Steel, the pillar of modern society, produces almost 10% of all carbon dioxide emissions an astronomically high environmental cost for a material holding up skyscrapers, bridges, cars, and countless other essentials. And the industry held on to a high-carbon-producing technique for decades, where each metric ton of steel produces nearly two metric tons of CO2 emissions. The conventional process relies on coke-fired blast furnaces to reduce the oxygen content of iron ore. Not only does this purify the iron, but also generates enormous amounts of greenhouse gases, which contribute significantly to global warming.
Come on Boston Metal, a MIT spinout committed to shaking up this legacy process with a revolutionary innovation: molten oxide electrolysis (MOE). This electrochemistry substitutes coke for electricity to purify iron ore, shattering its molecular bonds and leaving it with oxygen as the sole waste product. Powered by renewables like solar or wind, the process could produce steel with a zero carbon footprint—a game-changer for an industry grappling with its green legacy.
It all began at MIT when Professor Emeritus Donald Sadoway and his research team were researching electrochemical processing to produce aluminum. In the process of their research, they encountered an iron-chromium alloy that was ideal to be utilized as an inert anode, which is a central component in MOE technology. In contrast to conventional anodes that get consumed and emit CO2, Boston Metal’s inert anode does not get consumed and is stable, which allows for scalable and sustainable steelmaking. According to Chief Scientist Guillaume Lambotte, “All of the fundamental studies and the initial technologies came out of MIT. We spun out of research that was patented at MIT and licensed from MIT’s Technology Licensing Office.”
Boston Metal just achieved a milestone: producing over a ton of molten steel in its Woburn, Massachusetts commercial reactor. It is validation of the multi-anode process required to scale up the process. CEO Tadeu Carneiro proudly claimed, “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.” The reactor is currently producing only one or two tons of steel per month, but industrial-scale production is set to enter a larger demonstration plant by 2026.
Applications of MOE go beyond steelmaking. Boston Metal is already using the technology to recover precious metals from mining tailings at its Brazilian subsidiary, Boston Metal do Brasil. That use not only addresses waste but also addresses the versatility of MOE in addressing larger problems in the metal industry. 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.”
The steel sector worldwide has immense pressure to deliver climate objectives such as the Paris Agreement. The Iron and Steel Technology Roadmap by the International Energy Agency estimates that emissions from the sector need to drop by more than 50% by 2050 in order to stay on track to deliver sustainable development goals. Short-term emission reductions can be achieved with incremental efficiency improvements, but it is through radical technologies such as MOE that deep, long-term reductions are possible.
Boston Metal’s ambition is to have its technology licensed to steelmakers around the world for the installation of modular MOE cells, which will be sized to fit their production needs. One cell, roughly the length of a school bus, can produce 10 tons of steel per day if powered by 600,000 amps of electricity. Scalability is the lifeblood of an industry that produces over two billion metric tons of steel per year.
Its international aspirations are underpinned by massive investment, with over $370 million of investor capital from Europe, Asia, the Americas, and the Middle East. Its Brazilian plant is already running 100% on clean energy, and that offers a glimpse into how MOE can be applied in clean electricity grids. Lambotte stated, “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.”
While these positive steps have been taken, there are challenges. Expansion on a scale that can service the massive steel demand requires not only technological finetuning but an enormous injection of investment into infrastructure. Becoming green steel will also depend on availability of renewable energy and state policy action across the world.
Boston Metal’s work provides a glimpse of a future where steel production does not have to happen at the expense of the world. As Lambotte so aptly phrased it, “Steel produces around 10 percent of global emissions, so that is our north star.” With its revolutionary MOE technology, the company is not only reimagining steelmaking it’s setting the stage for an industrial era that’s cleaner and greener.
