Ni含量对负载型NiO/ZnO-TiO2吸附剂结构及吸附脱硫性能的影响

以ZnO-TiO₂为载体,采用等体积浸渍法制备了不同Ni含量的NiO/ZnO-TiO₂汽油脱硫吸附剂。采用X射线衍射（XRD）、压汞、H₂程序升温还原（H₂-TPR）和H₂程序升温脱附（H₂-TPD）等手段对吸附剂进行了表征。同时,采用FCC轻汽油为原料,在固定床反应装置中对不同Ni含量的NiO/ZnO-TiO₂吸附剂进行脱硫性能评价,以考察Ni含量对该吸附剂脱硫性能的影响。结果表明,Ni含量适量增加对于吸附剂比表面积、内部孔道分布和颗粒强度影响较小,同时能够增加具有脱硫活性的Ni⁰物种,促进吸附剂脱硫活性。当吸附剂中Ni质量分数达到5.48%后,吸附剂的内部孔道分布改变,吸附剂的比表面积和颗粒强度明显降低,对吸附剂脱硫活性极为不利。当Ni质量分数为4.45%时,吸附剂具有最佳脱硫性能,能够将FCC轻汽油中3×10^-4的总硫含量降低至5×10^-6以下,并维持脱硫时间达152 h,穿透硫容达11.24%（112.4 mg S/g吸附剂）,且脱硫后FCC轻汽油烯烃含量变化较小。     

Advanced gasoline engine development using optical diagnostics and numerical modeling

Twenty years ago, homogeneous-charge spark-ignition gasoline engines (using carburetion, throttle-body-, or port-fuel-injection) were the dominant automotive engines. Advanced automotive engine development remained largely empirical, and stratified-charge direct-injection gasoline-engine production was blocked by lack of robustness in its combustion process [W.G. Agnew, Proc. Combust. Inst. 20 (1984) 1-17]. Today, a wide range of direct-injection gasoline engines are in (or near) production, and combustion science is playing a direct role in advanced gasoline-engine development through the simultaneous application of advanced optical diagnostics, three-dimensional computational fluid dynamics (CFD) modeling, and traditional combustion diagnostics. This paper discusses the use of optical diagnostics and CFD in five gasoline-engine combustion systems: homogeneous spark-ignition port-fuel-injection (PFI), homogeneous spark-ignition direct-injection (DI), stratified wall-guided spark-ignition direct-injection (WG-SIDI), stratified spray-guided spark-ignition direct-injection (SG-SIDI), and homogeneous-charge compression-ignition (HCCI). The emphasis is on WG-SIDI, SG-SIDI, and HCCI engines. Key in-cylinder physical processes (e.g., sprays and vaporization, turbulent fuel-air mixing, wall wetting, ignition and early flame development, turbulent partially premixed flame propagation, and emissions formation) can be visualized, quantified, and optimized through optical engine experiments and CFD-based engine modeling. Outstanding issues for stratified engines include reducing piston wall-wetting, pool fires and smoke in WG-SIDI engines, eliminating intermittent misfires in SG-SIDI engines, and optimizing lean NO_x after-treatment systems. HCCI engines require better control of combustion timing and heat-release rate over wide speed/load operating ranges, smooth transitions between operating modes, and individual cylinder sensors and controls. Future directions in optical diagnostics and modeling are suggested to improve our fundamental understanding of important in-cylinder processes and to enhance CFD modeling capabilities.     

A study on the production and engine analysis of organic liquid fuel from jatropha and castor oil by catalytic cracking over solid acid catalysts

Catalytic cracking of non-edible oils such as jatropha and castor was done in fixed bed catalytic reactor. The microporous catalysts such as Hβ, HY and HZSM-5 and mesoporous catalyst like AlMCM-41 were synthesised and characterised by XRD and BET surface area analyzer. The reaction parameters such as temperature of reaction, WHSV (Weight hourly space velocity) and reaction time were optimised over Hβ catalyst using jatropha oil. Organic liquid products (OLP) comprising of green gasoline (GG), green kerosene (GK) and green diesel (GD) and gaseous products were found to be major products. The liquid products were analysed using gas chromatograph (Shimadzu GC-9A) fitted with Apeizon-L packed column and gaseous products were analysed using Poropak Q column. The % conversion, yield of OLP and selectivity towards GG, GK and GD were found to be higher at temperature of 400 °C, WHSV of 4.8 h^?1 and reaction time of 1 h. The cracking of jatropha oil was done over HY, HZSM-5 and AlMCM-41 at this optimised condition. Among the microporous materials HZSM-5 produced more OLP with more selectivity towards GG fraction (50%) but yielded higher % of gaseous products. While AlMCM-41 (Si/Al = 25) was selective towards middle distillates fraction like GK (45%) & GD (35%) and yielded low gaseous products. The mechanism of reaction proceeds via carbocation formation. The activity of HZSM-5 and AlMCM-41 were examined with castor oil. The OLP viability as a replacement fuel in a single-cylinder diesel engine under various loads was evaluated in an IC engine test. Here, we look at how different engine operating conditions affect fuel efficiency, Brake Thermal Efficiency (BTE), and emissions of Carbon Monoxide (CO), Carbon-di-oxide (CO2) and Nitrogen Oxide (NOx). Overall analysis indicates that OLP cracked from Jatropha oil serves as a best fuel in comparison with OLP obtained from Castor oil.     

