Mathematical modeling of the combustion of gases in bubbling fluidized beds

The combustion of gas mixtures in a bubbling fluidized bed is modeled using a three-phase dispersion hydrodynamic model. The non-iosthermality of the bed resulting from combustion reactions is taken into account through inclusion of an energy balance for the bubble phase. Steady state parametric analyses show that the ignition front moves closer to the distributor with increase in bed temperature and bed particle size, and decrease in the excess gas velocity. Comparison with experimental data shows that under typical fluidized bed combustion conditions, propane burns in a region of parametric sensitivity; thus, significant variations in calculated mole fractions result from comparatively minor variations in reaction rate parameters.