煤热解转化排放物对环境和健康的影响

讨论了煤热解转化过程中主要排放物对环境和健康的影响,诸如CS2、COS、H2S、NH3、HCN和BTX等排放物,其毒性对植物产生潜在的影响。文中列出中国发表的环境优先污染物“黑名单”。癌症是从事煤热解转化工厂工人的主要隐患。多环芳香碳氢化合物和一些有机化合物,如芳胺类、亚硝胺类和苯系化合物教师主要的潜在致癌化合物,文中讨论了其生成、分子结构及其致癌活性,并举职业危害为例证。     

由煤制取芳烃化合物的研究进展

综述了国内外由煤制取芳烃化合物的三种思路：一是通过将煤直接进行液化获取,或者先将煤液化再从产物中获得芳烃化合物;二是先对煤进行溶剂抽提,然后对产物分类加工制取芳烃化合物;三是将煤进行氧化处理来获得高价值的芳烃化合物。分析了由煤制取芳烃化合物的所面临的产物分离困难、污染环境等问题,并指出了今后需要在分离工艺和催化剂以及如何实现煤的定向转化等方面进行重点研究。     

Low severity coal conversion by an electroreduction route

The feasibility of electrochemical conversion of coal to low molecular weight hydrocarbons through an electroreduction route was demonstrated for the first time by Energy Research Corporation. This electroreduction process involves reaction of hydrogen ions with the coal surface leading to hydrogenation of coal molecules at low severity operating conditions. This process produced lower molecular weight hydrocarbons, similar to those obtained in conventional liquefaction by chemical reaction. In this proof-of-concept study, at low severity conditions (101 kPa and 250°C), the electroreduction behaviour of five coals as well as a charcoal and a devolatilized coal was investigated. The liquid product compositions (at room temperature) were dependent upon the parent coal and comprised a variety of aliphatic and aromatic compounds with phenolic aromatic compounds predominating. These compounds were found to fall in a low (100–400) molecular weight range which corresponds to oils (<400). The effects of the process variables were also investigated. Coal type was found to be the most important parameter affecting the product spectrum. The volatile components in the coal appeared to play an important role in controlling electroreduction products. No clear-cut relationship was established between temperature, volatile contents, structural origin (maceral composition), or applied potential and product quantity or composition.     

煤沥青加氢的有效途径

针对煤焦油沥青高芳香度、高缩合度和高杂原子含量的特点,在用作制备高性能沥青基炭纤维及其它高级炭材料的原料时,须对煤沥青进行改性处理。详细介绍了煤沥青加氢还原的有效途径,包括Birch还原法、溶剂加氢法、催化氢化法、醇类加氢法和电化学加氢法等,并对加氢作用机理及其应用前景作了详细评述。     

煤直接液化研究评述

比较了中国与国际基础研究水平的差距,对主要的新老工艺进行了分类和比较,发现成功的液化工艺都符合煤分子结构的特点。高温快速液化是一种基于煤分子结构特殊性的直接液化方案,在理论上提供了实现最高液化效率和最低液化成本的可能性,联产芳香族化合物和燃料油,开辟了一个新的研究方向。     

电化学法在煤炭预脱硫中的应用

脱硫是煤炭工业和电力工业中煤炭的洁净燃烧和加工技术的研究重点,目前有燃烧过程中脱硫和烟气脱硫,均为燃烧后的脱硫技术。近年来,多种新型的燃烧前脱硫技术涌现,电化学脱硫法为其中之一,通过电氧化作用将煤炭中的低价态无机硫和有机硫氧化为硫酸盐硫,达到脱硫的目的。本文综述了该技术的几种典型形式、脱硫原理、研究进展及其在实际煤炭处理中的应用情况,展望了电化学技术在前置煤脱硫中的发展方向和应用前景。     

煤及其模型化合物的电化学还原

本文介绍了有机物电化学还原的基本原理，讨论了煤及其模型化合物的电化学还原的研究现状，阐述了有机物电化学还原的溶剂化电子理论和电子转移理论，展望了煤电化学还原在我国的发展前景。     

