核桃壳热解特性及几种动力学模型结果比较  

PYROLYSIS CHARACTERISTICS OF WALNUT SHELL AND ITS KINETIC PARAMETERS WITH DIFFERENT METHODS

作　　者：郑志锋[1] 黄元波[1] 蒋剑春[2] 戴伟娣[2] 杨晓琴[1] 

机构地区：[1]西南林业大学西南山地森林资源保育与利用省部共建教育部重点实验室,昆明650224 [2]中国林业科学研究院林产化学工业研究所生物质化学利用国家工程实验室国家林业局林产化学工程重点开放性实验室,南京210042

出　　处：《太阳能学报》2011年第11期1677-1682,共6页Acta Energiae Solaris Sinica

基　　金：国家自然科学基金(30800867);国家科技支撑计划(2006BAD19B06);教育部科学技术研究重点项目(209117);中国博士后科学基金(20080430465);云南省社会发展科技计划(2007C068M);云南省教育厅科学研究基金重点项目(09Z0065)

摘　　要：利用热重分析在不同升温速率和氮气气氛下对核桃壳的热失重行为进行研究。根据热重实验数据,采用4种热分析动力学方法(Coats-Redfern法、Doyle法、Ozawa法和DAEM模型),计算核桃壳热解反应活化能E、反应级数n及频率因子A,并进行比较。结果表明:采用不同的动力学分析处理方法,得出的热解动力学参数不同。利用Coats-Redfern法,核桃壳在热解主要阶段(失重10%～95%)可由一段一级反应过程描述,升温速率20K/min时活化能为55.37kJ/mol。Doyle法和DAEM模型得到的结果较为接近,Ozawa法求得的活化能值最高。核桃壳热解包含分子键能断裂的一系列复杂、连续反应过程,并获得核桃壳的热解反应活化能随失重率的变化曲线。The pyrolysis characteristics of walnut shell sample at different heating rates （5 -50K/min） in a stream of N2 were studied by using thermogravimetric analysis. Four methods ： Coats-Redfern, Doyle, Ozawa and DAEM, were used to determine the kinetic parameters, including activation energies, reaction order and frequency factor. The results showed that the kinetic parameters are different with different methods. The pyrolysis process can be described by first-order global model for walnut shell and its activation energy was 55.37kJ/mol （ weight loss from 10w% to 95w% ） at the heating rate of 20K/min with the method of Coats-Redfern. Almost the same results were obtained with Doyle and DAEM model. The activation energy is the highest with the method of Ozawa. Pyrolysis of the walnut shell sample is a complicated reaction and their activation energy varied with increasing weight loss.

关 键 词：核桃壳 热解 热重分析 动力学 

分 类 号：TK61[动力工程及工程热物理—生物能]