Simulations of a bubbling/turbulent fluidized-bed reactor have been studied
using the catalytic oxidation of n-butane to maleic anhydride (MAN) in the
presence of a vanadium phosphorus oxide catalyst. The performance of the r
eactor was investigated using three different models: (a) a simple two-phas
e flow model, (b) a dynamic two-phase structure model, and (c) a plug-flow
model. The simple two-phase model was found to underpredict the performance
of the fluidized-bed reactors because of the oversimplified assumptions in
volved in this model. By analyzing the mass transfer in the two-phase model
s, it was shown that the conversion of reactants occurs mainly in the emuls
ion phase at low gas velocities and in the bubble phase at high gas velocit
ies. The performance of the reactor, in terms of n-butane conversion, yield
of MAN, and selectivity of produced MAN, was analyzed at different superfi
cial gas velocities, initial n-butane concentrations, and deactivation rate
s of the catalyst.