(716a) Application of an Efficient Discrete Particle Model to Simulate an Industrial FCC Regenerator

In past decades, the continuum approach was the only practical technique to simulate large-scale fluidized bed reactors because discrete approaches suffer from the cost of tracking huge numbers of particles and their collisions. This study significantly improved the computation speed of discrete particle methods in two steps: First, the time-driven hard-sphere (TDHS) algorithm with a larger time-step is proposed allowing a speedup of 20-60 times; second, the number of tracked particles is reduced by adopting the coarse-graining technique gaining an additional 2-3 orders of magnitude speedup of the simulations. A new velocity correction term was introduced and validated in TDHS to solve the over-packing issue in dense granular flow. The TDHS was then coupled with the coarse-graining technique to simulate the heat transfer and chemical reaction mechanisms in an industrial FCC regenerator in a reasonable time with little computational resources. The simulation results compared well with available industrial data and proved that this new approach can be used for efficient and reliable simulations of industrial-scale fluidized bed systems.