物理化学学报 >> 1986, Vol. 2 >> Issue (03): 199-206.doi: 10.3866/PKU.WHXB19860303

研究论文 上一篇    下一篇

与煤结构和煤液化有关的五个模型化合物热解反应动力学的研究

杨晓林; 杨惠星; 韩德刚   

  1. 北京大学化学系
  • 收稿日期:1985-01-08 修回日期:1985-07-04 发布日期:1986-06-15

KINETICS AND MECHANISM OF THE THERMOLYSIS FOR FIVE MODEL COMPOUNDS RELATED TO COAL STRUCTURE AND COAL LIQUEFACTION

Yang Xiaolin; Yang Huixing; Han Degang   

  1. Chemistry Department, Peking University
  • Received:1985-01-08 Revised:1985-07-04 Published:1986-06-15

摘要: 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 ℃/2 h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。

Abstract: The kinetics and mechanism of the thermolysis for five model compounds were studied in tetralin under N_2 pressure about 50-60 atm. The results show that:
(1) Diphenyl methane and diphenyl ether are stable under 435 ℃ for 2 hours reaction, which implies that the cracking of C—C and C—O bounds in coal liquefaction is not similiar to one of these compounds.
(2) The reaction of thermolysis of dibenzyl and phenyl benzyl ether are first Order and can he explained by free radical mechanism. Experimental rate constants are well consistent with the results of thermochemical kinetics calculation.
(3) The thermolysis of dibenzyl ether is well explained by te intramolecular hydrogen transfer model. Benzyl aldehyde produced by reaction is further deoxygenated. This is probably a very important deoxygenation process in coal liquefaction.