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阿魏酸和川芎嗪在超临界CO2中溶解度的测定 总被引:2,自引:0,他引:2
采用动态法分别测定了阿魏酸和川芎嗪在超临界CO2中的溶解度.实验结果表明在压力10~35MPa和温度308.15~338.15K范围内,阿魏酸在超临界CO2中的溶解度(摩尔分数)为6.936×10(7~26.527×10(7;在压力10~30MPa和温度318.15~338.15K范围内,川芎嗪在超临界CO2中的溶解度(摩尔分数)为0.010~0.131.阿魏酸在超临界CO2中的溶解度随着压力的增加而增大;温度对阿魏酸溶解度的影响较为复杂,出现了交迭压力行为.而川芎嗪在超临界CO2中的溶解度在实验范围内没有出现交迭压力行为.采用Chrastil方程分别对阿魏酸和川芎嗪在超临界CO2中的溶解度数据进行了关联,其AARD值分别为12.92%和4.23%. 相似文献
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超临界CO2在聚合物中的溶解度和扩散性研究 总被引:2,自引:0,他引:2
用重量分析法测量了静态条件下CO2在聚苯乙烯(PS)中的溶解度,研究了溶解度与压力和温度的关系,估算了CO2在聚合物PS中的扩散系数。用Henry系数表示了溶解度与温度的关系。实验压力在5-30MPa范围、温度在40-200℃范围。实验数据表明:CO2在PS中的溶解度随着压力的增加而增加,但随着温度的增加而降低。CO2在PS中的扩散系数随饱和时间增加而增加。当吸附量达到一定值时,扩散系数呈下降趋势。 相似文献
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α—细辛醚在超临界CO2中溶解度测定 总被引:1,自引:0,他引:1
测定了α-细辛醚在超临界CO2中的溶解度。考察了压力,温度等因素对α-细辛醚在超临界CO2中溶解度的影响。结果表明α-细辛醚在超临界CO2中的溶解度随着压力的增加而增大,随着温度的增加而减小,并符合经典的Chrastil表达式。 相似文献
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丁香油的超临界CO2萃取及其微胶囊的制备 总被引:2,自引:0,他引:2
在70℃和10 MPa条件下通过对丁香花蕾进行超临界CO2萃取得到丁香油,萃取率达19%~21%.气质联用分析结果表明,丁香油中主要化学成分包括丁香酚、β-石竹烯和乙酰基丁香酚等.以丁香油为囊芯,探讨利用干酵母细胞作为囊壁材料制备微胶囊的可行性.通过正交试验考察了包埋温度、包埋时间、丁香油与干酵母配比(芯材比)对微胶囊化丁香油的影响.结果表明,在包埋温度70℃、包埋时间9 h和芯材比为1∶1(w/w)的条件下,微胶囊中丁香油包埋率达到41.26%.通过扫描电镜观察,丁香油微胶囊呈规则的球形,大小均一,颗粒直径在2.0~4.0 μm.在100℃下对经微胶囊化的丁香油加热20 h,其挥发率只有15.04%,远低于相同条件下丁香油的挥发率(58.29%).这种新型的微胶囊化方法,具有制备过程简单、包埋率高和不引入有机溶剂的优点. 相似文献
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药物微粒化可改善其溶出度,提高生物利用度。为应用超临界流体技术制备阿昔洛韦(Acyclovir)微粒,用静态法测定了在313.15~413.15K,10.0~30.0MPa下阿昔洛韦在超临界CO2中的溶解度。阿昔洛韦的溶解度较小,在10^-5~10^-7(摩尔分率)之间,溶解度随着温度和压力的升高而增大,不存在文献报道的反向区。采用P-R方程对溶解度数据进行关联,平均相对误差为10.0%。 相似文献
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The equilibrium quaternary solubilities of dihydroxybenzene (resorcinol + pyrocatechol + hydroquinone + SCCO2) isomers were experimentally determined at 308, 318 and 328 K over a pressure range of 9.8–15.7 MPa by using a saturation method. The effects of temperature, pressure and the components on each other have been thoroughly investigated. The selectivity of SCCO2 for ternary (resorcinol + pyrocatechol + SCCO2) and quaternary systems was discussed. A new model equation for quaternary solubilities of solids has been developed by accounting for non-idealities by combining the solution model with Wilson activity coefficient model. The model equation has five adjustable parameters and correlates the quaternary solubilities of current data along with two other quaternary data reported in the literature. 相似文献
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In the present study, a mathematical modeling for extraction of oil from clove buds using supercritical carbon dioxide was performed. Mass transfer is based on local equilibrium between solvent and solid. The model was solved numerically, and model estimation was validated using experimental data. For optimization, the clove oil equilibrium constant between solid and supercritical phase was determined by a theoretical method using fugacity concept, consequently the genetic algorithm for obtaining optimal operational conditions was used. The optimal conditions which obtained the highest amount of clove oil were pressure of 10 MPa and temperature of 304.2 K. 相似文献
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超临界环境下梯恩梯和黑索金的溶解度参数计算 总被引:1,自引:0,他引:1
动静态结合法测试了TNT、RDX在超临界CO2中的溶解度,测试温度分别为303.0,308.0,323.0,338.0 K,压力范围10.0~50.0 MPa,利用Bartle半经验模型对测量结果进行了关联,由Kumar and Johnston理论计算了2种物质在超临界CO2中的偏摩尔体积。结果表明,TNT和RDX溶解度的理论值和实验值具有良好的一致性,平均相对误差是3.72%和8.91%;在303.0,308.0,323.0,338.0 K温度下,TNT和RDX的偏摩尔体积分别为-6 942.61,-6 213.46,-5 438.49,-4 834.76 cm3/mol和-4 510.63,-3 894.52,-3 428.69,-2 631.85 cm3/mol。 相似文献
