MODELLING A FLUIDIZED BED REACTOR BY INTEGRATING VARIOUS SCALES: PORE,
PARTICLE, AND REACTOR
This work proposes a novel population-balance based model for a bubbling
fluidized bed reactor. This model considers two continuum phases: bubble
and emulsion. The evolution of the bubble size distribution was modeled
using a population balance, considering both axial and radial motion.
This sub-model involves a new mathematical form for the aggregation
frequency, which predicts the migration of bubbles from the reactor wall
towards the reactor center. Additionally, the reacting particles were
considered as a lagrangian phase, which exchanges mass with the emulsion
phases. For each particle, the variation of the pore size distribution
was also considered. The model presented here accurately predicted the
experimental data for biochar gasification in a lab-scale bubbling
fluidized bed reactor. Finally, the aggregation frequency is shown to
serve as a scaling parameter.