氧清除剂用于增强吸热型碳氢燃料热氧化安定性

热氧化安定性是吸热型碳氢燃料贮存和使用过程中评价燃料品质的重要性质之一,反映了喷气燃料在260℃以下组分受溶解氧影响的程度和燃料氧化反应进行的深度。为评价氧清除剂,选用一种实验室自制的吸热型燃料,运用加速氧化法,配合滴定、红外光谱、粒度分布和JFTOT等测试方法对燃料的基础物性和热氧化安定性进行评估,比较了三苯基膦(TPP)、二环己基苯基膦(DCP)和1,2,5-三甲基吡咯(TMP)三种氧清除剂对吸热型碳氢燃料自氧化过程的影响,并确定了测试范围内的最佳添加量。结果显示,三种氧清除剂的添加对燃料的组成和基础物性无明显影响;燃料中的溶解氧浓度随添加量增加不断下降,最大可降低溶氧浓度31.95 mg/m~3;加速氧化后,样品的过氧化值和酸值均不同程度下降;胶团粒径分布趋向于更小粒径方向; JFTOT测试结果均满足国标规定。总体上,氧清除剂的添加均能有效提升燃料的热氧化安定性,三者的最优添加量均为质量分数1.5×10~(-5),作用效果优劣顺序为TMPTPP≈DCP。     

Classification of jet fuels by fuzzy rule-building expert systems applied to three-way data by fast gas chromatography--fast scanning quadrupole ion trap mass spectrometry

A fast method that can be used to classify unknown jet fuel types or detect possible property changes in jet fuel physical properties is of paramount interest to national defense and the airline industries. While fast gas chromatography (GC) has been used with conventional mass spectrometry (MS) to study jet fuels, fast GC was combined with fast scanning MS and used to classify jet fuels into lot numbers or origin for the first time by using fuzzy rule-building expert system (FuRES) classifiers. In the process of building classifiers, the data were pretreated with and without wavelet transformation and evaluated with respect to performance. Principal component transformation was used to compress the two-way data images prior to classification. Jet fuel samples were successfully classified with 99.8 ± 0.5% accuracy for both with and without wavelet compression. Ten bootstrapped Latin partitions were used to validate the generalized prediction accuracy. Optimized partial least squares (o-PLS) regression results were used as positively biased references for comparing the FuRES prediction results. The prediction results for the jet fuel samples obtained with these two methods were compared statistically. The projected difference resolution (PDR) method was also used to evaluate the fast GC and fast MS data. Two batches of aliquots of ten new samples were prepared and run independently 4 days apart to evaluate the robustness of the method. The only change in classification parameters was the use of polynomial retention time alignment to correct for drift that occurred during the 4-day span of the two collections. FuRES achieved perfect classifications for four models of uncompressed three-way data. This fast GC/fast MS method furnishes characteristics of high speed, accuracy, and robustness. This mode of measurement may be useful as a monitoring tool to track changes in the chemical composition of fuels that may also lead to property changes.     

Comprehensive two-dimensional gas chromatography for the analysis of synthetic and crude-derived jet fuels

Fully synthetic jet fuel (FSJF) produced via Fischer-Tropsch (FT) technology was recently approved by the international aviation fuel authorities. To receive approval, comparison of FSJF and crude-derived fuel and blends on their qualitative and quantitative hydrocarbon composition was of utmost importance. This was performed by comprehensive two-dimensional gas chromatography (GC×GC) in the reversed phase mode. The hydrocarbon composition of synthetic and crude-derived jet fuels is very similar and all compounds detected in the synthetic product are also present in crude-derived fuels. Quantitatively, the synthetic fuel consists of a higher degree of aliphatic branching with less than half the aromatic content of the crude-derived fuel. GC×GC analyses also indicated the presence of trace levels of hetero-atomic impurities in the crude-derived product that were absent in the synthetic product. While clay-treatment removed some of the impurities and improved the fuel stability, the crude-derived product still contained traces of cyclic and aromatic S-containing compounds afterwards. Lower level of aromatics and the absence of sulphur are some of the factors that contribute to the better fuel stability and environmental properties of the synthetic fuel. GC×GC was further applied for the analysis of products during Jet Fuel Thermal Oxidation Testing (JFTOT), which measures deposit formation of a fuel under simulated engine conditions. JFTOT showed the synthetic fuel to be much more stable than the crude-derived fuel.     

