关键词: 石油, 热解, 自由基调控, 反应机理, 普适性

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