Effect of CO₂ and H₂O on gasification dissolution and deep reaction of coke

To more comprehensively analyze the effect of CO₂ and H₂O on the gasification dissolution reaction and deep reaction of coke, the reactions of coke with CO₂ and H₂O using high temperature gas-solid reaction apparatus over the range of 950-1250℃ were studied, and the thermodynamic and kinetic analyses were also performed. The results show that the average reaction rate of coke with H₂O is about 1.3-6.5 times that with CO₂ in the experimental temperature range. At the same temperature, the endothermic effect of coke with H₂O is less than that with CO₂. As the pressure increases, the gasification dissolution reaction of coke shifts to the high-temperature zone. The use of hydrogen-rich fuels is conducive to decreasing the energy consumed inside the blast furnace, and a corresponding high-pressure operation will help to suppress the gasification dissolution reaction of coke and reduce its deterioration. The interfacial chemical reaction is the main rate-limiting step over the experimental temperature range. The activation energies of the reaction of coke with CO₂ and H₂O are 169.23 kJ·mol^-1 and 87.13 kJ·mol^-1, respectively. Additionally, water vapor is more likely to diffuse into the coke interior at a lower temperature and thus aggravates the deterioration of coke in the middle upper part of blast furnace.