Hydrogen Production by Biomass Gasification with Steam−O2 Mixtures Followed by a Catalytic Steam Reformer and a CO-Shift System

This paper studies the effect of adding a CO-shift reactor downstream from a fluidized-bed biomass gasifier and a steam-reforming catalytic bed. The upstream gasifier was of small pilot-plant scale, 10 (kg of biomass)/h, so the downstream catalytic reactors, steam-reformer and CO-shift, operated under a real gasification gas. The main gasifying agent used was H2O−O2 mixtures. Some results are also reported for gasification with air with some steam. The CO-shift catalytic system used had one high- (HT) and one low-temperature (LT) reactor. Commercial catalysts were used. CO conversions (eliminations) higher than 90% and a H2 content as high as 73 vol %, dry basis, have been obtained by the CO-shift system. The CO conversion and the increase (up to 14 vol %) of H2 content correlated well with the molar steam/CO ratio in the gasification gas at the inlet of the HT reactor.