摘要：利用循环流化床高温预热技术, 对大同煤在O₂-CO₂环境下预热前后的颗粒特性、燃料特性和燃料氮的转化特性开展研究。结果表明, 循环流化床可将大同煤稳定预热至850℃, 预热所需的热量全部由煤粉自身的部分燃烧提供。预热后的半焦颗粒粒径减小, 比表面积和孔容积分别增大10和2倍, 孔隙结构更加发达;大同煤在循环流化床O₂-CO₂预热中, 煤气中CO、H₂、CH₄和CO₂体积分数分别为11.5%, 9.7%, 2.11%和79.6%, 煤气热值为2 848.7 kJ·m^-3;预热过程, 煤中的N-Q和N-X向N-6和N-5发生了转化, N-6质量分数由原煤的17.28%增大到32.11%。

关键词：大同煤；循环流化床；O₂-CO₂；预热

Abstract：The particle characteristics, fuel characteristics and fuel-nitrogen conversion characteristics of Datong coal in the O₂-CO₂ environment were studied using the high temperature preheating technology of circulating fluidized bed. The results show that Datong coal can be preheated to 850 ℃ steadily by circulating fluidized bed, and the required heat to preheat is all provided by partial combustion of pulverized coal. After preheating, the particle size of semi-coke decreases, the specific surface area and the pore volume increase by 10 and 2 times, respectively, and the pore structure becomes developed. 72.10 %of carbon and 54.99 % of nitrogen are converted to the gas respectively during the process of preheating of Datong coal by circulating fluidized bed in O₂-CO₂ environment. The concentrations of CO, H₂, CH₄ and CO₂ in gas are 11.5 %, 9.7 %, 2.11 % and 79.6 %, respectively, and the gas heating value reaches 2 848.7 k J·m^-3. N-Q and N-X in coal are converted to N-6 and N-5, and the mass fraction of N-6 increase from 17.28 % to32.11 %.

Keywords: Datong coal；circulating fluidized bed；O₂-CO₂；preheating