Binary Vapor-liquid Equilibrium Data Research Articles

Vapor–liquid equilibria of the 1,1,1-trifluoroethane (HFC-143a) + dimethyl ether (DME) system

Binary vapor liquid equilibrium data were measured for the 1,1,1-trifluoroethane (HFC-143a) + dimethyl ether (DME) system at temperatures from 313.15 K to 363.15 K. These experiments were carried out with a circulating-type apparatus with on-line gas chromatograph analysis. The experimental data were correlated well by the Peng-Robinson equation of state using the Wong-Sandler mixing rules.

Excess Molar Volumes at 298.15 K and Isothermal Vapor−Liquid Equilibria at 333.15 K for the Binary Mixtures of Dimethyl Carbonate with Benzene, Toluene, n-Heptane, and Isooctane

Excess molar volumes (V E) of dimethyl carbonate (DMC) + benzene, DMC + toluene, DMC + n-heptane, and DMC + isooctane are obtained from the measured densities at 298.15 K by using a digital vibrating-tube densimeter. All the measured excess molar volumes are correlated with the five-parameter Redlich−Kister polynomial. Isothermal vapor−liquid equilibrium (VLE) data are measured for the binary systems of benzene + DMC, DMC + toluene, DMC + n-heptane, and DMC + isooctane at 333.15 K by a using headspace gas chromatography (HSGC) method. The experimental binary VLE data were correlated with common gE model equations.

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

Vapor–liquid equilibrium (VLE) at 101.3 kPa has been determined for diisopropyl ether + ethanol + 2,2,4-trimethylpentane ternary system, as well as for diisopropyl ether + ethanol and diisopropyl ether + 2,2,4-trimethylpentane (isooctane) binary systems. A minimum boiling azeotrope was found in the diisopropyl ether + ethanol system, while no azeotrope was observed in the diisopropyl ether + 2,2,4-trimethylpentane system or in the ternary system. Calculations of nonideality of the vapor-phase were made with Soave–Redlich–Kwong equation of state. The thermodynamic consistency of the binary VLE data was examined by both the direct test of Van Ness and the method of Kojima et al. The VLE data of the ternary system passed the thermodynamic consistency test of the McDermott–Ellis method as modified by Wisniak and Tamir. The activity coefficients of the binary mixtures were satisfactorily correlated as a function of mole fraction with the Wilson, NRTL, and UNIQUAC models. The models with their best-fitted binary parameters were used to predict the phase equilibrium behavior of the ternary system.

Measurement and Correlation of Vapor−Liquid Equilibria at T = 333.15 K and Excess Molar Volumes at T = 298.15 K for Ethanol + Dimethyl Carbonate (DMC), DMC + 1-Propanol, and DMC + 1-Butanol

Isothermal vapor−liquid equilibrium (VLE) data are measured for ethanol + dimethyl carbonate (DMC), DMC + 1-propanol, and DMC + 1-butanol at T = 333.15 K by a using headspace gas chromatography (HSGC) method. The binary systems containing ethanol and 1-propanol have minimum boiling azeotropes. The experimental binary VLE data were correlated with common gE model equations. Excess molar volumes (VE) of ethanol + DMC, 1-propanol + DMC, and 1-butanol + DMC are obtained from the measured densities at T = 298.15 K by using a digital vibrating tube densimeter. All measured VE are shown positive deviation from ideal mixing and are correlated with the five-parameter Redlich−Kister polynomial.

Vapor–liquid equilibria of the 1,1,1-trifluoroethane (HFC-143a) + propane (HC-290) system

Binary vapor–liquid equilibrium data were measured for the 1,1,1-trifluoroethane (HFC-143a) + propane (HC-290) system at temperature from 313.15 to 363.15 K. These experiments were carried out with a circulating-type apparatus with on-line gas chromatography. The experimental data were correlated well by Peng–Robinson Stryzek–Vera equation of state with the Wong–Sandler mixing rules. This system shows a positive azeotrope and the type I of critical behavior.

