Six-flow reactor technology applied to catalyst screening for the autothermal reforming of model biogas

International @ ING+MLU:NOG:FRM:YSCInternational audienceBiogas is a complex gas mixture produced from the anaerobic digestion of biomass, which contains methane and carbon dioxide as main components. It can be burnt directly, but it has a lower heating value as natural gas. Biogas can also be reformed into hydrogen, which is an essential feedstock in the chemical industry and can also be used as a fuel in fuel-cells to produce electricity. Hence, the production of hydrogen from biogas can contribute to reduce our reliance on fossil fuels and develop renewable energies.Autothermal reforming of model biogas on different nickel supported catalysts was performed at 700°C and atmospheric pressure. The carrier gas was a mixture composed of 42% steam, 14% CH4, 9% CO2, 7% O2 in a balance of inert Argon. Nickel-based catalysts are generally used for steam-reforming of methane because of their low cost and high activity. However, they are prone to oxidation, coking and sintering problems leading to catalyst deactivation. Catalysts were thus developed to prevent these issues. Nickel supported on mixed oxides, perovskites and spinels were synthesized. Long-term catalytic tests were performed in order to discriminate the catalysts resistance to deactivation. In order to save time with long-term experiments, a six parallel-flow reactor was successfully implemented to test six catalysts simultaneously under similar flow rate, temperature and feed composition. With the exception of LaNiO3, the catalysts showed the same deactivation profiles: a slow deactivation was observed followed by an abrupt loss of activity. The catalyst lifetime under time-on-stream differed depending on catalyst composition: Among the tested catalysts, nickel supported on magnesium spinel showed a high resistance to deactivation. Preliminary results showed that deactivation on the different catalysts was likely related to oxidation. Carbon was evidenced on spent catalysts, but does not appear as the main cause of deactivation