物理化学学报 >> 2006, Vol. 22 >> Issue (07): 786-790.doi: 10.1016/S1872-1508(06)60031-4

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基于差示扫描量热技术的生物质热解两步连续反应模型研究

陈海翔;刘乃安;范维澄   

  1. 中国科学技术大学火灾科学国家重点实验室, 合肥 230026
  • 收稿日期:2005-11-21 修回日期:2006-02-21 发布日期:2006-06-27
  • 通讯作者: 刘乃安 E-mail:liunai@ustc.edu.cn

Two-step Consecutive Reaction Model of Biomass Thermal Decomposition by DSC

CHEN Hai-Xiang;LIU Nai-An;FAN Wei-Cheng   

  1. State Key Laboratory of Fire Science, University of Science and Technology of China, Hefei 230026, P. R. China
  • Received:2005-11-21 Revised:2006-02-21 Published:2006-06-27
  • Contact: LIU Nai-An E-mail:liunai@ustc.edu.cn

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摘要： 采用差示扫描量热分析仪对我国的一种生物质试样在空气气氛中进行了实验, 发现试样从常温到923 K高温的低速升温过程中, 经历了两步明显的放热过程. 对放热机理的分析表明, 第一步主要是由半纤维素和纤维素的有氧热解过程控制, 第二步放热过程则受木质素热解和炭的氧化反应的共同作用. 采用等转化率方法和优化计算方法, 对热解过程的动力学模型进行了研究, 结果表明, 两步连续反应机理可用于描述生物质在空气气氛中热解的放热动力学.

关键词: 生物质, 热解, 动力学模型, 差示扫描量热

Abstract: The thermal decomposition of one kind of biomass in air has been investigated by differential scanning calorimetry (DSC) analyzer. The results indicate that the heating process of samples from ambient temperature to 923 K at low heating rates show two obvious exothermic peaks. According to the decomposition mechanism, the first exothermic step is attributed to oxidative degradation of hemicellulose and cellulose, and the second exothermic step is attributed to lignin degradation and char oxidation. The reaction model of the studied biomass thermal decomposition has been studied by iso-conversional methods and optimization computation. The results suggest that the two-step consecutive reaction model is suitable to describe the exotherm of biomass thermal decomposition in air.

Key words: Biomass, Thermal decomposition, Kinetic model, DSC