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Dynamic diffusion and reaction in a porous solid catalyst layer

The overall reaction is A ⇀ B and is far from equilibrium under conditions here. Reactant A adsorbs reversibly over catalyst surface sites S: A + S ⇌ AS. Click here for more information on the model. (opens in new tab)

Also see the Catalyst Pellet desktop simulation on the Download page. See on GitHub, shop plans, photos and publications for the Dynamic Diffusion Reactor, which is used to measure gas composition at the outside and the center of a porous catalyst pellet under dynamic conditions,

Click the Run button below. Hit the enter key or click out of field after changing inputs.

Select the "slow" rate determining step below: Model 1 (simple) or 2 (self-inhibiting).

Click here for more information (opens in new tab)

See space-time plot of rate, and average rate and conversion at bottom

Enter max inlet A conc:

Enter Kflow

Enter Kads

Enter Kdiff

Enter Thiele Modulus

Enter alpha

Enter B out scale factor

Enter cycling period

Enter square duty cycle % on



Gas profiles
catalyst layer

profiles in
catalyst layer

Average Rate (dimensionless turnover frequency) =



Average Conversion of A =

outer, gas-catalyst interface:

Space-Time plot of reaction rate

inner, sealed surface:

Click the Run button to start. Hit the enter key or click out of field after changing inputs.