Multi-component gas mixture diffusion through porous media: A 1D analytical solution

In this paper, the equations governing the transport of gas mixtures through porous media in 1D geometry and in absence of mass sources are examined. When the mass fluxes are determined by external conditions, the transport equations can be solved to find the variations of gas composition through the media. For this class of problems, we show that the convective transport mechanism can be, in many cases, neglected, regardless of the physical properties of the porous media and of the flux intensities. An estimate of the maximum error made in neglecting the convective term is provided. A matrix analytical solution of the diffusion equations is given for the general case of N-components gas mixtures. Explicit analytical solutions are derived in two particular cases.