废弃柞木段热解特性及其反应动力学研究

Study on characteristics and reactionkinetics of pyrolysis of waste oak segments

以废弃柞木段为研究对象,进行了不同升温速率（5,15,25℃/min）下的热解失重实验以及TG和DTG曲线分析,采用分布活化能模型（DAEM）和一级反应模型研究其反应动力学特性。结果表明,脱水干燥的废弃柞木段热解过程主要分为过渡、挥发分析出和碳化3个阶段,随着升温速率的提高,DTG曲线有向高温侧移动的趋势,不同升温速率下的最大热解速率所对应的温度在360~380℃;采用DAEM得到的主热解阶段活化能为210~260 k J/mol,一级反应模型得到的主热解阶段活化能约为62 k J/mol,两种模型都能够较好地描述废弃柞木段主热解阶段,而DAEM模型更为全面。

Thermogravimetric experiments of used oak segments were performed at different heating rates（5,15,25 ℃ /min）, and TG-DTG analysis techniques were adopted to study the pyrolysis characteristics. Distributed activation energy model（DAEM） and first-order reaction model were used to determine the kinetic parameters. The results indicated that the pyrolysis process of dehydrated oak segments includes three stages（transition,pyrolysis and carbonization）, and the DTG curve moves to higher temperature side as the heating rate increases. The maximum pyrolysis rates at different heating rates are mainly in the range of 360-380 ℃. The activation energy of main weight loss stage is between210-260 k J/mol for DAEM, and about 62 k J/mol for first-order reaction model. The pyrolysis process of used oak segments can be well described by the two models,and DAEM can describe it more efficiently.