合成高密度烃类燃料研究进展

本文对合成高密度烃类燃料的进展进行了总结,分别对多环烃类燃料、高张力笼状烃类燃料和添加纳米级微粒的燃料进行了评述.以烃类物质为原料,通过聚合、加氢、异构等工艺合成的多环高密度燃料拥有较高的能量密度和较佳的稳定性能,是目前高密度燃 料的发展重点.高张力笼状烃类燃料和添加纳米级微粒的燃料拥有更大的密度(一般大于1g/ cm3)和燃烧热值,是极具发展前景的新一代燃料。     

CCD近红外光谱快速测定喷气燃料的冰点

从化学计量学角度研究了近红外光谱技术测定航空燃料冰点的原理．使用偏最小二乘法分别建立了短波近红外和长波近红外的航空燃料冰点快速测定模型．将近红外法冰点测定结果和标准方法（ＧＢ ２４３０—８１）测定结果进行了比较，两种结果吻合得很好（标准偏差为１．４７℃。），近红外光谱法具有分析精度高（标准偏差为０．５３℃），快速（单个样品分析时间为 ｌｍｉｎ）和操作方便的优点．实际分析结果表明，石油化工科学研究院研制的ＣＣＤ短波近红外光谱仪分析性能达到进口傅立叶近红外光谱仪水平。     

高密度航空航天燃料合成化学

高密度液体碳氢燃料是为提高航空航天飞行器性能(航程、载荷、速度)而人工合成的燃料,与常规燃料(例如航空煤油和火箭煤油)相比,具有高密度和高体积热值等优点,具有重要的应用价值。本文首先从分子结构的角度阐述高密度燃料的特征及合成策略,然后综述了几类典型燃料的合成进展,包括通过加成、加氢、异构等反应合成多环烃类燃料和烷基金刚烃类燃料,通过环丙烷化和光化学等反应合成高张力燃料(环丙烷燃料、四环庚烷燃料和五环十一烷燃料),通过聚合、缩合、烷基化等反应合成高密度生物质燃料,通过纳米颗粒表面改性制备含有硼、铝、碳等固体颗粒的纳米悬浮燃料。同时,也总结了一些重要反应涉及的催化剂和量子化学机理,以及代表性燃料的性能参数等。最后,在此基础上对高密度燃料合成化学的发展趋势进行了展望。     

由生物质合成高密度喷气燃料

高密度喷气燃料是为先进航空航天飞行器而合成的燃料,以生物质基原料制备高密度喷气燃料符合国家可持续发展战略并可拓展燃料来源。本文综述了近年来由生物质基原料制备高密度喷气燃料的研究进展,燃料种类包括链烷烃、带支链的单环烷烃以及多环烷烃,燃料合成原料包括环酮（醇）、呋喃醛（醇）、芳香族含氧化合物（苯酚、苯甲醚、愈创木酚）、蒎烯等生物质及其平台化合物。发动机的推进性能高度依赖于所用燃料的性能,其中,最重要的性能是密度和低温性能。本文总结了典型燃料的性能以讨论分子结构的影响,增加燃料分子中环的个数会增加燃料密度但是也会导致低温性能不期望的变化,引入支链可改善低温性能。同时讨论了烷基化、缩合、加成、加氢脱氧等燃料合成反应涉及的催化剂、反应机理及其调控等关键因素,最后对由生物质基原料合成高密度喷气燃料的发展趋势进行了展望。本文将有助于探索及发展高密度燃料合成的方法及工艺。     

纳米金属燃料

应用纳米技术制备的纳米金属燃料已应用到社会生活和高科技领域。本文简单介绍它的热力学、制备方法和在各种领域中的应用。     

快速热裂解半焦作为粉煤锅炉及气化燃料的研究

用微分固定床反应器研究了云南先锋褐煤快速热裂解半焦和原煤的氧化和水蒸汽气化反应动力学,获得了动力学参数,并对动力学规律进行了讨论。还采用TG技术和自行设计的颗粒下落管式燃烧炉进一步探索了这种半焦作为粉煤锅炉燃料的可行性。     

