General Model with Interfacial and Intraparticle Gradients

Truly homogeneous model. Concentration profiles. From Wen [1968]. 

2 GENERAL MODEL WITH INTERFACIAL AND INTRAPARTICLE GRADIENTS 

When the particle is assumed to be isothermal, only differential material balances have to be written. The differential balance on the reacting gaseous component A—the continuity equation for A—contains an accumulation term accounting for 

The rates are based on weight of the particle, as in the preceding chapters on catalytic reactions. The dimensions of Fa are kmol Alkg part. s, of rs, kmol 5/kg part, s when only a component 5 of the solid reacts or kmol soUd/kg part, s when all the solid reacts. The concentration Cas is expressed in kmol AIvcdf and Cs is expressed in kmol 5/m p when only a component of the solid reacts or in kmol solid/m p when all the solid reacts. The initial and boundary conditions are At t= 0  

If it is assumed that the porosity depends linearly on the solid reactant 

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A General Model with Interfacial and Intraparticle Gradients ... 

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