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

Abstract

The EOS/ G E 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/ G E mixing rule is as simple as that for cubic EOSs, and the UNIFAC model was used as the G E model required. The application to the calculation of solubility of solids and solid mixtures in supercritical carbon dioxide shows that the proposed EOS/ G E 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/ G E type mixing rules may have great potentials for non-cubic EOSs, which could be as successful as those for cubic EOSs.