Steam reforming of biogas over a Rh/Al2O3 catalyst in an annular microreactor

The article deals with the catalytic steam reforming of biogas of model composition into hydrogen and carbon monoxide over a Rh/γ-Al2O3 catalyst in an annular microchannel reactor. The reforming of biogas consisting of 60% methane and 40% carbon dioxide in a steam medium has been experimentally investigated under isothermal conditions while activating the reactions on the inner convex wall of the annular microchannel with a thin catalyst layer. The experiments have been performed at a residence time of 0.12 s, reactor temperatures of 750 and 860°C, and a water: biogas molar ratio of 0.8 to 3.1 in the feed. The range of water: biogas molar ratios maximizing the hydrogen yield has been determined for the model biogas. By changing the reactor temperature and water: biogas molar ratio, it is possible to widely vary the hydrogen: carbon monoxide molar ratio in the resulting synthesis gas.