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本文主要介绍了超临界近5年来超临界二氧化碳中的有机反应研究的最新进展,包括加氢反应、氧化反应、羰基化反应、碳碳键形成反应、酯化反应和酶催化反应的研究现状;同时,还介绍了超临界二氧化碳作为反应底物用于合成碳酸酯和氨基甲酸酯的研究进展;并对未来的发展进行了展望。 相似文献
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ZrO2催化合成气制异丁烯 总被引:2,自引:0,他引:2
制得了纯净的单斜和四方晶形ZrO2,给出了制取单一晶形的条件:PH值保持在9.5左右能够生成单斜晶形成ZrO2;四方晶形ZrO2的生成需要PH≥11.5,催化反应结果表明,晶形对慢丁烯的选择性有着重要的影响,单斜晶形ZrO有利于异丁烯的生成;四方晶形ZrO2使异丁烯的生成量显著降低,不同方法制备的ZrO2催化性能有所没,超临界流体干燥法制得的ZrO2催化剂的舔生科物选择性均高于其它方法,文中对此反 相似文献
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超临界流体技术研究进展 总被引:21,自引:0,他引:21
本文综述了超临界流体技术在萃取、材料制备、化学反应及相转移催化等方面的应用, 介绍了有代表性的超临界萃取和反应装置。对今后工作提出了一些建议。 相似文献
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超临界流体干燥方法在丁烷选择性氧化制顺酐 总被引:2,自引:0,他引:2
分别用超临界流体干燥方法和传统方法制备了用于丁烷选择性氧化制顺酐的VPO催化剂. 用超临界流体干燥方法制备的催化剂VPOⅡ的比表面积高达38.8 m2/g,而用传统方法制备的催化剂VPOⅠ的比表面积只有10.7 m2/g. XRD分析表明,除催化剂VPOⅡ中的VOPO4相含量比催化剂VPOⅠ稍多外,这两种催化剂的主要结构均为(VO)2P2O7相. 在有氧和无氧条件下进行的丁烷氧化制顺酐的催化反应结果表明,用超临界流体干燥方法制备的催化剂不仅具有较高的顺酐收率,而且含有更多的可在无氧条件下参与选择性氧化反应的晶格氧(催化剂VPOⅡ的可利用选择性晶格氧量比催化剂VPOⅠ增加了1.5倍). 用超临界流体干燥方法可以改善催化剂性能的原因可能与催化剂具有较大的比表面积和较多的V5+有关. 相似文献
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超临界流体干燥方法在丁烷选择性氧化制顺酐VPO催化剂制备中的应用 总被引:2,自引:0,他引:2
分别用超临界流体干燥方法和传统方法制备了用于丁烷选择性氧化顺酐的VPO催化剂。用超临界流体干燥方法制备的催化剂VPOⅡ的比表面积高达38.8m^2/g,而用传统方法制备的催化剂VPOⅠ的比表面积只有10.7m^2/g。XRD分析表明,除催化剂VPOⅡ中的VOPO4相含量比催化剂VPOⅠ稍多外,这两种催化剂的主要结构均为(VO)2P2O7相。在有氧和无氧条件下进行的丁烷氧化制顺酐的催化反应结果表明,用超临界流体干燥方法制备的催化剂不仅具有较高的顺酐收率,而且含有更多的可在无氧条件下参与选择性氧化反应的晶格氧(催化剂VPOⅡ的可利用选择性晶格氧量比催化剂VPOⅠ增加了1.5倍)。用超临界流体干燥方法可以改善催化剂性能的原因可能与催化剂具有较大的比表面积和较多的V^5 有关。 相似文献
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超临界流体技术在萃取中的应用简介 总被引:3,自引:0,他引:3
超临界流体萃取技术具有许多传统技术所没有的快速、高效、高选择性、低能耗等优点,特别是超临界流体的特性是它可以代替高毒有机溶剂做反应介质,符合绿色化学的要求。本文综述了超临界流体的特性,介绍了超临界流体萃取的原理,归纳了超临界流体萃取的应用现状,并介绍了超临界流体的其他领域应用概况。 相似文献
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Sub- and Supercritical Fluid Chromatography (SFC) were used to separate seven purine and pyrimidine-based drugs. A two-pump system was used, where one pump delivered the carbon dioxide, and the other pump delivered modifier. The modifiers used in this work were methanol, and methanol containing 0.001 M tetrabutylammonium hydroxide. Two of the compounds studied were hydrochloride salts. These compounds were analyzed by a Supercritical Fluid Extraction (SFE)/SFC method. 相似文献
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渣油加氢转化催化剂初期结焦规律的研究 总被引:12,自引:3,他引:9
以孤岛减压渣油及其超临界流体萃取分馏所得的窄馏分为原料,采用齐鲁石化公司胜利炼油厂VRDS装置的主催化剂,在高压釜反应器内考察了渣油加氢转化催化剂的初期结焦规律。结果表明,焦炭的生成是一个动态过程,其产率和性质与反应体系的温度、时间、氢气初始压力及原料的性质密切相关;结焦催化剂的孔壁焦炭沉积和堵孔现象严重,导致其比表面积大大减小,孔分布向小孔范围迁移。 相似文献
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Ultraviolet Spectroscopy and UV Lasers, Edited by P. Misra and M. A. Dubinskii Supercritical Fluid Technology in materials
Science and Engineering (Syntheses, Properties and Applications), Edited by Ya-Ping Sun
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
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《Analytical letters》2012,45(6):1027-1039
