Decarbonization of iron and steel industries: A review of computational advancements to enhance furnace energy efficiency in the BF-BOF route

The iron and steel industry remains heavily reliant on fossil fuels for high-temperature operations and chemical reduction processes. Especially in the blast furnace-basic oxygen furnace (BF-BOF) route, which accounts for almost 70% of steel production, decarbonization remains an urgent challenge. This review comprehensively explores decarbonization strategies, focused on computational modeling approaches within three major furnaces in BF-BOF steelmaking: blast furnace (BF), basic oxygen furnace (BOF), and reheating furnace (RF). BF is a major emission-heavy unit where hydrogen injection can cut BF emissions by up to 55%, while biomass injection can achieve up to 40% reductions under optimized conditions. In BOF operations, multiphase jet-bath interactions dominate the decarburization and refining processes. RFs represent a significant energy sink due to intense thermal loads. Regenerative RF systems can deliver up to 20% fuel savings, while fuel-oxygen enrichment can reduce energy use by up to 26%. Across all furnace systems, decarbonization efforts have been increasingly relying on computational modeling for process optimization. Challenges remain in scaling high-fidelity models and integrating them with plant-level data. Future research should focus on advanced multiphysics modeling that can play a crucial role in this decarbonization effort through material flow optimization and heat and mass transfer enhancement. Further priorities include process integration for carbon capture and storage systems and digital twin development for real-time optimization of material and energy flows. • BF-BOF route produces nearly 70% of global steel and is a major decarbonization challenge. • Hydrogen and biomass injection in blast furnaces can cut emissions by up to 55% and 40%, respectively. • Reheating furnaces consume high energy; regenerative systems and oxygen enrichment can save up to 26%. • Computational modeling is key for optimizing furnace operations and reducing emissions. • Future focus should be on advanced multiphysics modeling, carbon capture integration, and digital twins.