Effect of particles cluster on behavior of catalytic cracking reaction in FCC riser

Based on the analysis of experimental phenomena of particles clustering in the gas-solid system, taking the catalytic cracking reactions of vacuum gas oil for example, the flow, heat transfer and the cracking reactions occurred on the spherical and ellipsoidal particles clusters were simulated. The distribution of gas velocity, temperature and species concentration as well as the reaction rate inside and outside the particles clusters were obtained. The simulated results showed that the particles clustering hinders the sufficient contact of oil gas and catalyst particles, thus leading to the non-uniform distribution of velocity and temperature, and affecting the catalytic cracking reactions. The rates of primary reactions on cluster particles are greatly lower than those on the isolated single particle, and the formation of cluster affects the reaction time notably, which results in a higher yield of light gas and coke, which is undesirable in the industry production. ©, 2015, Chemical Industry Press. All right reserved.