In easily my favorite sustainability story of the week, researchers at MIT have developed a process to manufacture steel without any greenhouse gas (GHG) byproducts. Not only is it a carbon-free process, but the steel produced is of a higher purity, and once scaled up it will actually prove to be cheaper, according to a paper published in the journal Nature.
Worldwide steel production totals about 1.5 billion tons per year. The most popular process heats iron ore (which is mostly iron oxide) along with carbon, producing CO2 as a byproduct; for every ton of steel produced, almost 1.8 tons of CO2 is emitted, which accounts for as much as 5% of the world’s total GHG emissions, according to MIT. Until now, the steel industry has had little luck in the search for carbon-free methods of production.
However, the story of how this was discovered is almost as unbelievable as the idea of carbon-free steel. MIT materials chemistry professor Donald Sandoway received a grant from NASA to look for ways to produce oxygen on the moon in order to create a lunar base. He found that, through a process called molten oxide electrolysis, he could use iron oxide from lunar soil to make oxygen in abundance with no special chemistry. Using lunar-like soil residue from an asteroid impact crater in Arizona, he was able to test this process and found that a high-purity steel was simply a byproduct.
With a few tweaks such as changing the chemical used as the anode, Sandoway was able to develop a process that was easy to scale up and could revolutionize the steel industry. Furthermore, the same process can be adapted to make nickel, titanium or ferromanganese.
There is no news yet on how or when these techniques will be implemented on the mass production scale, but what is one small step for the steel industry could prove to be one giant leap for mankind.