Study of Thermodynamic Modeling of Isothermal and Isobaric Binary Mixtures in Vapor-Liquid Equilibrium (VLE) of Tetrahydrofuran with Benzene (303.15 K) Cyclohexane (333.15 K), Methanol (103 kPa), and Ethanol (100 kPa)

Tetrahydrofuran (THF) is an aprotic solvent with multiple applications in diverse areas of chemical, petrochemical, and pharmaceutical industries with an important impact in chemical waste liquid with other solvents. In this work, 51 available VLE data, for isothermal binary mixtures of THF(1) + Benzene(2) and THF(1) + Cyclohexane(2) at 303.15 and 333.15 K, respectively, and isobaric THF(1) + Methanol(2) at 103 kPa and THF(1) + Ethanol(2) at 100 kPa were used in the development of the activity coefficient models. The quality of experimental data was checked using the Herington test. VLE binary data was correlated with models Wilson, NRTL UNIQUAC, and UNIFAC to obtain binary parameters and activity coefficients. The best thermodynamic consistency when conducting the Herington test for the VLE data was found for the THF(1) +Cyclohexane(2) isothermal system and THF(1) + Ethanol(2) isobaric system. The UNIQUAC model for isothermal systems THF(1) + Benzene(2) and THF(1) + Cyclohexane(2), the NRTL model for the isobaric system THF(1) + Methanol(2), and the UNIQUAC model for THF(1) + Ethanol(2) perform better than the other models.

Vapor−Liquid Equilibrium For The Mixture of m-Xylene, Ethylbenzene and 1, 2, 4-Trichlorobenzene at 101.3 kPa

The vapor-liquid phase equilibrium (VLE) data for binary systems of m-xylene + ethylbenzene, m-xylene + 1, 2, 4-trichlorobenzene, ethylbenzene + 1, 2, 4-trichlorobenzene and ternary system of m-xylene + ethylbenzene + 1, 2, 4-trichlorobenzene were determined with a modified Rose still at 101.3 kPa, and all the binary data passed the Wisniak’s test, which accorded with the thermodynamic consistency. Three activity coefficient models namely, Wilson, NRTL and UNIQUAC were used to correlate VLE data and get binary interaction parameters, then the ternary VLE data of m-xylene + ethylbenzene + 1, 2, 4-trichlorobenzene were estimated based on these model parameters using Aspen Plus software. The estimation values of the three models agree well with the experimental data. Moreover, the effect of 1, 2, 4-trichlorobenzene was analyzed, and it found to be an effective candidate extractant for the extractive distillation of ethylbenzene from mixed xylenes.

Prediction of Vapour Liquid Equilibria for Binary Azeotropic Systems using Activity Coefficient Models

Distillation operations are inevitable in chemical and petrochemical process industries. Design of distillation equipment requires knowledge of precise vapor-liquid equilibrium data. Due to the complexity and expenses incurred to obtain the VLE data experimentally for those systems for which the data are not available, solution thermodynamics and phase equilibria serve as an important tool in theoretical VLE prediction. In the current investigation five binary azeotropes namely Acetone-water, Acetone-methanol, Ethanol-water, Ethanol-benzene, and Methanol-water are taken for study. The theoretical prediction of VLE for these systems were computed using activity coefficient models namely NRTL, UNIQUAC, UNIFAC and modified form of Florry - Huggins equations (SRS and TCRS). The parameters for the five systems of four models viz. NRTL, UNIQUAC, SRS and TCRS were computed using Newton Raphson technique. UNIFAC model was adopted using Analytical solution of group contribution (ASOG) method. The performance of these models are tested using thermodynamic consistency test and validation from experimental VLE from literature. It was seen that the Acetone - Water system follows TCRS model, Acetone - Methanol and Ethanol - Water and Methanol - Water systems follow UNIFAC model, whereas SRS model suits for the Ethanol - Benzene system with highest accuracies.

Measurement and Modeling of Solubility of Galactose in Aqueous Ionic Liquids, 1-Butyl-3-Methyl Imidazolium Bromide, 1-Hexyl-3-Methyl Imidazolium Bromide and 1-Butyl-3-Methylimidazolium Chloride at T = (298.15 And 308.15) K

Background: Saccharides are considered as abundant, cheap and renewable starting materials for chemicals and fuels. Recently, ionic liquids have been used as green solvents for saccharides. The solubility values of galactose in aqueous ionic liquid solutions are not available. Thus, the main objective of this research was to determine the solubility of galactose in aqueous solutions containing ionic liquids, 1-butyl-3-methyl imidazolium bromide, [BMIm]Br, 1-butyl-3-methylimidazolium chloride [BMIm]Cl and 1-hexyl-3-methyl imidazolium bromide, [HMIm]Br at different mole fractions of ionic liquids at T = (298.15 and 308.15) K. Methods: In this study, the gravimetric method was used to measure the solubility of galactose in aqueous ionic liquids solutions. Results: The solubility values of galactose in water and aqueous ionic liquid solutions were correlated with the activity coefficient models of Wilson, NRTL, modified NRTL, NRF-NRTL, and UNIQUAC. Conclusion: It was concluded that with increasing the mole fraction of ionic liquids, the solubility values of galactose decrease and in fact all of these ionic liquids show salting-out effect on aqueous galactose solutions and this behavior is stronger in ionic liquid 1-butyl-3-methylimidazolium chloride.