A novel model based on multi-layer algorithms was developed and identified for multi-component gas adsorption, and the competitive behaviors of alkane adsorption were also investigated by this model. The results showed that the model with the intrinsic physical-chemistry parameters describes very well the adsorption equilibria for individual alkane adsorption and predicts reasonably well the multi-component adsorption equilibria for the systems studied in this paper. The competitive phenomena of alkane adsorptions, involving the layer growth, active site replacement, and equilibrium behaviors were explored. In addition, the effects of characteristic parameters of adsorbate and adsorbent on selectivity were also discussed.