Hydrogen in steel: A hard decarbonisation challenge
Steel production is one of the most difficult sectors to decarbonise. It accounts for around 7%-9% of global CO₂ emissions and remains heavily dependent on fossil fuels, both as an energy source and as a chemical reductant in ironmaking (IEA, World Steel Association).
Hydrogen offers a credible pathway to reduce these emissions. It can replace carbon in the reduction process, producing water instead of CO₂. However, its effectiveness depends on how it is produced, integrated, and scaled within industrial systems.
The challenge is not whether hydrogen can work. The challenge is how to make it work under real industrial conditions.
Why is steel difficult to decarbonise
Steelmaking is fundamentally different from many other industries. Fossil carbon is embedded in the process itself. It is used not only to remove oxygen from iron ore but also to generate heat.
This means that electrification alone is not enough. The chemistry must change.
Hydrogen provides that alternative. It acts as a reducing agent, enabling a shift away from carbon-based processes. However, this introduces a new dependency. Steel production becomes closely linked to hydrogen availability and electricity systems.
This is why hydrogen in steel is not a standalone solution. It is part of a broader energy transition.
The main hydrogen pathways in steelmaking
Hydrogen can be applied in several ways across the steel value chain. Each pathway has different implications for emissions, cost, and scalability.
Hydrogen-based direct reduction
Hydrogen-based direct reduction of iron, combined with electric arc furnace melting, is currently the most advanced pathway. This route is considered the closest to near-zero primary steel production.
According to the U.S. National Renewable Energy Laboratory, producing one tonne of steel via this route requires approximately 70 kg of hydrogen. A typical 1 million tonne plant would therefore require several hundred megawatts of electrolyser capacity.
This is not a simple retrofit. It is a full redesign of the production system.
Projects such as HYBRIT in Sweden demonstrate that hydrogen-based direct reduction is technically viable at pilot scale and moving towards industrial deployment.
Hydrogen injection in blast furnaces
Hydrogen can also be injected into existing blast furnaces to partially replace coal.
Industrial pilots, including those by thyssenkrupp Steel in Germany, show that this approach can reduce emissions without replacing the entire facility.
However, the reduction potential is limited. The process remains dependent on carbon-based infrastructure.
For this reason, hydrogen injection is best understood as a transitional step rather than a long-term solution.
Hydrogen in auxiliary processes
Hydrogen can replace natural gas in industrial heating applications within steel plants.
These include burners, preheating systems, and drying processes. While this does not eliminate emissions from ironmaking, it improves overall efficiency and reduces fuel-related emissions.
This type of integration is already relevant across multiple industries, including:
• Steel and metal processing
• Cement and construction materials
• Ceramics and mineral processing
• Glass manufacturing
• Chemical production
• Automotive manufacturing
• Food processing
This approach reflects a practical entry point for hydrogen. It enables gradual adoption without requiring full system transformation.
Emerging technologies
New hydrogen-based approaches are under development.
Technologies such as hydrogen plasma reduction and hydrogen-based smelting aim to further reduce emissions and increase process flexibility.
Solutions like HYFOR by Primetals Technologies explore using hydrogen to reduce iron ore fines, thereby avoiding the need for high-grade pellets.
These technologies are promising, but they remain at the pilot or early commercial stage.
The real constraint is system integration
Hydrogen in steel is often framed as a cost issue. In practice, it is a system challenge.
Key dependencies include:
• Hydrogen production cost
• Electricity price and availability
• Storage and transport infrastructure
• Ore quality and supply
• Process integration
The OECD highlights that most planned direct reduction capacity remains natural gas-based or hydrogen-ready, rather than fully hydrogen-powered.
This reflects the current reality. Hydrogen supply at scale is still limited and expensive.
Materials and system design challenges
Hydrogen introduces additional engineering considerations, particularly in materials.
One of the most important is hydrogen embrittlement. Under certain conditions, hydrogen can reduce the ductility and fatigue resistance of steel.
This is not a limitation of hydrogen-based steelmaking itself. It is a materials-and-design challenge that must be addressed at the system level.
In practice, this requires:
• Careful material selection
• Control of hydrogen diffusion
• Proper design of pipelines, vessels, and components
• Integration of safety standards from the outset
Hydrogen systems must be engineered as complete systems, not as isolated components.
Economics and scalability
Hydrogen-based steel is currently more expensive than conventional production.
The main driver is operating cost. Hydrogen production requires large amounts of electricity, and energy prices directly affect competitiveness.
Studies from IEAGHG show that hydrogen-based steel pathways have higher breakeven costs than traditional blast-furnace routes, especially without policy support.
At the same time, the IEA highlights that hydrogen costs must fall significantly to enable large-scale industrial adoption.
Deployment is therefore concentrated in regions with:
• Access to low-cost renewable electricity
• Strong industrial infrastructure
• Policy support mechanisms
• Demand for low-carbon materials
What this means for the industry
Hydrogen will not replace all steelmaking routes.
Instead, it will be applied where it delivers the most value.
Three directions are emerging:
First, hydrogen-based direct reduction in regions with strong energy and industrial integration.
Second, hydrogen injection and fuel substitution as transitional solutions.
Third, gradual integration into existing industrial processes.
Hydrogenera’s perspective
Hydrogen adoption in steel is not only about large-scale transformation. It is also about practical integration into existing industrial systems.
Applications such as hydrogen-supported combustion and process optimisation can already improve performance and reduce emissions.
These solutions align with real industrial needs. They do not require full infrastructure replacement. They support a gradual transition.
This approach extends beyond steel to multiple industrial sectors where hydrogen can improve efficiency and reduce carbon intensity.
Looking ahead
Hydrogen is not a single solution for steel. It is a system-level transition.
Its success depends on how well energy systems, infrastructure, and industrial processes evolve together.
The transition is already underway. Pilot projects are scaling. Industrial deployments are emerging.
The next phase will determine whether hydrogen becomes a core part of steel production or remains limited to specific applications.
Where deep decarbonisation is required, and conditions are right, hydrogen will play a central role.