Phase equilibria for the binary mixtures containing hydrogen fluoride and non-polar compound

Isothermal vapor–liquid equilibria for propane+hydrogen fluoride have been measured. The experimental data are correlated with the association model proposed by Lencka and Anderko for the mixtures containing hydrogen fluoride and the relevant parameters are presented. The recalculated parameters of the association model for pure hydrogen fluoride are presented. The problems occurred in the applications of the association model for the mixtures containing hydrogen fluoride are discussed. The correlation was found to be in good agreement with the experimental data. However, the calculated equilibrium pressures at very diluted compositions of hydrogen fluoride below about 0.01 were shown rather higher than the experimental values.     

Phase equilibria of binary and ternary polymer solutions using modified UNIQUAC-based local composition model

Journal of Thermal Analysis and Calorimetry - In the present research, a modification on UNIQUAC activity coefficient model was done based on the local composition concept. The model was applied...     

Phase equilibria in binary mixtures of ethane and hexadecane

This paper reports experimental results of a study of the phase behaviour of binary mixtures of ethane + hexadecane. In the near-critical region of ethane liquid + vapour and solid hexadecane + liquid two-phase boundaries have been measured. Also the three-phase equilibrium solid hexadecane + liquid + vapour has been determined experimentally. The experimental data cover the complete mole fraction range. Pressures up to 18 MPa were applied and the investigation was performed in a temperature region from about 260 K up to 450 K.     

(Vapor + liquid) equilibria of binary mixtures containing light alcohols and ionic liquids

This work presents (vapor + liquid) equilibrium (VLE) of binary mixtures containing methanol or ethanol and three imidazolium based ionic liquids: 1-butyl-3-methylimidazolium tetrafluoroborate, 1-butyl-3-methylimidazolium acetate, and 1-butyl-3-methylimidazolium hydrogen sulfate. VLE measurements were carried out over the whole range of composition between (283.15 and 298.15) K using a static apparatus. Activity coefficients γ_i of these solvents in the ionic liquids have been determined from the VLE data and correlated using the NRTL model. The results show that the NRTL model can be applied successfully with systems containing ionic liquids.     

Phase equilibria in binary mixtures of propane + acenaphthene

In the near-critical region of propane, phase equilibria of binary mixtures of propane + acenaphthene have been investigated experimentally. Apart from the three-phase equilibrium solid acenaphthene + liquid + vapour, two-phase boundaries liquid + vapour and solid acenaphthene + liquid have been investigated over the entire mole fraction range. The measurements were performed in the temperature region 350–420 K with pressures up to 10 MPa.     

Multiphase equilibria for binary and ternary mixtures containing propionic acid,n-butanol,butyl propionate,and water

Isothermal vapor–liquid equilibrium (VLE) data were measured for propionic acid + butyl propionate at 373.15 and 393.15 K, and isothermal vapor–liquid–liquid equilibrium (VLLE) data were also measured for n-butanol + water, butyl propionate + water, and water + n-butanol + butyl propionate at temperatures ranging from 323.15 to 393.15 K. No azeotrope was found in propionic acid + butyl propionate. The mutual solubility data of the binary aqueous systems were correlated well with the NRTL model accompanying with temperature-dependent parameters. Improvement on the calculation of saturated vapor compositions has been made by using two-term virial equation with one adjustable binary interaction parameter to represent the non-ideality of the vapor phase. The model parameters determined from the binary VLLE data of n-butanol + water and butyl propionate + water and the binary VLE data of n-butanol + butyl propionate are capable of predicting satisfactorily the VLLE properties for the ternary system of water + n-butanol + butyl propionate.     

Phase equilibria in binary systems containing N-monosubstituted amides and hydrocarbons

The binary vapour-liquid equilibrium of seven systems of -caprolactam + octane, + decane, + dodecane, octane, + decane, + dodecane, of N-methylacetamide + octane, of N-ethylacetamide of N-methylpropionamide + octane and of N-methylpropionamid + -caprolactam was measured in the temperature range from 363 to 423 K and in the low pressure region. A static equilibrium apparatus for the measurements was constructed.

In the system N-methylpropionamide + octane measurements of liquid-liquid equilibrium were carried out in the temperature range from 310 K up to the critical solution temperature.

The experimental results were correlated applying activity coefficients models such as NRTL. The data obtained from our measurements were used to estimate UNIFAC interaction parameters for the groups CH₂/CONHCH₂, CH₂/C₅H₁₀CONH and CONHCH₂/C₅H₁₀CONH.     

Investigation of excess enthalpies of selected binary and ternary solutions and mixtures

The excess enthalpies were investigated for 12 binary and 4 ternary systems, including mixtures and solutions of electrolytes and non-electrolytes. The excess enthalpies of mixtures and integral heats of solutions were measured with an isoperibol calorimeter at 35 °C. Heats of fusion and heat capacities as functions of temperature were measured with a Perkin Elmer Corp., DSC-2. Integral heats, heats of fusion and heat capacities allow investigations of excess enthalpies of solutions. For modelling of the experimental results, the modified Redlich-Kister equation was used with good success.

