Grape Seed Oil Supercritical Extraction Kinetic and Solubility Data: Critical Approach and Modeling

This paper focuses on supercritical CO2 extraction of grape seed oil which has been analyzed both experimentally and theoretically. Extractions on crushed seeds at pressures varying in the range 280 ÷ 550 bar and at a fixed temperature of 313 K were performed. From the initial linear portion of the experimental curves oil solubility data in the supercritical solvent have been obtained. By modeling the complete curves, the transport parameters regulating the oil mass transfer inside the seed particles have been calculated: the internal transport coefficient and the effective diffusivity. Three different extraction baskets (0.1, 0.2 and 0.5 liters) have been utilized: the differences in the extraction curves have been modeled and explained in terms of the different void volume of the apparatus for the various baskets. A procedure to obtain consistent solubility data when dealing with extractor vessel with non-negligible void volume has been described.