东胜煤有机溶剂分级萃取物的GC/MS分析研究

用气相色谱/质谱联用技术测定了东胜煤有机溶剂萃取物的化学组成，对其化学成分及化合物分布特征进行了研究。结果表明，萃取物主要由烷烃，芳烃和衍生物三种成分组成，其中烷烃主要是正构烷烃；芳烃是萃取物最主要的成分，以萘系，蒽系，菲系，芴系和芘系的0-3烷基取代物为主，和几种高丰度的5-6环稠环芳烃；衍生物主要是多环芳香族含硫化合物，还有一种煤中首次发现的4-氨基-9-芴酮，含氧化合物仅检测到几种。     

Effect of coal minerals on the thermal treatment of aromatic ethers and carbonyl compounds

To elucidate the effect of mineral matter in coal on coal liquefaction, the thermal decomposition of some model compounds of coal structure, aromatic ethers and carbonyl compounds, has been carried out in tetralin solvent and in the presence of coal ash obtained by low temperature combustion. The conversion of benzyl phenyl ether and dibenzyl ether was considerably enhanced; alkylated products such as benzyltetralin were obtained. The conversion of phenoxyphenanthrene and phenoxynaphthalene also was increased to some extent in the presence of coal ash. These effects can be attributed to the acidic components of coal minerals, because silica-alumina has shown the same effect, which is suppressed by quinoline. The addition of coal ash increases the yield of hydrocarbon from the corresponding aromatic carbonyl compounds by reduction. This effect is attributable to iron sulphide.     

主链型芳香族聚合物的研究进展

主链型芳香族聚合物具有热稳定性高，化学稳定性好、质地轻且牢固以及良好的加工成型性等优点，然而芳香族聚合物的应用受到芳香单体制备的限制，煤中富含合成聚合物所需的芳香单体。因此，由煤制“特异化学品”应当成为煤化工未来发展的重要方向，这为煤的非燃料利用提供了新的途径。     

甘肃窑街煤的两级溶剂萃取及萃取物分析

采用正己烷和甲醇两种溶剂对甘肃窑街煤进行索氏分级分次萃取,研究了一定时间段内该煤样萃取率的变化规律,并采用FTIR和GC对各次萃取物进行分析,研究可检测化合物的组成、结构和溶出规律。结果表明：该煤样的两级累积萃取率与累积萃取时间均服从一定的函数关系。小分子化合物的溶出过程符合秦志宏提出的＂前期溶出的主要为游离态小分子,中期开始部分溶出的主要为微孔嵌入态小分子,后期溶出的主要为网络嵌入态小分子＂的溶出规律;小分子化合物的溶出具有连续性、时序性、特殊性等特点。第一级正己烷萃取物中,脂肪族化合物与含羰基、醇、酚、醚等的含氧化合物占据重要地位,芳香族化合物含量较少且主要为单核芳香族化合物,第二级甲醇萃取物中则主要是聚合度较高的芳香族化合物,含氧基团主要为醌基和芳香酮。     

真菌降解光-氧氧化内蒙古胜利褐煤产物分析

为掌握黄孢原毛平革菌降解光-氧氧化内蒙古胜利褐煤固体残渣的成分、结构和热稳定性的变化规律,以及降解液的主要物质构成,为降解工艺的改进以及降解产物的分离和利用提供参考,对降解所得的固体和液体产物进行了检测分析。结果表明:光-氧氧化煤被黄孢原毛平革菌作用后,煤残渣的水分、灰分和挥发分的质量分数均增加,固定碳的质量分数降低,由元素分析可见,煤残渣的O,N和H元素质量分数增加,C和S元素质量分数降低;煤残渣的富氢度增大、总脂芳比增大、富氧度增加,说明煤结构中的含O和H基团增加,芳环结构被降解而减少;煤残渣的稳定性比光-氧氧化煤的稳定性差,总失重率增大,进而说明光-氧氧化煤在黄孢原毛平革菌的作用下发生了降解;氧化煤在黄孢原毛平革菌的作用下,发生了明显的降解,降解液中含有丰富的芳香化合物,而培养基溶煤产物中芳香化合物的含量较少;降解液中含有丰富的化合物,主要为酯、烷烃和杂环化合物等。     

