• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文会议>US Combustion Meeting; 20070325-28; San Diego,CA(US) >The Impact of the Distributions of Surface-Oxides and their Migration on Characterization of the Heterogeneous Carbon-Oxygen Reaction
【24h】

The Impact of the Distributions of Surface-Oxides and their Migration on Characterization of the Heterogeneous Carbon-Oxygen Reaction

机译：表面氧化物的分布及其迁移对非均相碳氧反应表征的影响

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

A study was undertaken to characterize the impact of the heterogeneity and migration of surface oxides on the char oxidation process. The char employed in this study was subjected to a series of kinetics-limited oxidation tests in a pressurized thermogravimetric analyzer (PTGA). Temperature Programmed Desorption and BET-CO_2 gas adsorption tests were also performed in order to characterize surface oxide complexes and specific surface areas. In agreement with other studies, the experiments indicated that the surface-oxide populations may be characterized in terms of a distribution of desorption activation energies and that migration of the surface oxide complexes is significant.A heterogeneous reaction mechanism was developed to account for the observed rates of O_2 adsorption, CO and CO_2 desorption, and surface-oxide accumulation, and used in a numerical algorithm that modeled the PTGA reaction environment. Surface species were characterized by activation energy-based distributions; account was made for the impact of surface area evolution on surface species concentrations. Analysis of calculated results indicate that a quasi-steady surface area assumption tends to under-predict surface species concentrations, especially at late conversions, and can over-predict these concentrations at early conversions. Calculated results also indicate that using less than five sites to approximate activation energy distributions yields results that are inconsistent with oxidation behaviors that are based on the full distributions.
机译：进行了一项研究，以表征表面氧化物的不均匀性和迁移对炭氧化过程的影响。在加压热重分析仪（PTGA）中，对本研究中使用的炭进行了一系列动力学受限的氧化测试。还进行了程序升温脱附和BET-CO_2气体吸附测试，以表征表面氧化物配合物和比表面积。与其他研究一致的是，实验表明可以根据解吸活化能的分布来表征表面氧化物的数量，并且表面氧化物配合物的迁移是重要的。 O_2的吸附，CO和CO_2的解吸以及表面氧化物的累积，并用于对PTGA反应环境进行建模的数值算法。表面物种的特征是基于活化能的分布。考虑了表面积变化对表面物种浓度的影响。对计算结果的分析表明，准稳态表面积假设趋于低估表面物种的浓度，尤其是在后期转换时，并且可能在早期转换时高估这些浓度。计算结果还表明，使用少于五个位点来近似活化能分布会产生与基于完整分布的氧化行为不一致的结果。

著录项

  • 来源
  • 会议地点 San DiegoCA(US)
  • 作者

    P. A. Campbell; R. E. Mitchell;

  • 作者单位

    Department of Mechanical Engineering, Faculty of Engineering and Computing University of Technology, Jamaica, Kingston 6, Jamaica, W.I.;

    Thermosciences Group, Mechanical Engineering Department Stanford University, Stanford, CA, 94305-3032, USA;

  • 会议组织
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类 理论;
  • 关键词

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