How Biochar Can Make the Steel Industry Climate-Smart
Steel is one of the world’s most essential materials, used in everything from bridges and cars to kitchen utensils and wind turbines. Sweden’s steel industry is already among the most sustainable, utilizing a high proportion of recycled scrap and fossil-free electricity. However, to achieve full climate neutrality, we must replace the fossil coal currently used in steelmaking.
Biochar presents a game-changing solution that can make steel production nearly emission-free. By replacing fossil coal in blast furnaces, direct reduction processes, and scrap melting, biochar significantly reduces emissions—helping to produce even greener steel.
Swedish Steel Industry – A Climate Leader
Sweden produces approximately 4.5 million tons of steel annually, with a significant portion made in electric arc furnaces that recycle scrap into new steel. This method is highly climate-efficient, requiring less energy and generating minimal emissions—especially in Sweden, where electricity is largely fossil-free.
However, recycled scrap alone cannot meet the growing demand for new steel products. Certain high-grade and specialty steels still require ore-based production, which remains the industry’s biggest climate challenge. This is where biochar plays a crucial role in making steel production more sustainable and accelerating the transition to a fossil-free future.
Biochar Can Replace Fossil Coal in Iron Production
Traditionally, iron is produced by heating iron ore with coke (a purified form of coal) in a blast furnace. During this process, oxygen is removed from the iron ore and bonds with carbon, releasing large amounts of fossil-derived CO₂.
Biochar as a Sustainable Alternative:
Biochar can replace fossil coal in multiple stages of this process:
🔹 In Blast Furnaces – By substituting part of the fossil coal with biochar, direct CO₂ emissions from fossil sources can be significantly reduced.
🔹 In Direct Reduction (DRI) – An alternative method where iron ore is converted into sponge iron at lower temperatures, making it easier to use biochar or other fossil-free alternatives.
Sweden utilizes a unique direct reduction method known as the Höganäs process, where iron ore is reduced in solid form using carbon. In this method, biochar and biofuels can replace fossil-based materials in powder metallurgy and specialized steel production.
Another groundbreaking initiative is H₂-DRI (Hydrogen Direct Reduced Iron), a Swedish innovation that replaces fossil coal with hydrogen (H₂) to produce iron. Instead of CO₂ emissions, the only byproduct is water vapor (H₂O)—a major climate breakthrough! The resulting sponge iron is then melted in an electric arc furnace (EAF) to produce steel.
Even in fossil-free steel production, carbon remains essential:
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Carbon gives steel its strength – Steel is an alloy of iron and carbon. Without carbon, pure iron is too soft and malleable. Carbon is necessary to maintain steel’s durability.
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Carbon is used in the melting process – When sponge iron is melted in electric arc furnaces, carbon helps control slag formation and achieve the correct composition.
Instead of using fossil coal, biochar provides a sustainable alternative—reducing fossil CO₂ emissions while maintaining high-quality steel production.
Biochar in Scrap Melting – A Fossil-Free Alternative
Electric arc furnaces (EAFs) use electricity to melt scrap metal, making them one of the most climate-friendly methods for steel production. However, even in these furnaces, a certain amount of carbon is needed to refine the steel and protect the molten metal (slag formation).By replacing fossil coal with biochar, the process becomes even more sustainable.
🔹 Biochar enhances slag formation, improving recycling of byproducts and reducing overall resource consumption.
🔹 It enables greater circularity, helping the steel industry reduce waste and improve material recovery.
Using biochar in EAFs is another step toward a fully fossil-free steel industry while improving efficiency and sustainability.
The Future of Biochar in the Steel Industry
By replacing fossil coal in multiple steelmaking processes, biochar can significantly reduce the industry's climate impact.
Its role in sustainable steel production is expected to grow in several key areas:
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Replacing fossil coal in blast furnaces and direct reduction – Cutting CO₂ emissions in primary ironmaking.
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Use in electric arc furnaces (EAFs) – Enhancing the sustainability of recycling-based steel production.
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Fuel for heating furnaces – Biochar can be gasified into syngas, replacing natural gas and propane with bio-based energy.
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Graphite electrodes – Ongoing research is exploring biochar-based alternatives to fossil graphite in EAF electrodes.
For biochar to become a widespread alternative, several factors must be addressed:
- Scaling biochar production – Increasing availability without competing with forestry and agricultural resources.
- Technical advancements – Ensuring biochar has the necessary properties for steel production.
- Economic competitiveness – Making biochar cost-effective compared to fossil coal.
Sweden Can Lead the Way
Sweden’s steel industry is already a global leader in sustainability and energy efficiency. By combining scrap-based steelmaking with biochar in iron production, the country can take the next step toward an almost fossil-free steel industry.
With continued research and strategic investments, biochar could become a key enabler of sustainable steel production. This shift would not only benefit the climate but also strengthen Sweden’s position as a pioneer in green industry.
🌍 The steel of the future is not just strong—it’s fossil-free!