Representation of the Solubility of Solids in Supercritical Fluids Using the SAFT Equation of State

Abstract

A SAFT equation of state (EOS) combined with eight mixing rules was used to evaluate the capability of the SAFT approach for modeling the solubility of solids in supercritical fluids (SCFs). The results show that the SAFT approach gives good correlative accuracy in general, and the results are satisfactory when the three-parameter mixing rules are used, where the average absolute deviation of solid solubility in the SCF phase is normally smaller than 10%. The present work shows that the SAFT approach can be used to model solid-SCF equilibria, which gives slightly better correlative accuracy than the cubic EOSs.

Supercritical CO2 Extraction and Purification of Compounds with Antioxidant Activity

“…It has been reported that EOSs do not perform well in systems asymmetric with respect to size and attractive energy, providing results sensitive to the mixing rules for the interaction energy and size parameters of the solute and solvent molecules. The van der Waals mixing rule has been found ineffective for solubility predictions concerning highly asymmetric systems, and several mixing rules have been proposed (97,115,116); its selection is more important than the equation itself (96)(97). Alternatively, mixtures with high nonideality were treated as a pseudo-binary system, and the Peng-Robinson EOS was successfully used to describe the phase behavior (117,118).…”

PVTx Measurements of the N-Methylpyrrolidone/Methanol Mixed Solvent: Cubic and SAFT EOS Analyses

“…The crossassociation energy, AE , and volume, κ AE , were obtained from correlation of the experimental PVTx data. The other parameters were also obtained from the same correlation together with the following mixing rules: 61 (mixing rule I) eqs 21, 22, 24, 26, To reach a more accurate representation of the derived excess properties, the density and molar excess volume values were correlated concurrently with the target function defined by eq 29:…”

Experimental Measurements and Correlation of the Solubility of Three Primary Amides in Supercritical CO2: Acetanilide, Propanamide, and Butanamide

“…A recent review paper outlines the wide variety of models that have been applied to correlate the solubility of a solid in a supercritical solvent. Additional details about the models, their advantages and range of applicability can be found in refs to , to mention just a few. The most common choice of researchers, however, are equations of state (both cubic and noncubic) because of their simplicity, easy implementation in a software environment, steady convergence performance, comparatively small number of pure component parameters required, and robustness in correlating experimental solubility data …”