Impacts and Applications of Hydrogen Injection in Blast Furnaces: A Review

The steel industry is one of the largest contributors to global CO2 emissions, and the transition to low-carbon production methods is crucial to achieving climate goals. Hydrogen injection into blast furnaces (BFs) has emerged as a promising technology to reduce carbon emissions and improve the sustainability of steel production, especially when the hydrogen comes from non-fossil sources. This review comprehensively examines the impacts and applications of hydrogen injection in BFs, focusing on thermodynamic, operational and environmental aspects. By analyzing recent studies, it highlights the benefits, challenges and future directions by producing hot metal from hydrogen. The review synthesizes findings from more than 90 studies, providing an understanding of how hydrogen injection (HI) influences operations. Some parameters were emphasized, such as theoretical flame temperature (RAFT), oxygen enrichment (OE), coke consumption (CR), pulverized coal injection rate (PCI), blowing temperature (TS), top gas temperature (TGT) and CO₂ emissions. The potential of hydrogen to replace traditional carbon-based reducers was discussed. Overall, HI can reduce coke consumption and greenhouse gas emissions, increase process productivity, but will require technical care to meet expectations.