Adsorption

Use this node to model adsorption of the (fluid phase) solute species onto the surface of the porous matrix. It is available as a subnode to the Porous Medium and the Unsaturated Porous Medium nodes.


	This feature is only available in a limited set of add-on products. See https://www.comsol.com/products/specifications/ for more details on availability.

Matrix Properties

The density of the porous media is needed when modeling adsorption to the surface of the porous matrix. Choose to input either the ρ, or the ρs. The former is the density of the porous matrix including empty pores, while the latter corresponds to the density of the pure solid phase. The density can be defined from the domain material by selecting , or from a user defined expression. When a is used on the selection, the density will be requested from a subfeature. Several features can be used to model a homogeneous mixture of several solid components.

Adsorption

Select an — , , , , or to specify how to compute cP, the amount of species sorbed to the solid phase (moles per unit dry weight of the solid):

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For :

Enter a kL,c (SI unit: m3/mol) and an cp,max,c (SI unit: mol/kg).

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For :

Enter a kF,c (SI unit: mol/kg), a NF,c (dimensionless), and a cref,c (SI unit: mol/m3).

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For :

and

Enter a bT,c (SI unit: m3/mol), a NT,c (dimensionless), and an cp,max,c (SI unit: mol/kg).

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For :

and

Enter a KB,c (dimensionless), a c0,c (SI unit: mol/kg), and an cS,c (SI unit: mol/m3).

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For enter an cP,c (SI unit: mol/kg):

For more information, see Adsorption in the theory section.