石炭におけるガス透過性と孔隙構造の関連性

This paper deals with basic data on gas permeability and diffusion coefficients of coal and correlation with characteristics of the macropore such as Klinkenberg's constant, mean pore radius, effective pore area and porosity. This paper aims at the possibility of reduction in the number of numerical constants of the numerical analysis by means of several equations between the numerical parameters. Test pieces made of lump coal and compressed fine coals were prepared. Measurements were performed by flowing methane, nitrogen and other gases through the test pieces. On the basis of experimental results for compressed fine coals, empirical equations between gas permeability and characteristics of macropore were obtained. For lump coal, the factors were determined to express its heterogeneity in comparison with equations for fine coals. Permeability flowing methane was less by 10 approximately 15% than that of nitrogen. This amount of reduction can be explained on the basis of the difference in mean free pass of molecules. The effect of adsorption on macropore surfaces was not evident for gas permeability.