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1.
The solubility of styrene from polystyrene in supercritical carbon dioxide is measuredat 323 K,333 K,and 343 K in the pressure range from 12 to 28 MPa.Based on the associationconcept and the theory of dense gas sorption in polymers,a displacement and association mechanismon supercritical fluid extraction of the monomer from the polymer is proposed.And,a novel math-ematical model for correlating the solubility data obtained from the experiments is also proposed inthe paper.  相似文献   

2.
    
The solubility of styrene from polystyrene in supercritical carbon dioxide is measured at 323 K, 333 K, and 343 K in the pressure range from 12 to 28 MPa. Based on the association concept and the theory of dense gas sorption in polymers, a displacement and association mechanism on supercritical fluid extraction of the monomer from the polymer is proposed. And, a novel mathematical model for correlating the solubility data obtained from the experiments is also proposed in the paper.  相似文献   

3.
固体在超临界二氧化碳中溶解度的关联与计算   总被引:4,自引:0,他引:4  
精确的溶解度数据是超临界流体萃取工艺设备设计和操作条件选择的关键 ,本文采用Peng -Robinson状态方程对 15种固体在超临界CO2 中的溶解度数据进行了关联计算 ,溶解度的计算值与文献的实验值符合很好 ,其平均相对偏差均小于 10 %。  相似文献   

4.
    
Essential oils and cuticular waxes were extracted from peppermint leaves with supercritical carbon dioxide in a semicontinuous-flow extractor. The effects of CO2 flow rate and pressure on the extraction rate were studied within the flow rate range of (4·1–9·8) × 10−5 kg s−1 and the pressure range of 10–30 MPa. Flow rate effect indicated that the intraparticle diffusion resistance was not dominant in this process. The extraction rate of cuticular waxes increased remarkably with the pressure, whereas that of essential oils was almost constant as compared with cuticular waxes. The concentration of cuticular waxes at the exit of the extractor was close to the solubility of triacontane while that of essential oils was much lower than the solubility of 1-menthol.  相似文献   

5.
介绍了超临界二氧化碳的特殊性质,综述了超临界二氧化碳为介质的高分子合成方面的应用进展情况.皿示出超临界二氧化碳是一种对环境无污染且价廉的绿色介质,具有广阔的应用前景。  相似文献   

6.
超临界CO_2萃取甘草素   总被引:14,自引:1,他引:14  
介绍在超临界状态下,用CO_2作萃取剂,用水-乙醇作夹带剂从甘草中萃取甘草素、异甘草素、甘草查耳酮A及甘草查耳酮B的实验方法;研究了超临界CO_2萃取过程中的最佳工艺条件。  相似文献   

7.
使用Chrastil模型对前文[1]报导的32号机油在超、亚临界CO2中的溶解度数据进行了关联,给出了关联参数。在自行研制的间歇式萃取装置上,压力为7.4~14.9MPa的范围内,使用超、亚临界CO2对32号机油进行了萃取试验,并对试验结果进行了分析讨论  相似文献   

8.
超临界二氧化碳精制辣椒红色素的研究   总被引:10,自引:0,他引:10  
朱凯  程康华  毛连山 《化工时刊》2004,18(12):25-27
采用超临界二氧化碳萃取技术对有机溶剂萃取的辣椒红粗提物进行提纯、精制,制备高色价、高质量的辣椒红色素产品。研究了萃取压力、萃取时间等因素对产品色价及收率的影响,添加夹带剂对萃取效果的影响,得到较佳的工艺条件为:萃取压力17MPa(添加夹带剂)、14MPa(添加夹带剂),萃取时间4h。结果:未添加夹带剂产品色价由原来的60提高到150,产品收率为93%;加有夹带剂的产品比未加夹带剂的产品色价高出20,产品收率高2%;辣素含量更低,基本无法检出:溶解性更好,无不溶物:脱辣、脱臭效果好,不含任何异味、杂味。  相似文献   

9.
介绍了超临界 C O2 萃取技术的国内外发展概况,云南省植物资源及应用现状,以及超临界 C O2 萃取技术在开发云南植物资源中的应用前景。  相似文献   

10.
超临界流体萃取技术的应用及研究进展   总被引:7,自引:0,他引:7  
金竹萍 《山西化工》2007,27(2):42-46
超临界流体萃取技术近年来被广泛应用于中草药、食品、香料、化工及环境保护等领域。介绍了超临界流体萃取技术与传统的萃取方法相比所具备的优势及其发展前景。  相似文献   

