140 g H2/kg biomass d.a.f. by a CO-shift reactor downstream from a FB biomass gasifier and a catalytic steam reformer

The effect of adding a CO-shift reactor downstream from a fluidized bed biomass gasifier and a steam reforming catalytic reactor is studied in this paper. The upstream gasifier was of small pilot plant scale, 10 kg biomass/h. Therefore, the downstream catalytic reactors, steam reformer and CO-shift, operated under a real gasification gas. The gasifying agent used was H2OH2O–O2O2 mixtures. The CO-shift catalytic reactor used had one high (HT) and one low temperature (LT) adiabatic beds. Two commercial catalysts were used throughout the process. CO-conversions (eliminations) were higher than 90% and a H2H2-content as high as 73 vol%, dry basis, were obtained by the CO-shift system. This H2H2 content is equivalent to a yield of 140gH2/kg biomass d.a.f. The CO conversion and the increase (up to 14 vol%) of the H2H2 content, correlate well with the molar steam/CO ratio in the gasification gas at the inlet of the HT bed.