Ab initio determination of dark structures in radiationless transitions for aromatic carbonyl compounds

Mechanistic photodissociation of a polyatomic molecule has long been regarded as an intellectually challenging area of chemical physics, the results of which are relevant to atmospheric chemistry, biological systems, and many application fields. Carbonyl compounds play a unique role in the development of our understanding of the spectroscopy, photochemistry, and photophysics of polyatomic molecules and their photodissociation has been the subject of numerous studies over many decades. Upon irradiation, a molecule can undergo internal conversion (IC) and intersystem crossing (ISC) processes, besides photochemical and other photophysical processes. Transient intermediates formed in the IC and ISC radiationless processes, which are termed "dark", are not amenable to detection by conventional light absorption or emission. However, these dark intermediates play critical roles in IC and ISC processes and thus are essential to understanding mechanistic photochemistry of a polyatomic molecule. We have applied the multiconfiguration complete active space self-consistent field (CASSCF) method to determine the dark transient structures involved in radiationless processes for acetophenone and the related aromatic carbonyl compounds. The electronic and geometric structures predicted for the dark states are in a good agreement with those determined by ultrafast electron diffraction experiments. Intersection structure of different electronic states provides a very efficient "funnel" for the IC or ISC process. However, experimental determination of the intersection structure involved in radiationless transitions of a polyatomic molecule is impossible at present. We have discovered a minimum energy crossing point among the three potential energy surfaces (S1, T1, and T2) that appears to be common to a wide variety of aromatic carbonyl compounds with a constant structure. This new type of crossing point holds the key to understanding much about radiationless processes after photoexcitation of aromatic carbonyl compounds. The importance of ab initio determination of transient structures in the photodissociation dynamics has been demonstrated for the case of the aromatic carbonyl compounds. In addition, the detailed knowledge of mechanistic photochemistry for aromatic carbonyl compounds forms the basis for further investigating photodissociation dynamics of a polyatomic molecule.     

煤制芳香化合物的探讨

综述了国内外两种煤制芳香化学品技术的研究现状,一种为煤热解制芳香化学品,包括煤快速热解和煤热解物定向催化转化技术;另一种为煤加氢液化制芳香化学品技术。今后在加强煤制芳香化学品研究的同时,还应加强对煤液化产品分离技术的研究。     

Thermal Dissolution of GZh Coal in Different Paste-Forming Agents

The thermal dissolution of grade 1GZh coal in different commercial paste-forming agents—coking tar, an anthracene fraction of coking tar, heavy semicoking tar, and petroleum gas oil—was studied. It was established that the presence of polycondensed molecules with a low degree of substitution of aromatic rings and compounds with hydrogen-donor and solvating activity in the solvent facilitated the efficient occurrence of the thermal dissolution of coal at a low temperature of 380°C. The highest yields of soluble pitch-like product (78–85%) were obtained in the processes performed in the anthracene fraction of coking tar and coking tar.     

Synthesis and Characterization of a Heteroleptic Ru(II) Complex of Phenanthroline Containing Oligo-Anthracenyl Carboxylic Acid Moieties

In an effort to develop new ruthenium(II) complexes, this work describes the design, synthesis and characterization of a ruthenium(II) functionalized phenanthroline complex with extended π-conjugation. The ligand were L(1) (4,7-bis(2,3-dimethylacrylic acid)-1,10-phenanthroline), synthesized by a direct aromatic substitution reaction, and L(2) (4,7-bis(trianthracenyl-2,3-dimethylacrylic acid)-1,10-phenanthroline), which was synthesized by the dehalogenation of halogenated aromatic compounds using a zero-valent palladium cross-catalyzed reaction in the absence of magnesium-diene complexes and/or cyclooctadienyl nickel (0) catalysts to generate a new carbon-carbon bond (C-C bond) polymerized hydrocarbon units. The ruthenium complex [RuL(1)L(2)(NCS)(2)] showed improved photophysical properties (red-shifted metal-to-ligand charge-transfer transition absorptions and enhanced molar extinction coefficients), luminescence and interesting electrochemical properties. Cyclic and square wave voltammetry revealed five major redox processes. The number of electron(s) transferred by the ruthenium complex was determined by chronocoulometry in each case. The results show that processes I, II and III are multi-electron transfer reactions while processes IV and V involved one-electron transfer reaction. The photophysical property of the complex makes it a promising candidate in the design of chemosensors and photosensitizers, while its redox-active nature makes the complex a potential mediator of electron transfer in photochemical processes.     

