ENZDYN - Dynamic Diffusion and Enzymatic Reaction

This example involves the same diffusion-reaction situation as in the previous example, ENZSPLIT, except that here a dynamic solution is obtained, using the method of finite differencing. The substrate concentration profile in the porous biocatalyst is shown in Fig. 5.252. 

With complex kinetics a steady-state split boundary problem of the type of Example ENZSPLIT may not converge satisfactorily. To overcome this, the problem may be reformulated in the more natural dynamic form. Expressed in dynamic terms, the model relations become. 

The kinetic equation used here is an enzymatic Michaelis-Menten form with product inhibition 

Using finite differencing techniques for any given element n, these relations 

Here Sq is the external substrate concentration and AX is the length of the finite difference element. Boundary conditions are given by the external concentrations Sq and Pq and by setting Sn+i = Sn and Pn+1 - Pn. at the slab centre. 

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