石炭の炭化初期段階に関する研究 (XVI)
石炭の微細孔隙構造の研究
1969 年 48 巻 4 号 p. 235-240
詳細
1969 年 48 巻 4 号 p. 235-240
The experiment of CO2 adsorption on twelve kinds of Japanese coals and five kinds of foreign coals was carried out and the applicability of Dubinin's theory of micro-pore volume filling was examined. The results were satisfactory.
The isosteric differential heat of adsorption evaluated from the characteristic curve was almost constant over the whole rank.
The evaluation of surface area was also made by Marsh's method. The plot of the surface areas of Japanese coals against C% showed a concave curve with a minimum at about 85%C and was somewhat smaller than that of foreign coals obtained by Marsh.
The rate of adsorption of CO2 on coals was usually slow and different in rank. The relative adsorption values (Vt/V∞) at adsorption time 1, 800sec were plotted against C%. The Vt/V∞ value increased with rank and had a maximum at about 85%C. This shape of curve was also observed in the plot of the gradient of rectilinear characteristic curve against C%.
In conclusion, the average pore diameter is small in low rank coals and, with the increase of coal rank, it increases and has a maximum of about 85%C and then decreases. On the contrary, the variation of the surface area with rank was entirely opposite to that of the average pore diameter.
