Chlor-Iron Process for the Low-Temperature, Direct Reduction of Iron Oxide for Green Steel

Abstract

The reduction of iron ores to metal for steelmaking produces comparable carbon emissions to all light-duty vehicles. We have identified a scalable electrochemical pathway for iron (Fe) production, which we term the chlor-iron process, that consumes only iron and salt water as reactants and could potentially be cost-competitive with iron produced in blast furnaces. Here, we report recent investigations on the mechanism of direct oxide reduction using naturally occurring and synthetic ores and identify key impurities that influence the current efficiency towards Fe. We present device-level data for continuous production of Fe and Cl2 at cell efficiencies < 5 MWh per tonne and with repeated harvesting of iron combined with technoeconomic analysis of pathways to cost competitive iron production. Lastly, we share ongoing scale-up efforts including recent data from a 100 cm2 bifacial cell. The process is unique in that the co-production of NaOH can lead to a net-negative emissions pathways for metals production.