Numerical Simulation of Hydrogen-Rich Fuel (Biomass, Coke Oven Gas) and Coal Co-Combustion in the Raceway of Blast Furnace

The blast furnace process, a significant contributor to energy consumption and CO₂ emissions in the steel industry, utilizes pulverized coal and coke to produce molten iron. The injection of hydrogen-rich fuels presents a promising near-term strategy for reducing CO₂ emissions until hydrogen reduction technology becomes commercially viable. This study introduces a three-dimensional CFD model of an industrial-scale blast furnace, with a focus on the pulverized coal injection (PCI) system, raceway, and coke bed. The model examines the effects of injecting hydrogen-rich fuels, such as biomass and coke oven gas, on raceway characteristics, including gas-particle hydrodynamics, temperature, and chemical reactions. Results indicate that pulverized coal-biomass injection maintained comparable raceway temperatures despite the reduced heat input from biomass, while also preventing the accumulation of unburned char in the lower furnace. Conversely, pulverized coal-coke oven gas injection initially elevated temperatures to over 2300 °C due to gas combustion. However, increased char gasification led to a potential temperature decrease of approximately 200 °C in the raceway boundary zone, which could hinder heat transfer to the coke bed and compromise blast furnace operation. Our findings suggest that a strategic combination of biomass and coke oven gas injection could be a promising approach to achieving both hydrogen reduction and carbon neutrality in blast furnace operations. The simulations provide valuable insights into predicting raceway characteristics under varying hydrogen-rich fuel injection rates, thereby contributing to stable operation in low-carbon blast furnace.