Transport and Adsorption
Model ID: 5
This model demonstrates how to model phenomena defined in different dimensions in a fully coupled manner using COMSOL Multiphysics.
Whereas in most cases the reaction rate expression is defined as a function of the concentrations of the reactants and products, in adsorption reactions it is also necessary to model the surface concentrations of the active sites or surface complex. This implies that the mass balance in the bulk of the reactor must be coupled to the mass balance for species present only at the surface of the device. This device could be a catalyst, a biochip, a semiconductor component, or any process with surface-specific species.
In this particular case, the model involves a small parallel-plate reactor with an active surface. It is a simple example of surface diffusion and surface reactions coupled to the transport of species between the reacting surface and the surrounding volume. Processes of this kind are found, for instance, in heterogeneous reactors and biacore chips.