Simulation and optimization of industrial FCC units using a 4-lump kinetic model

Abstract

Most of the previous work on the simulation and the bifurcation behavior of industrial FCC units involved a 3-lump kinetic model with coke and light hydrocarbon gases contributing one of the lumps with the ratio between them computed empirically ITom industrial data. In this study a 4-lump kinetic model is incorporated. This permits the calculation of the rate of coke formation thus decreasing the degree of empiricism in the model. The data ITom six different industrial units is used in the simulation. It was found that the model results are in good agreement with the corresponding plant data. The model predicts that the units are operated at the statically stable high temperature steady state whereas the use ofthe 3-lump kinetic model in previous work predicted that the units operate at the middle unstable steady state. This shows the importance of the structure of the kinetic model used for the determination of the stability characteristics of these important industrial units. The model is used to find the optimum operating conditions and the optimum performance is compared with the industrial performance.