Biocarbon steelmaking could be the next sustainability frontier At Ovako, we are well known for being the largest metal recycler in the Nordics, producing steel from around 97 percent recycled scrap. It is a foundation we are proud of, and one that already gives our steel one of the lowest carbon footprints in the industry. But there is a less visible part of the steelmaking process that we are working hard to decarbonize: our use of carbon itself.
This month, I want to share what we have been learning from our ongoing biocarbon pilot projects across all of our mills, and why we think it could be a new frontier in sustainable steelmaking. Carbon is a functional material that we use to reduce oxides, improve yield, and to give the steel its properties. The carbon content of steel directly determines its hardness, strength, and performance characteristics. We also use carbon to create a foamy slag that protects our graphite electrodes, the conductors that carry electricity into the melt.
Without carbon, the process does not work, so whether we use it is not up for debate. But there is still a good question to ask: where does that carbon come from?
Conventionally, the answer has been fossil coal; anthracite or similar. Our goal, in line with our Net Zero pathway and our transition plan for fossil-free carbon carriers, is to replace that fossil carbon with biochar. This is a porous, carbon-rich material similar to charcoal, produced by heating biomass in the absence of oxygen or under a limited oxygen atmosphere. That means biochar can be derived from renewable waste sources such as bamboo, food waste, tree branches, and other biological material that would not otherwise be used. What makes biochar different, and challenging
Biochar is not a straightforward drop-in replacement. Anyone working in steel production will tell you that the physical properties matter as much as the chemistry. Biochar is significantly lighter and more reactive than fossil coal. It behaves differently in the furnace, burns more readily, and requires careful handling to avoid losses before it even reaches the melt.
To make it workable, the material needs to be reshaped. That typically means compressing it into briquettes or chunks so that it can be transported safely, stored, and introduced into the process in a controlled way. From there, it can be added to the scrap buckets before melting, injected through a lancing system into the liquid steel, or used in the slag foaming process that protects the electrodes.
The practical learning required to understand how a new biocarbon product behaves in your specific furnace, with your specific charge mix and process parameters, is substantial. All three of our steel mills — Imatra, Hofors, and Smedjebacken — have been conducting trials to test the viability of replacing fossil carbon with biochar.
At the end of the day, from a steel quality perspective, carbon is carbon. Switching from fossil carbon to biochar does not affect the properties of the finished steel. The challenge is entirely operational, and is more about getting the handling, quantities, and process parameters right.
One approach we and others in the Swedish steel sector are exploring is a gradual blend of fossil and biochar. This could be a way to learn the behavior of biochar incrementally and plan a well-controlled introduction, rather than making a sudden switch. Availability and cost remain the primary constraints. Biochar is still a relatively limited commodity; production capacity across Europe is growing but has not yet reached the scale needed for large-volume industrial use. As a result, our use of biochar is currently confined to research and development contexts. In order to take the next step and start developing biocarbon solutions that result in steel products with extremely low CO2e footprint, we need more collaborations and partnerships with customers.
But the direction of travel is
clear, and the Swedish steel industry is broadly aligned on the importance of
this transition. We continue to press forward. Biochar trials at our steel
mills are helping us better understand the potential to replace traditional
coal as the market matures. And as our transition plan makes clear, fossil-free
carbon carriers could be a big step on our pathway to Net Zero by 2045.
It is incremental work, but then, so is steelmaking itself. One heat at a time — one improvement at a time. For more information about our biochar program, please reach out to your local sales contact.
Patrik Fredriksson, Head of Steel Mill Performance Development, Ovako Group
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