Liquid-liquid Equilibrium Determination and Data Correlation for 2,2,4-trimethyl Pentane - tripropylene Glycol Binary System (original) (raw)
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Journal of Chemical & Engineering Data, 2011
Liquid-liquid equilibrium (LLE) phase compositions for ternary and quaternary mixtures of water, methanol, 2-propanol, and 2,2,4-trimethylpentane were measured at 293.2 K. The universal quasichemical activity coefficient (UNIQUAC) model was used to model the experimental observations. Binary interaction parameters were estimated from the experimental equilibrium phase compositions. The agreement between calculations and experimental observations was very good with an overall root-mean-square deviation (rmsd) of 0.53 %.
Fluid Phase Equilibria, 2014
Vapor-liquid equilibrium data was determined by using a static method for the binary mixtures of dipropylene glycol (4-oxa-2,6-heptanediol) with benzene, toluene, ethylbenzene, o-xylene, m-xylene, and p-xylene at temperatures within 293.15 K-481.15 K. The p-T-x experimental data obtained was regressed with NRTL and UNIQUAC thermodynamic models in order to obtain the binary interaction parameters of the models, specific to each mixture. Furthermore, the T-x-y diagrams were determined based on these parameters and then compared with the diagrams calculated using the UNIFAC predictive model. We observed differences between the T-x curves calculated with the two models mentioned above and the UNIFAC predictive model.
Fluid Phase Equilibria, 2014
This paper describes an algorithm for the computation of the UNIQUAC interaction parameters 21 from liquid-liquid experimental data. The algorithm comprises two separate levels. The inner level 22 is devoted to the calculation of the interaction parameters, minimizing an objective function which 23 is function of the activities. The outer level uses the parameters by the inner level and aims to 24 minimize the error between experimental and calculated molar fractions through an adjustment of 25 the experimental molar fractions, provided that the condition of common tangent to the change of 26 the Gibbs free energy of mixing is matched.
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 …, 2006
The activity coefficients of the binary mixtures ethanol + 2,2,4-trimethylpentane, 1-butanol + 2,2,4trimethylpentane, and ethanol + o-xylene were determined at temperatures of (308.15, 313.15, and 318.15) K. The determination of the vapor phase composition at equilibrium was carried out using headspace gas chromatography analysis. Multiple headspace extraction was used to calibrate the headspace gas chromatograph. Comparison of the experimental phase diagrams with phase diagrams from the literature shows good agreement. The composition of the azeotropes are reported, where they exist. The molar Gibbs energy of mixing is reported for all mixtures studied. The infinite dilution activity coefficients are reported for all components of all mixtures. Some thermodynamic models (those of Wilson, NRTL, UNIQUAC, and Flory-Scatchard) have been compared with regard to their suitability for modeling the experimental data.
Brazilian Journal of Chemical Engineering, 2006
A correlation procedure for the prediction of vapor -liquid equilibrium of acetic acid -isopropanol -water -isopropyl acetate mixtures has been developed. It is based on the NRTL model for predicting liquid activity coefficients, and on the Hayden-O'Connell second virial coefficients for predicting the vapor phase of systems containing association components. When compared with experimental data the correlation shows a good agreement for binary and ternary data. The correlation also shows good prediction for reactive quaternary data.
Journal of Chemical and Engineering Data, 2010
The authors declare that data presented in the article entitled "Liquid-Liquid Equilibria for Monoethylene Glycol + Water + Alkane Systems in the Range (273 to 313) K and Atmospheric Pressure" [J. Chem. Eng. Data 2004, 49, 1577-1580 are completely erroneous. In the present study, the authors report new solubility data for two of the eight ternary systems mentioned in the previously cited article: monoethylene glycol (MEG) + water + n-hexane/2,2,4-trimethylpentane. The experimental protocol was first validated by studying the liquid-liquid equilibria of four binary mixtures, MEG + n-hexane/2,2,4-trimethylpentane and water + n-hexane/2,2,4-trimethylpentane, under atmospheric pressure at T ) 283.15 K, T ) 303.15 K, and T ) 323.15 K. The experimental results have been compared with the available literature data, and a good agreement has been found.
