Flow calorimetric technique was used to obtain information on the additional adsorption of carbon dioxide on two samples of Czech bituminous coal with pre-adsorbed methane. It was found that most of the adsorption sites for CO(2) remain unoccupied when the coal surface is saturated by pre-adsorbed methane. The calorimetric measurements then confirmed the displacement ability of carbon dioxide to methane molecules pre-adsorbed on the coal. (C) 2011 Elsevier B.V. All rights reserved.