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Min Jeong Noh Tae Gyun Kim In Kwon Hong Ki-Pung Yoo 《Korean Journal of Chemical Engineering》1995,12(1):48-55
A new transparent microscale circulation-type high pressure equilibrium cell with on-line sampling was devised. With this
apparatus, experimental solubility of molecularly complex species such as steroids (cholesterol, stigmasterol and ergosterol)
and fatty acids (palmitic acid and stearic acid) in supercritical carbon dioxide(sc-C02) were measured. Also, to find an appropriate substance for enhancing both the polarity and the solubility power of the SC-CO2 solvent, we arbitrarily selected three polar substances such as acetone, methanol and water and the effect of these cosolvents
on the solubility of solutes in SC-CO2 are examined. The supercritical phase equilibrium data of solute-cosolvent-sc-CO2 systems were quantitatively correlated using a new equation of state based on the lattice fluid theory incorporated with
the concept of multibody interaction. We found that the addition of tracer amount of acetone or methanol to SC-CO2 enhances the solubility of all solutes about thirty to sixty times when compared with the case of pure sc-CO2 However, for the case of cosolvent water, no further enhancement of the solubility of solutes was realized. Also, the versatile
fittability of the equation of state proposed in this work was demonstrated with the newly measured ternary supercritical
equilibrium data. 相似文献
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Sevan Platin Elif Ö. Özer Ugur Akman Öner Hortaçsu 《Journal of the American Oil Chemists' Society》1994,71(8):833-837
Effects of temperature (at 35, 45 or 55°C) and pressure (10–110 atm) on the relative distribution coefficients of the twelve
key components of spearmint oil (essential oil ofMentha cardiaca; Scotch spearmint) at equilibrium in dense CO2 were investigated under conditions ranging from subcritical to supercritical regions. Effects of vapor pressure, molecular
weight and polarity of the key components on their equilibrium distributions in sub/supercritical CO2 are discussed. At 35°C, all key components of spearmint oil are equally soluble in dense CO2 within the 12–102 atm pressure region. At 45 and 55°C, the key components are equally soluble for pressures greater than
about 60 atm. However, around either 45°C/27 atm or 55°C/35 atm conditions, the relative distribution coefficients of all
monoterpene hydrocarbons and of isomenthone (an oxygenated monoterpene) exhibit maxima, which are due to significantly higher
vapor pressures of these components and significantly lower solvating power of the dense-gas solvent at these particular temperatures
and pressures. Vapor-pressure effects, coupled with the decrease in solvating power, dominate the effects of polarity and
molecular mass of the key components. Deterpenation of spearmint oil with dense CO2 is possible around either 45°C/27 atm or 55°C/35 atm, where the monoterpene hydrocarbons tend to concentrate in the CO2-rich phase. 相似文献
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超临界CO2萃取八角茴香油及其化学成分研究 总被引:2,自引:0,他引:2
用超临界CO2萃取(SFE-CO2)技术,在压力16 MPa、温度35℃、反应时间2 h及CO2流量30L/h的条件下,对八角茴香的果实进行了萃取,得到八角茴香萃取物,并用水蒸气蒸馏法提取八角茴香精油.对不同提取工艺得到的八角茴香产品的得率及质量进行了分析比较,结果显示SFE-CO2法产品得率高,为10.5%,而水蒸气蒸馏法仅为7.5%.用GC-MS分别对SFE-CO2萃取物和水蒸气蒸馏精油的化学成分及相对含量进行了测定,共鉴定出40种化合物超临界CO2萃取物有39个,其中大茴香脑质量分数为78.91%;水蒸气蒸馏精油有37个,大茴香脑质量分数为83.8%. 相似文献
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Continuous supercritical carbon dioxide processing of palm oil 总被引:2,自引:0,他引:2
