Abstract:

Petroleum pyrolysis is an important step in the process of producing high-quality gas-liquid fuels and chemicals. It exists not only in the non-catalytic process, but also in the catalytic process, involving thermal cracking, coking, viscosity-reducing, high-temperature cracking, catalytic cracking, hydrocracking and dehydrocracking, etc. However, the reaction process and mechanism of petroleum pyrolysis process have not yet been clarified, and the experimental phenomena cannot be reasonably explained by the free radical chain reaction mechanism of thermal cracking and the positive carbon ion reaction mechanism of catalytic cracking. In this paper, it was proposed that the main body of chemical reaction in each process of petroleum pyrolysis was dominated by free radicals which were dissociated by heat. The difference between different pyrolysis processes mainly lied in the regulation of secondary free radicals. The free radical complex products and the stable products formed the product distribution of the specific pyrolysis process. The reaction mechanism was created of free radical regulation. At the same time, various application phenomena were analyzed reasonably and effectively of petroleum catalytic cracking, the technologies were effective guided to development of inferior heavy oil catalytic pyrolysis quickly-gasification coupling technique and direct crude grading millisecond catalytic pyrolysis gas phase chemical technology, according to the reaction mechanism of initial free radical generation, secondary free radical regulation and free radical compound. It can provide the direction and basis for process condition optimization, reaction regulation and strengthening, catalyst development and optimization and reaction equipment technology development and strengthening by the reaction mechanism of free radical regulation.

Key words: petroleum, pyrolysis, free radical regulation, reaction mechanism, universality

摘要：

石油热解是生产高品质气液燃料和化学品的重要步骤，不仅涉及非催化过程，也涉及催化过程。石油热解过程反应机理不仅为解析不同类型的热解反应过程、构建反应动力学模型以及定向调控和强化，而且对于工艺条件优化、反应调控和强化、催化剂开发和优化以及反应装备技术开发和强化等均能指明方向和提供依据，但现有热裂解自由基链式反应机理和催化裂化正碳离子反应机理均存在实验现象尚未能合理解释。本文提出了石油热解过程的化学反应主体均由受热离解的自由基主导的观点，创建了石油热解过程自由基调控反应机理，不同热解工艺区别主要在于二次自由基调控，自由基复合产物以及稳定产物形成了特定热解过程的产物分布。按照初始自由基产生、二次自由基调控和自由基复合3个阶段的反应机理，合理解析石油催化裂化过程各种应用现象，有效指导了劣质重油快速催化热解-气化耦合技术和原油直接分级气相毫秒催化裂解制化学品技术的开发，证实了石油热解过程自由基调控反应机理的普适性，为工艺条件优化、反应调控和强化、催化剂优化提升和反应装备技术强化等均能指明方向和提供依据。

关键词: 石油, 热解, 自由基调控, 反应机理, 普适性