An adaptive binary friction model for multicomponent gas transport in tight porous media

A new multicomponent gas transport model called the adaptive binary friction model (ABFM) was developed. The merit of the ABFM lies in the rigorous treatment of viscous slip and diffusion slip. The ABFM uses the general slip boundary condition to characterize viscous slip and thus is applicable in multiple flow regimes. The ABFM uses the Kramers and Kistemaker model to describe diffusion slip and thus satisfies Graham's law in a natural way. The ABFM also eliminates the restrictive assumptions made in previous models, such as uniform flow. Published experimental data on multicomponent gas transport were used to test the ABFM. The agreement of the ABFM results with the experimental data is good. Moreover, the ABFM can predict the transport of different gas mixtures under various conditions based on the determined pore structure parameters. Considering its versatility, the ABFM is anticipated to be useful in heterogeneous catalysis, membrane transport, etc.