Thirty Years with EoS/G^E Models—What Have We Learned?

Abstract

Thirty years of research and the use of EoS/G E mixing rules in cubic equations of state are reviewed. The most popular approaches are presented both from the derivation and application points of view and they are compared to each other. It is shown that all methods have significant capabilities but also limitations which are discussed. A useful approach is presented for analyzing the models by looking at the activity coefficient expression derived from the equations of state using various mixing rules. The size-asymmetric systems are investigated in detail, and an explanation is provided on how EoS/G E mixing rules should be developed so that such asymmetric mixtures are adequately represented.

Calculation of vapor–liquid equilibrium and PVTx properties of geological fluid system with SAFT-LJ EOS including multi-polar contribution. Part III. Extension to water–light hydrocarbons systems

“…Many studies tried to develop unconventional mixing rules to improve the capability of cubic EOS to model the phase behavior of highly non-ideal mixtures (such as size-asymmetric systems and systems containing association fluids) since 1980s. These mixing rules can be classified into two categories: empirical composition-dependent mixing rules, and mixing rules derived from excess Gibbs energy models or excess Helmholtz energy models (Wei and Sadus, 2000;Kontogeorgis and Coutsikos, 2012). Some of them combined with cubic EOS can represent the phase equilibria of binary water-light hydrocarbon systems (Daridon et al, 1993;Li et al, 1997;Escandell et al, 2011;Reshadi et al, 2011).…”

Solubility of polycyclic aromatic hydrocarbons in sub-critical water: A predictive approach using EoS/GE models

“…The predictive capability of the PR-LCVM method is not surprising since it has been highly successful in predicting Henry's constants, solid-gas equilibria, and infinite dilution activity coefficients of size asymmetric systems as well as mixtures consisting of polar compounds (including water) [29]. Readers interested in the explanation behind the predictive capability of the LCVM method are requested to look up the recent review by Kontogeorgis and Coutsikos [29] on Table 1 Parameters of the UNIFAC models.…”

“…Since the solubility of PAHs in SBCW is low (in the infinite dilution regime), the effect of the translation factor is expected to be insignificant and is neglected in our calculations. Expressions of the LCVM with the Peng-Robinson (PR) EoS are given in the literature [29,30].…”

“…In this case, the energy parameter of the mixture (a mix ), in the PR EoS, is obtained from the equation below [29,30]:…”

An extended corresponding states equation of state (EoS) for CCS industry

“…The used d, e, f and the non-randomness parameter α ji for CO 2 -water are listed in Table 1. A general discussion was made by Kontogeorgis and Coutsikos (2012), who reviewed the 30 years development of the activity coefficient models that are incorporated for cubic EoSs.…”