适应多种原料的生物航煤生产技术的开发

为了减少温室气体排放,扩大航煤的原料来源,生物航煤制备技术的开发受到许多国家的重视.中国石油化工股份有限公司(简称中国石化)开发出了适应多种原料的生物航煤制备技术,该技术以多种生物质油脂为原料,采用加氢法生产生物航煤.针对不同的产品需求,可有不同的产品方案,如最大量生产生物航煤方案,生物航煤兼顾生物柴油方案.以动植物油脂为原料,生物航煤质量收率为35%~45%,生物航煤的冰点可达48℃以下,同时还有7%~11%的柴油馏分和23%~29%的石脑油馏分.中国石化已在工业装置上生产出了符合ASTM D7566-11标准的生物航煤产品,并成功进行了试飞.     

Ru助剂对Co/SiO_2/HZSM-5催化剂合成航空燃油类烃的影响

以中孔硅胶和微孔HZSM-5分子筛为复合载体,添加Ru制备了钴基催化剂,考察了Ru添加量(1%~4%,质量分数)对催化剂结构和固定床费托合成航空燃油类烃的影响。实验结果表明,制备的复合载体催化剂有一定的微孔和中孔结构,Ru的添加有利于Co分散,Ru促进的催化剂低温还原过程提高了催化剂在150~750℃的还原度和CO转化率,复合载体中HZSM-5分子筛利用其微孔结构,提高了异构烃的收率。当Ru负载量为1%时,CO转化率达到62.8%,航空燃油类烃的收率达到37.7%,包括约10.9%的异构烃。Ru负载量超过2%时,增强的催化剂CO加氢活性和CH4选择性,导致合成产物向低碳烃方向偏移。     

Generation and mid-IR measurement of a gas-phase to predict security parameters of aviation jet fuel

The worldwide use of kerosene as aviation jet fuel makes its safety considerations of most importance not only for aircraft security but for the workers’ health (chronic and/or acute exposure). As most kerosene risks come from its vapours, this work focuses on predicting seven characteristics (flash point, freezing point, % of aromatics and four distillation points) which assess its potential hazards. Two experimental devices were implemented in order to, first, generate a kerosene vapour phase and, then, to measure its mid-IR spectrum. All the working conditions required to generate the gas phase were optimised either in a univariate or a multivariate (SIMPLEX) approach. Next, multivariate prediction models were deployed using partial least squares regression and it was found that both the average prediction errors and precision parameters were satisfactory, almost always well below the reference figures.     

Thermal analysis of kerosene with 1,2-methyl ethyl 1-methyl pyrrolidinium bis(trifluoromethanesulfonyl) amide as an additive

This paper reports the thermal characterization of kerosene fuel-doped ionic liquid (1, 2-methylethyl 1-methyl pyrrolidinium bis(trifluoromethanesulfonyl) amide) (MEMP TFSA), an antistatic additive used in jet fuel engines. The ionic liquids (ILs) samples are prepared with the mass of 5, 10 and 15% in the kerosene fuel. These fuel samples are subjected to thermal decomposition studies at different scanning rates of 5, 10 and 15 °C min^?1 using the differential scanning calorimetry (DSC) method. The onset temperatures of exothermic reactions of kerosene-doped ILs are increased from 360–465 °C, when the mass percentage of ILs increased in the kerosene fuel. The boiling point of the kerosene-doped ILs was displaced to the higher temperature when compared to the pure kerosene. This showed that the doping of antistatic additives of ILs with kerosene increased its thermal stability property than the pure kerosene fuel. The thermo-kinetic studies are also carried out using Ozawa’s Kinetic method to determine the activation energy (E_a) and pre-exponential factor (A). The FTIR analysis showed that the kerosene-doped ionic liquid forms a homogenous mixture rather than prevailing separately.