Industrial & Engineering Chemistry Research, 2010
This work analyzes the utility of a new model to correlate thermodynamic properties of solutions, the foundations of which have been published in a previous study. The model is applied to a set of experimental data for several properties of binary systems of methanol with four butyl alkanoates (vapor-liquid equilibria at p) 141.32 kPa and excess enthalpies and volumes at 298.15 and 318.15 K). Vapor-liquid equilibrium data (VLE) indicate that the four binary systems deviate positively from Raoult's law and do not present azeotrope. Excess enthalpies (h E) are positive for the entire range of compositions and decrease regularly with increasing length of the ester chain, with (∂h E /∂T) p,x > 0. The excess volumes (V E) decrease regularly with the length of the acid chain; they are positive for the binary systems of methanol with butyl (methanoate, ethanoate, and propanoate) and become negative for the system with butyl butanoate, with (∂V E /∂T) p,x > 0. The new model can be used to obtain a satisfactory correlation for Gibbs function g E) g E (p, T, x i), and for its derivatives. Correlation procedures for the data are described for the stages (x, h E) f [x, g E (T)] for the isobaric data reported here and (x, V E) f [x, g E (p)] for isothermal data reported in the literature. The new method allows a better correlation than the one obtained with the classical models of Wilson, NRTL, and UNIQUAC. We also present a unique correlation of all the properties of the methanol + butyl ethanoate system in the form of an analytical expression (p, T, x, y)) 0 and conclude that, on the whole, its implementation can be considered an advance in the data treatment of the properties of liquid solutions.
The Journal of Chemical Thermodynamics, 2010
In this work, isobaric (vapour + liquid) equilibrium data have been determined at (53.3 and 91.3) kPa for the binary mixtures of (1-propanol + 1-butanol). The thermodynamic consistency of the experimental values was checked by means the traditional area test and the direct test methods. According to the criteria for the test methods, the (vapour + liquid) equilibrium results were found to be thermodynamically consistent. The experimental values obtained were correlated by using the van Laar, Margules, Wilson, NRTL, and UNIQUAC activity-coefficient models. The binary interaction parameters of the activity-coefficient models have been determined and reported. They have been compared with those calculated by the activity-coefficient models. The average absolute deviation in boiling point and vapour-phase composition were determined. The calculated maximum average absolute deviations were 0.86 K and 0.0151 for the boiling point and vapour-phase composition, respectively. Therefore, it was shown that the activity-coefficient models used satisfactorily correlate the (vapour + liquid) equilibrium results of the mixture studied. However, the performance of the UNIQUAC model was superior to all other models mentioned.
Fluid Phase Equilibria, 2016
In this study, interactions between terpenes and alcohols or hydrocarbons have been considered and investigated. With this aim, the (solid þ liquid) equilibrium (SLE) phase diagrams for binary systems of {(À)-menthol, or thymol þ 1-decanol, or benzyl alcohol, or 2-cyclohexanethanol, or n-decane} were determined at ambient pressure. A dynamic method was used over a broad range of terpene mole fraction and temperature. The simple eutectic mixtures with a complete miscibility in the liquid phase were detected for all systems. The basic thermal properties of the pure terpenes and some solvents, i.e. melting temperatures as well as the enthalpy of fusion, have been measured with differential scanning calorimetry. Thermodynamic modelling of the phase diagrams in terms of the well-known group contribution method modified UNIFAC (Dortmund) as well as molecular-based PC-SAFT equation of state, was carried out in order to assess overall performance of these approaches when used to describe SLE in such complex cross-associating mixtures like these under study. In particular, different predictive strategies for assessing the binary interaction parameters of PC-SAFT model were proposed and tested.