The effect of particle size distribution on the performance of a catalytic fluidized bed reactor

The performance of a fluidized bed reactor has been investigated using the ozone decomposition reaction for fresh and spent fluid cracking catalysts, each having three particle size distributions - wide, narrow and bimodal - all with the same mean particle diameter. The superficial gas velocity was varied from 0.06 to 1.8 m/s and the rate constant from 1 to 9 s−1. The wide size distribution usually gave the highest reactor efficiency, while the narrow blend gave the lowest. The differences are not solely a function of the “fines content”. The reasons for the influence of particle size distribution were examined by testing the “bimodal” distribution with different fractions active. In the bubbling fluidization regime and for Group A particles, this influence can be predicted using the Two-Phase Bubbling Bed Reactor Model with modifications to allow for increased concentration of fine particles in the dilute phase.