纤维素热裂解过程动力学的试验分析研究

发布时间：2018-03-21 11:21

  本文选题：纤维素　切入点：反应动力学　出处：《浙江大学学报(工学版)》2002年02期 　论文类型：期刊论文

【摘要】：尽管针对纤维素热裂解动力学方面的研究已开展得比较广泛 ,但其表观动力学的确定仍是一具有争论性的问题 ,从而对纤维素热裂解机理的描述也就各不相同 .本文试图通过纤维素的热裂解动力学研究 ,对此种现象作出合理的解释 ,并给出相应的机理描述 .纤维素热裂解随温度的升高经历了五个不同的阶段 ,其中第三阶段是整个过程的主要部分 ,期间大量挥发分析出并造成明显失重 .试验发现随着升温速率的增加 ,热滞后现象的加重致使纤维素热裂解各个阶段向高温侧移动 ;同时高升温速率对炭的生成具有抑制作用 ,但有利于挥发分的生成 .通过对热裂解主反应区的热重分析 ,采用微商法求得对应的反应动力学参数 ,以 6 0 0 K作为分界点 ,低温段的活化能约在2 6 7k J/ m ol,较高温度段则体现为 174 k J/ mol左右的低活化能 .纤维素热裂解是一传热传质现象 ,与化学动力学机制相互影响、控制的过程 ,试验条件、传热传质过程的影响是造成结论存在差异的内在原因
[Abstract]:Although the research on the kinetics of cellulose pyrolysis has been carried out extensively, the determination of the apparent kinetics of cellulose is still a controversial issue. Therefore, the description of the mechanism of cellulose pyrolysis is different. This paper attempts to give a reasonable explanation of this phenomenon through the study of the pyrolysis kinetics of cellulose. The pyrolysis of cellulose goes through five different stages with the increase of temperature, and the third stage is the main part of the whole process. It was found that with the increase of heating rate and the increase of thermal hysteresis phenomenon, cellulose pyrolysis moved to the high temperature side in each stage. At the same time, the high heating rate can inhibit the formation of carbon, but it is beneficial to the formation of volatile matter. By thermogravimetric analysis of the main reaction zone of pyrolysis, the corresponding kinetic parameters of the reaction are obtained by microquotient method. The activation energy at low temperature is about 267kJ / mol, and the activation energy at higher temperature is about 174kJ / mol. The pyrolysis of cellulose is a heat and mass transfer phenomenon. Interaction with chemical kinetic mechanisms, controlled processes, experimental conditions, and effects of heat and mass transfer are the underlying reasons for the differences in conclusions.
【作者单位】： 浙江大学能源洁净利用与环境教育部重点实验室 浙江大学能源洁净利用与环境教育部重点实验室 浙江大学能源洁净利用与环境教育部重点实验室 浙江大学能源洁净利用与环境教育部重点实验室 浙江大学能源洁净利用与环境教育部重点实验室 浙江大学能源洁净利用与环境教育部重点实验
【基金】：国家自然科学基金资助项目 (5 0 1760 46)、(2 99760 3 9) 国家杰出青年科学基金资助项目 (5 0 0 2 5 618)
【分类号】：TQ351.2
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本文编号：1643628