Computation of the mass transfer coefficient of FCC particles in a thin bubbling fluidized bed using two- and three-dimensional CFD simulations

In this study, the standard kinetic theory based model with a modified drag correlation was successfully used to compute the mass transfer coefficients and the Sherwood numbers of FCC particles in a thin bubbling fluidized bed column using the additive diffusional and chemical reaction resistances concept. Also, the effects of the computational domain (two- or three-dimensional) and the reaction rate constant (low and high) are discussed.The computations show that the Sherwood numbers are in agreement with the measurement ranges for small particles in the fluidized bed system. The mass transfer coefficients and the Sherwood numbers are high near the inlet section, and decrease to a constant value with increasing height in the column. The two-dimensional computational domain simulations provide enough information to explain the phenomena inside a symmetrical system, but three-dimensional computational domain simulations are still needed for asymmetrical systems. Finally, the mass transfer coefficients and the Sherwood numbers increased with the larger reaction rate constant.

► Kinetic theory based model was successfully used to compute mass transfer phenomena in a thin bubbling fluidized bed column.
► The 2D simulation is detailed enough to explain the phenomena inside a symmetrical system.
► However, the 3D simulation is needed for asymmetrical systems.
► The mass transfer coefficients and the Sherwood numbers increase with increasing reaction rate constants.
► Mass transfer coefficient and Sherwood numbers are high near inlet and decrease to constant value with increasing column height.