多维气相色谱法测定清洁汽油中的含氧化合物

研究了多维气相色谱分析技术检测含有内标物MTBE（甲基叔丁基醚）汽油中含氧化合物（醇类和醚类）的方法。通过实验,考察了分流比、阀切换时间等因素对实验结果的影响,确定了最佳实验条件;同时对该方法的准确度和精密度进行验证,结果表明,该方法具有很好的精密度,加标回收率在90％-102％之间,样品分析周期为20min。由此可见,采用多维气相色谱分析技术,可以快速、准确地测定清洁汽油中的含氧化合物。     

气相色谱法测定汽油中有机含氧化合物含量

应用HP6890气相色谱对汽油中含氧化合物（醇类和醚类）含量的分析方法进行了研究。采用柱切换—反吹气相色谱技术,利用强极性的微填充TCEP不锈钢柱作预切柱,放空挥发性轻烃,保留醇醚类含氧化合物,并将其反吹至石英毛细管WCOT柱进行详细分离,分析了阀切换时间可能影响定量准确性的原因,通过调整预切柱位置建立最佳的实验条件,用内标法定量,同时对方法的准确度和精密度进行了验证。结果表明,采用气相色谱分析技术,可以快速、准确地测定清洁汽油中的含氧化合物含量。     

气相色谱法分析汽油中的含氧化合物

利用气相色谱技术找出测定汽油中某些含氧化合物的操作条件。     

GC和GC-MS在汽油分析检测中的应用进展

文章梳理了气相色谱法和气相色谱-质谱法在分析测定汽油中硫化物、苯胺类化合物、醛酯类含氧化合物、金属抗爆剂等物质的研究进展,并对其发展前景进行了展望。     

气相色谱法测定丙烯中含氧化合物

使用气相色谱分析方法同时使用HP-INNOWAX毛细管色谱柱对丙烯中含氧化合物的检测,明确了相应检测方法测试的限度、精度以及重复性和准确程度,根据具体的试验了解到,相应的方法能迅速测定出丙烯中含氧化合物,偏差较小,由此为类似的丙烯中含氧化合物的测定提供了可供参考的经验。     

合成甲醇液相产物的气相色谱分析

介绍了合成甲醇液相产物的气相色谱分析方法。选择高分子固定相,以避免水的干扰;运用保留值和保留指数规律定性;分别在ＦＩＤ和ＴＣＤ上分析含氧化合物杂质与水的含量,定量快速、准确。     

汽油中含氧化合物的检测与研究

采用Rtx-TCEP(60 m×250μm×0.4μm)与DB-1(30 m×250μm×0.5μm)常见的毛细管色谱柱和Deans switch微板流路控技术建立了一种全新的分析汽油中含氧化合物的二维气相色谱法。用该方法分析汽油中0%～10%的含氧化合物,各物质校正曲线的线性关系良好,相关系数均大于0.999;标准样品5次重复测定的相对标准偏差均小于2.2%;车用汽油实际样品测定结果和SH/T 0663标准方法测定结果一致。该方法是车用汽油中含氧化合物含量测定的一种简单快捷、准确可靠的分析方法。     

中红外光谱法测定汽油中含氧化物含量

利用IROX2000傅里叶红外光谱仪测定汽油中的含氧化物（醇类和醚类）,选用直馏汽油、重整汽油、催化裂化汽油等基础汽油配制36组不同浓度、不同含氧化物组分的标准样品,对成品汽油和配制的含氧汽油中的氧含量进行测定,并与气相色谱方法对比,验证了中红外光谱法测定汽油中含氧化物含量的可靠性.实验证明,中红外光谱法具有分析快速、重复性好、分析成本低等优点.     

