Transport Dispersive Model in CADET

Chromatography Modeling
1

Hi everyone!

I want to use CADET to model breakthorugh curves using the Transport Dispersive Model:

Formula TDM

I am struggling with the formulas a bit. Is this equivalent to the ‘Lumped Rate Models with Pores’ in CADET?
https://cadet.github.io/master/modelling/unit_operations/lumped_rate_model_with_pores.html

Thank you and best regards
Nils

2

Hi Nils,

The equation you’ve posted does look like the transport equation for the interstitial volume of the Lumped Rate Model With Pores (LRMP), assuming c_p is the liquid concentration inside the pores and a_f is the volumetric shape factor.
The transport dispersive model that I usually see in literature is similar to our Lumped Rate Model Without Pores (LRM).
The main difference between the models is that the LRMP additionally accounts for film diffusion into the particles, and thus describes two liquid phases: Liquid phase in the interstitial column volume/bulk, and liquid phase inside the pores, which can be subject to a binding model, i.e. can be adsorbed.
The LRM assumes film diffusion to be non-limiting and thus does not differentiate between the aforementioned liquid phases.

Best regards,
Jan

1 Like
3

Hi Jan,

thank you, that helps a lot!

Best
Nils