Applicability of the van Laar equation to correlation of strongly non-ideal systems

1979 ◽  
Vol 44 (12) ◽  
pp. 3490-3500
Author(s):  
Josef P. Novák ◽  
Eva Palacká ◽  
Petr Voňka ◽  
Jiří Pick
Keyword(s):  
Activity Coefficients ◽  
Suitable Choice ◽  
Wilson Equation ◽  
Nrtl Equation ◽  
Van Laar Equation ◽  
Kister Equation ◽  
Two Parameter

The performed analysis of the van Laar equation and its comparison with the results of analyses of the Redlich-Kister, NRTL and Wilson equations demonstrate that the Redlich-Kister equation have approximately the same range of applicability, the NRTL equation with a suitable choice of the parameter α allowing to attain higher limiting activity coefficients. For moderately asymmetric systems, the Wilson equation provides higher activity coefficients than other two-parameter equations but lower than the three-parameter ones. On the contrary, for very asymmetric systems, the Wilson equation allows to reach on the whole the highest limiting activity coefficients.

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

2013 ◽  
Vol 11 (3) ◽  
pp. 388-393 ◽  
Author(s):  
Mariana Hristova ◽  
Dimitar Damgaliev
Keyword(s):  
Experimental Data ◽  
Activity Coefficient ◽  
Binary Mixtures ◽  
Activity Coefficients ◽  
Thermodynamic Model ◽  
Flash Point ◽  
Wilson Equation ◽  
Nrtl Equation

AbstractThe 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.

Influence of nonideality of a ternary solvent on its extraction characteristics

1990 ◽  
Vol 55 (6) ◽  
pp. 1465-1471 ◽  
Author(s):  
Jana Ovečková ◽  
Elena Graczová ◽  
Július Surový
Keyword(s):  
Ethylene Glycol ◽  
Activity Coefficients ◽  
Diethylene Glycol ◽  
Mixed Solvent ◽  
Nrtl Equation ◽  
Kister Equation ◽  
The Ideal

Limiting selectivities and capacities for various compositions of the mixed solvent ethylene glycol (EG)-diethylene glycol (DEG)-N-methylpyrrolidone (NMP) with respect to toluene have been calculated from limiting activity coefficients of toluene and heptane. The calculations were made for both the ideal and real behaviour of the mixed solvent. The limiting activity coefficients of the model hydrocarbons toluene and heptane in the mixed solvent were calculated from experimentally determined binary coefficients of the Redlich-Kister equation, Wilson's equation as modified by Novak and co-workers, and the NRTL equation.

Isobaric vapour-liquid equilibrium data of the 1,2-dichloroethane-water system at 101.3 kPa

1989 ◽  
Vol 54 (11) ◽  
pp. 2848-2855 ◽  
Author(s):  
Daniel Bobok ◽  
Elemír Kossaczký ◽  
Július Surový
Keyword(s):  
Liquid Phase ◽  
Activity Coefficients ◽  
Water System ◽  
Vapour Phase ◽  
Solubility Data ◽  
Liquid Equilibrium ◽  
Equilibrium Data ◽  
Van Laar Equation

Isobaric vapour-liquid equilibrium data for the 1,2-dichloroethane-water system were calculated on the assumption of ideal behaviour of the vapour phase on using the van Laar equation for activity coefficients of the components in the liquid phase. The parameters of the van Laar equation were calculated from the solubility of 1,2-dichloroethane in water and of water in 1,2-dichloroethane determined experimentally in this work. On using the solubility data, the parameters of the heteroazeotropic point at the pressure of 101.3 kPa were also calculated.

