“…where ε p is the porosity, i.e., the fraction of the volume occupied by the pores, and τ p is the tortuosity. The diffusion coefficient D i is given as the sum of two resistances by the so-called Bosanquet equation [27], which is composed of the diffusion coefficient, corresponding to intermolecular collisions, i.e., D i,m , and the Knudsen diffusion coefficient, i.e., D i,K , corresponding to the collisions of the molecules with the pore wall:…”