The steel industry produces roughly 11 percent of the world’s carbon dioxide emissions, so cleaning up the industry is a top priority.
Now Boston Metal has successfully demonstrated that its Molten Oxide Electrolysis (MQE) industrial cell can be scaled up to produce large amounts of a steel, a big milestone for hopefully one day producing metal without the need for coke, a coal-based fuel.
As its name suggests, the MQE process requires electricity to create liquid iron, so much of its green energy accolades require electricity supplied from green sources, such as solar, wind, or even nuclear.
The world is hungry for steel. In 2024, the worldwide industry produced nearly 2 billion metric tons of the iron-carbon alloy while burping out about 11 percent of the total carbon dioxide emissions for the year. While transportation, energy production, and agriculture all take up bigger slices of that unsavory doomsday pie, steelmaking remains a large contributor to the global climate crisis.
The problem is the coal-based fuel called coke (no, not that Coke) that lies at the heart of the conventional steel-making process. Coke provides a dual role by delivering the heat required for steelmaking while also stealing away oxygen in the process, leaving behind molten iron—the key ingredient of steel. When coke combines with oxygen in this way, it’s eventually released as carbon dioxide, the greenhouse gas that’s slowly (but surely) imperiling life on Earth.
But if there’s one thing humans are good at, it’s engineering themselves out of a problem, and the green energy company Boston Steel, originally developed at MIT, believes it finally has a green steel solution that’s scalable. The company announced that it has successfully demonstrated its multi-inert anode Molten Oxide Electrolysis (MQE) industrial cell that can produce a ton or two of steel in a month. While that’s not enough to replace large-scale steelmaking, adding more anodes and more reactors can increase that capacity and eventually lead to wide-scale green steel adoption—or that’s the hope, anyway.
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“We are the only company with a direct and scalable approach to more efficient and clean steelmaking, and I can now say that tonnage steel is flowing from our multi-inert anode MOE cell,” Tadeu Carneiro, CEO of Boston Metal, said in a press statement. “With this milestone, we are taking a major step forward in making green steel a reality and we’re doing it right here in the U.S., demonstrating the critical innovation that can enhance domestic manufacturing.”
And like most green energy technologies, it relies on electrification. Instead of using coke for developing molten iron, MQE uses a metallic anode that sticks into the reactor and provides electricity, heating up the iron ore to 1,600 degrees Celsius (2,900 degrees Fahrenheit) and driving the reactions for creating molten iron. And the byproduct of this interaction? Oxygen. Of course one big piece of this green steel puzzle is that the supplied electricity must come from renewable resources in order to be truly zero emissions, so building out the world’s green energy infrastructure remains a top priority.
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According to MIT Technology Review, Boston Metal’s reactor has grown from the size of a coffee cup to this latest model that can produce a ton of metal in just 12 years. To really clean up the industry, Boston Metal will need to scale up even more, but now it’s proven that the technology is ready to go big or go home. The company anticipates having a demonstration plan up and running in late 2026 and wants to begin licensing the technology to steelmakers around the world.
“There is no lack of demand for green steel today,” Carneiro said in a video describing the company’s technology in 2022. “Once we go commercial by 2026…the application of our technology and the adoption will be very fast.”
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Darren lives in Portland, has a cat, and writes/edits about sci-fi and how our world works. You can find his previous stuff at Gizmodo and Paste if you look hard enough.