Mathematical Modelling of Oryzanol Separation from Rice Bran Oil by Silica-Based Batch Adsorption: Equilibrium and Mass Transfer Rate

Abstract

Mathematical modelling of batch adsorption of Oryzanol separation from Rice Bran Oil (RBO) has been set-up and tested by generated experimental data. The proposed model takes into account mass transfer and equilibrium phenomena. The effects of intra-particle gradient were considered, so the adsorption rate is controlled by the rate of solute mass transfer from the bulk liquid to the surface of particles and the intra-particle diffusion. In this model, the rate of Oryzanol mass transfer from the bulk liquid to the surface of the particle is described by film theory, while the intra-particle diffusion is assumed to be through the liquid inside the pore. Furthermore the Oryzanol in the liquid in the pore was assumed to be in equilibrium with the Oryzanol on the adjacent pore surface, in which equilibrium model applied was coefficient distribution approach. The values of the parameters involved in the models were obtained by curve fitting to the experimental data. It turned out that model proposed can quantitatively describe the batch adsorption of Oryzanol adsorption from rice bran oil with silica gel.