应用傅立叶变换红外光谱仪研究了煤在氧化自燃过程中不同温度下生成的气体产物.在30℃~100℃左右有水和二氧化碳气体析出,温度升至105℃~150℃左右时,有一氧化碳生成.采用密度泛函B3LYP方法,在6311G基组水平上研究了煤与氧发生自燃反应生成水和一氧化碳的反应体系,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,煤氧化自燃生成水的反应是氧分子攻击苯环侧链上的伯胺基团-C(29)H2-N(22)H2中间的N(22)原子,使煤分子苯环侧链上的伯胺基团生成了-CH2-N=O基团和水.由反应活化能可知,生成水的反应是一个自发式反应.
The gaseous product in the process of coal oxidized spontaneous combustion under different temperature has been studied by the Fourier transform infrared spectroscope experiment. When the temperature rises to about 30 ℃-100℃ water and carbon dioxide gas separated out, about 105 ℃-150 ℃, the carbon monoxide 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 water is the oxygen molecule attacks the N(22) atom in the middle of primary amines group (-C(29)H2-N(22)H2) on the benzene ring side chain, which causes the -C(29)H2-N (22)H2 group on the coal molecule benzene ring side chain to produce the -CH2-N =O group and the water. The reaction of coal spontaneous combustion producing water and carbon monoxide is a spontaneous reaction judging by the reaction activation energy.