Identification of V‐type nerve agents in vapor samples using a field‐portable capillary gas chromatography/membrane‐interfaced electron ionization quadrupole mass spectrometry instrument with Tri‐Bed concentrator and fluoridating conversion tube

A field‐portable gas chromatography–mass spectrometry (GC–MS) system (Hapsite ER) was evaluated for the detection of nonvolatile V‐type nerve agents (VX and Russian VX (RVX)) in the vapor phase. The Hapsite ER system consists of a Tri‐Bed concentrator gas sampler, a nonpolar low thermal‐mass capillary GC column and a hydrophobic membrane‐interfaced electron ionization quadrupole mass spectrometer evacuated by a non‐evaporative getter pump. The GC–MS system was attached to a VX‐G fluoridating conversion tube containing silver nitrate and potassium fluoride. Sample vapors of VX and RVX were converted into O‐ethyl methylphosphonofluoridate (EtGB) and O‐isobutyl methylphosphonofluoridate (iBuGB), respectively. These fluoridated derivatives were detected within 10 min. No compounds were detected when the VX and RVX samples were analyzed without the conversion tube. A vapor sample of tabun (GA) was analyzed, in which GA and O‐ethyl N,N‐dimethylphosphoramidofluoridate were detected. The molar recovery percentages of EtGB and iBuGB from VX and RVX vapors varied from 0.3 to 17%, which was attributed to variations in the vaporization efficiency of the glass vapor container. The conversion efficiencies of the VX‐G conversion tube for VX and RVX to their phosphonate derivatives were estimated to be 40%. VX and RVX vapors were detected at concentrations as low as 0.3 mg m⁻³. Gasoline vapor was found to interfere with the analyses of VX and RVX. In the presence of 160 mg m⁻³ gasoline, the detection limits of VX and RVX vapor were increased to 20 mg m⁻³. Copyright © 2017 John Wiley & Sons, Ltd.     

磷改性纳米HZSM-5沸石水热稳定性及其对全馏分FCC汽油烯烃组分催化裂解反应的性能

水热稳定性是决定沸石分子筛工业应用价值的重要影响因素.众所周知,沸石材料的水热稳定性主要受其拓扑机构及骨架硅铝组成的影响,但同时也受其晶粒尺寸的影响.纳米级HZSM-5沸石虽然具有优异的催化性能及抗积碳失活性能,但由于晶粒尺寸较小,导致其水热稳定性较差.如何提高纳米HZSM-5沸石的水热稳定性,使其能够在高苛刻度的水热环境下(如催化裂化过程,催化剂再生需在高于700℃的水热条件下进行)得到应用,是十分有意义的课题.已有研究表明,磷改性可以提高ZSM-5沸石的水热稳定性,但多集中于采用磷酸、磷酸氢二铵、磷酸二氢铵等无机磷化物进行改性,水热稳定性提高效果不能令人满意.我们研究组采用有机磷化合物磷酸三甲酯改性纳米HZSM-5沸石,在提高纳米HZSM-5沸石水热稳定性方面取得了较好的效果.采用X射线衍射(XRD)、氨气程序升温脱附(NH3-TPD)、氮气物理吸附、氨气吸附红外光谱等手段对改性沸石进行了表征.结果表明,采用磷酸三甲酯改性的纳米HZSM-5沸石水热稳定性得到明显提高,沸石经苛刻的高温水蒸气处理(800℃,4 h)后,在相对结晶度、孔结构、酸度的保留度方面具有较大提高,提高幅度明显高于无机磷化合物磷酸氢二铵改性的纳米HZSM-5沸石.在上述研究基础上,我们采用固定床微反模拟流化床反应条件对磷改性纳米HZSM-5沸石上全馏分FCC汽油烯烃组分催化裂解反应进行了研究.结果表明,在反应温度540℃,剂/油比等于4,油剂接触时间约为4 s的条件下,全馏分FCC汽油在磷改性纳米HZSM-5沸石上经烯烃组分催化裂解反应后,油品烯烃含量(尤其是重烯烃)明显降低,生成了大量高附加值的C2–C4烯烃,同时油品中芳烃含量增加.与此同时,经烯烃组分裂解后的油品还呈现出辛烷值升高,硫含量降低的有利变化.可以看出,磷改性纳米HZSM-5沸石上全馏分FCC汽油烯烃组分催化裂解是解决FCC汽油烯烃含量高的一条有效途径,充分克服了现有FCC汽油加工工艺存在的一些缺陷,如S-zorb工艺功能单一、成本高;加氢脱硫工艺油品辛烷值损失大、氢耗高;以及OTA技术(本研究组之前的工作)烯烃转化率低、催化剂积碳失活快等缺陷.值得注意的是,磷酸三甲酯改性的纳米HZSM-5沸石在全馏分FCC汽油烯烃组分催化裂解反应性能方面,明显比磷酸二氢铵改性的纳米HZSM-5沸石表现优异.通过我们的研究可以认为,磷酸三甲酯改性将会为纳米HZSM-5沸石在高苛刻度水热条件下的应用提供更多的机会.     

