Comparative assessment of chemical looping assisted biomass gasification for H2 production: A Thermochemical, Exergy, and Environmental Perspective

This study conducts a comparative simulation of chemical looping-assisted biomass gasification for hydrogen-rich syngas production using Aspen Plus and HYSYS. Three biomass types (wood, industrial bark of Picea abies , Norway spruce), gasifying agents (steam, air), and oxygen carriers (Fe 2 O 3 , FeTiO 3 ) were assessed under eight cases. Steam gasification significantly enhanced H 2 yield and efficiency, while air gasification led to higher CO 2 emissions. Energy, exergy, and environmental analyses highlight steam-based configurations as superior, confirming their promise for efficient, low-carbon hydrogen production.Bark-based configurations (Cases 5–8) show higher efficiencies (38.5–39.15%) than wood-based systems (31.24–31.82%) despite the lower heating value of bark, while steam-based chemical looping results in lower GWP, reaching minimum values of about 6130 kg CO 2 -eq/h. Techno-economic analysis indicates similar capital costs across all cases (∼11.27–11.32 million USD), with operating costs governing the hydrogen production cost, which varies between 0.90 and 1.08 USD/kg H 2 and is lowest for Fe 2 O 3 -based systems. The novelty of this work lies in the systematic comparison of steam- and air-based chemical looping gasification for underexplored biomass feedstocks under identical operating conditions, supported by integrated energy, exergy, environmental, and techno-economic analyses, highlighting industrial bark as a promising feedstock for low-carbon hydrogen production. • Aspen Plus–HYSYS simulations reveal efficient chemical looping biomass gasification for H 2 • Steam gasification outperforms air, enhancing H 2 yield, efficiency, and CO 2 reduction • Industrial bark achieves highest energy efficiency (38.5–39.15%) despite lower LHV • FeTiO 3 oxygen carrier shows superior redox stability under steam gasification • Lowest H 2 cost (∼0.90 USD/kg) achieved with Fe 2 O 3 -based chemical looping systems