福建无烟粉煤纸浆黑液富氧流化床催化气化研究

在实验室小型流化床反应器中研究了福建龙岩无烟粉煤纸浆黑液富氧催化气化的特性，考察了纸浆黑液催化剂添加量不同时氧体积分数变化对碳转化率、产气率、煤气组成与热值的影响。结果表明，纸浆黑液催化和富氧气体燃烧的双重作用明显地提高了煤的碳转化率和煤气有效组成；纸浆黑液中钠碱对煤焦气化的催化与对煤灰分中SiO2和Al2O3等氧化物的熔制反应同时发生并存在着竞争；纸浆黑液中钠碱对高温碳与气化剂之间多种反应表现出不同程度的促进。龙岩无烟粉煤在纸浆黑液富氧催化气化时适宜操作条件是氧的体积分数40％和蒸汽/富氧比为1.4kg/m3～2.0kg/m3。碳转化率94％、煤产气率为3.62m3/kg、煤气热值为7.33mJ/m3。     

黏胶废液对福建无烟煤水蒸气催化气化的动力学和补偿效应

采用黏胶废液为催化剂,对福建尤溪无烟粉煤在常压热分析仪中的水蒸气催化气化动力学进行了研究。在850℃～950℃测定了黏胶废液催化剂添加量（NaOH浓度为计算基准）从0～12%时的碳转化率随气化时间的变化,表明黏胶废液具有提高碳转化率和气化速率的作用,同时确定了该黏胶废液催化剂的加载饱和浓度。基此得出的尤溪无烟粉煤水蒸气催化气化反应动力学符合缩芯模型,并给出相应的动力学参数。进而分析表明,该催化气化过程存在明显的补偿效应,最后给出黏胶废液对尤溪无烟粉煤水蒸气催化气化包括补偿效应的动力学方程。     

高变质福建无烟煤连续流化床混合气催化气化

连续流化床（内径123mm、高1．2m）中,采用工业纯碱（碳酸钠）为催化剂进行了高变质程度无烟煤一福建永安煤（低挥发分k=5．47％、高灰Aad=29．45％）混合气（空气／水蒸气）催化气化的研究,考察了催化剂质量分数、气化温度、水汽比等操作参数的影响。实验结果表明,工业纯碱作为催化剂添加5％可使碳转化率增加3倍,实现了煤的高效转化;气化温度有明显催化气化促进作用,超过900℃时,流化床内易结渣。从同时满足高产气率及高煤气热值两个指标出发,在适宜操作条件（碳酸钠质量分数5％、850℃～880℃、适宜水汽比）下,产气率提高2倍,从无催化剂时的2．13m^3／kg～2．15m^3／kg提高到4．2m^3／kg～5．1m^3／kg;煤气热值提高5倍,从1．0MJ／m^3左右提高到5．0MJ／m^3;表明工业纯碱进行高变质福建无烟煤流化床混合气催化气化具有重要的工业应用价值和现实的开发意义。     

热重法福建无烟煤二氧化碳催化气化的研究

采用纸浆黑液为催化剂在一热重分析仪中及常压与750℃～950℃下进行了福建无烟煤二氧化碳催化气化的研究以给出催化剂浓度,即在不同3%、5%、8%、10% 钠黑液添加量时对碳转化率的影响。实验表明,在750℃～950℃催化剂浓度8%钠黑液添加量的催化活性比其他浓度更好。在反应控制条件下测定了三种福建高变质无烟煤的碳转化率与气化反应时间的关系。应用均相模型和缩芯模型分别关联了这三种煤的转化率与时间的关系并得出不同温度下的反应速率常数k,进而采用阿累尼乌斯方程 预测了实验所用三种煤的反应活化能Ea 和指前因子A。在适宜催化剂浓度8% 钠 黑液添加量时,其 Ea＝76.18kJ/mol～104.22kJ/mol明显小于无催化剂纯煤气化时的Ea＝150.93kJ/mol～185.44kJ/mol数值范围,这明显地表明纸浆黑液是一个廉价和有效的煤气化催化剂。     

Experimental study on catalytic hydrogasification of lignite

在加压固定床反应器中研究了碱金属K对褐煤加氢气化的催化作用,考察了温度、压力和催化剂添加量对褐煤加氢气化反应性能的影响.结果表明,碱金属K对褐煤加氢气化具有良好的催化效果,气化反应的碳转化率约为95％,产品气中甲烷的质量分数可达89％;升高温度、提高压力和增加催化剂添加量均能明显提高气化反应性能,催化剂的饱和添加量约为15％.利用扫描电子显微镜(SEM)和气体吸附/脱附分析,对不同催化剂添加量煤样的表面形态和孔结构进行分析,发现比表面积和孔容积随K添加量的增加先减少后增大.     

