The Balanced Particle—A Compromise

Correct formulation of the catalyst is a compromise between good fluid flow, activity, and stability. The relative importance of these factors depends upon the reaction, reactor design, process conditions, and economics. In Fig. 2.1, these are represented as three sides of a triangle to emphasize mutual dependence and interaction. 

Flow distribution Low pressure drop Mechanical strength 

Chemical activity High specific active surface Porous pellet 

An interesting example that demonstrates similar chemistry for different process conditions is found in the reversible reaction 

Both forward and reverse reactions are catalyzed by the same material, 

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