【作者】 杨志远；

【导师】 周安宁；

【作者基本信息】 西安科技大学 ， 矿业工程， 2006， 博士

【摘要】 在西部大开发中，如何对煤炭资源进行高效、洁净、高附加值转化利用，是目前迫切需要解决的战略问题。随着人类对环境的日益重视和“白色污染”的加剧，可降解材料的研究开发已成为世界瞩目的热点问题之一。煤基可降解材料的生产是实现煤炭非燃料高附加值利用和解决“白色污染”的有效途径，该材料降解周期精确控制的技术关键是阐明煤的光催化氧化降解反应性及动力学。 本文引入分形维数定量表征了煤超细粉体颗粒分布均匀程度和颗粒表面的光滑程度。超细煤粉体的FTIR图谱研究表明：随煤变质程度的提高，煤中含氧官能团减少，缩合程度增大，脂肪氢（Al-CH）含量下降和芳香氢（Ar-CH）的含量上升；羟基-羟基氢键、环羟基氢键呈减少趋势，而羟基-醚氢键呈增加趋势。 将煤结构与光化学理论相结合，采用分形分析及现代测试方法，在自行设计的紫外光光催化氧化反应装置上，首次系统研究了煤低温光催化氧化反应性及影响因素。研究发现：反应温度、氧气流量、光强度及煤粉粒度是影响煤光催化氧化反应性的重要外部因素；煤的光催化氧化反应分为三个阶段；低变质程度煤具有较高的光催化氧化反应活性；煤低温光催化氧化的气体产物组成为CO₂、CO、CH₄和C₂H₄等，进而揭示出在光催化氧化反应中存在煤大分子烷基侧链的NorrishⅡ型光分解反应。 通过超细粉碎-浮沉试验联合方法分离获得了煤的不同密度级组分，发现神府长焰煤的密度级组分主要富集在1.350-1.375g／cm³（D2），1.375-1.400g／cm³（D3）及＞1.400g／cm³（D4）三个密度级别中。首次通过不同密度级煤组分的结构和光催化氧化特性研究，揭示了煤的结构和光催化氧化反应性的关系。不同密度级煤组分的光催化氧化反应活性顺序为：D2＞D3＞D4。腐植酸产率随着光催化氧化时间的增加而增大，各密度级煤组分光催化氧化产物的腐植酸产率大小为：D2＞D3＞D4。在煤光催化氧化过程，存在煤大分子分解与交联两类竞争反应。煤光催化氧化后，煤不同密度组分的表面官能团结构的变化规律不同。 对比研究了原煤及其不同密度级组分的光催化氧化反应性与热氧化性的差异，结果表明：煤光催化氧化的反应活性高于其热氧化的反应活性。光氧化煤的腐植酸产率远高更多还原

【Abstract】 How to utilize coal resource with high efficiency, cleanliness and high-attached value is a strategic problem in grand development of West China. Due to "white pollution" becoming more and more serious and human focusing more and more on environment protection, the R & D of degradable materials are becoming a hotspot. The preparation of coal-based degradable materials is one effective way of coal in non-fuel utilization and high-attached value processing transformation. The technique key problem of accurate control in the degraded periods of the coal-based degradable materials is to clarify the reactivity and kinetics in coal photo-catalytic oxidation.In this paper, the grades of ultra-fine coal powder’s uniformity and coal granular surface morphology were characterized by the fractal dimensions. The functional groups of ultra-fine coal powder were studied by Fourier Transform Infrared spectroscopy (FTIR) and curve-fitting analysis. The results showed that oxygen-containing functional groups and content of aliphatic hydrogen (Al-CH) decreased, whereas the degree of ring condensation and content of aromatic hydrogen (Ar-CH) increased with increasing coal rank. Meanwhile, main hydrogen bonds in coal structure were OH-OH, cyclic OH tetramers and OH-ether O. With increasing coal rank, OH-OH and cyclic OH tetramers reduce, but OH-ether increases.The reactivity and their affecting factors of different rank coals in photo-catalytic oxidation were firstly systemically studied in a self-made photo-catalytic oxidation reactor on the basis of the combination of coal structure and photochemistry in theory, fractal analysis and modern characteristic methods. The experimental results indicated that the temperature, rate of oxygen flow, ultraviolet radiation intensity and coal particle’s size were important exterior factors in coal photo-catalytic oxidation, the reaction procedure of coal photo-catalytic oxidation could be divided into three periods. Low-rank coal has higher activity than high-rank coal in photo-catalytic oxidation. It can be deduced that there is the photolysis reaction of Norrish Ⅱ of coal macromolecule in photo- catalytic oxidation because更多还原