第七-八章-煤有机质的化学结构及研究方法.ppt

Complex intermolecular actions occur between two phases in coal. Coal organic matters are rich in aromatic ring structures (and always aliphatic rings as well). Coal macromolecules take these rings as structural units, and are polymerized by linkages of ―(CH2)n―、―O― and ―S― . The size and condensation degree of aromatic ring unit in coal increase with metamorphic grade of coal, while the number of linkages reduce. The small molecular phase of coal is also quite a complex organic system, and aliphatic, alicyclic and aromatic hydrocarbons as well as heteroaromatics and other polar compounds are involved. A composite model of coal The traditional two-phase structural model of coal based on the chemical covalence bonding has to be revised since recent discoveries of powerful mixed solvent such as CS2/NMP, giving extra high yields in coal extraction at room temperature. It is believed that the physically associated interactions play important roles in the structure of coal. A composite model of coal is suggested. The organic matter of coal is mainly composed of some parts: the rigid 3-D macromolecules linked with chemical bonds; the polar molecules of high and moderate molecular weights, corresponding to asphaltenes(沥青烯) and resins（树脂）; 　the hydrocarbons with lower molecular weights. The polar molecules are associated by physical interactions (such as hydrogen bonding（氢键）, charge transfer interactions（电荷转移作用）, π-π interactions of aromatic sheets, etc.) each other and with macromolecules to form the network structure（网状结构）, in which some smaller nonpolar molecules are trapped. It looks reasonable to pay more attention to the geological conditions including the salt, water, minerals and environments of the sedimentation. The evolution process of physically associated interactions in the composite structure of coal and the generation of oil is thought to be intimately （密切地）influenced by these factors. 一、煤的物理结构 煤结构模型的局限性 尽管每一模型都有相关实验证据的有力支持，但没有一种模型可以解释所有的实验现象。也许对于煤