Computation of system turbulences and dispersion coefficients in circulating fluidized bed downer using CFD simulation

► Computational fluid dynamics (CFD) model was used to simulate the CFB downer. ► System turbulences and dispersion coefficients were successfully computed. ► Turbulent kinetic energy was directly increased as the increasing of system depth. ► Laminar and turbulent dispersions were considerably high and low, respectively. ► Individual gas/solid particle dominates the flow structure inside the CFB downer.