The use of molecular orbital calculations to describe the phase behavior of hydrogen-bonding mixtures

Journal Article · Tue Jul 01 04:00:00 EDT 1997 · International Journal of Thermophysics

DOI:https://doi.org/10.1007/BF02575244· OSTI ID:675520

Wolbach, J P; Sandler, S I ^[1]

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1. Univ. of Delaware, Newark, DE (United States)

In previous studies, the authors have used Hartree-Fock theory and density functional theory to compute the enthalpy and entropy changes of dimerization for methanol and a number of small carboxylic acids. They have shown that by using these results in a physical equation of state, the statistical associating fluid theory (SAFT), they are able to model the phase behavior of these pure hydrogen-bonding compounds with a reduction in the number of adjustable parameters; in this study, they use the pure-component parameters derived from the results of the molecular orbital calculations to describe the phase behavior of mixtures containing one associating and one nonassociating compound, again using the SAFT equation of state. They show that the use of the pure-component SAFT parameters derived from the quantum-mechanical calculations results in correlations of mixture VLE data with no loss of accuracy, and frequently with improved accuracy, compared to the original parameters reported for use with the SAFT model.

• Sponsoring Organization: National Science Foundation, Washington, DC (United States); USDOE, Washington, DC (United States)
• DOE Contract Number: FG02-85ER13436
• OSTI ID: 675520
• Journal Information: International Journal of Thermophysics, Journal Name: International Journal of Thermophysics Journal Issue: 4 Vol. 18; ISSN 0195-928X; ISSN IJTHDY
• Country of Publication: United States
• Language: English

Related Subjects

40 CHEMISTRY
CHEMICAL BONDS
DIMERIZATION
ENTHALPY
ENTROPY
EQUATIONS OF STATE
HYDROGEN
MIXTURES
MOLECULAR ORBITAL METHOD
PHASE STUDIES