型煤热解的量子化学研究

Quantum Chemistry Study on Coal Pyrolysis Based on Gaussian Algorithm

将简化型煤和聚乙烯醇(PVA)分子结构模型,选取苯甲酸和苯酚作为褐煤含氧官能团模型化合物,取聚乙烯醇n=1时的化学结构作为PVA的官能团片段,采用密度泛函理论(DFT)中的B3LYP泛函方法进行PVA对型煤热解反应的影响的理论计算。通过量化分析,结果说明,PVA与煤分子反应之间所需的活化能小,首先使煤大分子结构裂解成小分子结构,缩短了型煤热解的时间,其次,PVA降低了苯酚自身裂解生成CO的反应所需的活化能,即降低了总反应的能垒,加快了型煤的热解速率。

This study would simplify the molecular structure model of coal and polyvinyl alcohol（PVA）.We select benzoic acid and phenol as model compounds of lignin-containing oxygen functionality.The chemical structure of polyvinyl alcohol（n=1）was used as a functional group segment of PVA,and the theoretical calculation of the influence of PVA on the pyrolysis reaction of briquette was performed using the B3 LYP functional method in density functional theory（DFT）.The results showed that the required activation energy between PVA and coal molecular reaction was low through quantitative analysis.Firstly,the coal macromolecular structure was cracked into small molecule structures,shortening the time for pyrolysis of coal briquettes.Secondly,PVA reduced the activation energy of the reaction that phenol cracked to CO so as to cut down the energy barrier of the total reaction and accelerate the pyrolysis rate of briquette.