升温速率及热解温度对煤热解过程的影响

摘要

为了研究煤热解过程中升温速率及热解温度对热解产物分布及热解过程吸热量的影响,采用热重和热红联用技术对煤热解过程进行了分析.研究了不同升温速率和热解温度对煤热解过程的气态产物分布的影响,并对所产生的焦炭性质进行了分析.结果表明:煤的整个热解过程的吸热量随升温速率的增加而减小；煤热解产生的焦油组分含量包括芳香族、脂环族和脂肪族含量达到最大值所对应的热解温度随升温速率的增加产生滞后现象,但是煤热解产生的煤气成分随着升温速率增加而急剧释放；随着热解温度的升高,焦炭结构逐渐致密,裂纹及裂缝产生,芳香晶核增大,同时焦炭中的氧和氮含量由于含氮和含氧化合物的继续分解而降低.%In order to investigate the effect of heating rate and pyrolysis temperature to products distribution and absorption of heat in the coal pyrolysis process, the coal pyrolysis processes were researched with TG/ DTG and TG-FTIR analysis in this paper. The influence of heating-up speed and temperature of coal pyrolysis to gas product distribution were investigated, and the properties of the coke from reaction were analyzed. The results indicate that the whole absorption of heat in the coal pyrolysis process decreased with the increase of the heating rate. The pyrolysis temperature, at which the coal tar components (mainly aromatic, aliphatic, fat ali-cyclic) reached a maximum content, increased with the heating rate, while the gas components released quickly with the increase of heating rate. Coke structure was gradually dense with the increase of pyrolysis temperature, crack produced in the coke and aromatic forms increased at higher temperature, and at the same time, the oxygen and nitrogen content of coke decreased with the increase of pyrolysis temperature due to the continuous cracks of nitrides and oxygenates.