An EOS/GE type mixing rule for perturbed hard-sphere equation of state and its application to the calculation of solid solubility in supercritical carbon dioxide

The EOS/GE type mixing rules have been successfully used in cubic EOSs. In this work, we made an attempt to derive a similar mixing rule for the Carnahan-Starling-Redilich-Kwong (CS-RK) EOS, which is a perturbed hard-sphere EOS with much better theoretical basis than cubic ones. The new derived EOS/GE mixing rule is as simple as that for cubic EOSs, and the UNIFAC model was used as the GE model required. The application to the calculation of solubility of solids and solid mixtures in supercritical carbon dioxide shows that the proposed EOS/GE mixing rule, which requires only a few group interaction parameters, gives comparable results with the two-parameter van der Waals mixing rule. The present work illustrates that the EOS/GE type mixing rules may have great potentials for non-cubic EOSs, which could be as successful as those for cubic EOSs.