Visualization approach on the industrial hydrogen-enriched blast furnace for low-carbon ironmaking

Injecting hydrogen from the tuyere of the blast furnace (BF) is one of the most viable green-steel innovations for traditional BF ironmaking. However, the black box characteristic of the BF complicates the direct assessment of hydrogen's impact on fossil fuel replacement and the intricate events occurring within the furnace. This study employed a novel 2-D digital twin technology for an industrial hydrogen-enriched BF, establishing a coke-ore layered structure that facilitated distinct chemical reactions in the two solid layers of the BF shaft, while enabling the mixing of the two-phase solids throughout their descent. Based on the mathematical model
considering mass and heat transfers, and chemical reactions, the impact of hydrogen content on the physical and chemical alterations was examined. The calculation domain covers the industrial scale region of BF from the lower throat to the bosh. The final results indicate that as the quantity of hydrogen injection increases from 0 to
40 and 100 m3/thm, (1) the carbon emissions decrease by 7.5 and 31.6 kg/thm, respectively; (2) The reduction of hematite accelerates by 19.98% and 25.61%, respectively; (3) The reduction of magnetite (Fe3O4→FeO) surpasses its production (Fe2O3→Fe3O4) during the same period, and the reduction of magnetite totally accelerates by 4.21% and 5.07%, respectively; (4) The wustite generates (Fe3O4→FeO) more than it consumes (FeO→Fe) simultaneously, resulting in a 65.71% and 99.92% deceleration in reduction, along with an enhancement of 4.43% and 9.68% in iron production, respectively; (5) The coke consumption at the shaft does not follow the expected trend of monotonic attenuation with the increase of hydrogen injection’ due to the complicated competition reactions in furnace. In conclusion, this research presents a digital and visual methodology for understanding and improving the hydrogen-enriched low-carbon ironmaking process.