2.3.2. Solubility measurement (static technique) and Chrastil
equation
The experimental values for solubility were obtained in triplicate
by the static method, for which the methodology has been
discussed in detail elsewhere [25,12]. The experimental conditions
were temperatures of 40 and 60 ◦C and pressures of 100, 200, 300
and 400 bar. In a typical experiment, 8 g of oil, adhered to glass
beads with an average diameter of 3mm,were placed in the equilibrium
cell. In each case, samples were taken after 3 h of equilibrium.
A knownamount of n-hexanewas then added to clean the collector.
The solvent was evaporated off in a vacuum oven at 50 ◦C to obtain
dry oil. The solubilitieswere calculated as the ratio of the totalmass
of extracted oil (extraction + cleaning process) to the CO2 mass in
the collector: