A novel system of biomass-based hydrogen production by combining steam bio-oil reforming and chemical looping process

Biomass to hydrogen is becoming a promising way to produce clean energy with zero or even negative carbon emission. In this study, a novel system containing a biomass pyrolysis process, a catalytic steam reforming of bio-oil process, a chemical looping unit using biochar as the reducing agent and other auxiliary processes including H-2 separation and thermal energy circulation processes for hydrogen production is proposed and simulated based on the previous studies. While, a waste heat recovery system is recommended for energy recuperation to make the entire system become auto-thermal. The effects of steam to carbon ratio in the catalytic steam reforming reaction and temperatures at reducing and steam reactors in the chemical looping unit on the system performance are analyzed in details. Under the optimum condition in the proposed system, about 6.9 kg/h of hydrogen could be produced from 100 kg/h of wood biomass with 58.3 kW of net power. Compared with the biomass direct chemical looping process for H-2 production, separating the bio-oil and biochar after the pyrolysis process and combining the steam bio-oil reforming process with the chemical looping unit using biochar for H-2 production can increase H-2 production efficiency from biomass by more than 50%. It is expected that this proposed system could be implemented in a practical application.