Characterization of Gasoline by Raman Spectroscopy with Chemometric Analysis

A rapid Raman spectroscopy protocol is reported to classify gasoline according to its distributor and to identify and quantify common adulterants. Gasoline from three distributors was collected from 19 stations in São Paulo, Brazil. Principal component analysis (PCA) showed specific clusters for each distributor, and partial least squares discriminant analysis (PLS-DA) correctly identified the origin of the samples. To evaluate the technique for the identification and quantification of the adulterants, authentic samples from each distributor were fortified at levels from 2.5 up to 25.0% (v/v) using ethanol, methanol, toluene, and turpentine to obtain 120 altered samples. PCA showed clear separation among the samples with the adulterants and PLS-DA precisely identified the adulterants (478 in 480 predictions by cross-validation), irrespective of the distributor and the concentration. One classification model was used to characterize all distributors. To quantify the adulterants, 36 multivariate calibration models were constructed using partial least squares (PLS), interval PLS, and PLS genetic algorithm for each distributor and for each adulterant. Cross-validation errors of less than 5.0% were obtained for all adulterants regardless of the distributor. Raman spectroscopy and multivariate analysis were shown to be powerful for rapid and inexpensive for the characterization of gasoline origin and the identification and quantification of common adulterants.     

气相色谱法检测M15甲醇汽油燃料尾气排放中甲醛的含量

建立了毛细管柱气相色谱法检测甲醛的方法。在GB/T 18204.26–2000方法基础上对色谱条件如色谱柱、柱温等进行优化。在确定的试验条件下吸附剂上甲醛量在0~20μg范围内与色谱峰面积呈现良好的线性,线性相关系数r2=0.999 7,检出限为0.18μg,重复性测定结果的相对标准偏差为1.6%~3.0%(n=8),回收率为103%~110%。利用该方法对M15甲醇汽油汽车尾气样品进行了检测。该法分离效果好、灵敏度高、检测结果准确。     

Identification and Quantification of Hydrocarbon Functional Groups in Gasoline Using 1H-NMR Spectroscopy for Property Prediction

Gasoline is one of the most important distillate fuels obtained from crude refining; it is mainly used as an automotive fuel to propel spark-ignited (SI) engines. It is a complex hydrocarbon fuel that is known to possess several hundred individual molecules of varying sizes and chemical classes. These large numbers of individual molecules can be assembled into a finite set of molecular moieties or functional groups that can independently represent the chemical composition. Identification and quantification of groups enables the prediction of many fuel properties that otherwise may be difficult and expensive to measure experimentally. In the present work, high resolution ¹H nuclear magnetic resonance (NMR) spectroscopy, an advanced structure elucidation technique, was employed for the molecular characterization of a gasoline sample in order to analyze the functional groups. The chemical composition of the gasoline sample was then expressed using six hydrocarbon functional groups, as follows: paraffinic groups (CH, CH₂ and CH₃), naphthenic CH-CH₂ groups and aromatic C-CH groups. The obtained functional groups were then used to predict a number of fuel properties, including research octane number (RON), motor octane number (MON), derived cetane number (DCN), threshold sooting index (TSI) and yield sooting index (YSI).     

汽油烷基化脱硫反应中噻吩及其衍生物的烷基化性能

 研究了噻吩、2-甲基噻吩、3-甲基噻吩和 2,5-二甲基噻吩等硫化物与己烯进行烷基化反应的性能. 结果发现,它们进行一次烷基化反应的能力都比较强,在实验条件下转化率几乎都达到了100%. 但噻吩衍生物与己烯进行二次以至多次烷基化反应的能力则随着噻吩环上支链的增加逐渐减弱,原因可能来自噻吩衍生物继续进行烷基化反应的热力学条件不利,以及环上已有侧链的空间位阻效应. 噻吩衍生物发生深度烷基化反应能力的减弱导致了另外两个并行竞争反应芳烃烷基化和烯烃烷基化(聚合)的反应程度增强,表现为芳烃转化率和己烯聚合量的升高,以及各自二次烷基化产物相对含量的增加.     

毛细管气相色谱活数据库定性

活数据库方法有效地解决了毛细管气相色谱程序升温下的无标样定性问题,详尽讨论了活数据库的方法原理和影响因素,最后以汽油为例,说明活数据库定性方法的实用性。