This paper presents a numerical investigation of the sorption kinetics under constant-pressure conditions using a finned adorption reactor. The governing equations, derived from local thermodynamic equilibrium and energy balance, are solved using an explicit scheme. The model is validated and used to analyze the effect of important design parameters on the performance of the adsorbent reactor. It is found that using metallic fins at sufficiently small intervals and reducing the contact resistance at the interface, metal-adsorbent can improve significantly sorption kinetics. However, the fin thickness and the nature of the metal have little effect on the rate of heat transfer. The model can be used to optimize the design of efficient adsorption heat exchangers.