Micropore surface areas, pore size distributions and pore volumes were
determined for four brown coals, one medium-volatile subbituminous co
al, one high-volatile subbituminous coal, and one low-volatile bitumin
ous coal by carbon dioxide adsorption at 273 K. For comparison, BET su
rface areas were determined for two of the brown coals by nitrogen ads
orption at 77 K. Surface areas were consistent with published values.
The micropore size distributions obtained using the Dubinin-Medek appr
oach were found to be independent of coal rank and functional groups.