C. K. Ooi A. Bhaskar M. S. Yener D. Q. Tuan J. Hsu S. S. H. Rizvi 《Journal of the American Oil Chemists' Society》1996,73(2):233-237
Crude palm oil was processed by continuous supercritical carbon dioxide. The process reduces the contents of free fatty acids,
monoglycerides and diglycerides, certain triglycerides, and some carotenes. The refined palm oil from the process has less
than 0.1% free fatty acids, higher carotene content, and low diglycerides. Solubility of palm oil in supercritical carbon
dioxide increased with pressure. A co-solvent improves the refining process of palm oil. 相似文献
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The effect of reaction conditions on the extent of conversion in hydrolysis of blackcurrant oil was investigated. The enzyme used was Lipozyme, a lipase from Mucor miehei immobilised on macroporous anionic resin. The reaction was carried out in a continuous flow reactor at 10- and 30-50°C with carbon dioxide saturated with oil and water (55-100%) flowing up through the enzyme bed. Analysis of product composition indicated unfavourable hydrodynamics with significant mixing in the reactor when solvent interstitial velocity was lower than , while above this velocity value the flow pattern was near to plug flow. Lipase stability was very good with no activity reduction observed during a long-term experiment. The reaction rate was a function of the ratio of enzyme load to solvent volumetric flow rate. A complete hydrolysis of oil was achieved in the experiments carried out with the enzyme load of and CO2 flow rate of 0.4-. The effects of pressure (10-) and temperature (30-40°C) on the reaction rate were small, and the effects of CO2 saturation with water and of enzyme distribution in the reactor were negligible. Lipozyme displayed specificity towards linolenic acids; the release of α-linolenic acid was faster and that of γ-linolenic acid slower than the release of other constituent acids present in blackcurrant oil. 相似文献
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Walnut (Juglans regia L.) oil was extracted with compressed carbon dioxide (CO2) in the temperature range of 308 to 321 K and in the pressure range of 18 to 23.4 MPa. The influence of particle size was
also studied at a superficial velocity of 0.068 cm/s, within a tubular extractor of 0.2 L capacity (cross-sectional area of
16.4 cm2). FFA, sterol, TAG, and tocopherol compositions were not different from those of oil obtained with n-hexane. The main FA was linoleic acid (56.5%), followed by oleic acid (21.2%) and linolenic acid (13.2%). The main TAG was
LLL (linoleic, linoleic, linoleic) (24.4%), followed by OLL (oleic, linoleic, linoleic) (19.6%) and LLLn (linoleic, linoleic,
linolenic) (18.4%). The main component of sterols was β-sitosterol (85.16%), followed by campesterol (5.06%). The amount of
cholesterol was low (0.31 and 0.16% for oils extracted by n-hexane and supercritical fluid extraction, respectively. The CO2-extracted oil presented a larger amount of tocopherols (405.7 μg/g oil) when compared with 303.2 μg/g oil obtained with n-hexane. Oxidative stability determined by PV and the Rancimat method revealed that walnut oil was readily oxidized. Oil extracted
by supercritical CO2 was clearer than that extracted by n-hexane, showing some refining. A central composite, nonfactorial design was used to optimize the extraction conditions using
the software Statistica, Version 5. The best results were found at 22 MPa, 308 K, and particle diameter (Dp) −0.1 mm. 相似文献