World-changing molten electrolysis process spun out of MIT can make steel with no emissions, may also be applied to other smelting processes.

In the crucible of industrial progress, steel stands as both the foundation and obstacle. Armed with its molten oxide electrolysis process, Boston Metal aims to revolutionize steelmaking that will join innovation with sustainability and offer a path toward greener steel production.

The advent of steel in industrial applications quickly shot progress forward in ways a generation prior could never comprehend. Now the backbone of modern living, steel is used from things like skyscrapers and bridges, to trains, planes, and automobiles. However, the cost of such a convenient building material is an extremely carbon-heavy process.

Steel is just purified iron. While fancy alloys have created even more durable steels, the first steel was just iron ore purified of excess carbon and other impurities in a blast furnace – this is also why steel production accounts for roughly 7 to 9% of the world's emissions.

Understanding that steel is not going anywhere, a startup out of Massachusetts Institute of Technology hopes to significantly reduce the carbon footprint of producing this ubiquitous material.

Boston Metal seeks to clean up the steelmaking industry using an electrochemical process called molten oxide electrolysis (MOE), which eliminates many steps in steelmaking and releases oxygen as its sole byproduct.

The company, which was founded by MIT Professor Emeritus Donald Sadoway, Professor Antoine Allanore, and James Yurko, PhD '01, is already using MOE to recover high-value metals from mining waste at its Brazilian subsidiary, Boston Metal do Brasil.

This work helps Boston Metal's team deploy its technology commercially and establish key partnerships with mining operators. It has also built a prototype MOE reactor to produce green steel at its headquarters in Massachusetts.

"There's a worldwide recognition that we need to act rapidly, and that's going to happen through technology solutions like this that can help us move away from incumbent technologies," said Boston Metal Chief Scientist and former MIT postdoc Guillaume Lambotte. "More and more, climate change is a part of our lives, so the pressure is on everyone to act fast."

Despite its name, Boston Metal has global ambitions, raising more than $370 million to date from organizations across Europe, Asia, the Americas, and the Middle East. The company expects to scale up rapidly to transform steel production in every corner of the world.

Decades-long search

Since the 1980s, Sadoway has researched the electrochemical process by which aluminum is produced.

The focus on such research was to find a replacement for the consumable anode used in that process – anodizing – which makes carbon dioxide as a byproduct. During this research, Sadoway began to conceptualize a similar electrochemical process to make iron.

But it wasn't until around 2012 that Sadoway and Allanore, then a postdoc at MIT, discovered an iron-chromium alloy that could serve as a cheap enough anode material to make the process commercially viable and produce oxygen as a byproduct.

That's when the pair partnered with James Yurko, a former student, to found Boston Metal.

"All of the fundamental studies and the initial technologies came out of MIT," said Lambotte. "We spun out of research that was patented at MIT and licensed from MIT's Technology Licensing Office."

Lambotte joined the company shortly after Sadoway's team published a 2013 paper in Nature describing the MOE platform.

"That's when it went from the lab, with a coffee cup-sized experiment to prove the fundamentals and produce a few grams, to a company that can produce hundreds of kilograms, and soon, tons of metal," he added.

MOE process

Massachusetts Institute of Technology

Boston Metal's process takes place in modular molten oxide electrolysis (MOE) cells, each roughly the size of a school bus.

Boston Metal's molten oxide electrolysis process takes place in modular molten oxide electrolysis (MOE) cells, each the size of a school bus.

Iron ore is fed into the cell, which contains the cathode (the negative terminal of the MOE cell) and an anode immersed in a liquid electrolyte.

The anode is inert, meaning it does not dissolve in the electrolyte or take part in the reaction other than serving as the positive terminal.

When electricity runs between the anode and cathode and the cell reaches nearly 3,000 degrees Fahrenheit (1,600 degrees Celsius), the iron oxide bonds in the ore are split, producing pure liquid metal at the bottom that can be tapped.

The byproduct of the reaction is oxygen, and the process does not require water, hazardous chemicals, or precious-metal catalysts.

The production of each cell depends on the size of its current. Lambotte adds that with about 600,000 amps, each cell could produce up to 10 tons of metal every day.

Steelmakers would license Boston Metal's technology and deploy as many cells as needed to reach their production targets.

"If you look around the world, a lot of the feedstocks for metal are oxides, and if it's an oxide, then there's a chance we can work with that feedstock," Lambotte continued. "There's a lot of excitement because everyone needs a solution capable of decarbonizing the metal industry, so a lot of people are interested to understand where MOE fits in their own processes."

Boston Metal is already using MOE to help mining companies recover high-value metals from their mining waste, which usually needs to undergo costly treatment or storage.

Lambotte also goes on to say that it could also be used to produce many other kinds of metals down the line, and Boston Metal was recently selected to negotiate grant funding to produce chromium metal – critical for a number of clean energy applications – in West Virginia.

Clean industrial revolution

Although the world feels oversaturated with stories of the next big, game-changing breakthrough, Boston Metal appears to have done the legwork to prove its technology's effectiveness and potential.

Slated to reach commercial scale in 2026, Boston Metals' steel decarbonization technology is already introducing the industry to MOE.

"I think it's a window for the metal industry to get acquainted with MOE and see how it works," Lambotte said. "You need people in the industry to grasp this technology. It's where you form connections and how new technology spreads."

It does not hurt that the electrical foundry company also has its Brazilian plant running on 100% renewable energy.

"We can be the beneficiary of this tremendous worldwide push to decarbonize the energy sector," said the MIT postdoc. "I think our approach goes hand in hand with that. Fully green steel requires green electricity, and I think what you'll see is deployment of this technology where [clean electricity] is already readily available."

Boston Metal's team is excited about MOE's application across the metals industry but is focused first and foremost on eliminating the gigatons of emissions from steel production.

"Steel produces around 10% of global emissions, so that is our north star," said Lambotte. "Everyone is pledging carbon reductions, emissions reductions, and making net zero goals, so the steel industry is really looking hard for viable technology solutions. People are ready for new approaches."