The importance of diffusion in catalyst pellets can often be determined by measuring the effect of pellet size on the observed reaction rate. in this exercise, consider an irreversible first-order reaction occurring in catalyst pellets where the surface concentration of reactant a is cas=0.15 m.
data:
diameter of sphere cm 0.2 0.06 0.02 0.01 0.008 0.006
robs (mol/h/cm3) 0.25 0.8 1.8 2.4 2.5 2.5
a.) calculate internal effectiveness factor for each particle size
b.) identify particles that experience no, negligible, intermediate, or strong diffusion limitation.
c.) estimate the thiele modulus for a catalyst particle of diameter 0.1 cm.