Study on the separation of 1-hexene and trans-3-hexene using ionic liquids

The separation of hexene isomers is very important but difficult since their close boiling points. Room temperature ionic liquids are green solvents and have potential for the separation of hexene isomers by extraction or extractive distillation. Therefore, isothermal vapor–liquid equilibrium data of 1-hexene and trans-3-hexene with 1-methyl-3-butylimidazolium hexafluorophosphate ([BMIM][PF 6]) or with a complex of 1-isobutenyl-3-methylimidazolium tetrafluoroborate ([ iBeMIM][BF 4]) ionic liquids with AgBF 4 were measured by a headspace gas chromatography method. The solubilities of 1-hexene and trans-3-hexene in ionic liquids were determined experimentally. The NRTL model was used to correlate the binary vapor–liquid equilibrium data to obtain interaction parameters. NRTL predictions for the ternary system are compared with the experimental data.

Experimental determination and calculation of thermodynamic properties of CO 2 + octane to high temperatures and high pressures

The phase behavior and critical points of carbon dioxide + octane are determined from 313 to 393 K, and their molar volumes and densities are measured both in the subcritical and supercritical (SC) regions using a variable-volume autoclave in this study. The critical curve of carbon dioxide + octane has been predicted with an equation of state (EOS) by Heilig and Franck, in which a repulsion term and a square-well potential attraction term for intermolecular interaction has been used. To use the pairwise combination rule for the square-well molecular interaction potential, three adjustable parameters are required. The thermodynamic properties including mole fractions, densities and molar volumes of this system are also calculated using the Heilig–Franck, the Peng–Robison (PR) and the Peng–Robinson–Stryjek–Vera (PRSV) equation of state. Among the equations of state, the Heilig–Franck equation of state has been found to have the best correlation with binary vapor–liquid equilibrium data of the carbon dioxide + octane system.

Isobaric Vapor−Liquid Equilibria of the Ternary System Methylbutyl Ketone + 1-Pentanol + Nonane

Isobaric vapor−liquid equilibria (VLE) were determined for the ternary system methylbutyl ketone + 1-pentanol + nonane and for the binaries methylbutyl ketone + 1-pentanol and 1-pentanol + nonane. Measurements were made in a semi-microebulliometer at the pressures of (26.66, 53.33, and 79.99) kPa. A minimum boiling azeotrope was observed in the 1-pentanol + nonane system. The Wilson and modified Wilson models were used to correlate the binary VLE data. The VLE data of the ternary system were predicted by the modified Wilson model.

Vapor–liquid equilibria in the ternary system isobutyl alcohol + isobutyl acetate + butyl propionate and the binary systems isobutyl alcohol + butyl propionate, isobutyl acetate + butyl propionate at 101.3 kPa

Consistent vapor–liquid equilibrium (VLE) data at 101.3 kPa have been determined for the ternary system isobutyl alcohol (IBA) + isobutyl acetate (IBAc) + butyl propionate (BUP) and two constituent binary systems: IBA + BUP and IBAc + BUP. The IBA + BUP system show lightly positive deviation from Raoult's law and IBAc + BUP system exhibits no deviation from ideal behaviour. The activity coefficients of the solutions were correlated with its composition by the Wilson, NRTL, UNIQUAC models. The ternary system is very well predicted from binary interaction parameters. BUP eliminates the IBA–IBAc binary azeotrope. The change of phase equilibria behaviour is significant therefore this solvent seems to be an effective agent for that azeotrope mixture separation. In fact, the mean relative volatility on a solvent free basis is 1.8. The binary VLE data measured in the present study passed the thermodynamic consistency test of Fredenslund et al. [A. Fredenslund, J. Gmehling, P. Rasmussen, Vapor–Liquid Equilibria Using UNIFAC, A Group Contribution Method, Elsevier, Amsterdam, 1977], and were correlated by the Wilson, NRTL and UNIQUAC models to relate activity coefficients with mole fractions. The VLE data obtained for the ternary system passed both the Wisniak L– W [J. Wisniak, Ind. Eng. Chem. Res. 32 (1993) 1531–1533] and McDermott–Ellis [C. McDermott, S.R. Ellis, Chem. Eng. Sci. 20 (1965) 293–296] consistency test. The parameters obtained from binary data were utilized directly to predict the phase behaviour of the ternary system. The results showed an excellent agreement with experimental values.