A simplified form of Stokes–Robinson equation

1976 ◽  
Vol 54 (1) ◽  
pp. 9-11 ◽  
Author(s):  
Chai-Fu Pan
Keyword(s):  
Sodium Chloride ◽  
Hydrogen Chloride ◽  
Activity Coefficients ◽  
Aqueous Electrolyte ◽  
Electrolyte Solutions ◽  
Solvent Interactions ◽  
Interionic Interactions ◽  
Two Parameter ◽  
Robinson Equation ◽  
Existing Data

In non-associated dilute aqueous electrolyte solutions, the deviation from ideality is principally attributed to the interionic interactions and hydration of ions. Stokes and Robinson combined Bjerrum's thermodynamic treatment of ion–solvent interactions with Debye–Hückel treatment of interionic interactions to obtain a two-parameter equation. In very dilute regions, the Stokes and Robinson's equation reduces to a much simpler form, i.e.[Formula: see text]Activity coefficients of an electrolyte at lower concentrations, say up to 0.1 m, can be calculated from the equation provided suitable values of &([a-z]+); and h are available. Solutions of hydrogen chloride and sodium chloride were chosen as examples. The results agree with the existing data very satisfactorily.

Isothermal and isobaric vapour-liquid equilibrium data in the tetrachloromethane-n-butyl alcohol system

1983 ◽  
Vol 48 (10) ◽  
pp. 2879-2887 ◽  
Author(s):  
Jan Linek
Keyword(s):  
Experimental Data ◽  
Boiling Point ◽  
Butyl Alcohol ◽  
Correlation Equations ◽  
Wilson Equation ◽  
Liquid Equilibrium ◽  
System A ◽  
Equilibrium Data ◽  
Alcohol System ◽  
Kister Equation

Isothermal vapour-liquid equilibrium data at 65, 73 and 80 °C and isobaric ones at 101.3 kPa were measured in the tetrachloromethane-n-butyl alcohol system. A modified circulation still of the Gilespie type was used for the measurements. Under the conditions of measurements, the system exhibits positive deviations from Raoult's law and minimum boiling-point azeotropes. The experimental data were fitted to a number of correlation equations. The best correlation was reached with the Wilson equation but the regression failed in some cases. Therefore the results for the 5th order Redlich-Kister equation are presented.

Vapour-liquid equilibrium in the benzene(1)-propionic acid(2)-acetic acid(3) ternary system

1986 ◽  
Vol 51 (12) ◽  
pp. 2665-2674 ◽  
Author(s):  
Ivona Malijevská ◽  
Helena Perničková ◽  
Karel Ledvinka ◽  
Bohuslav Doležal
Keyword(s):  
Acetic Acid ◽  
Ternary System ◽  
Propionic Acid ◽  
Activity Coefficients ◽  
Error Propagation ◽  
Binary Data ◽  
Normal Pressure ◽  
Wilson Equation ◽  
Liquid Equilibrium ◽  
Experimental Values

Results of measurement of vapour-liquid equilibria in the benzene-propionic acid-acetic acid ternary system at normal pressure are presented. The activity coefficients were, within the framework of inaccuracies determined on the basis of the law of error propagation, subjected to a test of consistency and correlated by the Wilson equation. The experimental values of activity coefficients are compared with the values calculated on the basis of the Wilson equation with its constants obtained both from the ternary and from the binary data and with the values estimated by the UNIFAC method.

Liquid-vapour equilibrium and heats of mixing in the ethanol-acetonitrile system

1982 ◽  
Vol 47 (12) ◽  
pp. 3177-3187 ◽  
Author(s):  
Vladimír Dohnal ◽  
František Veselý ◽  
Robert Holub ◽  
Jiří Pick
Keyword(s):  
Excess Functions ◽  
Data Sets ◽  
Wilson Equation ◽  
Liquid Equilibrium ◽  
Energy Parameters ◽  
Extensive Data ◽  
Heats Of Mixing ◽  
Equilibrium Data ◽  
The Individual ◽  
Two Parameter

Vapour-liquid equilibrium and heats of mixing were measured in the ethanol-acetonitrile system. The isobaric vapour-liquid equilibrium measurements were carried out at the pressures of 43.35, 56.44, 69.48 and 86.05 kPa and the heats of mixing were measured at the temperatures of 298.15, 308.15 and 318.15 K. The individual vapour-liquid equilibrium data sets were correlated by various two-parameter equations and the data on heats of mixing by the Redlich-Kister polynomial. The extensive data obtained for both excess functions, covering the temperature range of 50 K, were correlated successfully by the Wilson equation with the energy parameters linearly dependent on temperature.

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