Patent ID: 7223896

Claim:
A process for maintaining a particle size distribution in a reaction system, wherein the process comprises the steps of: (a) feeding a plurality of catalyst particles into a reaction zone, wherein the plurality of catalyst particles has a first median particle diameter, a d 2 of at least about 7 microns, a d 10 of less than about 45 microns, a d 50 between about 75 and about 100 microns, and a d 90 of less than about 150 microns; (b) contacting the plurality of catalyst particles with a feedstock in the reaction zone under conditions effective to convert at least a portion of the feedstock to product, (c) directing the product and at least a portion of the plurality of catalyst particles to a disengaging zone; (d) yielding the product and a portion of catalyst fines from the disengaging zone under conditions effective to increase one or more of the d 2 , the d 10 , the d 50 and the d 90 to provide an increased d 2 , an increased d 10 , an increased d 50 or an increased d 90 ; and (e) decreasing one or more of the increased d 2 , the increased d 10 , the increased d 50 or the increased d 90 by adding co-catalyst particles to the reaction system.