Vapor pressures of binary mixtures of hexane + 1-butanol, + 2-butanol, + 2-methyl-1-propanol, or +2-methyl-2-propanol at 298.15 K (original) (raw)
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Fluid Phase Equilibria, 1998
Vapour pressures of butanoneq 2-methyl-1-propanol or q2-methyl-2-propanol at several temperatures between 278.15 and 323.15 K were measured by a static method. Excess molar enthalpies and volumes for 2-methyl-1-propanol were also measured at 298.15 K. Reduction of the vapour pressures to obtain activity coefficients and excess molar Gibbs free energies was carried out by fitting the vapour pressure data to the Redlich-Kister correlation according to Barker's method. It is made as a comparison of the thermodynamic properties of mixtures of alcohols in butanone and n-hexane, and the results are qualitatively discussed.
Journal of Chemical & Engineering Data, 2012
In this work, the measurements of the isobaric vapor−liquid equilibrium (VLE) data at 101.32 kPa and the excess molar volumes (v E ), obtained at 10 K intervals of temperature in the range (288.15 to 328.15) K, for four binary systems comprised of methyl or ethyl butanoate with two alkanes (heptane and nonane) are presented. The v E are positive for the four mixtures, and their variation with temperature presents a thermal coefficient (∂v E /∂T) p > 0, and the behavior of these systems is interpreted. Experimental VLE data (p,T,x,y), obtained in a small capacity ebulliometer, present a positive consistency according to the method of Fredenslund. The methyl butanoate + heptane system presents a minimum boiling-temperature azeotrope with the following coordinates at the working pressure: (x 1,az = 0.404; T az = 367.65 K). Measurements of (T,p i o ) are also shown for all of the compounds and were determined using the same equilibrium equipment. Experimental data are correlated with an appropriate polynomial model proposed by the authors. A simultaneous correlation is performed for the characteristic VLE properties and the h E values taken from the literature. For the correlation of properties of methyl butanoate + heptane system, values of c p E from the literature were included in the correlation process. In all cases the multiproperty goodness of fit is acceptable. Another correlation procedure by successive steps in the order (x,c p E )→(x,h E )→(x,g E ) is also applied when the experimental data exist for the binaries studied; the results obtained with both procedures are similar. The universal functional activity coefficient (UNIFAC) method is applied to estimate the VLE values, h E and c p E , with different results. The VLE prediction is acceptable in all cases except for the methyl butanoate + heptane mixture, although the estimation of the other thermodynamic quantities is not adequate. a Uncertainties u are: u(T) = ± 0.02 K, u(n) = ± 0.0002, and u(ρ) = ± 0.02 kg·m −
Journal of Chemical & Engineering Data, 1994
Vapor-liquid equilibrium data were measured for binary systems of 1-butanol with 2-methyl-1-butanol, 3-methyl-1-butanol, 2-methyl-2-butano1, and 3-methyl-2-butanol at 30 and 100 kPa. The experimental data obtained in this work are thermodynamically consistent according to a point-to-point consistency test, and deviation from ideal behavior is small in all cases. They can be equally well correlated with the Margules, Van Laar, Wilson, NRTL, and UNIQUAC equations.
Journal of Chemical & Engineering Data, 2002
Isobaric vapor-liquid equilibrium has been experimentally studied for the binary mixtures 2-butanol + n-hexane and 2-butanol + 1-butylamine and for the ternary mixture 2-butanol + n-hexane + 1-butylamine at 101.3 kPa. The activity coefficients were found to be thermodynamically consistent, and they were satisfactorily correlated with the Margules, van Laar, Wilson, NRTL, and UNIQUAC equations. The activity coefficients were also compared with the results obtained from the application of the ASOG and modified UNIFAC group contribution methods. The boiling points of the solutions were correlated with compositions by the Wisniak-Tamir equations. The results obtained indicate that the binary system 2-butanol + n-hexane deviates positively from ideality, whereas 2-butanol + 1-butylamine deviates negatively from ideality. The ternary system deviates positively or negatively depending on the composition. Only the binary systems present azeotropy. Azeotropic behavior was not found in the ternary mixture.
Journal of Chemical & Engineering Data, 2012
A static method was used for measuring vapor pressures of (1-propanol + 1,8-cineole). Measurements were carried out at 10 temperatures between 278.15 K and 323.15 K and over the whole composition range. Experimentally determined vapor pressure data were reduced applying Barker's method and fitted using the Wilson equation, so activity coefficients and excess molar Gibbs energies were obtained. Vapor−liquid equilibrium (VLE) correlation and description of the volumetric behavior of the mixture were obtained by using three equations of state (EOS). Volume translation (VT) according to Peneloux was considered in two of them, modifications proposed by Mathias (PRM) and by Stryjek−Vera (PRSV) to the Peng−Robinson equation. The last model applied was the statistical associating fluid theory (SAFT), based on the theory of perturbations. This third model provides the best description of the volumetric behavior, although the Stryjek−Vera modification is the one that provides the best description of the phase equilibrium.
Journal of Chemical & Engineering Data, 2006
Vapor-liquid equilibrium data were measured using an automatic static total pressure apparatus for binary mixtures of 2-methylpropene + methanol, + 1-propanol, + 2-propanol, + 2-butanol, and + 2-methyl-2-propanol at 364.5 K. The measured p, T, z data were fitted against Legendre polynomials and reduced using Barker's method to obtain phase equilibrium data. In addition to Legendre polynomials, binary interaction parameters were also optimized for Wilson, UNIQUAC, and NRTL activity coefficient models. All binary data showed a positive deviation from the Raoult's law. In addition, azeotropic behavior was observed for the 2-methylpropene + methanol binary mixture.
Journal of Chemical & Engineering Data, 2008
Vapor-liquid equilibrium (VLE) data for 1-butene + methanol, + 1-propanol, + 2-propanol, + 2-butanol, and + 2-methyl-2-propanol were measured at 364.5 K with a static total pressure apparatus. Measured p, T, z data were reduced to liquid and vapor phase compositions using the Barker method. Azeotropic points were found for the 1-butene + methanol system (x 1 ) 0.877, T ) 364.5 K, p ) 1606.2 kPa). From measured data, the Wilson, NRTL, and UNIQUAC parameters were calculated. The fitted Legendre polynomial was compared with the predictive UNIFAC and UNIFAC-Dortmund methods, and an error analysis was made.
Vapor Liquid Equilibrium for Six Binary Systems of C 4 -Hydrocarbons + 2-Propanone
Journal of Chemical & Engineering Data, 2006
Isothermal vapor-liquid equilibrium of the six binary systems 2-propanone + n-butane, + 2-methylpropane, + 1-butene, + cis-2-butene, + 2-methylpropene, + trans-2-butene were measured from (364.1 to 365.46) K with an automated static total pressure apparatus. Measured pTz data was reduced into pTxy data using the Barker method. Error analysis was conducted for all measured and calculated data. All measured systems exhibited positive deviation from Raoult's law, and an azeotropic point was found for the n-butane + 2-propanone system. Parameters of Wilson and UNIQUAC activity coefficient models were regressed with the experimental VLE data. Results obtained with two predictive methods, UNIFAC and COSMO-RS, were compared with measured data.