中心切割气相色谱法测定汽油中的含氧化合物

采用安捷伦中心切割技术(Dean Switch),建立了一种测定汽油中含氧化合物的分析方法。该方法先将汽油样品通过非极性色谱柱DB-1,利用中心切割模块使得非极性柱中的极性含氧化合物和部分轻烃切割至强极性柱CP-lowox中进行分析。该方法避免了汽油中烃类物质对含氧化合物测定的干扰，同时对该方法的精密度和准确度进行了分析验证，结果表明，此方法较NB/SH/T 0663检出限更低，精密度更高，是一种准确可靠的分析方法。     

测定汽油中氧含量的方法比较及重要性分析

在成品油中氧含量是一个很重要的控制指标,氧含量测定值的高低将直接影响油品的质量。为使汽油燃烧完全,提高汽油的辛烷值降低挥发性,减少胶质的产生,以免堵塞活塞影响汽车性能和正常工作,油品生产厂家必须在汽油中加入醚类、醇类和其他含氧化合物来满足汽车适应性的要求。因此,运用何种测定方法来检测汽油中的氧含量就非常关键,继而来控制汽油中含氧化合物的含量。本文主要对氧含量的测定方法的比较、控制汽油中氧含量的重要性以及它的含量对汽车的影响做具体的分析。     

多维气相色谱法测定车用汽油含氧化合物方法改进研究

一直以来车用汽油中含氧化合物分析基本均采用ASTMD4815或SH/T0663的方法,但随着车用汽油产品标准GB/T17930-2006版的出台,ASTMD4815和SH/T0663两种方法存在着部分含氧化合物分离效果较差、甲醇检测限达不到要求的问题,因此该分析方法迫切需要改进。该文提出采用多维气相色谱,利用经过硅烷化处理后的约1mTCEP微填柱和30mHP-1弹性毛细管柱,TCD和FID双检测器进行样品分离及检测,经过对柱系统和操作条件的优化,可准确地分析车用汽油中C1～C4醇类和醚类含氧化合物,甲醇检测限达到0.05%。方法重复性的相对标准偏差(RSD)≤0.827%,标准样品回收率在90%～110%之间。     

The effect of oxygenates on soot formation in rich heptane mixtures: A shock tube study

There is a strong environmental interest in blending diesel fuels with oxygenates to reduce soot emissions. To investigate the influence of oxygenates on diesel soot emissions, soot formation in fuel-rich n-heptane/oxygen mixtures with added dimethyl ether, acetone, butanal, or 3-pentanone was investigated behind reflected shock waves at pressures from 20 to 30 atm and temperatures from 1600 to 1900 K. Soot formation histories were observed by simultaneously measuring the soot-induced laser light extinction at 633 nm and the light emission by soot particles at 670 nm. Uniform reflected shock conditions over the long test times needed to form soot were achieved by using a new driver insert method to modify shock tube performance. In measurements made under these uniform conditions, the soot formation window near 1700 K was found to be narrower than previously measured. A significant reduction in the overall soot yield was found with the addition of small quantities of oxygenates as well. On a per oxygen-mass basis, butanal was found to be the most effective additive in reducing soot among the oxygenates studied, consistent with the smoke point tests of Pepiot-Desjardins et al. [Pepiot-Desjardins P, Pitsch H, Malhotra R, Kirby SR, Boehman AL. Structural group analysis for soot reduction tendency of oxygenated fuels. Combust Flame 2008;154:191-205]. It was also found that normal alkyl-group chain length in oxygenates has little impact on soot reduction.     

Co-Pd双金属催化剂载体对甲烷-合成气两步梯阶转化催化性能的影响

采用浸渍法制备了不同载体负载的Co-Pd双金属催化剂,在自制的连续式步阶反应器上将CH4与合成气反应转化成C2+含氧化合物。研究表明,载体对催化剂催化性能有较大影响。Al2O3作载体时,两步梯阶转化催化剂活性和C2+含氧化合物的选择性最高,达70.9%;Al2O3载体更有利于活性金属Pd和Co的分散和还原,有利于得到催化反应所需的表面酸强度和酸量,从而提高了其催化性能。     

C4烃类含氧化合物脱除工艺研究进展

综述了现行C4烃类化合物中含氧化合物脱除的工艺方法--精馏法和吸附法,对不同脱除工艺的工业应用状况进行了分析比较,提出吸附分离工艺是一个重要的发展方向.     

