Abstract: Rice bran oil was extracted by solvent extraction method with three different solvents. The extraction process was kinetically analyzed, and oil yield was investigated as a function of solvent type, solid-to-solvent ratio, extraction temperature and auxiliary treatment methods. The results showed that the extraction process accorded with Fick’s second law, and the kinetic equation could accurately simulate it. Oil yield and the extraction rate varied greatly with the extraction conditions. Oil yield (Me) and mass transfer coefficient (k) of rice bran using isopropanol as the extraction solvent were higher than using anhydrous ethanol and n-hexane. Appropriately increased solvent dosage, increased extraction temperature, or dynamic treatment contributed to improving oil yield and mass transfer coefficient. Dynamic treatment increased the driving force for oil mass transfer, and oil yield was up to 90.12% under the conditions: isopropanol as the solvent, an extraction temperature of 50 ℃, solid-to-solvent ratio of 1:7.5 and use of dynamic treatment, which was 1.54 times higher than obtained with static treatment. In addition, the maximum effective diffusion coefficient was as high as 5.172 6 × 10-12 m2/s.

Key words: rice bran oil, oil extraction, isopropanol, kinetic equation