11.
近年来超临界流体萃取技术倍受人们青睐,超临界CO2作为有机溶剂的替代者促进了绿色工艺的发展。对于相对分子质量大的或亲水性分子及金属离子,CO2并不是一种好溶剂。采用反胶团体系可解决这一难题并开发许多新的工艺。本文概述了超临界CO2中反胶团技术的发展概况,重点阐述了反胶团在超临界CO2萃取中的应用。  相似文献   

12.
超临界二氧化碳萃取蛋黄油实验研究   总被引:1,自引:0,他引:1  
介绍超临界二氧化碳萃取技术提取蛋黄油的工作原理及工艺流程.设计了正交实验,考察了萃取压力、萃取温度、萃取时间等参数对萃取率的影响,确定了最佧工艺条件.  相似文献   

13.
由于生姜具有活血化瘀、驱风通脉的作用,使其成为很有特色的中草药。论证了用超临界二氧化碳技术提取的生姜提取物的性能及作为中草药添加物在洗去型发用产品中的应用实验与试用观察。  相似文献   

14.
采用超临界CO2提取方法探讨了从万寿菊中提取叶黄素的最佳工艺条件.通过单因素和正交实验确定影响叶黄素萃取的因素为:时间>温度>压力>CO2流量;优化工艺条件为:萃取时间3h,萃取压力25MPa,温度55℃,CO2流量10L·h-1,分离罐Ⅰ温度42℃,压力11MPa,分离罐Ⅱ温度38℃,压力同储罐.在该优化工艺条件下,...  相似文献   

15.
超临界气体提取技术进展   总被引:2,自引:0,他引:2  
讨论了超临界气体提取技术中气体的选择原则、提取装置的现状及其应用中工艺条件的选定,并对国内的研究工作提出了建议。  相似文献   

16.
超临界CO2萃取烟草中茄尼醇   总被引:11,自引:0,他引:11  
张歆  倪晋仁  黄文 《精细化工》2006,23(5):480-482,501
研究了萃取时间、解析温度、萃取压力等因素对超临界CO2萃取烟草中茄尼醇萃取率的影响。结合皂化等预处理措施,并通过正交实验得到了提取茄尼醇的最佳工艺条件,即以体积分数90%的乙醇为夹带剂,在萃取压力为35 MPa、萃取温度为50℃、解析温度为40℃时,萃取3 h后,产品茄尼醇质量分数为40.14%,萃取率达到98.53%。  相似文献   

17.
The extraction of wheat germ oil by liquid and supercritical CO2 is described from the point of view of both operative method and pretreatment of raw material. The best conditions for wheat germ oil extraction are: pressure, 150 bar; temperature, 40°C; and solvent flow rate, 1.5 L/min at standard temperature and pressure. The yields and fatty acid compositions obtained are very similar to those resulting from the conventional extraction process using hexane as solvent (8.0 wt%), although a higher-quality oil is obtained by using CO2 as solvent (free fatty acids, 12.4%; tocopherol content, 416.7 mg tocopherol/g wheat germ oil). These factors lead to the conclusion that the extraction process using CO2 could be economically competitive with the conventional process, since it considerably simplifies the oil refinement stages and completely eliminates the solvent distillation stage, which are the most costly processing steps in terms of energy consumption.  相似文献   

18.
超临界CO_2萃取芹菜籽油研究   总被引:14,自引:2,他引:14  
用超临界CO2萃取技术对广东白芹菜籽进行了萃取研究。结果表明,萃取压力低于15MPa时,较重的油树脂等成分难以被萃取出来;萃取温度为308K时对萃取最有利;解析温度对萃取效率影响较小;CO2流量对萃取效率的影响比床层高度引起的扩散阻力的影响大得多。超临界CO2萃取所得芹菜籽油品质优越,且其中的药用有效成分(3-正丁基-4,5-二氢苯并呋喃酮)含量比水汽法所得芹菜籽油的高五倍多。  相似文献   

19.
《分离科学与技术》2012,47(8):1139-1146
Purification of waste cooking oils (palm oil and soybean oil) using supercritical carbon dioxide (scCO2) extraction has been investigated. The purified oils were characterized by their acid value, conjugated diene value, total polar compound measurements, and high-performance size exclusion chromatography. Using optimal extractions conditions of 353.15 K, 20 MPa, and CO2 flow rate of 40 g/min, 80% of the oil was recovered and the purified oil compositions and properties were very close to those of the fresh oils. At higher pressures or lower temperatures, the separation efficiency of the scCO2 extraction was significantly reduced.  相似文献   

20.
本文阐述了我国超临界CO2萃取技术及其工业化现状,着重分析了超临界CO2萃取技术大型工业化过程中所存在的问题,并对超临界CO2萃取技术的工业化前景作了分析。  相似文献   

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