Isothermal vapor-liquid equilibria of mixtures containing organic compounds. Part 5: Excess Gibbs energies of dichloromethane or chlorobutane + linear ether or acetal mixtures at 25�C1

1991 ◽  
Vol 20 (1) ◽  
pp. 57-70 ◽  
Author(s):  
Luciano Lepori ◽  
Enrico Matteoli ◽  
Maria Rosaria Tin�
Keyword(s):  
Organic Compounds ◽  
Gibbs Energies ◽  
Excess Gibbs Energies ◽  
Vapor Liquid Equilibria ◽  
Vapor Liquid

Thermodynamics of mixtures with strongly negative deviations from Raoult's law. Part 3. Application of the DISQUAC model to mixtures of triethylamine with alkanols. Comparison with Dortmund UNIFAC and ERAS results

2000 ◽  
Vol 78 (10) ◽  
pp. 1272-1284 ◽  
Author(s):  
Juan Antonio González ◽  
Isaias Garcia de la Fuente ◽  
Jose Carlos Cobos
Keyword(s):  
Constant Pressure ◽  
Dipole Moments ◽  
Interaction Parameters ◽  
Short Discussion ◽  
Molar Excess ◽  
Gibbs Energies ◽  
Excess Gibbs Energies ◽  
Specific Parameter ◽  
Thermodynamics Of Mixtures ◽  
Vapor Liquid Equilibria

Binary mixtures of triethylamine (TEA) and alkanols have been investigated in the framework of DISQUAC. The systems are built by three contacts: aliphatic–hydroxyl, aliphatic–nitrogen, and hydroxyl–nitrogen. The corresponding interaction parameters are reported and discussed. The former are avalilable in the literature but were modified (particularly the third dispersive (DIS) and quasichemical (QUAC) interchange coefficients) for sec- and tert-alkanols + n-alkanes using recent data on excess heat capacities at constant pressure (CEP) for systems of these alkanols with n-heptane. The interaction parameters for aliphatic-nitrogen contacts are purely dispersive. The structure dependence of the DIS and QUAC interchange coefficients of the hydroxyl-nitrogen contacts in 1-alkanols + TEA systems is similar to that found in other solutions previously investigated. The QUAC interchange coefficients remain constant from ethanol and are also valid for 2-alkanols and tert-butanol. Methanol behaves differently. A short discussion in terms of effective dipole moments is also included. DISQUAC represents well the thermodynamic properties examined: vapor-liquid equilibria (VLE), molar excess Gibbs energies (GE) and molar excess enthalpies (HE). DISQUAC provides better results than the Dortmund version of UNIFAC using the published geometrical and interaction parameters. ERAS parameters for 1-alkanols + TEA systems are also reported. Interactions between unlike molecules are stronger for solutions with methanol or ethanol. DISQUAC improves ERAS results on HE, while both models give similar results for GE. However, ERAS needs an specific parameter, with unknown temperature-dependence, to describe properly GE. The main advantage of ERAS is its ability to provide information on VE. Its main limitation is that can be only applied to those systems where association is expected. DISQUAC, a purely physical model, can be applied to any type of binary mixture, as it is followed from this and previous studies.Key words: theory, liquids, associated, thermodynamics, group contributions.

DISQUAC structure-dependent interaction parameters for mixtures containing sec-alkanols and benzene, toluene, or n-alkanones

1998 ◽  
Vol 76 (10) ◽  
pp. 1418-1428 ◽  
Author(s):  
Juan Antonio González ◽  
I García de la Fuente ◽  
J C Cobos
Keyword(s):  
Interaction Parameters ◽  
Similar Model ◽  
Molar Excess ◽  
Gibbs Energies ◽  
Excess Gibbs Energies ◽  
Benzene Toluene ◽  
The Mean ◽  
Vapor Liquid Equilibria ◽  
Structure Association ◽  
Dependent Interaction

Mixtures containing sec-alkanols and benzene, toluene, or n-alkanones are characterized in terms of DISQUAC by means of structure-dependent interaction parameters. The quasichemical (QUAC) interchange coefficients are independent of the size alcohol for a given organic solvent; while the dispersive (DIS) ones change with the size of the alcohol. This behaviour has been found for other many alcoholic solutions. DISQUAC represents well the thermodynamic properties of these mixtures: vapor-liquid equilibria, VLE, molar excess Gibbs energies, GE, and molar excess enthalpies, HE. So, the mean deviations between experimental and calculated results are about 2% for pressure, and 8% for HE. A short comparison between DISQUAC results and those given by the Dortmund version of UNIFAC, the UNIQUAC association theory and other similar model is also presented. In the case of the Dortmund version of UNIFAC, poorer predictions are obtained for HE, as this property is more sensitive to molecular structure. Association theories provide better results because are used as correlation equations.Key words: thermodynamics, 2-alkanols, group contributions, interactions.

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