Dynamic Modeling and Simulation of Fluid Catalytic Cracking Unit Riser

This study developed and simulated a dynamic mathematical model for a Fluid Catalytic Cracking Unit (FCCU) riser reactor with consideration of coke deposition on the catalyst in the overall mass balance of the system. It also proposed a mathematical model that accounts for the dynamic effect of coke deposition on the hydrodynamics of the FCCU riser. The spatial derivatives are discretized using finite difference to obtain the dependency of the state variables on time. The resulting ordinary differential equations were simulated using Java Application Programme Interface, ODEToJava. An approach proposed in this study is in good agreement with experimental and numerical data available in the literature. The results showed an outlet vapor density of 2.76 kg/m3 which gave a +7.39 % deviation when compared with plant data. Also the temperature outlet of the riser predicted by the model deviated by -5.49% when compared with real plant data. The model also confirmed the acceptability of the general assumption of isothermal condition while modeling the FCCU riser. The model prediction of components yield along the height of the riser is within permissible limit when compared with that reported for industrial riser. The study concluded that the developed model accurately described the dynamic behavior of an FCCU riser and its predictions when compared with real plant data proved satisfactory.