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饱和烃中正构、异构烷烃的分离方法研究 总被引:1,自引:0,他引:1
季庆美 《中国石油和化工标准与质量》2013,(11):44
饱和烃样品是由原油或沥青A样品先经过中性层析硅胶、氧化铝吸脱附,用正己烷淋洗出来的。当饱和烃中异构烷烃含量很高时,由于柱分离效能的原因,不能完全将正、异构烷烃各组分分离。当饱和烃经过尿素络合分离后,就能将饱和烃中的正构、异构烷烃进行很好的分离开来。进而大大地提高了色谱数据的准确性。 相似文献
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测定分子量较低(C_6以下)馏分中正构烷烃的含量,用气液色谱法是方便而准确的。对180℃以上馏分,尿素络合法比较常用。但此法有一定的缺点,因为不仅是正构烷烃,而且异构烷烃、烃基环烷烃及烃基苯等,只要它们带有足够长的直链,也能和尿素络合;甚至3-甲基庚烷、2-甲基壬烷等,在可络合的正烷烃“诱导”下,也能生成络合物。其次,尿素与正构烃的络合反应是可逆的,因而生成络合物的反应难于进行到十分完全。此外,此法需要消耗较多的分析油样及大量石油醚(用作稀释剂)。对C_7~C_9间的馏分,由于相应的尿素-正构烃络合物很不稳定,也不能用尿素络合法分析。用一般气液色谱法分析该馏分亦有不少困 相似文献
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以吉林桦甸油页岩为研究对象,通过二氯甲烷、石油醚两级萃取,对油页岩原矿、两级萃余物进行SEM扫描,对二氯甲烷萃取液、石油醚萃取液进行GC/MS检测,研究桦甸油页岩在两级溶液的溶解行为以及各级萃余物表面物理形貌。结果表明,随着萃取的加深,油页岩颗粒相对光滑的片层结构逐渐消失,颗粒粒径趋于细小,表面沟壑逐渐增多,后级萃取时液固接触面积增加。二氯甲烷和石油醚对油页岩中烷烃溶出能力较强。两级萃取物组分主要由C15~C28饱和烷烃构成。溶剂萃取法可以有效地提取油页岩中一类或相似的化合物群,对研究油页岩构成及提取高经济价值成分有重要意义。 相似文献
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溶剂分级萃取法研究平朔煤的化学组成特征 总被引:3,自引:0,他引:3
采用7种不同有机溶剂对平朔煤进行分级萃取,并利用GC/MS测定分析各级萃取物的化合物成分,对其化学组成及结构特征进行了对比研究.结果表明,利用不同溶剂分级萃取的方法可以较有效地对煤中有机化合物族组分起到粗分离的作用.CS2萃取物的主要成分是2环~4环烷基取代芳烃;正已烷萃取物几乎均为长链烷烃;在甲醇萃取物中检测出形式多样的含氧和含氮化合物;在丙酮萃取物中检测出长链烷基环已烷系列;芳烃在苯萃取物中多为2环,而在丙酮萃取物和THF萃取物中则是4环~7环缩合程度较高的芳烃;另外,在煤中首次发现邻二氟苯和氯胺酮. 相似文献
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乙烯酮(双乙烯酮)是十分重要的化工中间体,其下游产品较多。江苏某化工厂开发生产乙烯酮(双乙烯酮)下游产品三十多个,年生产规模三万多吨,是国内以乙烯酮(双乙烯酮)为中间体生产精细化学品的综合骨干企业。针对乙烯酮(双乙烯酮)下游产品废水特点,该厂结合企业实际,开展了产品优化,结构调整,清洁生产,资源循环利用,节水降耗等工作,从源头削减了污染物的生产。同时投资二千多万元新建预处理装置三套,6000m3/d废水生化处理装置一套,使全厂乙烯酮(双乙烯酮)下游产品的废水得到了有效的治理。 相似文献
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D. G. Gordeev L. F. Gudarenko M. V. Zhernokletov V. G. Kudel’kin M. A. Mochalov 《Combustion, Explosion, and Shock Waves》2008,44(2):177-189
A semi-empirical equation of state for metals is described. Its capabilities are demonstrated by the example of the equation
of state for aluminum. New experimental data are presented on the location of the isentrope of aluminum for unloading from
the state at p = 229.71 GPa on the shock adiabat to an aerogel (SiO2) of density 0.08 g/cm3.
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Translated from Fizika Goreniya i Vzryva, Vol. 44, No. 2, pp. 61–75, March–April, 2008. 相似文献
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Jorge Marcelo Romero Soledad Bustillo Hugo Enrique Ramirez Maisuls Nelly Lidia Jorge Manuel Eduardo Gómez Vara Eduardo Alberto Castro Alicia H. Jubert 《International journal of molecular sciences》2007,8(7):688-694
A thermochemical rather simple experimental technique is applied to determine the enthalpy of formation of Diperoxide of ciclohexanone. The study is complemented with suitable theoretical calculations at the semiempirical and ab initio levels. A particular satisfactory agreement between both ways is found for the ab initio calculation at the 6–311G basis This set level. Some possible extensions of the present procedure are pointed out. 相似文献
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A perturbation viscometer is a differential capillary viscometer that measures the logarithmic viscosity gradient of the viscosity-composition curve for gas mixtures. Measurements are made at different gas mixture compositions. Integration of the logarithmic viscosity gradients measured over the full composition range gives the mixture viscosity relative to the viscosity of one of the pure components of the gas mixture. This method is attractive because, for measurements of equal precision, integration of the gradients is potentially an order of magnitude more precise than measurement of the viscosities directly. It can also work at high and low temperatures and perhaps high pressures.The perturbation viscometer has been used to make measurements on ideal gas mixtures at ambient and elevated temperatures. The situation is more complicated when the gas mixtures are non-ideal. Extra effects due to density differences, molar volume change on mixing and differential thermal expansion may be measured in addition to the desired viscosity change producing systematic errors in the results. Thus, a more sophisticated apparatus is required. The standard perturbation viscometer has been modified to separate out the extra effects to permit measurement of the true change in viscosity. In addition, the theoretical operation of the modified apparatus has been revised to account for the design changes to permit calculation of the viscosity-composition profiles from the results.The apparatus has been tested using helium-HFC-125 mixtures and two new viscosity-composition profiles are presented for these mixtures at 23 and . Internal consistency tests have been used to confirm that the data produced are of high quality with an estimated uncertainty in the viscosity ratio data at of 0.9% and at of 1.5%. 相似文献
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醋酸纤维素取代基分布与性质的关系 总被引:9,自引:0,他引:9
分析了以吡啶为溶剂的醋酸纤维素的13C-NMR核磁共振谱,得出了三种不同位置羟基的取代度。结合X—射线和DSC分析,初步说明具有相同取代度但未经水解和经过水解的醋酸纤维素(CA) 性质上的差异是由于三个羟基上的取代度分布不同及消晶程度差异所致。 相似文献