Mitsubishi Heavy Industries Technical Review
    Vol. 59 No. 4 (2022)   Carbon Neutral
    Technical Papers

    Breakthrough Pathways to Decarbonize the Steel Sector


    Today, the iron and steel sector is the most significant industrial CO2 emitter, contributing around 8% of global CO2 emissions. Fossil fuel-based BF (blast furnace) Ironmaking is the primary source of these emissions. Besides the scrap-based EAF (Electric Arc Furnace), hydrogen-based direct reduction shows immense potential to decarbonize the steel industry. Primetals Technologies, as part of MHI Group, is well positioned to facilitate the transition toward green steelmaking with its comprehensive portfolio of direct reduction and steelmaking technologies. This article presents an overview of different steel production routes and their related CO2 emissions based on the various iron sources, such as hot metal, DRI/HBI (Direct reduced iron/hot briquetted iron), and scrap. The article discusses transition scenarios, including hybrid EAF-BOF (Basic Oxygen Furnace) steelmaking and new green steel production routes using hydrogen-based direct reduction followed by EAF steelmaking for high-grade DRI, as well as the recently developed two-step process via a SMELTER and a BOF for low-grade DRI.