Reaction Mechanism and Thermodynamic Properties of Aliphatic Hydrocarbon Groups during Coal Self-Heating

作者：Xuyao Qi, Liangzhou Chen, Haihui Xin, Youcang Ji, Chengwu Bai, Runquan Song, Haibo Xue, Fangming Liu · 发表于：Energy & Fuels · 年份：2018 · DOI：10.1021/acs.energyfuels.8b02165 · 被引用次数：54 · 研究领域：Coal Properties and Utilization、Thermochemical Biomass Conversion Processes、Combustion and Detonation Processes

To further understand the development of coal self-heating, the reaction sequences and thermal properties of aliphatic hydrocarbon groups during coal self-heating were analyzed. The structural parameters, frontier orbital characteristics, molecular orbital, and perturbation energy of aliphatic hydrocarbons and oxygen were analyzed by the quantum chemistry method. Then, the reaction pathways of aliphatic hydrocarbon groups and the corresponding reaction model were proposed. The results indicate that the reactions of aliphatic hydrocarbon groups include three kinds, i.e., the hydrogen capture by oxygen, reaction between aliphatic hydrocarbon radicals and the hydroxyl radical, and reaction between aliphatic hydrocarbon radicals and oxygen. The main reactions include the reaction between carbon free radicals and oxygen (E1), the reaction between aliphatic hydrocarbon and the hydroxyl radical (E2), the reaction between methyne and oxygen (E3), and other spontaneous reactions caused by E1 and E3 (E2). There is only one reaction procedure for the carbon free radical (R • ) to turn into peroxide (R–O–O • ) and cause more heat release. Reaction E3 generates less heat compared to reaction E1, but it can form hydroxyl radicals, which then result in other spontaneous reaction sequences (E2) to generate R •, which will easily start reaction E1. Therefore, reaction sequence E3 includes two aspects of influence during coal reaction with oxygen, i.e., heat supply and the trigger of other fur...