The paper is focused on the idea of large-scale CFB boiler operation with oxygen/CO2-modified atmosphere inside combustion chamber. The following main advantages can be found for this technology: reduction of pollutant emissions, possibility of high efficiency separation of CO2 from the exhaust gases that results from increased CO2 concentration, lower chimney loss due to the reduction of flue gases in a volume, limitation of the combustion chamber dimensions etc. The paper presents a model of coal combustion in oxygen-enriched CFB environment, where air staging, desulfurization process, NOx formation and reduction as well as a stationary dense phase of coarse particles in the bottom part of combustion chamber and a circulating dilute phase in the upper part are included. (C) 2009 Elsevier B.V. All rights reserved.