Decarbonization Technologies in Iron and Steel Production

Currently, iron and steel production is responsible for approximately 7% of global CO₂ emissions. Traditional blast furnace–basic oxygen furnace routes rely on coking coal and account for the sector’s high carbon intensity. A suite of decarbonization pathways is under active development or commercial deployment. These include hydrogen-based direct reduction of iron ore followed by electric arc furnace steelmaking, which replaces carbon-based reductants with hydrogen generated via electrolysis powered by renewable electricity. Carbon capture and storage applied to blast furnace off-gases and direct reduced iron processes offers a route to abate unavoidable emissions. Biomass or biochar can partially substitute for coke, while electrification of heat supply and the progressive shift towards high-recycled scrap content in electric furnaces reduce primary material demand. Novel process concepts, such as top gas recycling in blast furnaces or molten oxide electrolysis, aim to lower process emissions further. Integrating these technologies requires addressing resource availability, system flexibility, infrastructure for hydrogen and CO₂ transport and storage, and economic competitiveness.

Research from Nature Portfolio

Recent studies have assessed the geographic and economic feasibility of hydrogen-based steelmaking at scale. One analysis highlights that optimal sites for renewables-driven direct reduction and electric arc furnace operations lie in regions with high solar or wind potential, abundant iron ore, and favourable labour costs, indicating competitive costs from around 2030 and improving towards 2050. Another investigation into century-long production data reveals that efficiency gains in steelmaking have been largely offset by exponential growth in output, leading to stagnating decarbonization progress since the mid-1990s. This work underscores the necessity of coupling supply-side measures such as low-carbon processes with demand-side mitigation to align future growth with 1.5 °C pathways.

Decarbonization Technologies in Iron and Steel Production publication trend

The graph below shows the total number of articles in decarbonization technologies in iron and steel production across all publications each year (not limited to Nature Index journals).

Technical terms

Direct reduced iron (DRI): Iron ore reduced to metallic iron at moderate temperatures using a reductant such as hydrogen or natural gas, bypassing the blast furnace.

Electric arc furnace (EAF): Steelmaking vessel that melts scrap or DRI using electrical energy, enabling high scrap use and integration with low-carbon electricity.

Green hydrogen: Hydrogen produced by water electrolysis powered exclusively by renewable electricity, yielding zero direct CO₂ emissions.

Carbon capture and storage (CCS): Technology to separate CO₂ from industrial emissions and permanently store it underground or in geological formations.

Electrification: Substitution of fossil fuel-derived heat or reductants with electrical energy, often sourced from renewable generation.

Top gas recycling: Process in which off-gas from a blast furnace is recycled, enriched in hydrogen or CO, to increase efficiency and reduce net CO₂ emissions.

References

1. Assessing the potential of decarbonization options for industrial sectors. Joule (2024).
2. Global green hydrogen-based steel opportunities surrounding high quality renewable energy and iron ore deposits. Nature Communications (2023).
3. Efficiency stagnation in global steel production urges joint supply- and demand-side mitigation efforts. Nature Communications (2021).
4. Power-to-Steel: Reducing CO2 through the Integration of Renewable Energy and Hydrogen into the German Steel Industry. Energies (2017).