Applications of cubic equations of state for determination of the solubilities of industrial solid compounds in supercritical carbon dioxide: A comparative study

Representation/predictions of the solubilities of industrial solid compounds in supercritical carbon dioxide have been a challenge since the last two decades. In this communication, the Soave–Redlich–Kwong (SRK), the Peng–Robinson (PR), the Patel–Teja–Valderrama (PTV), the Esmaeilzadeh–Roshanfekr (ER) and the modified Esmaeilzadeh–Roshanfekr (m-ER) equations of state (EoS) accompanied with several mixing rules including the Wong–Sandler (WS), the covolume-dependent (CVD) and the van der Waals one (vdW1) and two (vdW2) fluid mixing rules are applied to calculate/estimate the solubilities of 23 mostly used solid compounds in supercritical carbon dioxide. In addition, the Van-Laar excess Gibbs energy (Gex) activity model is also used in phase equilibrium calculations. The probable global optimal values of the proposed thermodynamic model parameters are evaluated by the differential evolution (DE) optimization strategy. The results indicate that the combination of the m-ER EoS with the WS mixing rule leads to more accurate predictions (AARD=7%) in comparison with other ones. Finally, application of Chrastil semi-empirical correlation for estimation of the solubilities of several compounds in supercritical carbon dioxide is investigated at wide ranges of temperatures.

► The aim is to represent the solubility of solid compounds in supercritical CO2.
► Several cubic EoSs and mixing rules have been used for a comparative study.
► Application of the Chrastil correlation has also been investigated for this purpose.
► The effects of intermolecular interactions are considered through WS mixing rule.
► The m-ER EoS and WS mixing rule leads to less AARD (7%) than the other equations.