...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Energy Conversion & Management >Two-step thermodegradation kinetics of cellulose, hemicelluloses, and lignin under isothermal torrefaction analyzed by particle swarm optimization
【24h】

Two-step thermodegradation kinetics of cellulose, hemicelluloses, and lignin under isothermal torrefaction analyzed by particle swarm optimization

机译：通过粒子群优化分析的等温烘焙基因纤维素，半纤维素和木质素的两步热降解动力学

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

The recognition of the isothermal thermodegradation of cellulose, hemicelluloses, and lignin plays a vital role for torrefaction to upgrade lignocellulosic biomass and produce biochar. This study adopts a two-step model with particle swarm optimization (PSO) algorithm to calculate and predict the isothermal torrefaction kinetics of cellulose, hemicelluloses, and lignin under the torrefaction temperatures of 200, 250, and 300 degrees C. A thermogravimetric analyzer is coupled with Fourier Transform Infrared (TG-FTIR) spectrometer to analyze the instantaneous weight losses and released gaseous products. The predictions suggest that cellulose shows the greatest weight loss and generates the most volatile products (81.70%) followed by a final residue (18.29%) at the isothermal torrefaction temperature of 300 degrees C. Hemicelluloses have severe weight loss at 250 degrees C, owing to their relatively weak structure compared to cellulose. The final residue yield is in the range of 60.04-74.05%, and the second prevalent product is the intermediate ranging from 3.34 to 8.20%. Lignin shows higher thermal resistance to torrefaction and produces the most intermediate under the isothermal torrefaction at temperatures lower than 300 degrees C, accounting for 86.41-97.50%. The activation energies of cellulose, hemicelluloses, and lignin are in the range of 166-260, 48-55, and 59-70 kJ mol(-1), respectively. The FTIR spectra indicate that CO and CO2 are the dominant gases in the torrefaction of the three model compounds due to the cleavages of methoxyl, ether, carboxyl, and carbonyl groups.
机译：识别纤维素，半纤维素和木质素的等温恒温降解对促进木质纤维素生物量并产生生物炭的造福作用至关重要的作用。本研究采用具有粒子群优化（PSO）算法的两步模型来计算和预测纤维素，半纤维素和木质素的等温渗流动力学，在200,250和300℃的烘焙温度下。热重分析仪耦合利用傅里叶变换红外（TG-FTIR）光谱仪分析瞬时体重损失和释放的气态产品。预测表明，纤维素显示最大的减肥，并产生最挥发性的产品（81.70％），然后在300摄氏度的等温烘焙温度下进行最终残留物（18.29％）。半纤维素在250℃下具有严重的体重减轻，欠与纤维素相比，它们的结构相对较弱。最终残留物收率在60.04-74.05％的范围内，第二次普照产物的中间体为3.34至8.20％。木质素显示出较高的热耐热性，并在低于300摄氏度的温度下产生最多的中间体，占86.41-97.50％。纤维素，半纤维素和木质素的活化能量分别为166-260,48-55和59-70kJ摩尔（-1）的范围。 FTIR光谱表明CO和CO2是由于甲氧基，醚，羧基和羰基的裂解引起的三种模型化合物的渗流中的主要气体。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号