The Direct Reduction of Iron Ore with Hydrogen

The steel industry represents about 7% of the world's anthropogenic CO2 emissions due to the high use of fossil fuels. The CO2-lean direct reduction of iron ore with hydrogen is considered to offer a high potential to reduce CO2 emissions, and this direct reduction of Fe2O3 powder is investigated in this research. The H-2 reduction reaction kinetics and fluidization characteristics of fine and cohesive Fe2O3 particles were examined in a vibrated fluidized bed reactor. A smooth bubbling fluidization was achieved. An increase in external force due to vibration slightly increased the pressure drop. The minimum fluidization velocity was nearly independent of the operating temperature. The yield of the direct H-2-driven reduction was examined and found to exceed 90%, with a maximum of 98% under the vibration of similar to 47 Hz with an amplitude of 0.6 mm, and operating temperatures close to 500 degrees C. Towards the future of direct steel ore reduction, cheap and green hydrogen sources need to be developed. H-2 can be formed through various techniques with the catalytic decomposition of NH3 (and CH4), methanol and ethanol offering an important potential towards production cost, yield and environmental CO2 emission reductions.

Automated summary

The steel industry accounts for about 7% of global anthropogenic CO2 emissions, with the direct reduction of iron ore using hydrogen considered to have high potential to reduce CO2 emissions. This research investigated the kinetics and fluidization characteristics of Fe2O3 powder in a vibrated fluidized bed reactor for H-2 reduction. The study showed high yield of direct H-2-driven reduction with smooth bubbling fluidization achieved.