Regeneration of iron fuel in fluidized beds Part II: Reduction experiments

Direct reduction of combusted iron powders using renewable energy is one the keys to ensure a carbon-neutral fuel cycle. Based on (de-)fluidization experimental study in Part I, experiments micron-sized hydrogen lab-scale gas-fluidized bed are conducted at temperatures ranging from 500 ∘C 650 ∘C. The effects temperature, velocity and concentration performance (including degree, particle morphology size change) sintering/defluidization behavior investigated. Overall, degree higher than 90% reached lower temperature ∘C, whereas serious problem sintering encountered, which leads quick defluidization thus relatively low degree. Temperature has been found have pronounced effect behavior, while gas process negligible. SEM images show that reduced porous with pore increasing temperature. These findings provide insights for design industrial hydrogen-based regeneration fuels.