【作者】 张杨；

【导师】 孙益民；

【作者基本信息】 安徽师范大学 ， 物理化学， 2003， 硕士

【摘要】 本论文主要研究了超临界CO₂萃取和超临界CO₂抗溶剂结晶（SAS）分离和纯化天然产物有效成分。以超临界CO₂为溶剂研究萃取柚子鲜花挥发成分，论证萃取的可行性，优化超临界CO₂萃取的工艺条件，探索超临界CO₂萃取在鲜花中的应用；以超临界CO₂为抗溶剂结晶（SAS）纯化穿心莲内酯，考察结晶器的长经比结构和压力对结晶的影响。 系统地研究了超临界CO₂萃取柚子鲜花时，操作温度、压力、时间和CO₂流量等工艺条件对萃取率的影响。结果表明：超临界CO₂萃取柚子鲜花中的挥发成分的工艺切实可行，并得到本实验室条件下较适宜的工艺条件。讨论分析了柚子鲜花中挥发成分的在超临界CO₂中溶解度，根据试验数据，经过处理和拟合得出柚子鲜花挥发成分在超临界CO₂中的体积溶解度与超临界CO₂密度的关系，为今后的设计和计算提供参考。 在SAS结晶过程中，设计制造了长径比为30的结晶器，比较长径比30结晶器和长径比3结晶器对结晶晶体大小、形貌、粒度分布和结构的影响。 结晶器的长径比和压力对结晶的晶体形貌、大小和粒度分布有一定的影响。在较高的压力（22MPa）时，长结晶器中得到的晶体颗粒粒度较小，而短结晶器中得到中的颗粒的粒度较前者大一倍。在较低的压力（8.5MPa）时结晶器的长径比对所到晶体颗粒的形貌和大小没有影响。长结晶器中，压力增加，所得到晶体颗粒的粒度大小由大减小。在短结晶器中，压力增加晶体颗粒粒度分布变得稍均匀，由10～50μm变化为50μm，形貌由不规则变成棒状。 利用SAS结晶过程，在相对高压下，长结晶器和短结晶器上部的晶体的晶体结构都不同于中部、下部的晶体的晶体结构。在相对低压下，两种结晶器上、中和下部的晶体的晶体结构基本相同，但是，在长结晶器中的晶体颗粒的晶体结构，不同于短结晶器中的晶体结构。 长、短结晶器中压力由低到高时，在结晶器的不同部位的晶体随压力的增加，上部的晶体生长可能不同于中部和下部的晶体生长。更多还原

【Abstract】 A study on the extraction of essential constituent from the fresh flowers of pomelo with supercritical carbon dioxide is described. The effects of operating temperature, pressure, time and flowing rate of carbon dioxide on the extraction rate are investigated systematically. The results showed: the technology of extraction of essential constituent from the fresh flowers of pomelo with supercritical carbon dioxide is feasible, and the products remained raw savor of the fresh flowers of pomelo. The optimum operating conditions are optimized between 13-18MPa, 47℃, 100-140 minutes, and the flowing rate of carbon dioxide between 22.8-27L/min. With processing and fitting the experimental data,, the model equation of the volume solubility of the essential constituent of the flowers on the density of supercritical carbon dioxide is concluded.The crystallizer with the ratio of 30:1 of length (30) to diameter (1) (long crystallizer) was designed and constructed to study on the dependence of the crystal size, particle-size distribution, crystal morphology on the structure of the crystallizer and the operating pressure using supercritical carbon dioxide as anti-solvent crystallization. As the operating pressure increasing, the crystal size decreased in the long crystallizer, and the crystal morphology was unchanged. The crystal morphology was changed in the short crystallizer. At relative high pressure (22MPa) the crystal size distribution of the long crystaliizer was uniform. However the crystal size distribution of the short crystallizer was various.At the relative high pressure (22MPa) the crystals of the crystallizer upper were different from the middle and lower in the long or short crystallizer. At the relative low pressure (8.5MPa) the crystals of the upper, middle, lower of the long or short crystallizer were uniform. With the operating pressure increasing, the growth of the upper crystal of the long or short crystallizer may be different from the middle and lower.更多还原