Biogas is considered a potential, renewable fuel to be used as a hydrogen source. At present, a steam reforming is widely used process in hydrogen production, but it needs to be operated at high temperature to achieve high hydrogen yield. Because biogas consists of mostly CO 2 , the hydrogen purification of a reformate gas obtained is another important issue, especially for fuel cell applications. In this study, an enhanced-adsorption steam reforming process in which steam reforming reaction and CO 2 adsorption are occurred in a single unit is investigated. A thermodynamic analysis is performed to study effects of important operating parameters on hydrogen yield and product distribution. It is found that a biogas processor should be operated at high temperatures and inlet steam-to-methane ratio. The content of CO in the reformate gas increases with increased operating temperature. The steam reforming of biogas coupled with a CO 2 adsorption gives a higher hydrogen product with considerable low CO content, compared to the conventional steam reforming of biogas.