This study shows that standard techniques used for carbons characterization, such as physical adsorption of CO 2 at 273K and N 2 at 77K, can be used to assess, with a good accuracy, the maximum capacity of carbons to capture CO 2 under post- and pre-combustion conditions. The analysis of the corresponding adsorption isotherms, within the general theoretical framework of Dubinin's theory, leads to the values of the micropore volume, W o , and the characteristic energy, E o , of the carbons, which provide direct information on the equilibrium CO 2 uptake of the carbons at different pressures and temperatures.Although in special cases slightly higher values can be obtained, an overall assessment of the textural parameters for a large variety of activated carbons, indicates that a CO 2 uptake upper-bound around 10–11wt% seems to be realistic for standard activated carbons under post-combustion conditions. In the case of pre-combustion conditions, this limit would not exceed 60–70wt%.