摘 要：在自制卧式干燥试验台上进行500~800 ℃褐煤高温干燥脱水实验，采用拉曼光谱和傅里叶红外光谱（FTIR）对干燥后煤样的化学结构进行测试和分析。结果表明，不同干燥温度对褐煤大分子结构以及官能团的演化有着不同程度的影响。500~700 ℃干燥下，随干燥温度升高，脂族和羧基等含氧官能团相继断键析出，形成小分子物质，脂族结构含量与芳族结构含量总体上呈现互补的演化趋势；芳环缩合性有所增强，导致小芳环系统向大芳环系统转变，交联效应促使烷基-芳基C-C键的新芳香结构生成，褐煤大分子结构的稳定性有所提高。而温度上升至800 ℃，煤中孔隙夹带的氧气与脂族等发生一系列氧化反应，导致此时含氧官能团数量高于700 ℃干燥处理煤样。此外，部分芳烃C=C和杂环断裂，无定形碳结构增加。

Abstract:The lignite was dried in the temperature range of 500~800 ℃ using a horizontally fixed bed dryer.The changes in the chemical structure of the lignite during the drying process were investigated using Raman and FTIR spectroscopy.The results indicated that the effect of the drying temperature on the evolution of the macromolecular structure and functional groups of the lignite are different from each other.In the drying temperature range of 500~700 ℃,the aliphatic structures and oxygen-containing groups such as carboxyls are decomposed and small molecular substances are produced with the increase in drying temperature.During the process,the content of aliphatic structure decreases and that of the aromatic structure increases.The size of the small aromatic rings shows an enlarging tendency due to the further aromatic ring condensation and the new Calkyl-Caryl structures are continuously formed due to the cross-linking effect.Therefore,the stability of coal macromolecular structure has been enhanced.With the drying temperature of 800 ℃,however,the reaction between the aliphatics and the oxygen present in the pore of the lignite results in increases oxygencontaining groups compared with the sample dried at 700 ℃.In addition,the partial aromatic C=C and heterocycles are destroyed and the amorphous phase of carbon increases.

TQ531.6

国家科技支撑计划项目(2012BAA04B01)；上海理工大学科技发展项目（16KJFZ094）