The process of supercritical fluid extraction (SFE) of a solute from raw material with a high initial oil content is studied within the framework of the shrinking core model. The extraction times under consideration are typical for experiments in laboratory and pilot scales, when the first stage with high extraction rates is observed. An analytical solution of the model equations is derived for a polydisperse packed bed and is specified for a particular case of the random mixture of particles of two different sizes a₀ a₁. Typical extraction regimes are analyzed in this limiting case of the ensemble of ground particles. The phase portrait of the SFE dynamics is plotted and discussed.
Salamatin et al. (Sat,) studied this question.