Coke behavior with H₂O in a hydrogen-enriched blast furnace: A review

Hydrogen-enriched blast furnace ironmaking has become an essential route to reduce CO₂ emissions in the ironmaking process. However, hydrogen-enriched reduction produces large amounts of H₂O, which places new demands on coke quality in a blast furnace. In a hydrogen-rich blast furnace, the presence of H₂O promotes the solution loss reaction. This result improves the reactivity of coke, which is 20%–30% higher in a pure H₂O atmosphere than in a pure CO₂ atmosphere. The activation energy range is 110–300 kJ/mol between coke and CO₂ and 80–170 kJ/mol between coke and H₂O. CO₂ and H₂O are shown to have different effects on coke degradation mechanisms. This review provides a comprehensive overview of the effect of H₂O on the structure and properties of coke. By exploring the interactions between H₂O and coke, several unresolved issues in the field requiring further research were identified. This review aims to provide valuable insights into coke behavior in hydrogen-rich environments and promote the further development of hydrogen-rich blast furnace ironmaking processes.