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.     

Isobaric vapor–liquid equilibria for the binary systems isobutyl alcohol + isobutyl acetate and tert-butyl alcohol + tert-butyl acetate at 20 and 101.3 kPa

New consistent vapor–liquid equilibrium data for the binary systems isobutyl alcohol (IBA) + isobutyl acetate (IBAc) and tert-butyl alcohol (TBA) + tert-butyl acetate (TBAc) are reported at 20 and 101.3 kPa. The IBA + IBAc system, which deviates positively from ideal behavior, can be described as symmetric solution and presents azeotrope at both pressures. The TBA + TBAc system shows positive deviations from ideal behavior and presents azeotrope only at 20 kPa. The activity coefficients and boiling points of the solutions were correlated with their composition by the Wilson, UNIQUAC, NRTL and Wisniak–Tamir equations.     

(Liquid + liquid) equilibria of (water + propionic acid + 2-ethyl-1-hexanol): Experimental data and correlation

(Liquid + liquid) equilibrium (LLE) data for (water + propionic acid + 2-ethyl-1-hexanol) were determined at atmospheric pressure over the temperature range of (298.15 to 308.15) K. A type-1 LLE phase diagram was obtained for this ternary system. The LLE data were correlated fairly well with UNIQUAC model, indicating the reliability of the UNIQUAC equation for this ternary system. The average root mean square deviation between the observed and calculated mole fractions was 1.57%. Distribution coefficients and separation factors were measured to evaluate the extracting capability of the solvent.     

Isobaric vapor–liquid phase equilibria for the binary systems of tert-butanol + 2-ethyl-1-hexanol and n-butanol + 2-ethyl-1-hexanol

Isobaric vapor–liquid equilibria for the binary mixtures of tert-butanol (TBA) + 2-ethyl-1-hexanol and n-butanol (NBA) + 2-ethyl-1-hexanol were experimentally investigated at atmospheric pressure in the temperature range of 353.2–458.2 K. The raw experimental data were correlated using the UNIQUAC and NRTL models and used to estimate the interaction parameters between each pair of components in the systems. The experimental activity coefficients were obtained using the gas chromatographic method and compared with the calculated data obtained from these equilibrium models. The results show that UNIQUAC model gives better correlation than NRTL for these binary systems. The liquid–liquid extraction of TBA from aqueous solution using 2-ethyl-1-hexanol was demonstrated by simulation and the variation of separation factor of TBA at several temperatures was reported.     

Density,viscosity, isothermal (vapour + liquid) equilibrium,excess molar volume,viscosity deviation,and their correlations for chloroform + methyl isobutyl ketone binary system

Density and viscosity measurements for pure chloroform and methyl isobutyl ketone at T = (283.15, 293.15, 303.15, and 313.15) K as well as for the binary system {x₁ chloroform + (1 − x₁) methyl isobutyl ketone} at the same temperatures were made over the whole concentration range. The experimental results were fitted to empirical equations, which permit the calculation of these properties over the whole concentration and temperature ranges studied. Data of the binary mixture were further used to calculate the excess molar volume and viscosity deviation. The (vapour + liquid) equilibrium (VLE) at T = 303.15 K for this binary system was also measured in order to calculate the activity coefficients and the excess molar Gibbs energy. This binary system shows no azeotrope and negative deviations from ideal behaviour. The excess or deviation properties were fitted to the Redlich–Kister polynomial relation to obtain their coefficients and standard deviations.     

(Liquid + liquid) equilibria in (water + ethanol + 2-ethyl-1-hexanol) at T=(298.2, 303.2, 308.2, and 313.2) K

(Liquid + liquid) equilibrium data for (water + ethanol + 2-ethyl-1-hexanol) were measured at atmospheric pressure in the temperature range (298.2 to 313.2) K. A type 1 (liquid + liquid) phase diagram was obtained for this ternary system. The experimental tie-line data for this system were correlated with the UNIQUAC solution model. The values of the interaction parameters between each pair of components in the system were obtained for the UNIQUAC model with the experimental results. The root mean square deviation between the observed and calculated mole per cent was 1.70%. The mutual solubility of 2-ethyl-1-hexanol and water was also investigated by the addition of ethanol at different temperatures.     

Density,speed of sound and refractive index of (n-hexane + cyclohexane + 1-hexanol) atT = 298.15 K

Densities, speeds of sound and refractive indices have been measured for (n -hexane  +  cyclohexane  +  1-hexanol) and its corresponding binaries atT =  298.15 K. In addition, ideal isentropic compressibilities were calculated from the speeds of sound, densities, and literature heat capacities and cubic expansion coefficients. The excess molar volumes and excess isentropic compressibilities, and deviations of the speed of sound and refractive index are correlated by polynomials and discussed.The Nitta–Chao model was used to estimate binary and ternary excess molar volumes, and several empirical equations were also used to calculate the excess and deviation properties.     

