Supercritical Fluid Extraction of the Seed Fatty Oil: Sensitivity to the Solute Axial Dispersion

Abstract

© 2020 American Chemical Society. Successful development of an industrial-scale process for supercritical fluid extraction (SFE) of oil from ground plant material requires detailed analysis of the effects associated with the solute transport in porous media. In the present paper, a case of the raw material with high initial oil content is considered, and the influence of the axial flow dispersion on the extraction dynamics is analyzed numerically and analytically. The typical one-dimensional convection-dispersion mass-transfer model on the extractor-scale level is revisited, and the widely accepted shrinking core model is used to describe the solute diffusion on the particle-scale level. The SFE description also accounts for the polydispersity of the ground material. The set of dimensionless parameters required for complete analysis of different extraction regimes is defined. The influence of the axial flow dispersion on the extraction kinetics manifests itself mainly via polydispersity of the ground raw material, despite being insignificant in typical SFE implementations.