Boston Metal: Steel production without emissions

8 January 2021

Climate Investment

Boston Metal has developed a novel technology that enables a more efficient, more environmentally sustainable, and less costly production of critical metals, including steel.

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Deployment case study

Boston Metal: Steel production without emissions

Using clean electricity and molten oxide electrolysis to clean-up an ancient formula.

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The 3,000 year old formula for making steel results in almost two tonnes of carbon dioxide emissions per tonne of metal produced. 8% of global emissions in 2019 were attributable to steel, making it one of the largest industrial sources of carbon dioxide. But as a low cost, high strength alloy, global demand has seen annual production reach over 1,800 million tonnes.


The traditional production formula combines iron ore and carbon (coal), resulting in iron and carbon dioxide outputs. By replacing the old formula with a process of molten oxide electrolysis (MOE), Boston Metal removed the carbon input, creating steel without carbon dioxide emissions.


In 2021, Boston Metal commissioned its first industrial-scale pilot cell and will produce the first tonnes of green steel at its facility outside Boston, USA. Each tonne of steel will directly eliminate two tonnes of CO2 emissions. Early data shows that with no water or reagent use, the process results in better metal at lower energy consumption rates.


Expanding impact

Decarbonizing the steel industry has the potential to eliminate two billion tonnes of carbon dioxide emissions a year. Boston Metal’s molten oxide electrolysis process allows significant flexibility in iron ore, creating a larger addressable market and much lower exposure to iron ore price volatility than H2/DRI/EAF processes that require premium grade ores. Boston Metal aims to commission the first pilot plant in 2024, and modular technology will allow for rapid scaling from 2025 once the pilot is validated.