A combinatorial activity coefficient model for symmetric and asymmetric mixtures

A modified free-volume-based model for predicting vapor–liquid and solid–liquid equilibria for size asymmetric systems

“…In comparison to the EFV model, the MEFV model can more accurately predict the phase behavior of size-asymmetric systems for both athermal and non-athemal mixture [13]. It was shown that both the EFV and MEFV models significantly underestimate activity coefficients of heavy molecule (γ 2 ) at finite and infinite concentrations [4][5][6][7]13]. It should be also noted that entropic-FV based models consider the combinatorial and free-volume terms in a single term.…”

“…This effect can be examined either in a combined combinatorial-FV term, entropic-FV based models, or an additional FV term such as UNIFAC-FV based models. During the recent years a large number of free-volume activity coefficient models have been proposed [4][5][6][7][8]12]. The same concept for combinatorial term as those in the F-H and S-G models is taken into account for these free-volume-based activity coefficient models which is shortly described hereafter.…”

“…VLE, LLE and SLE, can be observed in size-asymmetric systems. Study of SLE phase behavior for size-asymmetric systems is often important in solvent selection [3][4][5][6][7]. A number of thermodynamic models have been developed to study the phase behavior of size-asymmetric systems.…”

Predicting infinite dilution activity coefficients with the group contribution solvation model: an extension of its applicability to aqueous systems

“…The expression of the combinatorial term in the UNI-QUAC model (the Staverman-Guggenheim expression [29] derived based on the lattice theory) has been however analysed and criticized, and its deficiencies have led to the introduction of different modifications or other expressions that seem to be more reliable [9][10][11]46]. Among such expressions, the Chain-FV model proposed by Kontogeorgis et al [47] seems to be more appropriate since it includes all other effects (i.e.…”

VLE calculation of carbon dioxide+n-alkanes binary mixtures with MHV2 mixing rule

“…A number of investigations over the last years have shown that most EOS/G E models (MHV2, PSRK, Wong-Sandler) fail to represent these asymmetric systems [10,11].…”