Population Balance Modelling of Bubbling Fluidized Bed Reactors-i. Well-stirred Dense Phase

A detailed population balance model is presented for a duidized bed reactor incorporating: the formation of bubbles at the grid plate, their rise with velocities governed by their sizes, random coalescence between bubbIes, gas exchange between bubbles and the dense phase, and a first order chemical reaction in the dense phase under well-mixed conditions. Reaction conversion is calculated as a function of dimensionless parameters relating the rates of various competing processes such as coalescence, dense phase mixing, mass exchange between bubbles and dense phase and reaction rate. Comparison ofconversions with those of Davidson et al. (1977) show significant variations indicating that the dynamics of bubble size distributions could have non-trivial erects on the extent of reaction. Fluctuations in bubble populations did not seem strong enough to translate to strong fluctuations in reaction conversion.