Diffusion and Reaction in a Single Cylindrical Pore within the Catalyst Pellet

5 Diffusion and Reaction in a Single Cylindrical Pore within the Catalyst Pellet 

Consider a section of the pore volume of thickness Ax at a distance x from the pore mouth. A diffuses into the pore and as it moves through the pore, it imdergoes reaction by coming into contact with the catalyst material available at tiie active sites on the inner surface of the pore. The flux of A through the pore is 

C concentration of A in the gas at position x within the pore Specific reaction rate of A is 

Diffusion and reaction in a single pore in the catalyst pellet. 

Taking a steady-state balance of A across this section of the pore volume 

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