Demonstration of the DMX™ technology for carbon capture and storage in steel production: An environmental assessment

Abstract

Post-combustion carbon capture and storage (CCS) can be retrofitted to existing industrial plants to reduce CO₂ emissions. However, implementing CCS requires the construction and operation of additional process equipment, transport infrastructure, and geological storage facilities. The environmental impacts of the additional industrial infrastructure and its operation can be quantified using the life-cycle assessment methodology. However, life-cycle assessments often rely on generic CCS supply chain models or proxies due to a lack of data. This study evaluates the environmental impact of a megatonne-scale CCS supply chain applied to the blast furnace gas of a steel plant based on detailed data generated in the DMX™ Demonstration in Dunkirk project. In particular, a CCS supply chain is investigated that uses the DMX™ technology, a second-generation amine-based post-combustion CCS technology. Our assessment indicates high life-cycle CCS efficiencies of the supply chain under a wide range of scenarios, with life-cycle emissions below 100 kg of CO₂-eq. per tonne of CO₂ captured and stored. This efficiency results from the local energy supply’s low greenhouse-gas-intensity and efficient offshore transport. Compared to primary steel production, non-climate-related impacts of the CCS supply chain are small, except for ionizing radiation, water scarcity, resource use of energy carriers, and ozone depletion, where impacts could be reduced with renewable electricity. While CCS can substantially reduce greenhouse gas emissions in steel production already today, we show that CCS is insufficient to achieve net-zero emission steel. Given high costs and supply chain complexity, CCS must be integrated into broader decarbonization strategies to avoid stranded assets.