Biogas as hydrogen source for fuel cell applications

In the last decade, production of biogas from biomass degradation has attracted the attention of several research groups. The interest on this hydrogen source is focused on the potential use of this gas as raw material to supply high temperature fuel cells (HTFC). This paper reports a wide research investigation carried out at CNR-ITAE on biogas reforming processes (steam reforming, autothermal reforming and partial oxidation). A mathematical model was developed, in Aspen Plus, and an experimental validation was made in order to confirm model results. Simulations were performed to determine the reformed gas composition and the system energy balance as a function of process temperature and pressure. The value of Gas Hour Space Velocity (GHSV) was selected for calculating compositions at full equilibrium, as it is expected in operative large scale plant. To obtain a realistic evaluation of the reforming processes efficiency, the energy balance for each examined process was developed as available energy of outlet syngas on inlet required energy ratio. The comparison between values of efficiency process gives useful indication about their reliability to be integrate with fuel cell systems.