Computational Investigation of a Turbulent Fluidized-bed FCC Regenerator

This paper presents a CFD modeling of hydrodynamics, heat transfer, and coke combustion in an industrial turbulent fluidized-bed FCC regenerator. Based on the Eulerian-Eulerian model, a CFD model including heat transfer and coke combustion reactions is established. The detailed hydrodynamics, temperature, and species concentration distribution inside the regenerator are obtained under various operating conditions. The flow behavior in the regenerator shows more turbulent disorder, causing the axial and radial nonuniformity of catalyst content, temperature, and species concentration. Increasing operating pressure and superficial gas velocity accelerates the coke combustion, leading to a higher combustion efficiency. However, the increases in initial coke content and spent catalyst circulation rate deteriorate the regeneration performances. The simulated regenerator could not burn more coke at the current operating conditions because of its limited coke-burning capacity. Improving entrance configuration, enhancing gas-particle contact, and prolonging reaction time would benefit the coke combustion.