Calculation of HmE for binary mixtures: some consequences of the conversion of cubic equations of state to hard-sphere versions

It has been reported by Mosedale and Wormald [1], and by Christensen et al. [2,3], that replacement in cubic equations of state (EOS) of the free volume term, 1/( V m- b), with a hard-sphere expression improves the fit to the enthalpies of mixing, H m E, at near critical, constant, temperatures and...

Full description

Saved in:
Bibliographic Details
Published in:Thermochimica acta 1989-11, Vol.154 (1), p.107-117
Main Author: Zebolsky, Don M.
Format: Article
Language:English
Subjects:
Chemical thermodynamics
Chemistry
Exact sciences and technology
General and physical chemistry
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:It has been reported by Mosedale and Wormald [1], and by Christensen et al. [2,3], that replacement in cubic equations of state (EOS) of the free volume term, 1/( V m- b), with a hard-sphere expression improves the fit to the enthalpies of mixing, H m E, at near critical, constant, temperatures and pressures for binary mixtures. Further improvements can be obtained in some cases with Kreglewski's square-well combining rule for a 12 [4], and with a temperature-dependent b parameter [5]. For mixtures of CO 2 with a hydrocarbon, the improvements appear to allow estimates of H m E data that are as reliable as correlations with one adjustable interaction parameter. Attempts to use a hard-sphere expression in the Peng-Robinson equation lead to an unacceptable EOS. Singularities can be used to forecast when a hard-sphere version will be unacceptable.
ISSN:0040-6031
1872-762X
DOI:10.1016/0040-6031(89)87123-0