.15 K. LLE data for six ternary systems {DIPE + water + EMISE} and {DIPE + water + [Bmim][BF₄]} at 293.15 K, 303.15 K, and 313.15 K were also reported. Experiments were carried out at atmospheric pressure using stirred and thermo-regulated cells. The experimental data were correlated with the well-known NRTL and UNIQUAC activity coefficient models. In addition, distribution coefficients and selectivities of the ionic liquids EMISE and [Bmim][BF₄] for water in the DIPE phase were measured.     

Isobaric vapour–liquid equilibria for mixtures containing halogenated hydrocarbons at atmospheric pressure: I. Binary mixtures of trichloromethane+1,2-dichloroethane, 1,2-dichloroethane+1,1,2,2-tetrachloroethane,trichloromethane+1,1,2,2-tetrachloroethane and n-heptane+1,1,2,2-tetrachloroethane

Vapour–liquid equilibria at atmospheric pressure for mixtures of trichloromethane+1,2-dichloroethane, 1,2-dichloroethane+1,1,2,2-tetrachloroethane, trichloromethane+1,1,2,2-tetrachloroethane and n-heptane+1,1,2,2-tetrachloroethane have been determined. These have been shown to be thermodynamically consistent.     

Vapor–liquid equilibria for binary mixtures containing ethyl tert butyl ether (ETBE) + (p-xylene,m-xylene and ethylbenzene) at 101.3 kPa

Isobaric vapor–liquid equilibria data at 101.3?kPa were reported for the binary mixtures ethyl tert butyl ether (ETBE)?+?(p-xylene, m-xylene and ethylbenzene). VLE experimental data were tested for thermodynamic consistency by means of a modified Dechema test and was demonstrated to be consistent. The activity coefficients were correlated with the Margules, van Laar, UNIQUAC, NRTL, and Wilson equations. The Analytical Solution Of Groups (ASOG) model also was applied for prediction.     

Vapor–liquid equilibria and excess properties of octane + 1,1-dimethylpropyl methyl ether (TAME) mixtures

Vapor–liquid equilibrium (VLE) data are reported for the binary mixtures formed by octane and the branched ether 1,1-dimethylpropyl methyl ether (tert-amyl methyl ether or TAME). A Gibbs–van Ness type apparatus was used to obtain total vapor pressure measurements as a function of composition at 298.15, 308.15, 318.15 and 328.15 K. The system shows positive deviations from Raoult’s law. These VLE data are analyzed together with data previously reported for octane+TAME mixtures: VLE data at 323.15 and 423.15 K, excess enthalpy (H_m^E) data at 298.15 and 313.15 K and excess volume (V_m^E) data at 298.15 K. The UNIQUAC model, the lattice–fluid (LF) model, and the Flory theory are used to simultaneously correlate VLE and H_m^E data. The two latter models are then used to predict V_m^E data. The original UNIFAC group contribution model and the modified UNIFAC (Dortmund model) are used to predict VLE data.     

Isothermal vapor–liquid equilibria and excess molar volumes for the ternary mixtures containing 2-methyl pyrazine

Isothermal vapor–liquid equilibrium (VLE) data at 353.15 K and excess molar volumes (V^E) at 298.15 K are reported for the binary systems of ethyl acetate (EA)+cyclohexane and EA+n-hexane and also for the ternary systems of EA+cyclohexane+2-methyl pyrazine (2MP) and EA+n-hexane+2MP. The experimental binary VLE data were correlated with common g^E model equations. The correlated Wilson parameters of the constituent binary systems were used to calculate the phase behavior of the ternary mixtures. The calculated ternary VLE data using Wilson parameters were compared with experimental ternary data. The experimental excess molar volumes were correlated with the Redlich–Kister equation for the binary mixtures, and Cibulka’s equation for the ternary mixtures.     

Vapor—liquid equilibrium measurements for the methanol—acetone system at 372.8, 397.7 and 422.6 K

A static high pressure equilibrium facility has been used to obtain P − x − y measurements for the methanol—acetone binary for the three isotherms 372.8, 397.7 and 422.6 K. These measurements show that maximum pressure azeotropic behaviour exists at each of these temperatures. The data obtained have been correlated satisfactorily using the three suffix Margules equation. A comparison has been made between the information resulting from this study and the high pressure data of Griswold and Wong. Parameters of the three suffix Margules equation have been correlated with temperature over the range 285–425 K using additional vapor—liquid equilibrium and excess enthalpy data available in the literature. These correlations have been used to predict isobaric behavior. Auxiliary expressions have been developed which relate azeotropic pressure and composition to temperature.     

