【作者】 贾建波；

【导师】 谢克昌； 曾凡桂；

【作者基本信息】 太原理工大学 ， 化学工程与技术， 2010， 博士

【摘要】 随着我国可持续发展进程的加速,西部作为我国战略纵深的地位日益受到重视。西部煤炭资源占我国煤炭储量的40%,所以以西部煤炭资源为原料,生产多元化、科技含量高和附加值高的产品将是西部煤炭利用的合理方式。因此有针对性的对具有弱还原性质的西部煤进行煤化学基础研究和热转化技术基础研究,将对目前和今后西部煤炭资源的高效和洁净化利用都有重要的意义。本文以西部神东煤作为研究对象,利用浮沉离心法得到了其镜质组显微组分（SV）,利用固体¹³C CP/MAS NMR、计算机辅助分子设计（CAMD）、热重质谱（TG-MS）和分子模拟技术对SV结构特征和热解产物甲烷的生成机理进行了系统的研究,主要内容如下:1、采用固体¹³C CP/MAS NMR测试技术对SV的结构特征进行了分析,结果表明,SV的芳香结构单元主要是以缩合程度为2的萘的结构为主,其余芳香结构单元则主要是苯环和含有杂原子的芳香杂环。2、基于¹³C CP/MAS NMR测试结果并结合SV的元素分析和XPS分析结果,构建了SV的初始化学结构模型,利用ACD/CNMR preditor软件对SV的初始化学结构模型¹³C NMR谱进行了模拟,根据模拟谱和实验谱的对比结果,对SV的初始化学结构模型进行了修正,得到了和实验结果拟合较好的SV化学结构模型。3、采用分子模拟（MM和MD）对SV模型能量最小化几何构型、弛豫过程和热处理下模型结构变化的可逆性进行了模拟,结果表明:由SV结构模型测得的微晶结构参数（d002,La,Lc） 3.83 （?）, 12.6 （?）和8.09 （?）和由XRD测得的实验值3.85 （?）, 12.3 （?）和8.52 （?）基本一致;在煤的大分子结构中起到稳定的凝聚整个大分子骨架的力主要来自于结构中的非成键能,而非成键能主要以范德华能为主;非成键能中的氢键能则主要来自于分子间的相互作用;结构模型中芳香层片之间以近似平行的方式排列,SV模型的密度模拟值为1.13g·cm^-3。弛豫过程模拟结果显示,温度升高到623 K时其结构发生了显著的变化;由温度引起的SV模型在结构上的变化是不可逆的。4、利用量子化学半经验方法（AM1）对SV结构模型的研究结果表明:醚键中和脂肪碳原子相连的C-O键、交联程度比较高的C-C以及和羰基碳原子相连的C-C键的活性比较高,在热解过程中容易发生断裂;SV结构模型中N、O及边缘甲基C原子都有较多的负电荷,而结构中的芳香碳原子所带电荷较少。5、在利用量子化学半经验方法（AM1）对SV和SI结构和反应活性分析基础上,对SV和SI的热解反应过程进行了描述。对于SV来说,初次裂解主要发生在煤结构中交联程度比较高的位置以及和羰基碳原子相连的C-C键;对于SI来说初次裂解主要发生在煤结构中和芳碳相连的β位C-C键及和羰基碳原子相连的C-C键。6、通过量子化学计算和TG-MS实验相结合的方法对SV热解产物甲烷的生成机理进行了系统分析,结果表明:甲烷的生成包含8种反应类型。（1）处于200℃左右的反应,主是煤中吸附甲烷的物理脱附;（2）处于300℃左右的反应,主要是甲氧基和部分β位脂甲基的脱除反应;（3）处于400℃左右的反应,主要是煤的大分子结构在解聚和分解反应中生成的自由基中间体通过β位裂解反应脱除脂甲基的反应;（4）处于460℃左右的反应,主要是煤结构中β位脂甲基的脱除反应;（5）和（6）是处于500℃-700℃之间的反应,该温度区间的前半段是煤结构本身自有的芳甲基和在400℃左右生成的芳甲基在氢自由基作用下的脱除及类似于1-甲基茚满结构的β位脂甲基的脱除反应,后半段则主要是煤结构在芳构化作用中生成的芳甲基在氢自由作用下的脱除反应;（7）处于800℃左右的反应是煤在经过前期热解后残留的芳甲基的直接脱除反应;（8）处于900℃-1000℃之间的反应,是煤热解过程中生成的H2和煤缩聚反应生成的类石墨结构活性位的反应。更多还原

