MODULATING LATTICE OXYGEN ACTIVITY OF CA2FE2-XMXO5 BROWNMILLERITE FOR PRODUCTION OF HIGH PURITY HYDROGEN FROM BIOMASS RESOURCES

Abstract

Chemical looping (CL) technology offers a promising avenue for producing high-purity hydrogen with inherent CO2 separation. A critical challenge lies in identifying oxygen carriers with high performance and sustained activity across multiple redox cycles. This study investigates the influence of metal doping (Co, Cu, Ni) on the performance of brownmillerite-structured Ca2Fe2O5 for biomass gasification and hydrogen production. Carriers were synthesized via a citric acid-assisted sol-gel method and tested in a fixed-bed reactor under atmospheric conditions. The study systematically examined the effects of temperature, water injection rate (steam/biomass ratio), and catalysts on biomass conversion. An optimal water injection rate of 0.1 mL/min with Ni-doped Ca2Fe2O5catalyst significantly enhanced hydrogen yield by 82.4% compared to the undoped carrier. Increasing temperature consistently improved H₂ yield throughout the gasification process. Notably, doping with Ni and Co significantly increased H₂ yield from 27.82 g/mol biomass (undoped) to 33.15 g/mol biomass (Ni) and 32.05 g/mol biomass (Co), respectively. Furthermore, this research explored the valuable application of adding biochar to the asphalt mixture. The results revealed that incorporating biochar significantly improved the asphalt's performance against rutting and cracking, offering a promising and sustainable approach to enhance pavement longevity.