Modeling And Steady-State Simulation Of Fluid Catalytic Cracking Riser-Regenerator Systems Using Special Pseudo-Components

As a very important role in the process of refining, fluid catalytic cracking unit (FCCU) has features of large flux, high efficiency, and so on. At present, the total processing capacity of FCCUs in our country is about 150 Mt/a, so carrying on the design and optimization works on FCC has important and practical significance. Related research of fluid catalytic cracking (FCC) process is very challenging. The optimization, control and stability analysis research based on this complex process generally require a detailed and accurate mathematical mechanism model for replacing the actual device object. The catalytic cracking related research progress and results were reviewed in this paper, and then take a typical high and low side-by-side FCC riser-regenerator unit as the research object, around the problem of modeling and steady-state simulation of the riser-regenerator system, do the following works:(1) Based on quasi-stable state assumptions, the riser reactor quasi steady-state mathematical model which has three kinetics parameters is established, and then the reaction kinetics mechanism and model parameter identification problems are improved. Finally, using three sets of industrial datas, the results of the riser model are respectively 2.655%,-1.08% and-1.71% for products yields’max.errors and 0.0113, 1.70×10-4, 1.08×10-4 for 1/λ values;(2) Combined with coke combustion dynamics model, based on the steady-state model assumptions, establish the regenerator steady mathematical model which contains the dense and dilute phases. Complete the simulation analysis of the regenerator steady-state model with industrial data, the results of the regenerator model are respectively 0.24% for gases yields’max.errors,-0.98℃ and -4.57℃ for tempretures of dense bed and stack gas;(3) With using the sequential module method as the iterative solution strategy of the overall model, unite several input-output modules like the riser, regenerator, stripper and mixer to construct a steady-state model for FCC riser-regenerator system. Use some production datas of Jiu jiang factory’s FCCU to realize the whole FCC steady-state simulation, the results of the overall model are respectively 3.565% for products yields’max.errors and-3.15℃ for important tempretures, and GDEM is very effective for solving the overall steady-state model.