稳定剂对COM燃料流动性的影响

ＣＯＭ(油煤混合燃料 )燃料是将煤粉分散在燃油中 ,加入稳定剂制得的一种流体燃料。由于使用方便、热值高、价格便宜。因此 ,作为廉价的石油替代品具有广阔的用途。ＣＯＭ燃料的质量指标主要有 :稳定性、流动性、碳含量的高低。前文已讨论了稳定剂结构对ＣＯＭ稳定性的影响[1] ,至于影响ＣＯＭ流动性的主要因素 ,至今文献报道的很少。中昭广、杉山浩等较详细地讨论了多支链高分子量非离子型表面活性剂对水煤浆 (ＣＷＳ)流动性的影响[2 ] 。他们的研究结果表明 :稳定剂的支链越多、分子量又较大时 ,ＣＷＳ的流动性就越好。本文以多元醇 -ＰＯ…     

DME洁净燃料技术的研究开发(英文)

二甲醚（ＤＭＥ）由于具有高的十六烷值,在燃烧过程中可降低氮氧化物等有害气体的排放,实现无烟燃烧,可作柴油发动机的洁净替代燃料,被认为是"二十一世纪的洁净燃料"。此外,ＤＭＥ液化气的物性与液化石油气相似,燃烧性能优于液化石油气（ＬＰＧ）,可作优良的民用洁净燃料。九十年代初,中国科学院山西煤炭化学研究所在国内首先提出以ＤＭＥ替代ＬＰＧ作洁净民用燃料。他们在实验室研究开发了氧化铝和分子筛两种类型的甲醇脱水制二甲醚催化剂,考察了工艺条件对反应的影响;确定了产品的分离、精制过程;对催化剂制备放大后进行了寿命试验并在１升催化剂的模试装置上进行了验证;提出了适合中、小规模生产的甲醇催化脱水制ＤＭＥ液化气工艺流程并进行了５００ｔ／ａ甲醇脱水制ＤＭＥ液化气的工业试验,甲醇单程转化率为～７８％,ＤＭＥ收率为～９８％：对所生产的ＤＭＥ液化气进行燃烧试验、环境卫生及卫生防疫检测,结果符合国内有关标准。     

美科学家研制光学燃料或可取代石油燃料

据国外媒体报道,美国堪萨斯州立大学科学家不久前研制出一种光学燃料,这种光学燃料可以取代石油燃料成为汽车的代用燃料。     

异辛烷/正庚烷/乙醇三组分燃料着火的化学动力学模型

提出一个包括异辛烷、正庚烷和乙醇的三组分燃料的着火动力学模型, 该机理包括50 个组分和193 个反应. 通过路径分析和灵敏度分析, 给出了基础燃料在高低温条件下的不同反应路径和影响氧化过程的重要基元反应. 该机理预测的单组分(异辛烷、正庚烷、乙醇)燃料、双组分基础燃料和三组分燃料的点火延迟时间与实验值有很高一致性. 本文机理包含较少的组分数与反应数, 因而可适用汽油掺烧乙醇的多维计算流体动力学(CFD)数值模拟.     

二氧化碳和丙烯直接合成甲基丙烯酸的NiPMo/TiO2催化剂的研究

用溶胶-凝胶法以磷钼酸(MPA)的镍盐溶液水解钛酸四丁酯制备了NiPMo/TiO2催化剂.使用ICP、 XRD、 TG-DTA、 IR、 TPD-MS和微反应技术研究了催化剂的化学组成、热稳定性、化学吸附性质和催化反应性能.杂多钼酸盐与TiO2通过O2-在TiO2表面发生了键合.在623 K下,杂多阴离子仍保持原有的Keggin结构.CO2在Lewis酸位Ni(Ⅱ)和Lewis碱位Ni-O-Mo的桥氧协同作用下生成CO2卧式吸附态Ni(Ⅱ)←O-(CO)←(O--Ni).丙烯有多种吸附态在催化剂上吸附.在563 K、 1 MPa和空速1500 h-1的反应条件下,丙烯的摩尔转化率为3.2%,产物MAA选择性为95%.     

Synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives

Different approaches for the synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives from simple amino acids have been investigated. A library of 33 precursors for the preparation of N-hydroxy pyrazinones was obtained in moderate to good yields.     

Toward new camptothecins. Part 6: Synthesis of crucial ketones and their use in Friedländer reaction

In the context of the preparation of camptothecin and luotonin A analogs, the synthesis of some key keto-precursors and their use in Friedländer condensation are described. This paper also focuses on the stability of these keto intermediates and emphasizes the major differences between indolizinones and pyrroloquinazolinones series. Noteworthy is also the report of some original structures isolated as by-products of some experiments.     

