Dynamic modeling of catalyst consumption in catalytic cracking

Abstract

This article proposes a mathematical model of catalyst consumption in fluidized-bed catalytic cracking units which have dust collection equipment that continuously return the catalysts to the process. The equilibrium characteristics of the fluidized system and the dust collection system is influenced by the following factors: the rate of increase of the amount of fine fractions as a result of abrasion of the large particles, the rate of entrainment of solid particles from the bed to the cyclone zone, and the efficiency of collection of the fine fractions. The most important parameters of the equilibrium are the particle size distribution of the catalyst in the system and the rate of loss of mass from the system. It is concluded that the described mathematical model gives a sufficiently correct description of the interrelation among the basic parameters of the solid phase that influence the catalyst consumption in fluidized-bed systems, and that the model can be used in practical calculations.