(Liquid + liquid) equilibria for (water + acetic acid + 2-ethyl-1-hexanol): experimental data and prediction

(Liquid + liquid) equilibrium (LLE) data for (water + acetic acid + 2-ethyl-1-hexanol) were measured at atmospheric pressure in the temperature range of (298.2 to 313.2) K. The UNIFAC model was used to predict the observed LLE data with a root-mean-square deviation value of 2.03%. A high degree of consistency of experimental data was obtained using the Othmer–Tobias correlation. The solubility of water in 2-ethyl-1-hexanol was measured at different temperatures.     

High-pressure phase equilibria in the (carbon dioxide + 1-hexanol) system

(Vapour + liquid) equilibria (VLE) and (vapour + liquid + liquid) equilibria (VLLE) data for the (carbon dioxide + 1-hexanol) system were measured at (293.15, 303.15, 313.15, 333.15, and 353.15) K. Phase behaviour measurements were made in a high-pressure visual cell with variable volume, based on the static-analytic method. The pressure range under investigation was between (0.6 and 14.49) MPa. The Soave–Redlich–Kwong (SRK) equation of state (EOS) with classical van der Waals mixing rules (two-parameters conventional mixing rule, 2PCMR), was used in a semi-predictive approach, in order to represent the complex phase behaviour (critical curve, LLV line, isothermal VLE, LLE, and VLLE) of the system. The topology of phase behaviour is reasonably well predicted.     

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.     

Estimation of (vapour + liquid) equilibrium of binary systems (tert-butanol + 2-ethyl-1-hexanol) and (n-butanol + 2-ethyl-1-hexanol) using an artificial neural network

(Vapour + liquid) equilibrium (VLE) data are important for designing and modelling of process equipment. Since it is not always possible to carry out experiments at all possible temperatures and pressures, generally thermodynamic models based on equations of state are used for estimation of VLE. In this paper, an alternate tool, i.e. the artificial neural network technique has been applied for estimation of VLE for the binary systems viz. (tert-butanol + 2-ethyl-1-hexanol) and (n-butanol + 2-ethyl-1-hexanol). The temperature range over which these models are valid is (353.2 to 458.2) K at atmospheric pressure. The average absolute deviation for the temperature output was in range 2% to 3.3%. The results were then compared with experimental data.     

Isobaric vapor–liquid equilibria for 1-propanol + water + copper(II) chloride at 100 kPa

Isobaric vapor–liquid equilibria for the ternary system 1-propanol + water + copper(II) chloride has been measured at 100 kPa using a recirculating still. The addition of copper(II) chloride to the solvent mixture produced a salting-out effect of the alcohol, but the azeotrope did not tend to be eliminated when the salt content increased. The experimental data sets were fitted with the electrolyte NRTL model and the parameters of Mock's model were estimated. This model has proved to be suitable to represent experimental data in the entire range of compositions. The effect of copper(II) chloride on the vapor–liquid equilibrium of the 1-propanol + water system has been compared with that produced by other salts.     

Estimation of VLE of binary systems (tert-butanol + 2-ethyl-1-hexanol) and (n-butanol + 2-ethyl-1-hexanol) using GMDH-type neural network

The group method of data handling (GMDH) method was used to estimate (vapour + liquid) equilibrium (VLE) for the binary systems of (tert-butanol + 2-ethy1-1-hexanol) and (n-butanol + 2-ethy1-1-hexanol). Using this method, a new model was proposed, which is suitable for predicting the VLE data. In this publication, the proposed model was ‘trained’ before requested predictions. The data set was divided into two parts: 70% were used as data for ‘training’ (either 10 or 12), and 30% were used as a test set, which were randomly extracted from the database (either 14 or 16). After the training on the input–output process, the predicted values were compared with those of experimental values in order to evaluate the performance of the GMDH neural network method. The model values showed a very good regression with the experimental results.     

Volumetric and viscometric behaviour of binary systems: (1-hexanol + hydrocarbons)

Densities and viscosities of binary liquid mixtures of (1-hexanol  + n -hexane, or cyclohexane, or benzene) have been measured at a number of mole fractions at T =  (303, 313, and 323) K. The excess molar volume V_m^Eand apparent molar volume V_φhave been calculated from the density data. TheV_m^E anddV_m^E / dT for the system, (1-hexanol  + n -hexane) have been found negative, while those for the systems, (1-hexanol  +  cyclohexane) and (1-hexanol  +  benzene), were found to be positive. Excess viscosities η^Ecalculated from viscosity data, have been found to be negative over the whole composition range at the temperatures studied for all the three systems. Volumetric and viscometric behaviours indicate that dispersion is the major force of interaction between the components in (1-hexanol  +  cyclohexane, or benzene), while inclusion of hydrocarbon chains into the interstices of polymolecular ring structures of alcohol formed by hydrogen bonding has been assumed to play a significant role apart from dispersion in the system (1-hexanol  + n -hexane). Thermodynamic parameters of activation for viscous flow have been calculated from the viscosity data at different temperatures and a possible explanation suggested.     

