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运用Klason法从4种不同生物质中制备木质素,采用元素及红外分析对不同木质素的化学结构进行表征,运用TG-FTIR研究不同来源木质素慢速热解特性的影响,发现不同来源的木质素热解过程表现为两个主要失重阶段,对应芳香族类化合物的析出与小分子气体的析出过程;其中枫木木质素的热解活性较高,可在较低的温度点(378℃)达到失重最大速率,这与其含有丰富的甲氧基结构有关。在实验分析的基础上建立分阶段反应动力学模型,计算其在不同热解阶段的动力学参数,发现第一阶段活化能主要在19.95~33.66 k J/mol之间,热解第二阶段的活化能在34.82~48.99 k J/mol之间。
The lignin was prepared from four different biomass by Klason method. The chemical structure of different lignin was characterized by elemental and infrared analysis. The effects of different pyrolysis of lignin from different sources were studied by TG-FTIR. The lignin pyrolysis process showed two main stages of weightlessness, corresponding to the precipitation of aromatics and the precipitation of small molecule gases. The maple lignin pyrolysis activity is higher, at a lower temperature (378 ℃ ) Reached the maximum rate of weight loss, which is related to its rich methoxy structure. Based on the experimental analysis, a staged reaction kinetic model was established and its kinetic parameters were calculated at different pyrolysis stages. The activation energy of the first stage was found to be between 19.95 and 33.66 kJ / mol. The second stage of pyrolysis The activation energy is between 34.82 and 48.99 kJ / mol.