---

Zusammenfassung Für 12 binäre und temäre Systeme, darunter Mischungen und Lösungen von Elektrolyten und Nichtelektrolyten, wurden die Exzessenthalpien untersucht. Die Exzessenthalpien der Mischungen und die integralen Lösungsenthalpien wurden mit einem isoperibolen Kalorimeter bei 35 °C gemessen. Die Schmelzwärmen und spezifischen Wärmekapazitäten in Abhängigkeit von der Temperatur wurden mit einem DSC 2 der Fa. Perkin-Elmer bestimmt. Die integralen Wärmen, Schmelzwärmen und Wärmekapazitäten erlauben, die Exzessenthalpien der Lösungen zu untersuchen. Die Versuchsergebnisse lassen sich erfolgreich mit modifizierten Redlich-Kister-Gleichungen modellieren.

---

12 4 , . 35° . -2 - . , . -.

---

---

The author expresses his gratitude to the leader of the Teaching and Research TEAM, Prof. Dr. H. Schuberth, and to Dr. G. Figurski, for help and discussions.     

Flash point of organic binary mixtures containing alcohols: experiment and prediction

The flash points of three organic binary mixtures containing alcohols were measured in the present work. The experimental data was obtained using the Pensky-Martens closed cup tester. The experimental data were compared with the values calculated by the Liaw model. Activity coefficients were calculated by the Wilson equation and NRTL equation. The accuracy of predicted flash point values is dependent on the thermodynamic model used for activity coefficient.     

Determination of the number of transport units from data on equilibria in binary mixtures

Relations for analytical determination of the number of transport units are suggested. These relations contain coefficients found from experimental data on equilibria in binary mixtures. Examples for four binary mixtures are considered.     

Solubility of 2,5-dimethylphenol and 3,4-dimethylphenol in binary solvent mixtures containing alcohols

Solubilities are reported for 3,4-dimethylphenol and 2,5-dimethylphenol in binary mixtures of ethyl acetate with alcohols (methanol, 1-butanol, 1-hexanol), as well as for 2,5-dimethylphenol in binary mixtures of hexane with 1-butanol. The results of these measurements are compared to those obtained from the predictions by the Wilson equation for the excess Gibbs free energy of mixing (G^E). Parameters in binary solute—solvent systems were regressed from solid—liquid equilibrium data, whereas for binary mixed solvents they were taken from literature data of vapour—liquid equilibrium as well as from solid—liquid equilibrium data in ternary mixtures for equimolar compositions of binary solvents. The systems containing 3,4-dimethylphenol—ethyl acetate+alcohol mixed solvents were found to exhibit a small synergistic effect of solubility.     

Phase equilibria for mixtures containing nonionic surfactant systems: Modeling and experiments

Surfactants are important materials with numerous applications in the cosmetic, pharmaceutical, and food industries due to inter-associating and intra-associating bond. We present a lattice fluid equation-of-state that combines the quasi-chemical nonrandom lattice fluid model with Veytsman statistics for (intra + inter) molecular association to calculate phase behavior for mixtures containing nonionic surfactants. We also measured binary (vapor + liquid) equilibrium data for {2-butoxyethanol (C₄E₁) + n-hexane} and {2-butoxyethanol (C₄E₁) + n-heptane} systems at temperatures ranging from (303.15 to 323.15) K. A static apparatus was used in this study. The presented equation-of-state correlated well with the measured and published data for mixtures containing nonionic surfactant systems.     

Isothermal vapor-liquid equilibria for binary and ternary mixtures formed by 1-butanol,acetonitrile and benzene

Isothermal vapor-liquid equilibrium data are presented for the binary acetonitrile-1-butanol and ternary 1-butanol-acetonitrile-benzene systems at 60 °C. The experimental results are well correlated with the UNIQUAC associated-solution model.     

(Solid + liquid) phase equilibria of binary mixtures containing N-methyl-2-pyrrolidinone and alcohol at atmospheric pressure

The (solid + liquid) equilibria of {N-methyl-2-pyrrolidinone + 1-propanol, or 2-propanol, or 1-butanol, or 2-methyl-1-propanol, or 2-methyl-2-propanol, or 1-pentanol} has been measured by a dynamic method. The experimental results have been correlated using the Wilson, UNIQUAC ASM and two modified NRTL equations. The root-mean-square deviations of the solubility temperatures for all the calculated values vary from (0.5 to 2.1) K and depend on the particular equation used. The specific interaction between the carbonyl group of the NMP molecule and the alcohol has been discussed.     

二元及三元离子交换体系的统计热力学

本文用统计热力学方法对二元及三元离子交换体系进行了研究,得到了修正选择系数与交换剂组成关系的理论表达式,并得到二元交换体系的交换剂组分活度系数与组成的关系式,即Kielland公式。     

Phase equilibria analysis of the binary N2-NH3 and H2-NH3 systems and prediction of ternary phase equilibria

The high-pressure phase equilibria of binary mixtures, hydrogen-ammonia and nitrogen-ammonia, have been analyzed. A combined Chemical Association + Redlich–Kwong Equation of State (A + RKEOS) approach is adopted to represent gas-phase non-idealities while the liquid phase non-idealities are modeled using the NRTL equations. The proposed approach gave better representation as compared to other modified Redlich–Kwong Equations of State. The new approach was satisfactorily used to predict the phase equilibria of the ternary system of hydrogen–nitrogen–ammonia.