Competitive Models and Mechanisms of Gasification Reactions on Hydrogen-Rich Smelting Process of Blast Furnace
摘要
Blast furnace hydrogen-rich smelting effectively reduces CO2 emissions; however, the introduction of H2 generates H2O within the blast furnace, which influences the gasification reaction of coke. This study investigates the gasification reaction rates of coke in CO2/H2O single gas and CO2–H2O mixed gas atmospheres, employing an analog circuit method to construct the corresponding model. The results indicate that external gas diffusion is the rate-limiting step in the coke gasification process. In a CO2–H2O–N2 (40–20–40%) mixed gas environment, the coke gasification rate is lower than the sum of the rates observed in CO2–N2 (40–60%) and H2O–N2 (20–80%) atmospheres, suggesting a competitive interaction between CO2 and H2O in the gasification reaction of coke. Six different methods were employed to calculate the gasification reaction rates of coke in CO2/H2O single gases and CO2–H2O mixed gases, and the results reveal that method 6 most accurately elucidates their interaction. Additionally, the effect of H2O in the CO2–H2O–N2 mixture on coke gasification is more pronounced than that of CO2. Compared to coke gasification with only H2O, the CO2–H2O mixed gas promotes the conversion of amorphous carbon, reduces the consumption of aromatics, and increases the microcrystalline size.