The experiment and simulation of mass transfer in bubbling fluidized beds

Abstract

The effects of meso-structure on gas–solid mass transfer in bubbling fluidized beds (BFBs) were studied and validated with carbon monoxide oxidation over Pt/Al2O3 catalyst and catalytic decomposition of ozone as the model reactions. To model the meso-structure effects, the structure in BFBs was assumed to be consisted of three phases as the emulsion phase, the bubble phase and inter-phase. Consequently, new mass transfer coefficients accounting for the heterogeneous structure were obtained according to the balance between reaction and mass transfer. Besides, the mass transfer behaviors of carbon monoxide oxidation over a Pt/Al2O3 catalyst were simulated and compared with experimental data based on the mass transfer model. It showed that the simulation results were in good agreement with the experimental data. Moreover, the new mass transfer model was also applied to simulate the catalytic decomposition of ozone in a bubbling fluidized bed. It revealed that the axial ozone distribution also exhibited good agreement with those of experiments, demonstrating wide applicability of the new mass transfer model.