A NETWORK MODEL FOR THE PERMEABILITY OF CONDENSABLE VAPORS THROUGH MESOPOROUS MEDIA

The paper aims at introducing a discrete (network) approach to modelli ng transport of condensable vapours in mesoporous structures. Such mod els possess the potential for improving the understanding of the mecha nisms responsible for the observed transport behaviour. The basic elem ents of a typical pore network representing a mesoporous medium are su mmarized and the current state concerning the simulation of the relate d phenomena is given. The main processes involved (adsorption, mass di ffusion, surface flow, capillary condensation) are simulated over the entire range of relative pressure. Finally, the effects of material st ructural parameters (average pore radius, pore size distribution and s tandard deviation, pore connectivity) and other relevant factors (rela tive pressure. temperature, resistance to surface flow, total pressure drop) on vapour permeability are presented and the future research di rections are pointed out.