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-O-2 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 H-2 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 H-2 content correlated well with the molar steam/CO ratio in the gasification gas at the inlet of the HT reactor.