Effect of potassium carbonate on the kinetic behaviors of coke gasification in a hydrogen-rich blast furnace

Abstract

To simulate the composition of hydrogen-rich blast furnace (BF) gas, coke gasification reactions with and without potassium carbonate were carried out by thermogravimetry. The experimental temperature was 1173–1573 K. The effects of potassium carbonate on the kinetic behaviors of coke gasification under hydrogen-rich BF gas were compared and analyzed, and the mechanisms of influence were discussed. The results showed that potassium carbonate had a strong catalytic effect on the coke gasification reaction. The presence of potassium carbonate could reduce the internal diffusion and interfacial reaction activation energy in coke gasification, could increase the rate of internal diffusion and interfacial reactions, and had a greater effect on internal diffusion than on interfacial reactions. After potassium ions were adsorbed onto the surface of the coke, the CC bond length on the surface of the coke increased, the number of electrons of C atoms on the surface of the coke increased, and the energy of the coke matrix increased. These effects decreased the stability of the coke matrix structure, promoting the coke gasification reaction.