Experimental and numerical performance assessment of green-hydrogen production from biomass oxy-steam gasification

The production of hydrogen from residual biomass represents a sustainable alternative to integrate the production of renewable hydrogen in coming years. This work shows the results obtained during an experimental campaign dedicated to analysing the performance of a downdraft gasifier of about 100 kWt fed with woody biomass and oxy-steam mixtures. With suitable oxygen-steam ratios it was possible to produce a syngas with a hydrogen content higher than 40%vol, with a cold gas efficiency of more than 80%. The experimental syngas composition is used as input of a numerical model, created in Aspen Plus® and dedicated to evaluating the performance of the plant section for the pure H2-production. The numerical analysis highlighted the possibility of obtaining approximately 5% by mass of hydrogen with respect to the biomass used, also evidencing how the correct use of thermal waste and residues makes the whole plant (gasifier plus hydrogenizer) independent on heat supply.