In considering with morphological physicochemical transformations of the coal samples pyrolysed in CO2 atmosphere at different temperatures, the change of their adsorptive capacities have been investigated. It was seen that the change occurred in the monolayer adsorption capacities as parallel to morphological transformations of the coal surface is particularly connected with the amount of organic sulfur present in the coal matrix. Adsorption capacity is not affected from the contents of pyritic sulfur and ash of coal samples. The measurements of zeta potential of the pyrolysed coal samples also showed that pyrolysis modified the functional groups on surface of the coal, depending on the pyrolysis temperature. (C) 2002 Elsevier Science Ltd. All rights reserved.