Vapor–liquid equilibrium data for the propane+1,1,1,2,3,3,3-heptafluoropropane (R227ea) system at temperatures from 293.16 to 353.18 K and pressures up to 3.4 MPa

Isothermal vapor–liquid equilibrium (VLE) data for the propane+1,1,1,2,3,3,3-heptafluoropropane (R227ea) binary system were measured at 293.16, 303.14, 313.14, 333.15, 343.16 and 353.18 K and pressures up to 3.5 MPa. The experimental method, used in this work, is of the static-analytic type. It takes advantage of two pneumatic capillary samplers (Rolsi™, Armines’ patent) developed in the Cenerg/TEP laboratory. The peculiarity of R227ea–propane binary system is to present azeotropic behavior at each studied temperature.The six sets of isothermal P, x, y data are represented with the Soave–Redlich–Kwong (SRK) equation of state (EoS) and several mixing rules involving the NRTL model.     

Vapor–liquid equilibria and density measurement for binary mixtures of toluene,benzene, o-xylene,m-xylene,sulfolane and nonane at 333.15 K and 353.15 K

Isothermal vapor–liquid equilibria at 333.15 K and 353.15 K for four binary mixtures of benzene + nonane, toluene + o-xylene, m-xylene + sulfolane and o-xylene + sulfolane have been obtained at pressures ranged from 0 to 101.3 kPa over the whole composition range. The Wilson, NRTL and UNIQUAC activity coefficient models have been employed to correlate experimental pressures and liquid mole fractions. The non-ideal behavior of the vapor phase has been considered by using the Peng–Robinson equation of state in calculating the vapor mole fraction. Liquid and vapor densities of these solutions were measured by using two vibrating tube densitometers. The excess molar volumes of the liquid phase were also determined. The P–x–y phase behavior indicates that mixtures of m-xylene + sulfolane, o-xylene + sulfolane and benzene + nonane present large positive deviations from the ideal solution and belong to endothermic mixings because their excess Gibbs energies are positive.     

Liquid–liquid equilibria for butyl tert-butyl ether + (methanol or ethanol) + water at several temperatures

Liquid–liquid equilibrium (LLE) data for butyl tert-butyl ether + (methanol or ethanol) + water were measured experimentally at 298.15, 308.15 and 318.15 K. The experimental data were correlated with the NRTL and UNIQUAC equations. The equations were used to perform the correlation of each temperature data set and for the three temperatures data set simultaneously. The best results were found with UNIQUAC and NRTL (α = 0.1), respectively. Data prediction was carried out using the UNIFAC method, however the results found were not quantitative.     

Surface tension of binary and two ternary mixtures containing water–acetonitrile–methanol/ethanol at 298.15 K: experimental data,correlation and prediction by various models

Surface tension of two ternary mixtures of water/acetonitrile/methanol and water/acetonitrile/ethanol, and their constituent binaries, were measured over the whole range of composition at 298.15 K and ambient pressure. The experimental data were used to calculate in the surface tension deviations (Δσ). The negative values of Δσ for the binary and ternary systems indicate the strong hydrogen bonding between unlike molecules of mixtures (particularly in the high concentration of water). Surface tension data of the binary systems were correlated with Fu et al., Wang–Chen, Redlich–Kister and Myers–Scott models. The mean standard deviation obtained from the comparison of experimental and calculated surface tension values for binary systems with four models is less than 0.42. Finally, the concentration dependence of the surface tension deviation of the ternary mixtures at 298.15 K was correlated using Pando et al. and Ku et al. models, with satisfactory results.     

Isobaric vapour–liquid equilibrium for the binary systems formed by a cyclic ether and bromocyclohexane at 40.0 and 101.3 kPa

Experimental data of vapour–liquid equilibrium (VLE) for the binary systems tetrahydrofuran, or tetrahydropyran, or 2-methyl-tetrahydrofuran, or 2,5-dimethyl-tetrahydrofuran with bromocyclohexane have been measured in isobaric conditions at two pressures, 40.0 and 101.3?kPa. The equipment used was a dynamic recirculating still. The consistency of the measured VLE data has been tested with the Van Ness’ point-to-point method. The activity coefficients have been correlated with the mole fraction through Wilson, NRTL and UNIQUAC equations.     

Vapor–liquid equilibrium data for the carbon dioxide (CO2) + difluoromethane (R32) system at temperatures from 283.12 to 343.25 K and pressures up to 7.46 MPa

Isothermal vapor–liquid equilibrium (VLE) data have been measured for the binary system carbon dioxide (CO₂)+difluoromethane(R32) at eight temperatures between 283.12 and 343.25 K, and at pressures in the range 1.11–7.46 MPa. The experimental method used in this work is of the static-analytic type, taking advantage of two pneumatic capillary samplers (Rolsi™, Armines’ Patent) developed in the Cenerg/TEP laboratory. The data were obtained with uncertainties within ±0.02 K, ±0.002 MPa, and ±1% for molar compositions. The isothermal P, x, and y data are well represented with the Peng–Robinson equation of state (PR EoS) using the Mathias Copeman alpha function and the Wong–Sandler mixing rules involving the NRTL model.     

