Abstract:

The pyrolysis behaviors of wood and its three chemical components（cellulose，hemicellulose and lignin）were investigated in a thermo-gravimetric analyzer（TGA）. Meanwhile，the thermo-gravimetric behavior of liquefied residues under same liquefaction conditions were also studied. Regarding thermal stability，TGA results showed that lignin was the most difficult one to be pyrolyzed，hemicellulose was the easiest one，and cellulose was in the middle. The thermal degradation of wood was considered as the sum of the thermal degradations of each individual chemical component. It was achieved in a step-wise manner，i.e. hemicellulose breaken down first at 236～333 ℃，cellulose next at 332～383 ℃ and lignin at 250～630 ℃. Lignin was the most susceptible wood component to the liquefaction reaction among the three main wood components，then hemicellulose，and cellulose at last. In the liquefaction process，the rapid liquefaction stage was mainly attributed to lignin and hemicellulose，which were easily and firstly liquefied，while the second stage，characterized by the slow decrease of residues，mainly depended upon the progress of cellulose liquefaction.

摘要：

分别对木粉主要组分（纤维素、半纤维素和木质素）及其在相同液化条件下的液化残渣的热重行为进行了研究。热重实验结果表明，木粉主要组分的热稳定性为：木质素 > 纤维素 > 半纤维素。木粉的热解过程可以认为是这3种主要组分热解行为的综合：木质素的热解比较缓慢，热解温度区间最宽，主要失重温度为250～630 ℃；而纤维素和半纤维素的主要热解温度分别为332～383 ℃和236～333 ℃。在液化反应过程中，木粉主要组分发生降解从易到难的顺序为：木质素 > 半纤维素 > 纤维素。在木粉的液化过程中，快速液化阶段主要与半纤维素和木质素有关，而液化残渣率的高低主要与纤维素液化程度有关。