How electrically produced green steel can clean up a filthy industry
Industrial steel production emits about two tons of carbon dioxide emissions for every ton of steel produced – accounting for almost 10% of such emissions worldwide. The global steel market is expected to grow by about 30% by 2050, a time when some largest steel producer committed to net zero emissions. Unless major and rapid changes come to the industry, that goal may be out of reach.
Boston Metal’s new reactor, recently installed at its headquarters north of Boston, is an important step in the company’s journey to becoming a commercial steelmaker. Since its founding in 2013, the start-up has developed a green steel manufacturing process, machining parts in smaller vessels. The new reactor, along with the upcoming fundraising round, represents the company’s next big leap as it tries to scale.
If Boston Metal can truly scale up its clean manufacturing processes and access enough renewable electricity to operate, the company could help solve one of the world’s toughest emissions control challenges. carbon.
A new approach
Steel is used in everything from cars to buildings to wind turbines, but the decarbonization industry is unappealing. “People don’t pay too much attention to the industrial sector,” said Tadeu Carneiro, CEO of Boston Metal. “It’s a very conservative industry and it’s hard to downplay.”
Fossil fuels are essential for today’s steel production. Most steelmaking begins in a blast furnace, where a coal-based material called coke, which is almost pure carbon, reacts with iron ore, a mixture of iron oxides and minerals. other substance. The reaction sucks oxygen out, leaving behind liquid iron. The carbon and oxygen are then released together as carbon dioxide.
Boston Metal’s solution is an entirely new approach, known as molten oxide electrolysis (MOE). Instead of using carbon to remove oxygen, the process relies on electricity, which runs through a cell filled with a mixture of dissolved iron oxides along with other oxides and materials. Electricity heats the cell up to about 1,600°C (nearly 3,000°F), melting everything into a hot oxide soup.
In addition to heating things up, electricity promotes chemical reactions that remove oxygen. The molten iron is concentrated at the bottom of the reactor, and oxygen is released instead of carbon dioxide.
Since the impurities are mostly outside of the reaction, the MOE process can handle low-quality iron ore, which could be a key benefit of the technology, says Carneiro.