Retooling steel production for a greener future

Iron and steel form the backbone of society, yet the traditional methods to produce them are responsible for a significant portion of carbon emissions.
 
In the fall 2024 Wulff Lecture on October 23, Antoine Allanore of MIT’s Department of Materials Science and Engineering emphasized the need for more sustainable metals production, presenting his own research into cleaner processes.
 
The Wulff Lecture is a twice-yearly talk open to all but specifically targeted at first-year undergraduates, highlighting materials science and engineering and its impact on society.

“Today we emit 1.85 tons of CO2 per ton of steel that is made,” said Allanore, professor of metallurgy and the Heather N. Lechtman Professor of Materials Science and Engineering. “So you multiply the number and you see the math. That material supply comes with an even greater mass of carbon dioxide.”
 
Allanore contrasted blast furnace methods of producing iron and steel with new electrochemical processes designed to reduce carbon emissions. One promising technique, molten oxide electrolysis, eliminates the need for carbon in metals production.
 
Central to the new process are the anode and cathode—components that must withstand extremely high temperatures. The anode converts oxygen ions from iron ore into oxygen gas, while the cathode turns metal ions into solid metal.
 
“Now the problem is, you have to make this carbon-free, so you need to find materials to do the anode,” said Allanore.
 
He showed examples of chromium anodes tested at MIT, which form the basis of Boston Metal, a DMSE startup co-founded by Allanore, Professor Emeritus Donald Sadoway, and DMSE alum Jim Yurko, who now leads Apple’s product design materials engineering team.
 
Allanore also explored the potential of using sulfides in metal production, explaining that sulfur-based metal production processes generate fewer carbon emissions than traditional methods.
 
Concluding his talk, Allanore noted that materials science knowledge will remain relevant in future advancements.
 
“So if you have interest in how building blocks come together and give you condensed matter, this is the right place to be.”