Isobaric Vapor−Liquid Equilibria for Binary and Ternary Mixtures of Methanol, Ethanoic Acid, and Propanoic Acid

Abstract

Vapor-liquid equilibrium (VLE) data for the strongly associating ternary system methanol + ethanoic acid + propanoic acid and three constituent binary systems: methanol + ethanoic acid, methanol + propanoic acid, and ethanoic acid + propanoic acid have been determined by different liquid-phase compositions using a novel pump ebulliometer at 101.3 kPa. The vapor-phase compositions y of these binary systems had been calculated from T-p-x according to the Q function of molar excess Gibbs energy by the indirect method. The experimental T-x data are used to estimate Wilson, nonrandom two-liquid (NRTL), Margules, and van Laar model parameters, and these parameters in turn are used to calculate vapor-phase compositions y. The activity coefficients of the solution were correlated with its composition by the Wilson, NRTL, Margules, and van Laar models through the least-squares method. The VLE data of the ternary system were well-predicted from these binary interaction parameters of the Wilson, NRTL, Margules, and van Laar model parameters without any additional adjustment to build the thermodynamic model of VLE for the ternary system and obtain the vapor-phase compositions y and the calculated bubble points. The calculated bubble points with the model parameters of activity coefficients were in good agreement with the experimental data.

Measurements and Correlation of Isobaric Vapor–Liquid Equilibrium Data for Binary Mixtures of Furan, Oxolane, and Furan-2-Carbaldehyde and Application of the Binary Model Parameters for Further Prediction of the Ternary System

“…In Table , the densities and refractive indices at 293.15 K together with the normal boiling points of the pure components are compared with those from the reference of Riddick et al The results confirm that the measurement values closely approach those of the literature. The methods for measuring densities and refractive indices of the compositions have been previously reported. ,, The densities were determined at 293.15 K with a bicapillary pycnometer formerly explained by Rao and Naidu, with a precision of ±0.01 kg·m –3 , and the refractive indexes of the pure components were determined with an Abbe refractometer (Carl-Zeiss-Jena, accuracy ±0.0001) at 293.15 K after calibration with standard samples, equipped with the device.…”

“…The methods for measuring densities and refractive indices of the compositions have been previously reported. 13,14,28 The densities were determined at 293.15 K with a bicapillary pycnometer formerly explained by Rao and Naidu, 29 with a precision of ±0.01 kg•m −3 , and the refractive indexes of the pure components were determined with an Abbe refractometer (Carl-Zeiss-Jena, accuracy ±0.0001) at 293.15 K after calibration with standard samples, equipped with the device.…”

“…However, Wisniak’s group applied the new model-free computation method and boundary conditions to the VLE data for azeotropic systems . Moreover, Segura and co-workers presented a model-free strategy to deal with VLE data of ternary systems. , In addition, our group reported that the model-free technique was widely applied to distillation separation for the associating system of organic acid in the chemical industry. − …”

Computation of Isobaric Vapor-Liquid Equilibrium Data for Binary and Ternary Mixtures of Methanol, Water, and Ethanoic Acid from T, p, x, and Gao1, Zhang2, Lücking3 et al. 2012Journal of ThermodynamicsSelf Cite

“…Moreover, Guan et al investigated that the isobaric vapor-liquid equilibria for water + ethanoic acid + n-pentyl acetate, isopropyl acetate, N-methyl pyrrolidone, or N-methyl acetamide were correlated and predicted by both the nonrandom two-liquid (NRTL) and universal quasichemical activity coefficient (UNIQUAC) models used in combination with the Hayden-O'Connell (HOC) method [11][12][13][14]. In our recent work, we have concluded that the VLE data for the associating systems containing the carboxylic acid system can be correlated and predicted [15,16]. Although the VLE data of the mixture containing the associating systems were previously reported by the different research groups [17][18][19][20][21], respectively, the VLE data for the associating binary system containing the carboxylic acid have been still extensively studied because of the extensive association effects occurring in them and the difficulty of properly calculating the activity coefficients [22][23][24][25].…”

“…Therefore, the challenge for the VLE data of the associating systems has evoked more and more researchers to focus on new strategies for exploring them. The VLE data for methanol + water + ethanoic acid ternary system and the constituent binary systems are indispensable in distillation separation process to the product of methanol carboxylation through the correlation and prediction by the new method, while some of the isobaric VLE data for these binary and ternary systems are correlated and predicted earlier [9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25]. To provide the new correlation and prediction for some necessary basic thermodynamic data on the separation process of methanol carboxylation, therefore, it is very indispensable for these systems studied on the VLE data of the constituent binary and ternary systems using the new method.…”