Effects of hydrogen-rich fuel injection on the states of the raceway in blast furnace

The application of hydrogen-rich fuels such as hydrogen (H2), natural gas (NG), coke oven gas (COG), and recycling top gas (RTG) to blast furnace (BF) ironmaking can effectually reduce CO2 emissions. In this study, the characteristics in the tuyere and raceway with H2, NG, COG and RTG injection are compared. The simulation results show that COG starts to combust at the nearest place after leaving the gas lance, the gas velocity is highest at the tuyere and the penetrability of the gas is strongest in four cases; And the maximum temperature generated by combustion along the pulverized coal plume is the highest and the lowest, and the difference is higher as RTG and NG are injected from the gas lance. And the mole fraction of reducing gas produced in the raceway is the highest when NG is injected, followed by COG and RTG, and the least with H2 injection. Finally, the burnout of PC in the raceway from high to low: RTG injection (81.76%), H2 injection (79.86%), COG injection (78.04%), NG injection (75.72%) as the same rate of gas is injected. The research will provide a basis for the selection of hydrogen-rich fuel injection in practice.