异丙醇提取稻米油动力学特性

Kinetics of Rice Bran Oil Extraction with Isopropanol

采用溶剂浸出法从米糠中提取油脂,以提油率为指标,对不同工艺条件下稻米油提取过程进行动力学分析,研究溶剂、料液比、提取温度以及辅助处理方法对米糠提油率的影响。结果表明:稻米油提取过程符合菲克第二定律,且该动力学方程能较为准确地模拟溶剂法提取稻米油的过程;提取条件不同时,提油率及提取速率差异较明显。相比无水乙醇和正己烷,异丙醇作为提取溶剂时,米糠总提油率Me和传质系数k均较高。适当地增加溶剂用量、提高提取温度以及动态处理均有助于提高总提油率和传质系数。动态处理增大了油脂扩散的传质驱动力,以异丙醇为溶剂,在提取温度为50℃、料液比为1∶7.5、动态处理的条件下,米糠提油率达到90.12%,比静态处理提高了0.54倍,最大有效扩散系数达到5.172 6×10^-12 m2/s。

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.