【作者】 侯锦秀；

【导师】 张子敏； 孔留安；

【作者基本信息】 河南理工大学 ， 安全技术及工程， 2009， 硕士

【摘要】 论文基于“煤结构决定煤的性质”这一学术思想,在研究煤的结构和演化特征的基础上,从煤的微观结构来研究煤的瓦斯吸附、放散特性。以共生煤层的原生结构煤与构造煤的对比分析为主线,采用索氏溶剂萃取法、质谱/色谱联用等温吸附分析技术等分析手段,研究了煤的大分子结构与演化特征和构造煤中低分子化合物的赋存形式和起源以及构造煤溶剂萃取的动力学特征,分析了不同煤岩组分煤的吸附特征,不同粒度、不同破坏程度煤的瓦斯放散特征,讨论了煤结构和组成,探讨了溶剂萃取对煤与瓦斯吸附、放散特征的影响及其作用机理。并在煤粒瓦斯扩散理论及模型的基础上构建了构造煤煤粒瓦斯放散模型。研究结果表明:(1)构造煤的反射率比原生结构煤大,构造煤较原生结构煤稠环、碳原子数量多,各向异性大;(2)通过煤溶剂萃取动力学分析可知,萃取过程可分两个阶段,第一阶段速率比第二阶段萃取速率要大一个数量级。推测煤中低分子质化合物有游离态、吸附态和共溶态三种存在形式,游离态和吸附态易被萃取,而共溶态不易被萃取。所研究的煤中可溶低分子化合物有两种来源:一是原生的,它来源于成煤母质,二是后生的,源于成煤过程中生成的降解产物。构造煤氯仿萃取率比原生结构煤的大得多,多达两倍多,表明构造煤的形成过程中,生成并保存了大量的可溶低分子化合物;(3)与原生结构煤相比,构造煤的饱和烃中重质组分相对含量明显增多,并检测到原生结构煤中所不存在的的两个C14二环倍半萜烷和三个C15二环倍半萜烷异构体,而芳烃化合物的结构稳定,不同破坏类型煤的主要芳烃化合物除了相对数量关系变化之外,在种属构成上有着明显的相似性;(4)水分平衡条件下煤吸附甲烷能力随煤阶的增加而呈现三段式变化关系,煤的吸附量主要受控于煤化作用过程中煤的亲甲烷能力和孔隙度的变化;煤体中惰质组含量较高时,其对煤体的吸附容量的影响较为明显,主要与惰质组中丝质体的高吸附能力有关;(5)构造煤的甲烷、氮气吸附量大于原生结构煤;推测煤的吸附性能与煤中低分子化合物的量和性质有关,溶剂萃取不仅改变了煤的孔隙结构,也改变了煤的表面性质;煤溶剂萃余物瓦斯吸附、放散能力与萃取前存在较大差异;(6)煤瓦斯放散特征与煤的颗粒粒度和煤的破坏程度有关。存在一极限粒度,在小于极限粒度范围内,瓦斯流动与颗粒的组成有关,随着颗粒直径的增大,对瓦斯流动的阻力增大,瓦斯放散速度就减小。当颗粒尺寸大于极限粒度时,煤的瓦斯放散速度与颗粒直径的大小没有关系。煤的破坏类型越高,瓦斯放散初速度越大,瓦斯放散能力强,瓦斯放散速度随时间衰减快。溶剂萃取后,萃余物的瓦斯放散初速度远小于萃取前的瓦斯放散速度,构造煤减小幅度大于原生结构煤。更多还原

【Abstract】 Based on the academic thought that "coal structure decides the nature of coal", which is from the microstructure of coal to study the gas adsorption, emission characteristics. Take the paragenesis coal bed’s primary structure coal and the structure coal’s comparative analysis as a master line, using adsorption isotherm analysis techniques, Soxhlet solvent extraction, and MS / GC and other analytical tools to study the different components of coal and rock coal Absorption features of different granularity, different damage characteristics of coal gas emission, and discuss the structure and composition of coal, coal analysis of low-molecular-weight compounds as well as the occurrence form and the origin of tectonic coal solvent extraction kinetic characteristics of solvent extraction of coal and gas adsorption, emission characteristics and its mechanism. Coal particles in the gas diffusion theory and model built on the basic coal of structure of coal gas emission model.The results show that:(1) Coal methane adsorption capacity increase with the coal rank under the conditions of water balance and present the relationship between three-Change, and coal adsorption is mainly controlled by the process of coalification of coal and methane pro-porosity changes; When coal body inertinite content is high, the effects of its adsorption capacity of the coal are more obvious, and mainly with relation to the inertinite fusinite high adsorption capacity;(2) The emission characteristics of coal gas and coal and coal particle size on the extent of the damage. Particle size at less than the limit range of gas flow and composition of particles, with the particle diameter increases, the resistance to the flow of gas increases, gas emission rate of the decrease, which exist a limit particle size. When the particle size is greater than the limits of particle size, the coal gas emission rate and particle diameter size do not matter. The higher the damage of coal type, the greater the initial velocity of gas emission, and gas emission ability strong, gas emission rate of decay quickly;(3) solvent extraction of coal through the kinetic analysis, we can see that extraction process can be divided into two phases, the first rate is faster than the second phase of an order of magnitude. There are free, adsorbed and dissolved states a total of three forms of existence in coal quality low-molecular-weight compounds by speculation, and free state and adsorbed easily are extracted, but total dissolved state can not easily be extracted. Studied coal soluble low-molecular-weight compounds have two sources: First, the original, and it comes from coal-parent material, the second is younger, from the process of coal-generated degradation products. Tectonic coal chloroform extraction rate than the native structure of coal is much more than two times greater, indicating that generates and stores a large amount of soluble low-molecular-weight compounds in the formation of tectonic coal process;(4) Compared to the original structure of coal, construction of coal saturated hydrocarbons in the relative content of heavy fraction increased significantly and detecting the original structure of coal does not exist in the two bicyclic sesquiterpene C14 and three C15 alkyl bicyclic sesquiterpene alkane isomers, but the aromatic hydrocarbon compound’s structure is stable, the main aromatic compounds of different destruction type coal apart from the relationship between the relative changes in quantity, but the species composition has a clear similarity;(5) Tectonic coal methane, nitrogen adsorption capacity are greater than the original structure of coal; the adsorption properties of coal and in the low-molecular-weight compounds of coal and the nature are realated by speculation, not only changed solvent extraction of coal the pore structure, but also changed the coal surface properties; coal solvent extraction residue gas adsorption, emission capacity and there were greater differences before extraction.更多还原