1975 年 91 巻 1054 号 p. 759-764
We estimated total surface area of some Japanese coal by the volumetric gas adsorption method. From these results, the relations between pore size and surface area in coals were clarified. For the confirmation of the relations in question, we used the Kelvin equation that based on the capillary condensation theory.
Using the B.E.T. method, the surface areas of coals were derived from adsorption isotherms of nitrogen (at-196°C) and carbon dioxide (at-78°C).
The results obtained are as follows.
1) The surface areas determined with carbon dioxide, are greater than those with nitrogen.
2) If we give the physical and chemical reactivity of coal by means of the surface area and pore size distribution, one of the most responsible coal is Oshima.
3) The values of surface area do not always have definite connection with its pore size distribution. Namely, even if the coals have practically equal surface area, the pore size distribution of these coals are fairly different.