Isothermal vapour–liquid equilibria in the binary and ternary systems composed of 2-propanol, diisopropyl ether and 4-methyl-2-pentanone

Vapour–liquid equilibrium data in the two binary 2-propanol + 4-methyl-2-pentanone, and diisopropyl ether + 4-methyl-2-pentanone systems, and in the ternary 2-propanol + diisopropyl ether + 4-methyl-2-pentanone system are reported. The data were measured isothermally at 330.00 and 340.00 K covering the pressure range 12–100 kPa. The binary vapour–liquid equilibrium data were correlated using the Wilson, NRTL and Redlich–Kister equations; resulting parameters were then used for calculation of phase behaviour in the ternary system and for subsequent comparison with experimental data.

Vapor−Liquid Equilibria for the Ternary Systems of Methyl tert-Butyl Ether + Methanol + Methylcyclohexane and Methyl tert-Butyl Ether + Methanol + n-Heptane and Constituent Binary Systems at 313.15 K

Isothermal vapor−liquid equilibrium (VLE) data are measured for the ternary systems of methyl tert-butyl ether (MTBE) + methanol + methylcyclohexane (MCH) and MTBE + methanol + n-heptane and constituent four binary systems, MTBE + MCH, MTBE + n-heptane, methanol + MCH, and methanol + n-heptane, at 313.15 K. The experimental binary VLE data were correlated with common gE model equations. The correlated Wilson and NRTL parameters of the constituent binary systems were used to calculate the phase behavior of the ternary mixtures. The calculated ternary VLE data using Wilson and NRTL parameters and the predicted data using modified UNIFAC (Dortmund) model were compared with experimental ternary data.

Measurement and correlation of vapor-liquid equilibria of the binary carbon dioxide-chloroform mixture system

Binary vapor liquid equilibrium data of the carbon dioxide+chloroform system were measured at five isotherms from 310.13 K to 333.32 K. A circulating type apparatus with on-line gas chromatography was used in this study. The experimental data were correlated by classical Peng-Robinson equation of state using van der Waals one fluid mixing rules and the multi-fluid nonrandom lattice fluid (MF-NLF) equation of state.

Isothermal vapour–liquid equilibria in the binary and ternary systems composed of 2-propanol, diisopropyl ether and 1-methoxy-2-propanol

Vapour pressures for 1-methoxy-2-propanol are reported as well as the vapour–liquid equilibrium data in the two binary 2-propanol + 1-methoxy-2-propanol, and diisopropyl ether + 1-methoxy-2-propanol systems, and in the ternary 2-propanol + diisopropyl ether + 1-methoxy-2-propanol system. The data were measured isothermally at 330.00 and 340.00 K covering the pressure range 5–98 kPa. The binary vapour–liquid equilibrium data were correlated using the Wilson, NRTL, and Redlich–Kister equations; resulting parameters were then used for calculation of phase behaviour in the ternary system and for subsequent comparison with experimental data.

Isothermal vapour?liquid equilibria in the binary and ternary systems composed of 2-propanol, diisopropyl ether and 1-methoxy-2-propanol

Vapour pressures for 1-methoxy-2-propanol are reported as well as the vapour–liquid equilibrium data in the two binary 2-propanol + 1-methoxy-2-propanol, and diisopropyl ether + 1-methoxy-2-propanol systems, and in the ternary 2-propanol + diisopropyl ether + 1-methoxy-2-propanol system. The data were measured isothermally at 330.00 and 340.00 K covering the pressure range 5–98 kPa. The binary vapour–liquid equilibrium data were correlated using the Wilson, NRTL, and Redlich–Kister equations; resulting parameters were then used for calculation of phase behaviour in the ternary system and for subsequent comparison with experimental data.

