Coolbrook's Electric Furnace Aims to Forge a Zero-Carbon Steel Industry

HELSINKI, FINLAND – June 29, 2026 – In the global race to decarbonize heavy industry, the steel sector has long been one of the toughest mountains to climb, responsible for roughly 8% of the world's CO2 emissions. Now, a Finnish technology firm believes it has the key to unlock a fossil-fuel-free future for steelmaking. Coolbrook has secured a significant €2.5 million grant from Business Finland to adapt its revolutionary electric heating technology for the intense demands of steel production, signaling a major push to electrify one of the planet's most carbon-intensive processes.

The funding supports Coolbrook’s role within the ambitious FutSteel project, an industrial ecosystem led by the pioneering Swedish steelmaker SSAB. This move isn't a shot in the dark; it's a calculated scale-up of a technology already proven in the equally challenging cement industry. By replacing the burning of fossil fuels with high-temperature heat generated from renewable electricity, Coolbrook is moving beyond theoretical models and into the heart of industrial transformation, where real-world impact is measured in megawatts and megatons of averted carbon.

The Technology: A Turbine in Reverse

At the core of this industrial pivot is Coolbrook's RotoDynamic Heater™ (RDH™), a technology that sounds like it was lifted from a science fiction novel but is grounded in sophisticated engineering. Combining principles from turbomachinery, aerospace science, and chemical engineering, the RDH functions like a jet engine running in reverse. Instead of burning fuel to create thrust, it uses electric motors to spin a rotor at high speeds, directly converting electrical energy into high-temperature process heat with staggering efficiency—up to 95%.

This method allows the RDH to achieve temperatures of 1700°C, a critical threshold for processes like iron ore reduction and steel reheating that has historically made fossil fuels seem indispensable. Most alternative electric heating solutions struggle to surpass 600°C, making them unsuitable for the core of steel manufacturing. Coolbrook’s technology shatters that thermal ceiling, offering a viable, zero-emission alternative to the blast furnaces that have defined the industry for over a century.

The company's confidence is bolstered by its recent success in the cement sector. A commercial-scale deployment with Ambuja Cement, part of the Adani Group, demonstrated the RDH's commercial viability and operational robustness. This prior success provides a crucial blueprint for tackling steel. "Having already demonstrated the commercial viability of our electrification technology in the cement sector, we are now focused on delivering the same transformative impact for steel," said Joonas Rauramo, CEO of Coolbrook. This transition from one heavy industry to another underscores the technology's adaptability and its potential as a platform solution for decarbonization.

Forging a Greener Future Through Collaboration

This initiative is not a solo effort. The €2.5 million grant, part of a larger €5 million project scope for Coolbrook, firmly embeds the company within the FutSteel ecosystem. This collaborative framework, spearheaded by SSAB, is a prime example of the public-private partnership model essential for driving systemic change. Business Finland's investment is a strategic move to cement Finland's position as a hub for green technology exports while helping a critical global industry clean up its act.

SSAB itself is a formidable partner, having aggressively pursued decarbonization with its HYBRIT (Hydrogen Breakthrough Ironmaking Technology) project, which produced the world's first fossil-free steel in 2021. The company's goal to largely eliminate its own Nordic production emissions by 2030 puts it at the vanguard of the industry. The collaboration with Coolbrook is a natural fit, aimed at accelerating the electrification of various high-temperature stages in the steelmaking process.

"We see great potential in Coolbrook’s RotoDynamic Heater technology to support the electrification of high-temperature steelmaking processes," noted Jarmo Lilja, Process Development Manager at SSAB. "Advancing innovative solutions like RDH™ is essential to accelerating the steel industry’s transition toward lower-emission production, and our collaborations within the FutSteel ecosystem help bring promising technologies closer to industrial deployment." This ecosystem approach de-risks innovation, pools expertise, and creates a clear pathway from pilot testing to industrial-scale adoption.

From Blueprint to Blast Furnace

The project's focus is intensely practical, targeting the integration of RDH technology into multiple, critical stages of the steel production chain. For traditional blast furnaces, which will remain operational for years during the transition, the RDH can be retrofitted to pre-heat combustion air in hot stoves. This application alone can increase energy efficiency by 10% and reduce coke consumption, chipping away at emissions from existing infrastructure.

For more modern production routes, the potential is even greater. The RDH can replace fossil fuel burners in reheating furnaces, effectively transforming them into high-temperature electric furnaces. In scrap-based steelmaking, using the RDH to preheat scrap before it enters an Electric Arc Furnace (EAF) can boost process throughput by up to 10%. Furthermore, by using an inert gas like nitrogen as the heating medium instead of combustion gas, the technology can prevent the formation of mill scale (oxide layers), improving material yield by a valuable 1-3%.

Perhaps most critically, the RDH is poised to become a key enabling technology for hydrogen-based steelmaking. The production of Direct Reduced Iron (DRI) using green hydrogen requires immense heat. The RDH can efficiently provide this heat for pre-heating raw materials and for the hydrogen itself, optimizing the energy balance of what is already an electricity-intensive process. By making the entire heating process electric, Coolbrook’s technology ensures that the "green" in green hydrogen steel isn't compromised by fossil fuels burned elsewhere in the facility.

Navigating the Decarbonization Landscape

Coolbrook enters a dynamic but challenging landscape. The dominant long-term vision for green steel centers on the combination of hydrogen-based DRI and EAFs powered by renewables. Giants like ArcelorMittal and new players like H2 Green Steel are betting billions on this pathway. Other innovations, such as Boston Metal's Molten Oxide Electrolysis (MOE), aim to bypass hydrogen altogether with a direct electrochemical process.

Yet, the RDH is not necessarily a direct competitor to these technologies; in many cases, it is a powerful enabler. Its unique ability to deliver carbon-free heat at extreme temperatures fills a critical gap that other electrification methods cannot. The World Economic Forum has recognized its potential, ranking it as a top furnace technology for advancing steel decarbonization.

The transition will not be without hurdles. The massive demand for renewable electricity, the cost and availability of green hydrogen, and the capital investment required to overhaul century-old industrial sites are all significant challenges. However, Coolbrook's technology offers tangible economic incentives to ease the transition. By eliminating reliance on volatile fossil fuel markets and avoiding escalating carbon taxes, the operational cost savings can be substantial. The technology’s compact footprint and potential for retrofitting also offer a more manageable capital expenditure compared to building entirely new plants.

This latest funding from Business Finland is more than just a financial boost; it's a vote of confidence in a technology that could fundamentally rewire the energy DNA of the steel industry. As Coolbrook refines its RDH for the fiery heart of the forge, it is laying the groundwork for a future where one of our most essential materials can be produced without compromising the health of our planet.