     

喷气燃料裂解产物中芳烃的全二维气相色谱-质谱分析

采用全二维气相色谱-质谱联用仪(GC×GC-MS),通过优化程序升温和调制周期,建立了喷气燃料裂解产物中芳烃的定性定量分析方法。该方法对多环芳烃(PAH)同分异构体具有良好的分离能力。利用MS检测器谱库检索结果、芳烃标准品及相关的文献报道,对喷气燃料裂解产物中常见的单环芳烃、二环芳烃、三环芳烃及四环芳烃等共27种芳烃进行了准确定性,并利用外标GC×GC-FID法对其进行定量。定量结果表明,芳烃含量均随着裂解产气率的增加而增大,当裂解产气率达到22%时,二环芳烃开始产生,且其含量随着裂解产气率的增加呈指数形式增加。该方法与传统的气相色谱-质谱相比,具有更好的分离及定性能力,可应用于复杂样品的分离及其定性定量分析。     

废轮胎热解油重质馏分制备的道路沥青老化性能研究

针对废轮胎热解油重质馏分(＞350℃)组成上具有蜡含量低,芳香分、胶质和沥青质含量高的特点,研究了废轮胎热解油重质馏分采用蒸馏法生产道路沥青的可行性。结果表明,废轮胎热解油中＞420℃、＞430℃、＞440℃三种渣油的性质可以满足不同牌号道路石油沥青老化实验前的技术指标,特别是延展性能优异,但是抗老化性能较差。渣油老化前后的族组成、官能团、氢分布及分子量分布变化表明,渣油在老化过程中存在氧化反应以及脱氢缩合反应,使渣油的化学组成发生变化,即芳香分、胶质含量减少,沥青质含量明显增加,使得沥青胶体体系中分散相明显增多而分散介质相对减少,造成热解油的渣油抗老化性能较差。     

Rapid gas-chromatographic determination of hydrocarbon types by selective absorption and flame ionization detection

A fast one-step technique has been developed for the resolution of hydrocarbons into aromatics, olefines and saturates. The analyser consists of three branches with different capillary restrictions, specific absorbers and delayers, and can be applied to gaseous or liquid samples of hydrocarbons with a boiling point of up to 220°C. The time required for an analysis under optimal conditions is 6 min. The analyser is installed directly in the oven of the gas chromatograph, using a single flame ionisation detector. It was tested by selected hydrocarbons occurring in gasoline in significant amounts in different concentration ranges. Leaded and unleaded commercial gasolines were examined as real samples. The method had been successfully applied to the fast identification of hydrocarbons in the case of fuel spills.     

Calibration transfer of near‐IR partial least squares property models of fuels using virtual standards

Partial least squares (PLS) models of 10 important jet and diesel fuel properties were built using spectra from a master near‐IR dispersive instrument and then subsequently transferred to a secondary dispersive instrument via a novel calibration transfer method using virtual standards and a slope‐bias correction. Implementation of the transfer requires that only seven spectra of neat solvents be acquired on the master and secondary instruments. The spectra of the neat solvents are then used to digitally replicate spectra from the calibration set to generate virtual standards. Comparison of PLS predictions for the master and secondary instrument virtual standards provides a simple but effective slope‐bias correction for transfer. The transferred fuel properties include American Petroleum Institute gravity, % aromatics, cetane index, flashpoint, hydrogen content, % saturates, and distillation temperatures at 10%, 20%, 50%, and 90% volume recovered. Transfer error was lower than using either the pure solvents with a slope‐bias correction or than using a piecewise direct standardization calibration transfer using fuel spectra. Transfer error was higher than when using actual fuels to transfer the calibration. The use of virtual standards eliminates the need to maintain either complex fuel standards or the master instrument for future instrument calibration transfers. Copyright © 2011 John Wiley & Sons, Ltd.     

