A Review on the Modeling and Optimization of Fluid Catalytic Cracking Unit

Fluid catalytic cracking is one of the most crucial refinery processes to upgrade heavy hydrocarbon feedstock to light higher qualified products. Due to the high impact of this process, many scientists investigated different aspects of this process. In this paper, a comprehensive review of the related studies is carried out. The main focus of the review is on three categories including kinetic networks, steady and unsteady modeling, and process optimization. A review of researches since 1970, reveals that kinetic investigations were majorly based on the lumping methodology in which the reactive mixture is divided into main groups with different categories that may be defined based on carbon number of species or kind of components. Mainly the related number of lumps was limited to three to nineteen. Moreover, in the process modeling researches mainly two main equipment including riser-reactor and regenerator were considered. The primary regenerator model includes single-phase regenerator models, simple contact with plug flow and dissipated reactions with series tanks that were also considered in the researches. Also, different studies were carried out to consider more equipment. Also, the application of the momentum equation besides mass and energy equations in the regenerator was considered in some studies. The main challenge in the development of the related model was the determination of the parameters. Investigation of the impact of input catalyst temperature and catalyst to oil ratio were also carried out in the other researches. The optimization of the process was usually in the steady-state. However, dynamic optimization was applied less. Various algorithms, including genetics and particle swarm, were evaluated and compared. It was found that the particle swarm algorithm is adjusted easier than the genetic algorithm and the handling is better.