Evaluation of the porous structure development of chars from pyrolysis of rice straw: Effects of pyrolysis temperature and heating rate
Evaluation of the porous structure development of chars from pyrolysis of rice straw: Effects of pyrolysis temperature and heating rate
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稻草热解炭多孔结构发展的评价：热解温度和加热速率的影响
DOI：
10.1016/j.jaap.2012.08.005
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发表时间：
2012-11-01
影响因子：
6
通讯作者：
Wang, Jing
中科院分区：
文献类型：
--
作者：
Fu, Peng;Hu, Song;Wang, Jing
研究了热解温度和升温速率对稻草焦孔结构特征的影响。热解在大气压和600至1000摄氏度的温度下在低加热速率（LHR）和高加热速率（HEIR）条件下进行。采用元素分析、场发射扫描电镜（FESEM）、氦密度测定和N2物理吸附法对煤焦进行了表征。结果表明，温度对半焦的孔隙特性有明显的影响。随着温度从600 ℃升高到1000 ℃，焦炭产率降低约16%。碳结构收缩和孔变窄发生在高于600 ℃。随着温度从600 ℃升高到1000 ℃，碳骨架的收缩率增加了22%以上。在HHR条件下，随着热解温度的升高，孔隙率的发展逐渐增加，而最大孔隙率的发展出现在900 ℃。总表面积（S-总）和总表面积（S-微）在900 ℃时达到最大值30.94和21.81 m2/g，并在较高温度下略有下降。升温速率对总硫和微硫的影响小于热解温度。孔表面分形维数与平均孔径呈良好的线性关系。(C)2012爱思唯尔有限公司版权所有。
The effects of pyrolysis temperature and heating rate on the porous structure characteristics of rice straw chars were investigated. The pyrolysis was done at atmospheric pressure and at temperatures ranging from 600 to 1000 degrees C under low heating rate (LHR) and high heating rates (HEIR) conditions. The chars were characterized by ultimate analysis, field emission scanning electron microscope (FESEM), helium density measurement and N-2 physisorption method. The results showed that temperature had obvious influence on the char porous characteristics. The char yield decreased by approximately 16% with increasing temperature from 600 to 1000 degrees C. The carbon structure shrinkage and pore narrowing occurred above 600 degrees C. The shrinkage of carbon skeleton increased by more than 22% with temperatures rising from 600 to 1000 degrees C. At HHR condition, progressive increases in porosity development with increasing pyrolysis temperature occurred, whereas a maximum porosity development appeared at 900 degrees C. The total surface area (S-total) and micropore surface area (S-micro) reached maximum values of 30.94 and 21.81 m(2)/g at 900 degrees C and decreased slightly at higher temperatures. The influence of heating rate on S-total and S-micro was less significant than that of pyrolysis temperature. The pore surface fractal dimension and average pore diameter showed a good linear relationship. (C) 2012 Elsevier B.V. All rights reserved.