煤基质中甲烷扩散动力学特性研究

基金项目:

“973”国家重点基础研究发展规划项目课题“煤层的吸附特征和储气机理(2002CB211703)”

详细信息

Study on dynamic diffusion characteristics of methane in coal matrix

摘要: 甲烷在煤基质中的质量传递过程可用费克第一定律或费克第二定律来模拟。本文通过等温吸附-解吸实验的动力学数据,以费克第二定律为理论基础,对煤基质球形单元模型建立了试验求取扩散特性的方法。晋城煤样等温吸附及解吸实验的数据处理结果表明,吸附-解吸速率均随压力及煤样气含量的增加而增加;吸附速率与解吸速率随压力的变化曲线基本相同。
- 煤 /
- 甲烷 /
- 吸附 /
- 解吸 /
- 扩散
Abstract: The approach to modeling coal matrix methane transport is based upon the solution to Fick's first law or Fick's second law.This paper presents an experimental method for determining diffusivities from high-pressure methane adsorption-desorption volumetric isotherm data.The numerical model of this method is based on Fick's second law for spherically symmetric flow.The example of this measurement method is given through Jincheng's coal sample.The result shows that adsorption-rate is consistent with desorption-rate,both increasing with pressure.
- coal /
- methane /
- adsorption /
- desorption /
- diffusion