氟化氢铵消解-电感耦合等离子体质谱(ICP-MS)法测定地球化学样品中的钨锡钼

建立了氟化氢铵消解地球化学样品,电感耦合等离子体质谱(IC P-M S)法测定样品中钨、锡和钼的方法.方法经过国家土壤和水系沉积物标准参考物质验证,方法的检出限钨为0.048μg/g、锡为0.079μg/g、钼为0.063μg/g,准确度(相对误差)钨为0.64％ ～6.28％、锡为0.29％ ～3.74％、钼为2.1...     

固相萃取采样和气相色谱-质谱检测液化石油气中的芳烃杂质（英文）

建立石墨化碳(GCB)为吸附剂的动态采样系统,可实现液化石油气(LPG)中芳烃杂质的采样和同步萃取富集。LPG中的芳烃杂质(苯、甲苯、二甲苯、苯乙烯和萘)被快速捕集后,进行气相色谱-质谱(GC-MS)定性定量分析。与C18和苯乙烯二乙烯苯吸附剂(PS-DVB)相比,GCB填充柱对芳烃杂质的萃取效率最高。评价了基于GCB填充柱采样的吸附效率、重现性和贮存稳定性。采样和分析方法对氮气模拟气流中8种芳烃的定量分析线性范围为15~1 000μg/m~3。所开发的方法具有回收率高(92.9%~109.0%)、检出限低(1.0~6.2μg/m~3)、准确性好(相对标准偏差为0.6%~5.8%)和准确度高(标准偏差为0.8%~8.2%)等优点。     

煤焦油馏分油对辽河稠油热生焦性能的影响

从煤焦油馏分油自身及与辽河稠油共炼生焦规律出发,利用元素分析、核磁共振氢谱、同步荧光光谱及族组成分析等方法对馏分油进行表征,研究了煤焦油馏分油对辽河稠油热生焦性能的影响。结果表明,辽河稠油掺炼煤焦油馏分油可以改善辽河稠油的热生焦性能。实验条件下,掺炼体系加权生焦率为3.3%-6.4%,实验生焦率为0.5%-5.9%,表现出良好的协同效果。不同馏分油的协同作用程度取决于馏分油的化学组成和含量。饱和烃、单环芳烃和缩合四环芳烃会促进生焦,而双环芳烃、三环芳烃和缩合双环芳烃有减缓生焦的作用。     

纳米HZSM-5催化剂催化烃类转化反应

制备了纳米(20~50 nm)HZSM-5催化剂, 用XRF, TEM和NH3-TPD等手段对催化剂进行了表征. 以正辛烷及苯和正辛烷混合物的转化为模型反应, 研究了单烃和混合烃在纳米HZSM-5催化剂上的转化行为, 考察了反应条件对产物分布的影响. 结果表明, 纳米HZSM-5沸石催化剂具有很强的烃类转化能力, 烃类通过芳构化、 异构化和烷基化等反应转化为高辛烷值的异构烷烃和芳烃, 产物中异构烷烃(C4~C6)和芳烃的质量分数超过90%. 直链烷烃转化为芳烃以生成苯环为主, 混合烃转化为芳烃以苯和小分子烃的烷基化为主. 控制反应条件可抑制苯和C+9芳烃的生成. 产物分析结果表明, 烃类在纳米HZSM-5催化剂上的裂解、芳构化和异构化等遵循正碳离子机理.     

Empirical correction to the Peng–Robinson equation of state for the saturated region

This work presents an empirical correction to improve the Peng–Robinson equation of state (PR EOS) for representing the densities of pure liquids and liquid mixtures in the saturated region using the volume translation method. A temperature-dependent volume correction is employed to improve the original PR EOS so that it can match the true critical point of pure fluids. The volume correction is generalized as a function of the critical parameters and the reduced temperature. The volume translation PR (VTPR) EOS with the generalized volume correction accurately represents the saturated liquid densities for different polar and non-polar fluids, including alkanes, cycloparaffins, halogenated hydrocarbons, olefins, cyclic olefins, aromatics and inorganic molecules. The average relative deviations for 91 pure compounds was 1.37%. The generalized VTPR EOS was also used to predict the saturated liquid density of 53 binary mixtures with a relative deviation of 0.98%. The generalized VTPR EOS can also be extended to other materials. The accuracy of the generalized VTPR EOS compares well with other methods and equations of state.     

