This paper deals with the spatial discretization of distributed parameter systems. The originality of the proposed approach is to combine geometrical modelling and finite element discretization method to preserve the model structure associated with both mass and energy balances during the reduction. The approach is presented through the example of an adsorption process whose main feature is that it is an heterogeneous system. The methodology is described on the microporous phase and simulations are carried out on the full multilevel adsorption column. (C) 2008 Elsevier Ltd. All rights reserved.