The production of hydrogen from waste biomass could play an important role in the world
energy scenario if efficient and reliable processes will be developed. Via kinetic and thermodynamic
simulation and experimental data system, realized during the European
project UNIfHY, to produce pure hydrogen from biomass is analysed. The plant is mainly
composed of bubbling fluidized bed gasifier with catalytic filter candles, Water Gas Shift
and Pressure Swing Adsorption (PSA). Focussing on the hydrogen production, a sensitivity
study was carried out varying parameters as the steam to biomass ratio and the gasifier
operating temperature. The results show that the hydrogen yield increases at increasing
temperature and steam to biomass ratio, even if the required energy input increases as
well. The global efficiency depends substantially on the PSA unit: the off gas of this unit is
composed of residual CO, CH4 and H2, that can be burned in the combustor of the dual
fluidized bed gasifier to supply the extra-heat to the gasification process avoiding the input
of auxiliary fuel.