1. Presentation of the adsorption phenomenon

The analyses described below can easily be applied to particles with a poorly dispersed pore distribution and uniform transport and transfer properties. However, in the case of particles obtained by agglomeration of porous microcrystallites, the average size of macropores (of the order of 1 µm) is very different from that of micropores (of the order of 10 nm). As a result, the apparent diffusivities of constituents in the two pore types, D _M (macropores) and D _m (micropores) respectively, are very different. The same is true for other quantities characteristic of transport and transfer (permeability, thermal conductivity, etc.). Note that macropore size is sufficient for convective flow to be superimposed on diffusional flow, but in what follows we assume it to be negligible, since the total pressure...