Oxidative reforming of biomass derived ethanol for hydrogen production in fuel cell applications

Oxidative reforming of biomass derived ethanol over an inexpensive Ni–Cu/SiO₂ catalyst has been carried out with respect to solid polymer fuel cell (SPFC) applications. Two types of runs were performed, either under diluted conditions (with helium as diluent) or under conditions corresponding to an on-board reformer. Selectivities of ethanol reforming have been analyzed as a function of operating parameters: reaction temperature, H₂O/EtOH molar ratio and O₂/EtOH molar ratio of the feed to the reformer. The hydrogen content and the CO₂/CO_x molar ratio in the outlet gases were used as parameters to optimize the operating conditions in the reforming reactor. The tests carried out at on-board reformer conditions evidenced that an H₂O/EtOH molar ratio=1.6 and an O₂/EtOH molar ratio=0.68 at 973 K allow a hydrogen rich mixture (33%) that can be considered of high interest for SPFC. Furthermore, the use of oxygen decreases the production of methane and coke which increases in turn the lifetime of the catalyst. The stability of this catalyst has been fully demonstrated by long time runs.