【Abstract】 With the development of sustainable development strategy in China, west China playing a role of the strategic depth has been increasingly concerned. Coal reserve of the west China accounts for 40% of it in China. As a result, taking the Western coal as material, the product with diversification, high technological content and high added value will be a reasonable way to make use of the Western coal. Basic research on coal chemistry and thermal conversion technology of Western coal with weak reduction properties have important significance for high efficient and clean burning at present and in the future.Taking Shendong coal from west China as the research object, sink-float centrifugation was used to get the vitrinite. ¹³C CP/MAS NMR, computer assistant molecular design （CAMD）, thermal gravimetry–mass spectrum （TG-MS） and molecular simulation were used to study the structural characteristics of SV and formation mechanism of methane in the pyrolysis products, main content as follow:1. ¹³C CP/MAS NMR was used to study the structural characteristics of SV. The result showed that aromatic structure units were dominated by naphthalene including two rings. Furthermore, benzene rings and heterocyclic aromatic containing heteroatom were the predominant in the other aromatic structure units.2. Based on the test results of ¹³C CP/MAS NMR and ultimate analysis of SV combined with XPS analysis results, initial chemical structure model of SV was constructed. ACD/CNMR preditor software was used to simulate the ¹³C NMR spectra of initial chemical structure model. According to the comparison results of simulation spectrum with experimental spectra, initial chemical structure model of SV was modified. Furthermore, chemical structure model of SV was in good agreement with the results of experiments.3. Molecular Simulation （MM and MD） was adopted to simulate the minimization geometry of SV model, relaxation process and reversibility of model structure changing after heat- treatment. It is showed that structural parameters （d002= 3.83 （?）, La=12.6 （?） and Lc =8.09 （?）） of SV structural model was basically identical with experimental data （d002=3.85 （?）, La=12.3 （?） and Lc = 8.52） of XRD. Force condensing the whole macromolecule framework in the coal macromolecule is mainly from non-bonding energy, while the non-bonding energy is dominated by van der Waals energy. Hydrogen bond in the non-bonding energy was mainly caused by molecular interaction. Aromatic lamella of structure model were almost in parallel permutation, and simulation value of SV model density was 1.13 g·cm-3. In the simulation results of relaxation process, the structure changed distinctly when the temperature reached 623 K. SV model structure caused from temperature changing is irreversible.4. The model structure for SV calculated by semi empirical method（AM1） suggested that C-O bond between ether bond and aromatic carbon, C-C with highcrosslinking degree and C-C bond linked with carbonyl carbon are highly active, which break easily in the pyrolysis process. In SV structure model, there were more negative charge in the N, O and edge C, while there were less charge in structural aromatic carbon.5. Based on the semi empirical method and reactivity analysis for SV and SI , in the SV pyrolysis process, primary cracking located in high crosslinking degree of coal structure and C-C bond linked with carbonyl carbon; in the SI pyrolysis process, primary cracking located inβsite C-C bond linked with aromatic carbon and C-C bond linked with carbonyl carbon.6. By means of quantum chemistry calculation combined with TG-MS, systematical analysis on formation mechanism of methane in the SV pyrolysis products indicate that there are 8 reaction types during methane generation. （1） At about 200℃. Physical desorption of adsorptive methane in coal; （2） At about 300℃. Deprotective reactions for methoxy and partial adeps- methyl ofβsite; （3） At about 400℃. Removal adeps- methyl for free radical intermediates which formed during depolymerization and decomposition of coal macromolecular structure byβsite cracking; （4） At about 460℃. Removal from methyl ofβsite in coal structure; （5） and （6） Between 500-700℃, on hydrogen free-radical. In front half part, removal for aryl-methyl in the coal structure of their own and formed at 400℃, and removal ofβsite adeps- methyl similar with 1-hexamethylindane structure; in bottom half, removal of aryl-methyl formed in the aromatization; （7） At 800℃. Direct removal of residual aryl-methyl after previous coal pyrolysis; （8） Between 900-1000℃. Reactions between H2 from pyrolysis and active sites of graphite-like structure from coal condensation reaction.更多还原