Modeling Solubility of Solids in Supercritical Fluids using Fusion Properties

Proceedings (su CD e senza ISBN) della Conferenza "8th International Conference on Properties and Phase equilibria for Product and Process design", Noordwijkerhout (NL), 26 aprile - 1 maggio 1998. - The modelling of solid solubilities in supercritical fluids is usually performed by means of thermodynamic models based on cubic equations of state together with the use of correlations for estimating the solid properties. However, it was shown in the literature, that the sublimation pressure, very low for high molecular weight compounds, is in many cases responsible of large deviations between experimental and calculated solubilities. In this work, the sublimation pressure of solids is estimated by using experimental fusion data and liquid-vapour equilibrium properties obtained from the equation of state. The results provided by this method are compared with those obtained using sublimation pressures from literature. It is shown that this method leads to realistic values of binary interaction parameters k12 and allows satisfactory solubility predictions for two solids in supercritical fluids.