Finf out Rate Limiting Surface Reaction or Mass Transfer

Question

We have a catalyst 1/8-in in diameter in a slurry reactor that gives 90% conversion. Which step is rate limiting, surface reaction or mass transfer under each of the following conditions:

a)    The conversion increases when we double the stirring rate but doesn’t change further when we double it again.
b)    The conversion is unchanged when we replace the catalyst by pellets 1/4-in in diameter, holding the total weight of catalyst the same.
c)    The conversion decreases when we replace the catalyst by pellets 1/4-in in diameter, holding the total weight of catalyst the same.
d)    The reaction rate increases by a factor of 10 when the temperature is increased by 10 K.
e)    The reaction rate is unchanged when the temperature is increased by 10 K.

Summary

The question belongs to Chemical Engineering and it is about a catalyst with gives 90% conversion. The step in rate limiting, surface reaction or mass transfer under the given conditions have been answered in the solution.