长白山地区主要森林类型地表凋落物热解实验研究

Experimental study on pyrolysis of surface litter of main forest types in Changbai Mountains

通过热解实验及热解动力学求解,研究了 6 种长白山地区主要森林类型地表凋落物的热解特性。实验材料选取长白山黄松蒲林场的白桦林、针叶混交林、针阔混交林、落叶松林、阔叶混交林和杨树林 6 种主要森林类型的地表凋落物,采取热重分析法研究 6 种地表凋落物的热解特性,并采取 Gorbatchev 积分法进行动力学研究。结果表明:6 种地表凋落物的热解过程均包括失水、微失重、主要失重和炭化 4 个阶段;6 种地表凋落物失重率大小排序为:白桦林>针叶混交林>针阔混交林>落叶松林>阔叶混交林>杨树林;升温速率越大,失重率越大;凋落物粒径为178~250 μm 时,热解失重率最高;6 种地表凋落物在空气气氛中的热解失重率更大,热解更充分。活化能大小排序与失重率排序一致,其中白桦林凋落物的活化能最高,为 95.5 kJ·mol^(-1),杨树林凋落物热解活化能最低,为 68.8 kJ·mol^(-1)。

The pyrolysis characteristics of surface litter of 6 main forest types in Changbai Mountain were studied through pyrolysis experiments and pyrolysis kinetics solutions. The surface litter of 6 major forest types:birch forest, coniferous mixed forest, coniferous and broad-leaved mixed forest, larch forest,broad-leaved mixed forest and poplar forest in Huangsongpu Forest Farm of Changbai Mountain is selected as the research object. The pyrolysis characteristics of 6 kinds of surface litter were studied by thermogravimetric analysis, and the kinetics was studied by Gorbatchev integral method. The results show that: the pyrolysis process of the six surface litters includes 4 stages of water loss, slight weight loss, main weight loss and carbonization. The order of weight loss rate of the 6 surface litters is: birch forest>coniferous mixed forest>coniferous and broad-leaved mixed forest>larch forest>broad-leaved mixed forest>poplar forest. The higher the heating rate, the faster the weight loss rate of the surface litters. When the particle diameter was 178~250 μm, the pyrolysis weight loss rate is the highest. The pyrolysis weight loss rate of the surface litters in the air atmosphere is greater, and the pyrolysis is more complete. The order of activation energy is consistent with the order of weight loss rate. Among them, the activation energy of birch forest litter is the highest, which is 95.5 kJ · mol^(-1), and the pyrolysis activation energy of poplar forest litter is the lowest, which is 68.8kJ·mol^(-1)