离子对色谱法同时分离测定吡啶及咪唑离子液体阳离子

建立了用紫外检测的反相离子对色谱梯度淋洗同时分离测定4种吡啶离子液体阳离子和5种咪唑离子液体阳离子的方法。实验采用ZORBAX Eclipse XDB-C18反相色谱柱,以离子对试剂水溶液(用柠檬酸调节pH值)+乙腈为流动相,考察了离子对试剂种类和浓度、乙腈浓度和色谱柱温度对保留的影响,探讨了相关保留规律,确定最佳色谱条件为:流速1.0 mL/min、柱温30℃,以1.0 mmol/L庚烷磺酸钠水溶液(pH 4.0)-乙腈为淋洗液进行梯度洗脱。在此条件下,4种吡啶阳离子和5种咪唑阳离子在15 min内达到基线分离。检出限(S/N=3)为0.31～0.54 mg/L,峰面积的相对标准偏差为0.10%～0.75%。将该方法用于实验室合成的离子液体样品分析,加标回收率为94%～98%。该方法准确、可靠,具有较好的实用性。     

Determination of total and polycyclic aromatic hydrocarbons in aviation jet fuel

The aviation jet fuel widely used in turbine engine aircraft is manufactured from straight-run kerosene. The combustion quality of jet fuel is largely related to the hydrocarbon composition of the fuel itself; paraffins have better burning properties than aromatic compounds, especially naphthalenes and light polycyclic aromatic hydrocarbons (PAHs), which are characterised as soot and smoke producers. For this reason the burning quality of fuel is generally measured as smoke fermation. This evaluation is carried out with UV spectrophotometric determination of total naphthalene hydrocarbons and a chromatographic analysis to determine the total aromatic compounds. These methods can be considered insufficient to evaluate the human health impact of these compounds due to their inability to measure trace (ppm) amounts of each aromatic hyrcarbon and each PAH in accordance with limitations imposed because of their toxicological properties. In this paper two analytical methods are presented. Both are based on a gas chromatographic technique with a mass detector operating in be selected ion monitoring mode. The first method was able to determine more than 60 aromatic hydrocarbons in a fuel sample in a 35-min chromatographic run, while the second was able to carry out the analysis of more than 30 PAHs in a 40-min chromatographic run. The linearity and sensitivity of the methods in measuring these analytes at trace levels are described.     

A modification of the internal normalization method with sample splitting

Summary The procedure of sending a part of the sample vapor directly to the detector has been proposed earlier. This permits the quantitative determination of any sample component by relating its peak area to that of the total peak. This method represents a modification of the internal normalization method, with sample splitting. The necessary operating conditions and the applicability range of the method are considered. The dependence of the analytical results on the errors of splitting detector response factors and peak area measurements is discussed. Different types of split systems and flow paths have been tested. The possibilities of this method are demonstrated by determining the total amount of paraffins and cycloparaffins in platforming gasolines enriched in aromatics.     

Estimation of isotopic composition of plutonium from thermal reactors by neutron coincidence counting through isotopic correlation technique

Correlations have been established between %Eff ²⁴⁰Pu and various plutonium isotopes formed in thermal reactors. Based on these correlations, a method has been developed for the estimation of isotopic composition of plutonium obtained from thermal reactors. The method is simple, fast, non-destructive and finds application for the verification of plutonium isotopic composition in the finished products of known plutonium content. The method could be applied in the nuclear fuel fabrication to verify and confirm the fissile content (²³⁹Pu+²⁴¹Pu) specification. It has also been shown that in principle, similar correlations could be established for Pu obtained from different thermal reactor fuels with reactor specific fitting parameters.