(427d) Multiphase Simulation of a Commercial Fluidized Catalytic Cracking Regenerator

A multiphase, thermal, and chemically reacting simulation of a commercial Fluidized Catalytic Cracking (FCC) regenerator was conducted. The simulation was full-scale, 3-dimensional, and included complex internal structures. The regenerator is 68 ft tall, with a diameter of 47 ft. The particle inventory in the system is about 400 tons. The computational method used was an Eulerian-Lagrangian approach called MP-PIC (multi-phase particle-in-cell). Barracuda® VR, a commercially available CFD software package, was used to perform the simulation. Discrete particle-level chemistry was applied for the chemical reactions of coke burn-off from the catalyst particles.

The simulation had several goals, including: (1) gain insight into the performance of the unit regarding effectiveness of coke combustion from the spent catalyst particles; (2) predict the severity of afterburn in the freeboard, and understand its causes; (3) predict the production rates of pollutants such as NOx and SOx from the regenerator; and (4) identify any maldistribution of particles or gas from the highly complex spent catalyst distributor.

Results of the simulation will be presented, including particle-fluid flow behavior, thermal profiles throughout the vessel, and gas compositions exiting the system. A comparison of actual operations with the simulation results will be presented to demonstrate the predictive capability of the computational model.