Density and surface tension variation with temperature for n-nonane + 1-hexanol

New experimental densities and surface tensions for n-nonane + 1-hexanol at 288.15, 298.15 and 308.15 K are reported. Densities were measured with an Anton Paar DMA 4500 densimeter, and surface tensions using a Lauda TVT2 automated tensiometer, which uses the principle of the pending drop volume. The experimental data of pure liquids and mixtures have been used to calculate excess molar volumes and surface tension deviations of n-nonane + 1-hexanol as a function of mole fractions. A comparative study of these properties together with those available in the literature for the n-alkane + 1-alkanol mixtures has been performed. In addition, the magnitude of these experimental quantities is discussed in terms of the nature and type of intermolecular interactions in binary mixtures.     

Isobaric (vapor + liquid) equilibrium data for the binary system methanol + 2-butyl alcohol and the quaternary system methyl acetate + methanol + 2-butyl alcohol + 2-butyl acetate at P = 101.33 kPa

In this paper, isobaric (vapor + liquid) equilibrium (VLE) data for the binary system methanol + 2-butyl alcohol and the quaternary system methyl acetate + methanol + 2-butyl alcohol + 2-butyl acetate were determined at P = 101.33 kPa in a modified Rose still. The binary VLE data were found to be thermodynamic consistency by the Herrington method. The VLE data for the binary system were correlated by the Wilson and NRTL equations respectively, which were used to predict the VLE data of the quaternary system. The results showed that the Wilson and NRTL models matched well with the (vapor + liquid) phase equilibrium data. The deviations for the vapor-phase compositions and the equilibrium temperatures are reasonably small and the models are both suitable for these systems.     

(Liquid + liquid) equilibria in ternary aqueous mixtures of phosphoric acid with organic solvents at T = 298.2 K

(Liquid + liquid) equilibrium (LLE) data for the ternary mixtures of {water (1) + phosphoric acid (2) + organic solvents (3)} were determined at T = 298.2 K and atmospheric pressure. The organic solvents were cyclohexane, 2-methyl-2-butanol (tert-amyl alcohol), and isobutyl acetate. All the investigated systems exhibit Type-1 behaviour of LLE. The immiscibility region was found to be larger for the (water + phosphoric acid + cyclohexane) ternary system. The experimental LLE results were correlated with the NRTL model, and the binary interaction parameters were obtained. The reliability of the experimental tie-line results was tested through the Othmer–Tobias and Bachman correlation equations. Distribution coefficients and separation factors were evaluated over the immiscibility regions and a comparison of the extracting capabilities of the solvents was made with respect to these factors. The experimental results indicate the superiority of cyclohexane as the preferred solvent for the extraction of phosphoric acid from its aqueous solutions.     

Measurements and modeling of LLE and HE for (methanol + 2,4,4-trimethyl-1-pentene), and LLE for (water + methanol + 2,4,4-trimethyl-1-pentene)

Excess enthalpy (H^E) for the binary system of (methanol + 2,4,4-trimethyl-1-pentene) (TMP-1) is reported at T = 298.15 K and 101 kPa. (Liquid + liquid) equilibrium (LLE) for the same system is measured at atmospheric pressure (101 kPa). LLE for ternary system of (water + methanol + 2,4,4-trimethyl-1-pentene) is measured at T = (283 and 298) K.The parameters of Non-Random Two-Liquid (NRTL) model were regressed for the system of (methanol + TMP-1) using H^E and LLE from this work combined with isobaric (101 kPa) and isothermal (T = 331 K) VLE data from literature. The NRTL parameters for the binary system of (water + TMP-1) were fitted to a binary LLE data set from literature. NRTL parameters for the binary system of (water + methanol) were taken from ASPEN PLUS. The LLE for the ternary system was modeled by the three binary NRTL interaction parameters systems. The binary and ternary models were compared against the measured data.     

Phase equilibria properties of binary and ternary systems containing di-isopropyl ether + isobutanol + benzene at 313.15 K

Isothermal vapour–liquid equilibrium data have been measured for the ternary system (di-isopropyl ether + isobutanol + benzene) and two of the binary systems involved (di-isopropyl ether + isobutanol) and (isobutanol + benzene) at 313.15 K. A static technique consisting of an isothermal total pressure cell was used for the measurements. 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.     

Total pressure and excess Gibbs energy for the ternary mixture di-isopropyl ether + 1-propanol + benzene and its corresponding binary systems at 313.15 K

Total pressure measurements are reported for the ternary system ‘di-isopropyl ether + 1-propanol + benzene’ and two of the binary systems involved ‘di-isopropyl ether + 1-propanol’ and ‘1-propanol + benzene’ at 313.15 K. 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.