Treatment of flue gas from coal combustion is one of the most important way for reaching the CO2 limits into the atmosphere. Adsorption is a promising technology for the effective CO2 capture from flue gas. Testing CO2 physical adsorbents (zeolite 4A, activated carbons) for applications in various adsorption installations is the main idea of this paper. For the first time, the study was carried out using 100% CO2 and modeling flue gas mixtures with different content of CO2: 90, 50, 40, 30 and 20%. Research provided information on the impact of CO2 concentration on sorption capacity via thermogravimetric analyzer. The obtained results can be used for modeling and optimizing processes for CO2 capture from flue gas also CO2 sequestration technology.