混合气气氛下纸浆黑液和钙混合催化剂的催化气化特性

采用热重法在单一和混合催化剂(即3%钙和5%钠-黑液单-催化剂及一种3%钙和5%钠-黑液混合催化剂),温度750℃～950℃及常压条件下对三种高变质无烟煤(福建龙岩、丰海和尤溪煤)研究了混合气气化过程中对碳转化率、气化反应速率及有害污染含硫气体相对量的催化效应.纸浆黑液和钙混合催化剂具有两者的的协同作用,在混合气气化过程中,3%钙和5%钠-黑液混合催化剂可极大地增加碳转化率和气化反应速率系由于该混合催化剂碱性表面化合物[-COM]、[-CO2M]及可交换的钙酚盐和羧酸钙[(-COO)2Ca]的存在加速了反应C 2CO2=2CO和C H2O→CO H2的结果,且这一催化作用比水蒸气气化过程更强烈.通过添加碳酸钙于纸浆黑液催化剂的气化方法,除去促进催化剂功效和增加碳转化率以外,也可达到有效的脱硫作用,但是这一较好的操作温度需低于900℃.     

福建无烟粉煤流化床混合气催化气化表观动力学的研究

在一模试流化床中,首次报道了福建劣质无烟粉煤（挥发分〈５％）采用工业副产碱盐为主制备的复合催化剂进行混合气催化气化的结果,指出这一复合催化剂适宜的添加饱和度为１０％;表观动力学实验表明在该添加饱和度下,使反应表观活化能由无催化剂时的Ｅａ＝７６．０３ｋＪ／ｍｏｌ降为Ｅａ＝４５．８３ｋＪ／ｍｏｌ（几乎降低了４０％）,并且在气化温度８５０℃条件下,其表观反应速率常数比无催化剂时提高２．７倍;在气化温度８５０－９００℃,催化剂浓度１０％的适宜操作范围,可获得产气率Ｖ＝３．７７－３．５８ｍ＾３／ｋｇ（１ｋｇ煤）,煤气热值ＱＬＨＶ＝５．３１＝６．０３ＭＪ／ｍ＾３与冷煤气效率η＝７９．７２＝８５．７３％的良好结果,这对劣质无烟粉煤催化气化生产燃料气与化工副产碱盐制取廉价催化的工业化实践具有重要的应用价值与可操作的现实意义。     

褐煤催化加氢气化实验研究

在加压固定床反应器中研究了碱金属K对褐煤加氢气化的催化作用,考察了温度、压力和催化剂添加量对褐煤加氢气化反应性能的影响。结果表明,碱金属K对褐煤加氢气化具有良好的催化效果,气化反应的碳转化率约为95%,产品气中甲烷的质量分数可达89%;升高温度、提高压力和增加催化剂添加量均能明显提高气化反应性能,催化剂的饱和添加量约为15%。利用扫描电子显微镜(SEM)和气体吸附/脱附分析,对不同催化剂添加量煤样的表面形态和孔结构进行分析,发现比表面积和孔容积随K添加量的增加先减少后增大。     

低活性无烟煤固定床二氧化碳催化气化反应动力学研究

在内径18 mm的固定床反应器中研究了福建低活性无烟煤二氧化碳催化气化反应动力学。考察了消除内外扩散影响的实验条件。在750 ℃～907 ℃，以碳酸钠为催化剂分别测定了永安丰海筛无烟煤、永安加福筛无烟煤和永定无烟煤的转化率与时间的关系；以碳酸钾及纸浆黑液为催化剂测定了永定无烟煤的转化率与时间的关系。永安加福筛无烟煤采用均相一级反应模型及未反应缩芯模型进行拟合，得出气化反应速率常数、反应活化能和指前因子，与热天平的实验结果进行比较，固定床反应速率常数明显变大，活化能和指前因子也大，是由于固定床中有较高的二氧化碳到煤粒表面的传递速率和较高的升温速率所致。     

福建无烟粉煤催化气化

报导了福建无烟粉煤在碱性催化剂作用下的催化气化工作进展,在小型Φ１８ｍｍ固定床与Φ２０ｍｍ流化床中,进行了水蒸气气化、混合气（空气／水蒸气）气化,采用复合１催化剂添加量８％,８５０～９００℃及流化床条件下,即可获得产气率Ｖ＞３ｍ３／ｋｇ煤（无催化剂时,Ｖ＜１．６ｍ３／ｋｇ煤）及煤气热值ＱＬＶＨ＞９ＭＪ／ｍ３（水蒸气气化）与＞６ＭＪ／ｍ３（混合气气化）的结果,并与无烟煤气化的工业装置进行了比较,这为无烟粉煤有效转化的工业化试验提供了最重要的依据     

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%.     

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.     

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.     

Selective syntheses of 2H-1,3-oxazines and 1H-pyrrol-3(2H)-ones via temperature-dependent Rh(II)-carbenoid-mediated 2H-azirine-ring expansion

The Rh(II)-catalyzed reaction of 2-carbonyl-substituted 2H-azirines with ethyl 2-cyano-2-diazoacetate or 2-diazo-3,3,3-trifluoropropionate provides an easy access to 2H-1,3-oxazines and 1H-pyrrol-3(2H)-ones. These compounds can be selectively prepared from the same starting material using temperature as the only varied parameter. The 2-azabuta-1,3-diene intermediate, a common precursor for both heterocyclic products, isomerizes into 2H-1,3-oxazine under kinetic control, while 1H-pyrrol-3(2H)-one is the sole product of the reaction at elevated temperatures. According to DFT-calculations a one-atom oxazine ring contraction involving ring-opening to a 2-azabuta-1,3-diene intermediate, followed by a 1,5- and 1,2-prototropic shift leads to the consecutive formation of imidoylketene and azomethine ylide, which then further undergo cyclization to the pyrrole derivative.     

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.