Action of aerobic microorganisms on the macromolecular fraction of lignite

Microorganisms able to utilize untreated Morwell lignite and the fraction insoluble in tetrahydrofuran (THF) as their sole carbon and energy source were isolated by enrichment from coal exposures in Victoria. Most isolates can use a variety of long-chain aliphatic and single-ring aromatic compounds but not more complex aromatic substrates, indicating that their growth on whole lignite is due to use of the low-molecular-weight compounds constituting the mobile phase and bound aliphatic moieties which can be cleaved from the macromolecular coal matrix. Organisms able to utilize THF-insoluble lignite are less abundant than those able to use whole coal. Amongst these are isolates able to utilize diaryl compounds and anthraquinones, compounds with structures analogous to components of the macromolecular matrix of lignite. Two fungal isolates, CJ2 and CJ4, were found to alter the elution profile of alkali-solubilized Morwell lignite in size-exclusion chromatography. When incubated with these fungi in growth medium, the apparent molecular weight of the lignite increased by 10000. However, when polyvalent metal ions were removed, the apparent molecular weight was lower than that of uninoculated coal, indicating attack on the macromolecular matrix of the lignite.     

The electrochemistry of coal and coal liquids. II. Cyclic voltammetry of H-coal liquids

The electrochemical behaviour of three H-coal liquids, ASO, ASB and VSO, has been characterized by cyclic voltammetry at glassy carbon electrodes. Voltammograms obtained for the three intact coal liquids in methanol/water solution showed a broad, irreversible anodic wave at +0.5 V versus saturated calomel electrode. In order to determine which components of the coal liquids were primarily responsible for the observed electrochemistry, two column chromatography procedures were employed to separate the ASO, ASB and VSO into several fractions on the basis of functional group content. Subsequent cyclic voltammograms recorded for the resulting chromatographic fractions exhibited substantial anodic current only for the fractions designated as containing predominantly aromatic, polar aromatic/N-heterocyclic, and monophenolic components. Of these, the phenolic fractions appeared to account largely for the +0.5 V wave observed for the intact coal liquids. Chromatographic fractions corresponding to other functional groups exhibited only slight electrochemical activity, or none at all, under the conditions employed.     

Effects of Lewis acid catalysts on the hydrogenation and cracking of three-ring aromatic and hydroaromatic structures related to coal

Little is known about the hydrogenation and cracking of fused aromatic nuclei during the liquefaction of coal under the influence of Lewis acid catalysts. This study was conducted to establish the effects of catalyst acidity on the activity and selectivity of Lewis acid catalysts, the sources of hydrogen involved in hydrogenation and cracking, and the relationships between reactant structure and reactivity. Three-ring aromatic and hydroaromatic compounds were used to simulate some of the structural units present in coal. The catalysts examined were ZnCl₂ and AlCl₃. It has been established that the rates of both processes are strongly influenced by the Brönsted acidity of the active catalyst, e.g. H⁺ (MX_nY)^?, and the Brönsted basicity of the aromatic portions of the reactant. The source of the hydrogen used for hydrogenation depends on the choice of catalyst. In the presence of AlCl₃, Scholl condensation of aromatic nuclei serves as the principal source of hydrogen. Molecular hydrogen is used exclusively, however, when hydrogenation is catalysed by ZnCl₂. The formation of reaction products and the trends in reactant reactivity are discussed on the basis of cationic mechanisms. The results of this study contribute to an understanding of the processes which occur during the liquefaction of coal using ZnCl₂ or AlCl₃.