Correlating and predicting the solubilities of polycyclic aromatic hydrocarbons in supercritical fluids using the compressed gas model and the reference solubilities

The solubilities of some polycyclic aromatic hydrocarbons (PAHs) in supercritical fluids were correlated and predicted using the compressed gas model and the reference solubilities. By introducing the reference solubilities, the compressed gas models combined with Peng–Robinson equation of state, Carnahan–Starling–van der Waals hard sphere equation of state and van der Waals one-parameter mixing rules can yield the overall averages of the average absolute relative deviations (AARDs) of 7.45% and 8.16% in solubility correlation for PAHs in supercritical fluids, respectively, which are much less than the values obtained using the compressed gas model combined with the corresponding equation of state and the sublimation pressures of the solutes. By introducing the reference solubilities, the calculated solubilities are not sensitive to the binary interaction parameters and the solubilities of PAHs in the corresponding supercritical fluid can be predicted with a specific binary interaction parameter. When using reference solubilities in the compressed gas model, the two equations of state provide comparable average AARDs in solubility prediction for PAHs in supercritical fluids, which are 14.00% and 14.19%, respectively. The introduction of reference solubilities into the compressed gas model provides a feasible and simple solubility prediction method for the compounds in supercritical fluids without using their sublimation pressures. Moreover, combined with the reference solubilities and the compressed gas model, the hard sphere equation of state provides a more simple method to predict the solubilities of solutes in supercritical fluids with only their solid molar volumes.