Mathematical modeling of FCC riser reactor and comparison with downer reactors

Abstract

The aim of this study is to develop a one dimensional hetrogeneous two phase model for the adiabatic FCC reactor assuming a plug flow for both the solid and gaseous phases. The reaction kinetics of the cracking reactions are represented by the four lump kinetic scheme. The hydrodynamics of the riser are considered taking the slip factor into account. The model consists of ordinary differential equations is solved in order to get the yield patterns and study the effect of process variables like input catalyst temperature, and catalyst oil ratio on the yield of gasoline. Another model is developed for the downer reactor using hydrodynamic modeling, mass and energy balances. The model developed is solved using Runge- kutta IV order implemented in MATLAB and the differences in the axial profiles and gasoline yield as compared with the riser reactor are discussed.