Zero CO2 Steel by Molten Oxide Electrolysis: A Path to 100% Global Steel Decarbonization

Features Published: September 20, 2022

Iron and steel production is one of the largest global energy consumers in the manufacturing sector and generates about 10% of global carbon dioxide (CO2) emissions. Steel has also been one of the most difficult industries to decarbonize as the dominant production method — blast furnace and basic oxygen furnace (BF-BOF) — is fueled mainly by coal. Technologies such as carbon capture and sequestration (CCS), natural gas-based direct reduced iron (NG-DRI) and hydrogen-based direct reduced iron (H2-DRI) offer alternatives to coal-powered steel production and have the potential to reduce greenhouse gas emissions in the steel industry. However, these technologies have significant limitations in that they: (i) offer only incremental improvements in process emissions; (ii) can only address a small portion of the market; (iii) have structural cost disadvantages over traditional steel production; or (iv) are dependent on limited global supply chains for critical feedstock. Boston Metal has developed a technology called molten oxide electrolysis (MOE) that circumvents all of these limitations. The MOE process uses renewable electricity to convert crude iron ore directly into high-purity molten iron. This one step process avoids CO2 emissions from primary steel production and does not generate waste, offering a simple, scalable and truly decarbonized solution..

To accelerate the transition to a zero-emission economy, the United States must invest in technologies that can achieve long-term impact through full decarbonization of “hard to abate” industrial sectors. This requires a fundamental shift in sourcing and processing within the global steel industry where an ideal technology would be:

  1. A truly CO2 emissions-free process;
  2. Able to use 100% of globally available iron ore feedstock;
  3. Cost-competitive without long-term subsidies or regulatory pressures; and
  4. Capable of global deployment through a modular, incrementally scalable pathway.

In addition to true global decarbonization potential, emerging steel technologies must enable key domestic policy objectives, including maintaining high levels of resource efficiency, strengthening supply chain resilience and sustaining future generations through regional economic and environmental impacts.

Boston Metal’s MOE process meets all the technical decarbonization requirements and can strengthen domestic policy priorities. At full production scale, MOE has the potential to be cost-competitive with today’s coal-based steel. With abundant low-cost renewable power, Boston Metal’s MOE process will become more cost-effective than traditional steelmaking, without subsidies. Like aluminum smelting, MOE runs in modular reactors and can be economically scaled in steps of less than 100,000 tons/year of production capacity. This reduces the financial barrier to adopting MOE and provides maximum deployment flexibility that caters to all sized organizations as an additional revenue stream to mini mills using Electric Arc Furnaces (EAF) through large steel producers. Since MOE adoption will be driven by simplicity, environmental benefits, lower cost, and a growing demand for green steel, it will be insulated from future changes in political priorities and international events and is the only technology that can meet 100% of the global steel production demand with emissions-free iron.

Global Decarbonization Requirements Comparison: MOE vs. Alternative Technologies

Requirement #1: Be a truly CO2 emissions-free process To abate 100% of global steel emissions, the process used to produce iron must not generate CO2 emissions. While technologies like NG-DRI and CCS reduce emissions significantly (~30% and 80% compared to coal-based processes, respectively), they are insufficient to reach 100% global decarbonization. MOE is a zero-CO2 emission process that uses direct electrolysis of iron oxide to produce high-purity iron plus oxygen, enabling full global decarbonization of the steel industry. 

Requirement #2: Be able to use 100% of globally available iron ore feedstock Today’s coal-based steel production uses the full range of traded iron ore grades. To serve the entire global market, any technology must be able to use the same range of feedstocks. Processes like NG-DRI-EAF and H2-DRI-EAF are limited to only high-purity premium iron ore feedstock (~3% of global iron ore supply), severely limiting the total fraction of the global market they can address with an extremely high-cost input. Conversely, technologies like BF-BOF with CCS can use all grades of ore but do not fundamentally eliminate CO2 emissions (Requirement #1).  Iron production using MOE can use all traded ore qualities (demonstrated with purity less than 58% iron), ensuring that this technology has the potential to serve the entire global steel market. 

Requirement #3: Be cost-competitive without subsidies While the United States is currently in a political climate that strongly encourages industries to decarbonize, this may not always be the case.  As such, investments by the government today should focus on those technologies that have the potential to be cost-competitive, long-term solutions without subsidies or other regulatory pressure relative to the incumbent coal-based processes.  For example, while there will continue to be improvements in the cost of CCS, it will always be a cost-adder on top of the price of steel (~25% increase to levelized cost of steel) and will never compete on cost in the absence of subsidies. NG-DRI and H2-DRI are more cost-competitive but are still more expensive than coal-based steel; incurring a green premium that will limit widespread adoption. A simplified MOE process reduces the energy and environmental burden of steelmaking by reducing the incumbent multi-step process to a single step. This process can minimize energy inputs, improve process efficiencies, and reduce the physical footprint required for steel production. Investment to transition MOE into commercial production will create a long-term decarbonization solution that will continue to grow in market share based on commercial drivers, enabling the transition to 100% global decarbonization regardless of future events. 

Requirement #4:  Be capable of global deployment through a modular, incrementally scalable pathway The steel industry is extremely conservative due to historically low profit margins, long investment cycles, capital-intensive infrastructure and competition from unregulated international markets. This makes it very difficult to get this industry to invest in new technologies that require megaton-scale to be cost-competitive, such as H2-DRI and CCS. MOE uses a modular reactor design, similar to that used for aluminum smelting, which can be deployed in increments of less than 100,000 tons/year. This minimizes the barrier to adoption and enables MOE to serve the entire market when each organization is ready to transition as expanded capacity and even retrofits in existing primary and secondary steelmaking facilities across the U.S., as well as new MOE plant construction at >1M-ton scale. 

Domestic Policy Priorities The lingering effects of the COVID-19 pandemic, combined with the Russian invasion of Ukraine and reliance on imports of critical materials have led to significant volatility in the global supply chain for our commercial and defense industries. In response, the U.S. government has enacted a record $2 trillion of new programs through the Bipartisan Infrastructure Law and Inflation Reduction Act to prioritize technologies that are the most efficient use of our limited resources, can strengthen domestic supply chains and are enabled through community sustaining jobs. MOE converts crude iron ore into pure molten iron and oxygen, with the remaining material being a drop-in replacement for the construction industry. This process has full resource utilization, resulting in zero waste, and will provide positive community benefits through scalable iron production capacity with high quality jobs. Boston Metal’s MOE is well positioned to deploy across the U.S., bringing demand for renewable energy while offering a distributed, highly efficient technology and revenue stream to large and small regions alike. 

Originally published on September 20, 2022. Revised version published on August 23, 2023 

About Boston Metal

Boston Metal is commercializing Molten Oxide Electrolysis (MOE), a tonnage metals technology platform powered by electricity, to decarbonize steelmaking and transform how metals are made. MOE provides the metals industry with a scalable, cost-competitive and green solution for the production of steel and high-value metals from a variety of feedstocks and iron ore grades. Backed by visionary investors and led by a world-class team, Boston Metal is headquartered in Woburn, Massachusetts and has a wholly owned subsidiary in Brazil.

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