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本文对二苯甲烷、二苯乙烷、二苯醚、苯基苄基醚和二苄醚等五个与煤的化学结构和煤液化有关的模型化合物在供氢溶剂四氢萘中、N_2压力为50—60大气压下的热解反应动力学及反应机理进行了研究。结果表明:(1) 二苯甲烷和=苯醚在435℃/2h条件下依然比较稳定,这意味着,在实际煤液化过程中,C—C、C—O键的断裂不能靠这些简单结构方式的裂解加以解释;(2) 二苯乙烷和苯基苄基醚的热解有一级反应特征,其反应机理为自由基过程,反应速度方程和速度常数的理论计算与实验结果完全一致;(3) 二苄醚的热解可用分子内氢转移模型得到较好解释,热解产物苯甲醛进一步脱氧生成甲苯,这可能是煤液化中除氧的一条很重要的途径。
In this paper, five compounds, including diphenylmethane, diphenylethane, diphenyl ether, phenylbenzyl ether and dibenzyl ether, which are related to coal chemical structure and coal liquefaction, The pyrolysis kinetics and reaction mechanism at 50-60 atm were studied. The results show that: (1) Diphenylmethane and p-phenylene ether are still stable at 435 ℃ / 2h, which means that the fracture of C-C and C-O bonds can not be achieved by these simple structures (2) The pyrolysis of diphenylethane and phenylbenzyl ether has the first order reaction characteristic and the reaction mechanism is the free radical process. The theoretical calculation of the reaction rate equation and the velocity constant are in good agreement with the experimental results. (3) The pyrolysis of dibenzyl ether can be well explained by the intramolecular hydrogen transfer model. Further degradation of the benzaldehyde from the pyrolysis product to toluene can be an important way to remove oxygen in coal liquefaction.