Abstract Standard Ar/77 K and n-butane/273 K adsorption isotherms of a non-porous carbon are presented. The comparison with other non-porous reference materials showed an acceptable agreement although, depending on the selected adsorptive, some differences at high relative pressures appeared. Both standard adsorption isotherms were employed to anlayse the microporous texture of a series of CO 2-activated carbons prepared from almond shell. The results obtained showed the suitability of both the DR and the α s methods to analyze the hydrocarbon adsorption isotherms of carbons. Depending on the approach considered to determine the micropore volume of carbons, N 2/77 K and, to a lesser extent, Ar/77 K gave different results from hydrocarbons, although the α s method generally produced more reliable results.