Excess molar volume measurements of ternary mixtures [2-propanol+ethyl acetate+n-hexane] and their binary constituents at 298.15, 308.15 and 313.15 K

The excess molar volume of the ternary mixture [2-propanol?+?ethyl acetate?+?n-hexane], and its binary constituents; [2-propanol?+?ethyl acetate], [2-propanol?+?n-hexane] and [ethyl acetate?+?n-hexane] were evaluated by the mixtures density measurements over the whole concentration range at three temperatures 298.15, 308.15 and 313.15?K. The excess molar volumes data were fitted to the Redlich–Kister (RK) type equation and the parameters of this equation have been calculated and presented for the studied mixtures.     

Thermodynamic properties of binary mixtures containing n-alkylamines: II. Isothermal vapour–liquid equilibrium and excess molar enthalpy of n-alkylamine+ethylbenzene mixtures. Measurement and analysis in terms of group contributions

Molar excess enthalpies, H^E, at 303.15 K and atmospheric pressure, of n-propyl-, n-butyl-, n-pentyl-, n-octyl- or n-decylamine+ethylbenzene, as well as the isothermal vapour–liquid equilibrium (VLE) of n-butylamine+ethylbenzene at 298.15 K have been determined. These experimental results, along with the data available in the literature on molar excess Gibbs energies, G^E, for n-alkylamine+ethylbenzene mixtures are examined on the basis of the DISQUAC group contribution model. The modified (mod.) UNIFAC is also used to describe the mixtures.     

Measurement and correlation of liquid–liquid equilibria for water + ethanol + mixed solvents (dichloromethane or chloroform + diethyl ether) at T = 293.15 K

Liquid–liquid equilibrium (LLE) data for the quaternary systems (water + ethanol + dichloromethane (DCM) or chloroform (CHCl₃) + diethyl ether (DEE)) were experimentally investigated at 293.15 K. The thermodynamic consistency of the data was performed using the Othmer–Tobias and Hand plots. The experimental tie-line data were correlated using the non-random, two-liquid (NRTL) model. As a result, the comparison of the extracting capabilities of the mixed solvents with respect to the distribution coefficients and separation factors showed that the (50% DCM +50% DEE) system had a higher separation factor for the (water + ethanol + DCM + DEE) system. On the other hand, the (50% CHCl₃ +50% DEE) system had a higher separation factor for the (water + ethanol + CHCl₃ + DEE) system. The last solvent (50% CHCl₃ +50% DEE) was found to be the best solvent, with a positive synergistic effect on DEE, high separation factor, and very low solubility in water.     

Ternary liquid–liquid equilibria for mixtures of 1-hexyl-3-methylimidozolium (tetrafluoroborate or hexafluorophosphate) + ethanol + an alkene at T=298.2 K

Liquid–liquid equilibrium data are presented for mixtures of {1-hexyl-3-methylimidozolium(tetrafluoroborate or hexafluorophospate) + ethanol + (1-hexene or 1-heptene)} at T=298.2 K. The data presented provides valuable insight into how variation of the anion of the environmentally friendly ionic liquid solvent can have a marked effect upon the separation power of ionic liquids. The sloping of the tie lines towards the ethanol vertex is observed for mixtures of {1-hexyl-3-methylimadozolium tetrafluoroborate + ethanol + (1-hexene or 1-heptene)}, whilst the reverse, i.e. sloping of the tie lines towards the ionic liquid vertex is observed for mixtures of {1-hexyl-3-methylimadozolium hexafluorophospate + ethanol + (1-hexene or 1-heptene)}. The tie line data have been correlated through the use of the NTRL model for statistical consistency. Selectivity values, derived from the tie line data, indicate that these two ionic liquids are suitable solvents for the liquid–liquid extraction of ethanol from olefins.     

Vapor–liquid equilibrium measurement and modeling for the difluoromethane + pentafluoroethane + propane ternary mixture

Vapor–liquid equilibrium data for the difluoromethane (R32) + pentafluoroethane (R125) + propane (R290) ternary mixture were measured at 5 isotherms between 263.15 K and 323.15 K. The measurement was carried out using a circulation-type apparatus recently developed, which was validated with binary mixtures. With binary interaction parameters obtained for the three corresponding binary mixtures, VLE modeling and prediction were performed for the ternary mixture using the Peng–Robinson equation of state with the classical mixing rules and MHV1 mixing rules. Hou's group contribution model for VLE of new refrigerant mixtures was further tested with the experimental data for the ternary system. The predicted pressure and vapor phase composition were compared with experimental ones.