关键词: 煤焦, 气化, 动力学, 等温热重法, CO2

Abstract: The char-CO2 gasification reactions at elevated temperature were studied kinetically by the isothermal thermogravimetry using STA409PC thermal analyzer. The effects of coal type, gasification temperature and gas flowrate on gasification reaction were investigated with relevant kinetic parameters calculated. The results showed that when the gasification temperature is lower than the fusion point of char ash, the coal char-CO2 conversion rate and the peak value of reaction rate both increase with increasing gasification temperature. However, when the gasification temperature is higher than the fusion point, the carbon conversion and reaction rates both change so slowly even tend to decrease. The kinetic parameters on gasification reaction with different types of coal char used differ from each other, e.g., the activation energy of coal char used in Ansteel and Bensteel is 140 kJ/mol, while that of the coal char from Fuxin is just 70 kJ/mol. Then, the diffusion becomes the main bottleneck to the gasification reaction if the gasification temperature is higher than the fusion point of char ash. So, increasing the gas flowrate will benefit the char-CO2 gasification reaction.