Extension to Other Reaction Orders and Particle Geometries

3 Extension to Other Reaction Orders and Particle Geometries 

Expressions for the effectiveness factor, similar to Eqn. (9-9), can be derived for other particle shapes, other reaction orders, and for reversible as well as irreversible reactions. Fortunately, if the Thiele modulus is redefined somewhat, all of these solutions can be approximated by a single curve of rj versus 0. 

The geometric surface area (Ao) is the external area of the catalyst particle, i.e., the area that is in contact with the fluid. For example, the characteristic dimension of a sphere is k = A/3)7iR /AnR = R/3. 

The given dinriRnsirms of the catalyst particle will be used to calculate the geometric volume Vo and the geometric area Aq- Then Ic will be calculated from Eqn. (9-10). 

Note that the outer area, the inner area, and the area of the ends of the ring all were taken into account in the calculation of Ag- From Eqn. (10-9), 

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