J.P. Kopasz, Z. Zeng, D. Ellis, J. Rebohar, J. Krogstad, M. Sankaran
Argonne National Laboratory,
United States
Keywords: hydrogen plasma, iron making, hematite, magnetite, iron
Summary:
The steel industry currently accounts for about 8% of global CO2 emissions, and emits approximately 1.8 tons of CO2 per ton of steel produced, about one third of that from making iron. We are developing a cold hydrogen plasma-rotary kiln furnace process to reduce iron ore and potentially eliminate CO2 emissions associated with the ironmaking process. Hydrogen replaces the coal or natural gas currently being used in the BF/BOF and DRI/EAF processes. We use an atmospheric pressure non-equilibrium hydrogen-plasma rather than molecular hydrogen to improve the thermodynamics and kinetics of iron ore reduction and reduce the temperature required. A rotary kiln design is used to control the residence time of the ore in the plasma and to recover the thermal energy from the plasma. If renewable energy is used to provide the electricity for the plasma and for electrolysis to produce the hydrogen, the process could be zero-carbon. We have demonstrated H-plasma reduction of both hematite and magnetite rich ores at temperatures down to 600C. We will discuss results from the H-Plasma reduction and scale-up and integration of the cold H-plasma into a rotary kiln and prospects for increasing the efficiency of this ironmaking process while reducing GHG emissions.