Evaluation of thermodynamic consistency of isobaric and isothermal binary vapor–liquid equilibrium data using the PAI test

The aim of this work is to evaluate the thermodynamic consistency (TC) of binary vapor–liquid equilibrium (VLE) data at low pressure using the PAI test proposed in our previous study. In this work, the PAI test was incorporated with the NRTL equation for fitting data. The PAI test permits an overall check of the data by combining three tests: the point test, the area test, and the infinite dilution test. The PAI test was applied to four miscible alcohol+water systems (169 data sets) at constant pressure and under isothermal conditions, and to one partially miscible 2-butanone+water system (11 data sets) at standard atmosphere. The results of the consistency test for the VLE data showed that the PAI test combined with the NRTL equation permitted screening of reliable data.

Simulation of Salt-Containing Extractive Distillation for the System of Ethanol/Water/Ethanediol/KAc. 1. Calculation of the Vapor−Liquid Equilibrium for the Salt-Containing System

Quaternary vapor−liquid equilibrium (VLE) data were measured for the system of ethanol/water/ethanediol/potassium acetate (KAc). Binary salt-containing VLE data were correlated with the salt-containing local composition model (SCLCM). For a multicomponent system, ternary and quaternary VLE data predicted by SCLCM are in agreement with the literature data and data in this work. The influence of KAc, ethanediol, and the mixture of KAc and ethanediol on the system was investigated by the SCLCM method, and the results showed that the additives have different influences on the volatility of ethanol and water. The calculation method of the salt-containing VLE is simple and effective for the system.

Vapor−Liquid Equilibria of Binary Carbon Dioxide + Alkyl Carbonate Mixture Systems

We measured binary vapor liquid equilibrium data of the carbon dioxide + dimethyl carbonate system and the carbon dioxide + diethyl carbonate system at temperatures from 310 K to 340 K. A circulating type apparatus with on-line gas chromatography was used in this study. The measured data were correlated well by the Peng−Robinson equation of state using van der Waals one fluid mixing rules.

Vapor−Liquid Equilibria of the Binary Carbon Dioxide−Tetrahydrofuran Mixture System

Binary vapor liquid equilibrium data were measured for the carbon dioxide + tetrahydrofuran system at five temperatures from (311.01 to 331.33) K. A circulating type apparatus with on-line gas chromatography was used in this study. The measured data were correlated well by the Peng−Robinson equation of state with van der Waals one fluid mixing rules.

Multiphase equilibria for binary and ternary mixtures containing propionic acid, n-butanol, butyl propionate, and water

Isothermal vapor–liquid equilibrium (VLE) data were measured for propionic acid + butyl propionate at 373.15 and 393.15 K, and isothermal vapor–liquid–liquid equilibrium (VLLE) data were also measured for n-butanol + water, butyl propionate + water, and water + n-butanol + butyl propionate at temperatures ranging from 323.15 to 393.15 K. No azeotrope was found in propionic acid + butyl propionate. The mutual solubility data of the binary aqueous systems were correlated well with the NRTL model accompanying with temperature-dependent parameters. Improvement on the calculation of saturated vapor compositions has been made by using two-term virial equation with one adjustable binary interaction parameter to represent the non-ideality of the vapor phase. The model parameters determined from the binary VLLE data of n-butanol + water and butyl propionate + water and the binary VLE data of n-butanol + butyl propionate are capable of predicting satisfactorily the VLLE properties for the ternary system of water + n-butanol + butyl propionate.

Vapor–liquid equilibria for the ternary systems of methyl tert-butyl ether + methanol + benzene and methyl tert-butyl ether + methanol + toluene and constituent binary systems at 313.15 K

Isothermal vapor–liquid equilibria (VLE) data are measured for the ternary systems of methyl tert-butyl ether (MTBE)+methanol+benzene and MTBE+methanol+toluene and constituent five binary systems, MTBE+methanol, MTBE+benzene, MTBE+toluene, methanol+benzene, and methanol+toluene, at 313.15 K. The experimental binary VLE data were correlated with common g E model equations. And the correlated Wilson and NRTL parameters of the constituent binary systems were used to calculate the phase behavior of the ternary mixtures. The calculated ternary VLE data using Wilson and NRTL parameters were compared with experimental ternary data.