CWRU Think: SALT SOLUTION Rohan Akolkar is developing a greener way to make steel and process rare-earth metals

image of person head and shoulders -- CMI project lead Rohan Akolkar, Case Western Reserve University
 Rohan Akolkar, Case Western Reserve University

Every year, steel production pumps almost 3 billion tons of carbon dioxide (CO2) into our atmosphere—almost three times the amount produced annually by commercial air travel. And as demand keeps growing, Rohan Akolkar believes it's time for a new, greener way to make steel.

"We have no choice but to really come up with a revolutionary process that offers both sustainability and cost effectiveness," said Akolkar, PhD, professor of chemical engineering at Case Western Reserve.

The bulk of steel's greenhouse-gas emissions comes from the energy-intensive process of producing iron. In its natural form, iron ore is composed of molecules containing iron and oxygen. To separate the pure iron metal, steelmakers combine the ore with carbon at temperatures up to 1,700° Celsius. The process is a double whammy for the environment: It not only releases carbon dioxide as a byproduct, but many of the furnaces are powered by burning coal.

With several grants from the U.S. Department of Energy (DOE) and in collaboration with partners including Lawrence Livermore National Laboratory, Argonne National Laboratory and Cleveland Cliffs Inc., a major steelmaker, Akolkar is working to show the process can work efficiently enough to be economically competitive with conventional blast furnaces.

Molten-salt electrolysis is also a more sustainable way to purify rare-earth metals, materials that are ubiquitous in modern digital gadgets and essential for making the strong, powerful magnets inside green tech such as wind turbines and electric vehicle motors. Contrary to their name, rare-earths are not particularly rare, but are typically scattered in low concentration among other, less valuable materials. The conventional method for separating different types of rare-earths relies on environmentally damaging solvents and emits powerful greenhouse gases.

Some national security experts worry the United States depends too heavily on China for rare-earths, which are a key ingredient in U.S. military might. If the supply were cut off, everyday consumers and the armed forces would both feel the pinch.

To Akolkar, molten-salt electrolysis presents a unique opportunity to build a greener domestic rare-earths industry from the ground up. He and his colleagues have already demonstrated the process in the lab, with support from the DOE and its Critical Materials Innovation Hub. The next step is taking the process to factory scale.

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