煤自燃生成甲烷的反应机理研究.pdf

煤自燃生成甲烷的反应机理研究 * 王继仁，邓存宝 ，邓汉忠，叶兵 辽宁工程技术大学 辽宁 阜新 123000 Email：dengcunbao323@ 摘要:应用傅利叶变换红外光谱仪实验研究了煤在氧化自燃过程中不同温度下生成的气体产 物。温度升至 120～170℃左右时，有甲烷生成。采用密度泛函B3LYP方法,在 6-311G基组水 平上研究了煤与氧发生自燃反应生成甲烷的反应体系，对反应势能面上各驻点的几何构型进 行了全优化，用频率分析方法和内禀反应坐标(IRC)方法对过渡态进行了验证。计算结果表 明，煤氧化自燃生成甲烷的反应是氧分子攻击苯环侧链上的丙基中间的碳原子，使苯环侧链 上丙基生成带酸的基团（-CH -COOH ）和甲烷。由反应活化能可知，生成CH 的反应是一个 2 4 自发式反应。 关键词：煤自燃；红外光谱；密度泛函；反应机理 中图号：TD 文献标识码：A 文章编号： Coal Spontaneous Combustion producing Methane Reaction Mechanism Research WANG Ji-ren, DENG Cun-bao, DENG Han-zhong, YE Bing Liaoning Technical University, Fuxin 123000, China Abstract: The gaseous product in the process of coal oxidized spontaneous combustion under different temperature has been studied by the FTI spectroscope experiment. when the temperature rises to about 120～170℃, methane has been produced 。Using the DFT B3LYP method, we studied the reaction system of the coal and the oxygen having the spontaneous combustion reaction and producing methane under 6-311G base group, and have carried on optimization of all stagnation points geometry configuration on reaction potential energy surface, with the frequency analysis method and the IRC method have carried on confirmation to the transient formation. The calculation results indicate that the reaction of coal oxidized spontaneous combustion producing methane is the oxygen molecule attacks the carbon atom in the middle of propyl on the benzene ring side chain, which causes the propyl to produce the acid group (-CH2-COOH)and the methane. The reaction of producing CH4 is a spontaneous reaction judging by the reaction activation energy. Key words: coa