Influence of extra-framework Al in Fe-MOR catalysts for the direct conversion of methane to oxygenates by nitrous oxide

Iron-containing zeolites play an important role in the selective oxidation of methane to oxygenates by nitrous oxide. A solid-state ion exchange method is adopted to prepare Fe-MOR zeolite catalysts with different amounts of extra-framework Al. EPR spectra and UV–vis spectra show that the percentage of iron ions in tetrahedral or octahedral coordination increases while those of clustered Fe species decrease by the addition of extra-framework Al species. Nitrous oxide titration reveals that more active Fe centers are formed, which promote the nitrous oxide consumption. The number of active centers in the catalyst with the introduction of extra-framework Al is about four times that of the catalyst without the addition of extra-framework Al. Due to this, there is an increase in the methane conversion, total selectivity and yield of oxygenates.     

Selective oxidation of propane to oxygenates over mesoporous SBA-15-supported potassium catalysts

As a novel catalyst system for the selective oxidation of low alkanes, mesoporous SBA-15-supported potassium catalysts were firstly employed for the selective oxidation of propane to oxygenates by using molecular oxygen as oxidant. It was found, compared with bare mesoporous SBA-15, that the selectivities to the oxygenates including formaldehyde, acetaldehyde, acrolein and acetone were remarkably enhanced over K _x /SBA-15(K:Si = x:100, mol) catalysts, and the main products were acrolein and acetone. At 500 °C, the yield of the oxygenates can reach 464% over K_3.0/SBA-15, which is the highest value over SBA-15–supported potassium catalysts. The catalysts were characterized by XRD and BET techniques. The results demonstrated that the catalytic performance was strongly dependent on the potassium content of the catalysts. Furthermore, the highly dispersed potassium on the catalyst surface was shown to be important to orientate the reaction toward the production of oxygenates. The obtained results showed that mesoporous structure, uniform pore sizes and appropriate pore surface area were favorable for the selective oxidation of propane. The samples with moderate amount of potassium promoted the selectivity to the oxygenates.     

(VO)2P2O7 Catalysed Partial Oxidation of Propane in Dense CO2

The aim of this study was to elucidate the catalytic partial oxidation of propane to oxygenates on vanadyl pyrophosphate ((VO)₂P₂O₇) in dense carbon dioxide acting as a solvent. The reaction was carried out in continuous flow experiments at 673 K at a molar ratio of CO₂ :synthetic airpropane of 86131, a residence time of 19 s and sub- to supercritical pressures ranging from 2.4 to 9.7 MPa. The catalytic tests revealed the formation of acrylic and acetic acid besides total oxidation products. The selectivity to acetic acid increased with rising pressure, whereas that of acrylic acid decreased. These results may be attributed to a diverging adsorption of both the oxygenates with pressure, which was investigated by supercritical fluid chromatography. Additionally, critical data of both the reaction feed and the product mixture were determined in a high-pressure optical cell by the opalescence method.     

气相色谱法测定石脑油中含氧化合物含量

本文论述了利用气相色谱法检测石脑油中含氧化合物的方法,考察了无阀切换技术、分离模式的设计、操作条件的优化等方面的问题。提出利用多维气相色谱法,采用一根非极性柱和一根极性柱进行独立和串联分离,通过改变辅助载气压力的无阀切换方式进行柱分离,应用双FID检测器进行信号检测,数据利用Agilent的chemestation工作站采集和输出。该方法操作简单,分析时间在23 min以内,重复测定结果的相对标准偏差(RSD)小于1.5%,标准加入回收率在95～105%范围内,方法准确可靠。