CoFe2O4自形成磁性液体场致结构化对磁化的影响

The Langevin paramagnetic theory can’t describe the relation between magnetization of ferrofluids and applied magnetic field. The structuralization of ferrofluids, which is considered the main influence factor of the magnetization, is regarded. The part of magnetization works is deposited when the structure is forming. This action influences the magnetization of ferrofluids directly or indirectly. On the base of the “compressing” model, the Langevin function that usually describes the magnetization of ferrofluid is modified, and a well-fitted curve is obtained. An equation of the relation between the equivalent volume fraction after being “compressed” and the intensity of magnetic field is discovered, which approximately describes the process of magnetization. The relation between the approximate initial susceptibility and the volume fraction can be obtained from modified formula.     

Highly regioselective Buchwald–Hartwig amination at C-2 of 2,4-dichloropyridine enabling a novel approach to 2,4-bisanilinopyridine (BAPyd) libraries

The highly regioselective Buchwald–Hartwig amination at C-2 of the cheap and readily accessible reagent, 2,4-dichloropyridine with a range of anilines and heterocyclic amines is described. This new methodology is robust and provides a facile access to 4-chloro-N-phenylpyridin-2-amines on 0.25 mol scale. These intermediates undergo a further Buchwald–Hartwig amination at higher temperature to enable rapid exploration of the chemical space at C-4 and to provide a library of 2,4-bisaminopyridines.     

KMnO4-mediated oxidative CN bond cleavage of tertiary amines: Synthesis of amides and sulfonamides

KMnO₄-mediated oxidative CN bond cleavage of tertiary amines producing secondary amine was introduced, which was trapped by electrophiles (acyl chloride and sulfonyl chloride) to form amides and sulfonamides. The reaction could take place at mild condition, tolerating a wide range of function groups and affording products in moderate to excellent yields.     

Chemistry of heterocyclic compounds at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences, over 50 years (Review)

The review contains a concise historical account and information on the most significant researches undertaken by the staff at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences on the Chemistry of Heterocyclic Compounds. Dedicated to Academician of the Russian Academy of Sciences B. A. Trofimov on his 70th jubilee. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1443–1502, October, 2008.     

A general and convenient synthesis of 4-(tosylmethyl)semicarbazones and their use in amidoalkylation of hydrogen,heteroatom, and carbon nucleophiles

A general synthesis of previously unknown semicarbazone-based α-amidoalkylating reagents, 4-(tosylmethyl)semicarbazones, has been developed. The synthesis involved three-component condensation of semicarbazones of aliphatic or aromatic aldehydes with the same or other aldehydes and p-toluenesulfinic acid. The scope and limitations of this reaction were investigated. The compounds obtained were demonstrated to be an efficient α-(4-semicarbazono)alkylating agents. They were reacted with H- (sodium borohydride), O- (sodium methylate), S- (sodium phenylthiolate), N- (pyrrolidine, sodium succinimide), P- (trialkyl phosphites), and C-nucleophiles (sodium diethyl malonate) to give the corresponding products of the tosyl group substitution, 4-substituted semicarbazones, including analogues of nitrofurazone. Among the prepared compounds tested in vitro for antibacterial and antifungal activity, three nitrofuryl-containing semicarbazones exhibited high biological activities with minimum inhibitory concentration (MIC) values of 8–32 μg/mL.     

Sulfur-directed metal-free and regiospecific methyl C(sp3)–H imidation of thioanisoles

Regiospecific and direct imidation of the methyl C(sp³)–H bond of thioanisoles is realized under mild and metal-free conditions with N-fluorobis(benzenesulfonyl)imide as an oxidant and nitrogen source. Proposed mechanism suggests that thionium ion intermediates and a Pummerer-type reaction are involved. The imidation has advantages such as high step-economy, excellent functionality tolerance, and regiospecificity, giving structurally diverse imidation products.     

Synthesis of novel chiral bidentate hydroxyalkyl-N-heterocyclic carbene ligands and their application in palladium-catalyzed Mizoroki–Heck couplings and asymmetric addition of diethylzinc to benzaldehyde

A small library of new chiral bidentate hydroxyalkyl-imidazolium salts 1 is conveniently synthesized on multi-gram scale from inexpensive and commercially available chiral pool amino acids. The corresponding carbenes, generated by deprotonation of imidazolium salts 1, in combination with palladium(II) chloride were tested in the Mizoroki–Heck coupling reaction. The most significant results in terms of yields and reactivities were achieved with low catalyst loading. The catalytic activities of these imidazolium salts were also investigated in the asymmetric addition of diethylzinc to benzaldehyde. The use of MgO nanoparticles as an additive in conjunction with these ligands played a crucial role in increasing the efficiency of these reactions.