纳米铁基催化剂对低阶煤热解产物及反应动力学的影响

Effect of Nano-Iron-Based Catalysts on Low-Rank Coal Pyrolysis Products and Reaction Kinetics

摘要: 低阶煤的催化热解能够调节热解产物的分布，实现煤的定向转化，对低阶煤的高效洁净利用具有重要意义。本文以纳米Fe₂O₃为催化剂，考察了催化剂添加量和热解温度等条件对海拉尔褐煤催化热解产物及催化热解动力学方面的影响。研究表明，在317℃~430℃和430℃~560℃两个温度区间内，海拉尔褐煤的催化热解过程均符合一级单一反应模型，不同添加量下催化热解的表观活化能均低于非催化热解的活化能，说明催化剂更有利于褐煤在低温阶段热解；在实验条件下，纳米Fe₂O₃添加量从0增加到5%时，最大失重速率由0.23增加到0.394，并且在580℃时，热解基本完成。同时，焦油产率由0.56%增加到6.5%，气相产率由6.89%增至33.5%。

Abstract: The catalytic pyrolysis of low-rank coal can regulate the distribution of pyrolysis products and re-alize the directional transformation of coal, which is of great significance for the efficient and clean utilization of low rank coal. In this paper, nano-Fe₂O₃ was used as catalyst to investigate the effects of catalyst addition and pyrolysis temperature on catalytic pyrolysis products and catalytic pyrolysis kinetics of Hailar lignite. The results show that the catalytic pyrolysis process of Hailar lignite conforms to the first-order single reaction model in the temperature range of 317˚C - 430˚C and 430˚C - 560˚C. The apparent activation energy of catalytic pyrolysis under different addition amounts is lower than that of non-catalytic pyrolysis, indicating that the catalyst is more favorable for pyrolysis of lignite in the low temperature stage. Under experimental conditions, when the nano-Fe₂O₃ addition increased from zero to 5%, the maximum weight loss rate is increased from 0.23 to 0.394, and pyrolysis is basically completed at 580˚C. At the same time, the tar yield in-creased from 0.56% to 6.5%, and the gas yield increased from 6.89% to 33.5%.