Theoretical and experimental investigation on the effect of biomass injection on the utilization factor of pulverized coal and the raceway state in blast furnace

[Display omitted] •The first industrial practice of biomass injection in blast furnace in China was carried out.•Biomass injection improves utilization factor of pulverized coal in blast furnace.•The biomass particles have higher dispersion in the raceway of blast furnace.•Biomass injection reduces the theoretical flame temperature in the blast furnace raceway. The study at Capital Steel Co.’s 2650 m3 blast furnace (BF) explores the impact of biomass injection technology on the utilization factor (UF) of pulverized coal and the state of the BF raceway. It was divided into three phases: base, trial, and comparison, with a thorough assessment of the effects of biomass injection through various analyses. During the trial stage, the UF of pulverized coal rose significantly to 97.57 %, exceeding that of the base and comparison phases. Petrographic analysis revealed a change in the morphology ratio between unconsumed pulverized coal and coke post-biomass injection. Tuyere imaging captured the enhanced dispersion of fuel particles and a reduction in flame intensity due to biomass, providing visual proof of its impact on combustion. Although the theoretical flame temperature (TFT) experienced a slight decrease, it still had a positive thermal effect, mainly due to the increased BF gas volume resulting from the high hydrogen content in biomass. These results support the integration of biomass in the steel industry, advancing sustainable ironmaking methods.