异丁烷热裂解反应机理的分子模拟

摘要

The pyrolysis mechanism of isobutane was researched using molecular simulation method. The reaction path was built. In order to determine the possibility and difficulty level of each reaction, thermodynamics and kinetics calculations were made for each elementary reaction. The results showed that the rate-controlling step was the breaking of C-C bond in the molecule of isobutane, and the products were CH3 free radical and I-C3H7 free radical. Formation of propylene was the main reaction path, which was supported by kinetics. The yield ratio of propylene and isobutylene was 1. 40 ! 1, which coincided with the experimental fact.%用分子模拟方法对异丁烷的热裂解反应机理进行了研究,建立了可能的反应路径,为了确定每个反应发生的可能性和难易程度,对各个基元反应做了热力学和动力学的计算.结果表明,其热裂解反应的速率控制步骤为异丁烷分子中C—C键断裂生成CH3自由基和i-C3 H7自由基的反应,动力学上最支持生成丙烯的反应路径,目的产物中丙烯与异丁烯的比例为1.40∶1,与实验值较接近.