Effective use of hydrogen in gaseous reduction of iron ore agglomerates with H₂-CO

Effective use of hydrogen in ironmaking is one of the important measures to reduce CO₂ emission in steal works. The following four fundamental works carried out by the present authors are introduced here to discuss the CO₂ reduction in the ironmaking fields: (1) Effect of water-gas shift reaction on reduction of iron oxide powder packed bed with H₂-CO mixtures; (2) Fundamental experiments on the H₂ gas injection into the lower part of a blast furnace shaft; (3) Pre-reduction of iron oxide by coal carbonization gas for total iron bath smelting reduction process; (4) Effect of residual volatile matter, especially H₂, in char on reduction of iron oxide in carbon composite pellets. In addition, (5) Effect of hydrogen injection into the blast furnace on its operation conditions is also evaluated and discussed by the mass and heat balance model, which shows hydrogen injection causes both decrements of carbon consumption and heat supply.