The selective catalytic reduction (SCR) catalysts are rendered inactive by sintering and poisoning during the operation of denitrification systems, resulting in large amounts of waste catalysts. By introducing the waste denitrification catalysts containing V (active component), Ce (additive component), and TiO₂ (carrier) as the oxygen carrier (OC) into the biomass chemical looping gasification (CLG) system, we propose a strategy for the disposal of waste resources and the generation of hydrogen-rich syngas. The ethanol effluent is also fed into the CLG system to improve the efficiency of hydrogen production. Experiments are carried out at various temperatures with different compositions of OCs and gasification agents, reaching the optimum H₂ yield of 0.651 L with 0.5g corn stalk and 5V-10Ce/TiO₂ at oxygen excess ratio Ω = 0.2, T = 800 ℃, and 10 mL ethanol solution. A fraction of Ce⁴⁺ from CeO₂ in the waste SCR catalyst are incorporated into the V₂O₅ lattice to form CeVO₄ solid solution, which together with the V₂O₃ in the catalyst promote the cracking of CH₄ to syngas. The kinetic and thermodynamic analysis further verifies that the waste SCR catalyst and the ethanol wastewater boost biomass CLG for hydrogen generation. The proposed CLG strategy has dual advantages of waste treatment and energy conversion.
 

SCR catalyst,Biomass,Chemical looping gasification,Hydrogen,Liquid waste