Direct reduction of metal oxides to metals for sustainable manufacturing

Description:
Direct, electrochemical reduction of metal oxides to metals can improve the throughput and efficiency of metal production by avoiding separate processes for dissolution. Using technoeconomic analysis, we have identified electrified pathways for iron (Fe) reduction that lead to levelized costs < $400 per tonne Fe, competitive with iron produced in blast furnaces. We report systematic electrochemical studies investigating the mechanism for direct plating and the role of metal oxide impurities in the iron-oxide feedstock. Lastly, we report device-level data from a 4 cm^2 pilot cell that takes in low-cost brine, Fe oxide, and electricity and yields high-purity metallic Fe at current densities 0.1-0.3 A cm-2 and cell efficiencies < 5 MWh per tonne Fe. In comparison to the blast furnace process for iron reduction, this process requires similar amounts of energy but reduces the carbon footprint of steel by 80%.

Speaker: Paul Kempler - University of Oregon