Mathematical modeling of vegetable oils extraction by supercritical fluids

The aim of this paper is to provide a comprehensive mathematical model to describe the supercritical fluid extraction of vegetable oils. The complexity of the plant solid matrix structure, the effect of size, controlling effect of phase equilibrium, interaction between solute and solid matrix have been taken into account as well as axial dispersion in fluid phase. As two new attempts, profile of concentration for the inner region of particle along with concept of free solute on the surface of the particle was considered and equilibrium concentration dependence on concentration of free solute was presented. Obtained differential equations are partial and solved numerically. The ability of the model to predict the extraction yield was checked out under changing operating parameters of solvent flow rate, pressure, temperature and particle size, for the extraction of neem seed oil that percentage of sum of squared differences (SSD%) between the model prediction and the experimental data obtained 1%, 0.4%, 0.3% and 0.3%, respectively. Also for the extraction ofsunflower seed oil, the effect of solvent flow rate was investigated that the SSD% was obtained 0.5%.