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Innovation economy

Woburn startup wants to steer the steel industry away from coal

Boston Metal has developed a way to manufacture iron using sustainable electricity.

Research and development engineers Alex Marshall (left) and Santana Huck worked on a semi-industrial furnace inside Boston Metal.Jessica Rinaldi/Globe Staff

In a two-story industrial bay, seven workers buzz around a big metal chamber, getting it ready to go online. A bright yellow crane slides back and forth above them, helping to move heavy components. And in big barrels toward the front of the bay there is raw iron ore shipped from Australia.

You might not expect such an operation in Woburn in 2022, but this is a startup working to make iron. (Yes, that same dull grey metal, #26 on your periodic table, that was made starting in the 1640s just down the road at the Saugus Iron Works.) Iron is the key ingredient in steel, and making steel accounts for about 8 percent of global greenhouse gas emissions, according to the World Steel Association.


The startup, Boston Metal, wants to help the steel industry reduce its dependence on burning coal-based fuel and use electricity instead — ideally sustainably produced electricity from sources such as hydropower or solar. Many of the world’s steelmakers, points out Boston Metal chief executive Tadeu Carneiro, “have made pledges to be carbon neutral by 2050, and they still don’t have the solutions to get there.” His company wants to be one of those solutions.

Boston Metal was founded a decade ago by two MIT professors and an alum with a doctorate in metallurgy. The process that Boston Metal uses, called molten oxide electrolysis, or MOE, can be used to make all kinds of metals, from titanium to steel to ferrochromium.

CEO Tadeu Carneiro poses for a portrait inside Boston Metal. Jessica Rinaldi/Globe Staff

Carneiro joined the company in 2017 after a four-decade career working in the metal industry in Brazil. “I said, we have to pick a bet. We can’t keep shooting everywhere,” he recalls. “We selected steel for the importance that it represents environmentally, and the size of the market.” About two billion tons of steel are produced annually today, and various estimates have that number rising to 2.5 billion tons by 2050, Carneiro says. Every ton of new steel manufactured spits out two tons of carbon dioxide into the environment. (Some steel is made from recycled metal, and that remelting process generates fewer CO2 emissions.)


In traditional steel manufacturing, a special form of coal is used to fuel a reaction that turns iron ore, an oxide, into pure iron. Then you can add elements like chromium to the molten iron to make stainless steel, or manganese to make structural steel, explains Adam Rauwerdink, a senior vice president at Boston Metal. But the iron production stage “is where the overwhelming majority of the emissions come from,” he says.

The company starts with the same input — iron ore — but it feeds it into a chamber called an electrolysis cell, along with a “soup of oxides,” in Carneiro’s words, that serves as an electrolyte. When electrical current is passed from an anode to a cathode inside the cell, it does two things: frees up those oxygen molecules, which exit the chamber through an exhaust pipe, and produces molten iron.

But key to making iron and steel production less environmentally damaging is getting access to sustainable power from wind, solar, hydro, or nuclear, and finding ways to store that power to use when it’s needed, such as in large-scale batteries. Ten years ago, Carneiro says, “you couldn’t dream of having abundant, reliable, green, and cheap electricity, but now the world has decided that that would be the case.” (Some of that infrastructure, he admits, is still being developed and perfected.)


Boston Metal hopes to eventually license its technology to metal producers, rather than making and selling its own equipment. Much of the gear can be purchased off-the-shelf, Carneiro says, but perfecting the process that takes place in the chamber is Boston Metal’s unique intellectual property.

But Boston Metal won’t be selling the only solution to making steel more sustainably. John Speer, director of the Advanced Steel Processing and Products Research Center at the Colorado School of Mines, says that activity in the sector includes not only startups working on new technologies, but also bigger companies exploring new avenues for reducing emissions, like using hydrogen as a fuel source. “There are significant public and private forces that are driving the whole supply chain to focus on decarbonization right now,” Speer says.

Kevin Dempsey, chief executive of the American Iron and Steel Institute, an industry trade group, says that sustainability is the “No. 1 focus for the industry, and it has been for the last several years.” In the United States, it has grown in importance not because of government regulation, Dempsey says, but largely because of “competitive pressure and costs.” Steelmakers want to “market their product as a cleaner product,” he says, and fuel represents a big chunk of their overall costs.

Boston Metal has 96 employees. The company got its earliest funding from federal grants but has since raised $85 million from private investors, including Fine Structure Ventures, an investment firm affiliated with the parent company of Fidelity Investments; the carmaker BMW’s venture capital arm; and Breakthrough Energy Ventures, a fund formed by Bill Gates in 2015. More funding could come later this year. “Do you know any company like ours that is pre-revenue, and is not always raising money?” Carneiro asks.


The next milestone for the company is getting its largest chamber up and running. This one, being finished in the big two-story bay, will be capable of producing more than a ton of steel in a single production run. Carneiro says the company hopes to test it out by mid-September. But even after that, there’s still lots of work to do refining the process. Boston Metal doesn’t plan to start licensing its technology to customers until 2026 and “towards the end of the 20s, we should have plants manufacturing green steel,” Carneiro says.

The upcoming pilot plant will produce a half a ton of steel a day that will be carbon free inside Boston Metal. Jessica Rinaldi/Globe Staff

That’s a long road. But Carneiro believes the company has the wind at its back, given the steel industry’s commitment to cut its emissions. “There is a world conspiracy in our favor,” he says. “Everyone wants us to succeed very quickly.”

Scott Kirsner can be reached at kirsner@pobox.com. Follow him @ScottKirsner.