The node inherits all valid domains from its parent feature. For the invalid domains, not applicable is shown.

Select Diffusion model — Millington and Quirk model (the default), Bruggeman model, Tortuosity model, or User defined to describe the effective correction of the diffusion coefficient in the pellet. In the case of the Tortuosity model, a tortuosity factor for the tortuosity τpe within the pellet is required. Use this section to specify diffusion models and diffusion coefficients inside the reactive pellets.

From the Diffusion coefficient list, select diffusion coefficient for different species. If a User defined diffusion model is selected, an Effective diffusion coefficient Dpeff,c (SI unit: m2/s) is entered. The default value is 1·10-9 m2/s.

Diffusion coefficients calculated in Chemistry are available in the list when Chemistry (with the Define variables for porous pellets selected under Pellet Chemistry section) is coupled to the Packed Bed feature.