Tadeu Carneiro Is Trying to Make Steel Sustainable

“A technology that will revolutionize the way metals are manufactured is something you cannot say no to after working your whole career with metals,” he says.That technology is Boston Metal’s Molten Oxide Electrolysis, or MOE. Whereas traditional steelmaking involves mixing iron ore with coking coal, then melting them together in a giant blast furnace that emits massive amounts of carbon dioxide, Boston Metal’s patented MOE technology uses scads of electricity to melt iron ore and separate its contents, dividing pure liquid iron from impurities like magnesium, silica, and calcium. Instead of carbon dioxide, the only byproduct is oxygen. This is potentially revolutionary, because steelmaking by some estimates generates nearly 10% of all global greenhouse gas emissions.“We’re not transforming the way steel is manufactured for the ego of it. It’s necessary,” Carneiro says. “A process is needed that will eliminate 10% of the CO2 in the world, and this is the only process that can scale to do that.”To be clear, there are other viable options for decarbonizing steel. But Boston Metal argues that MOE is superior because it’s more forgiving: The leading alternative, hydrogen direct reduced iron, extracts pure iron from iron ore using hot hydrogen gas instead of coal or coke. Although it’s clean, it requires high-quality inputs with few impurities, whereas MOE works with all grades of iron ore.There’s just one catch. “The electricity needs to be clean,” Carneiro says. “Otherwise, it defeats the purpose.” Despite the persistence of petroleum, he has faith in renewable energy’s future. “There are places in the world today where you already have clean electricity at affordable prices,” Carneiro says, citing examples like Canada, Scandinavia, and his native Brazil, where Boston Metal is opening its first industrial facility later this year.Because steelmaking is extremely capital-intensive and cost-sensitive, that facility won’t make steel. Neither will two more planned facilities in Pennsylvania and Texas, both of which are expected to come online in 2029. Instead, all three will use MOE to recover from existing mining and metallurgical waste streams low-volume, high-value metals like niobium, tantalum, and nickel that are used in industries like electrification, AI, and defense. Given the low supply of these metals globally, Boston Metal is betting its technology can satisfy demand in a way that’s faster, more cost-effective, and more sustainable than establishing new mines.Investors seem to agree: In May 2026, the company announced $75 million in new venture capital, bringing its total raised to over $500 million. That money and the metal-recovery operations it funds will generate the income, interest, and evidence Boston Metal needs to tackle steelmaking. “Once we mature the technology and scale it with planned efficiencies, we can be competitive with the way steel is manufactured today,” Carneiro says.