A port-based distributed parameter model of an adsorption column under isothermal conditions is presented. This model is made using bond graph terminology and basic axioms of irreversible thermodynamics. The particularity of this model is to split each phenomenon in basic elements with particular energetic behaviour, such as accumulation or dissipation. These basic elements are interconnected using the port variables and some interconnection power conserving structures, named Dirac structures. These energetic elements are presented in terms of the geometry of the different scales of the adsorption column. Moreover it is shown that each scale of the model has the same bond graph structure. The different scales of the model are also connected by a power conserving structure.