Abstract

This article illustrates an application of the volumetric dispersion model in supercritical carbon dioxide extraction. The objectives were to obtain more insight into the mass transfer mechanisms and to clarify a specific rate-dominating mechanism for kinetics to incorporate with the flow model in the extraction process. Experimental results and predictions from models were calibrated to exhibit the role of axial dispersion. The residual oil in pressed oil-palm fibers was extracted in the first experiment. In the second experiment, α-tocopherol was extracted from palm oil. Two-mechanisms, the extraction of easily accessible solute from damaged cells and diffusion-controlled extraction from intact cells, were unified using a suitable switching function. Axial dispersion played a significant role in the constant extraction-rate period in the first experiment. The α-tocopherol extraction rates confirmed the role of axial dispersion through estimated Peclet numbers between 2.5 and 4.5.