Abstract Saffron is one of the most expensive spices. Consequently, it is not so difficult to understand that fraudulent saffron exists. Thus, it was interesting to study the most important flavouring component, in terms of aroma, volatile compound of saffron - safranal - by 13C isotopic analysis. Five saffron samples from different countries have been analysed. Safranal has been extracted by methanol or by Supercritical Fluid Extraction (SFE). The results indicate that there is a significant difference between the synthetic safranal and the natural one. On the contrary, it is difficult to conclude on the difference between the various geographical origins, as the isotopic variations are small. Moreover, it has been found that Supercritical Fluid Extraction allowed the selective extraction of volatile compounds from saffron under optimised conditions. It is a cleaner and faster method of extraction compared to the extraction using organic solvent. Nevertheless, an isotopic fractionation occurs in relation to the extraction yield of safranal. 相似文献
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太湖水体中有机污染物的分析 总被引:5,自引:0,他引:5
利用超临界流体萃取与热脱附两种样品预自理方法的优势互补,与气相色谱分析相结合对太湖水体中不同沸点有机污染物进行了分析,发现太湖水中除了烃类污染物外还存在大量含氮有机污染物。其分布表明入湖河道中排放的工业污染物的流入是导致太湖水富营养化的一个重要因素。 相似文献
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Summary Supercritical Fluid Chromatograph was constructed using two pumps and two restrictors. With this system in conjunction with
the fused silica column packed with relatively large particles (40 μm), the flow rate was controlled both for isobaric and
pressure programmed operations. Application of this system to the determination of molecular weight distribution of polystyrene
oligomers was presented. 相似文献
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A. Kamangerpour M. Ashraf-Khorassani L. T. Taylor H. M. McNair L. Chorida 《Chromatographia》2002,55(7-8):417-421
Summary Supercritical Fluid Chromatography with a packed column on a mixture of eight polyphenols has been optimized. Carbon dioxide
which was modified with methanol which contained less than 1% (w/w) citric acid as a secondary additive served as the mobile
phase. Two tandem diol columns were used sequentially. The optimized method was applied to a supercritical fluid grape seed
extract. Various components in the extract could be identified by retention time and ultraviolet spectral comparison with
our synthetic mixture of polyphenols. 相似文献
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Since technical silicone oils are widely used, high performance analysis and exact quality control are necessary. The quantity of low molecular cyclic components is of special importance for the properties of the oils. Supercritical Fluid Chromatography (SFC) provides a facility for determining such cyclic components. Accurate assignment of linear and cyclic polydimethylsiloxanes is possible by coupling SFC with mass spectrometry (MS) or by using standard materials. 相似文献
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Klaus Albert Ulrich Braumann Roman Streck Manfred Spraul Rainer Ecker 《Analytical and bioanalytical chemistry》1995,352(5):521-528
The separation of monomeric acrylates was performed with High Performance Liquid Chromatography (HPLC) and Supercritical Fluid Chromatography (SFC). A direct on-line structural assignment of all compounds by continuous-flow 1HNMR spectroscopy is possible with both separation techniques. The direct SFC-NMR coupling offers the advantage that the recorded continuous-flow 1HNMR spectrum is not obscured by solvent signals. 相似文献