超临界CO_2萃取不同强化方法的比较与动力学模型

Comparison and Dynamic Models of Supercritical CO_2 Extraction Enhanced by Different Technologies

为了改善单纯超临界CO2萃取在应用范围和萃取效率方面存在的不足,试验以人参中人参皂苷为萃取对象,研究了夹带剂强化超临界CO2萃取(SCE)、超声联合夹带剂强化超临界CO2萃取(USCE)、超临界CO2反相微乳强化萃取(SCRME)和超声强化超临界CO2反相微乳萃取(USCRME)四种不同强化方法对超临界CO2萃取的影响,并由微分质量衡算模型,建立了SC萃取人参皂苷的动力学模型。试验结果表明,在各自优化的工艺条件下,SCE、USCE、SCRME、USCRME萃取的皂苷产率分别达0.26%、0.45%、0.76%和1.15%,萃取速率顺序为与萃取产率相同,所建萃取动力学模型与各试验数据的拟合度均超过99.5%,其中以USCRME的模型模拟得出的E∞和k值最大,分别为1.213%和0.659,是SCE的3.95倍和1.32倍,说明在超临界CO2萃取过程中同时引入超声和反相微乳技术能提高对极性物质的萃取产率和萃取速率。

In order to extend the scope and improve the efficiency of supercrifical CO2 extraction, four enhanced technologies including supercritical CO2 extraction with modifier （SCE）, supercritical CO2 extraction with ultrasound combined modifier（USCE）, supercritical CO2 reverse microemulsion extraction （SCRME） and supercritical CO2 reverse microemulsion extraction with ultrasound0dSCRME） were applied to extract ginsenosides from ginseng. Their extracting kinetic models were built based on transfer theory and principle of mass balance. The results showed that the extraction yields of ginsensides by SCE, USCE, SCRME and USCRME were 0.26%, 0.45%, 0.76% and 1.15%, respectively. The extraction rates of ginsensides by four methods showed similar order to the extraction yield. The fitting degree of the model and the experimental data was more than 99.5%. The maximum Eoo （1.213%） and k （0.659） values were obtained by USCRME model simulation, which were 3.95 and 1.32 times, respectively, of those by SCE. The results demonstrated that supercritical CO2 extraction enhanced by ultransound combined with reverse microemulsion could improve the extraction yield and rate of polar material ginsensides.