A cogeneration plant is provided that includes a gas turbine, a heat recovery steam generator, a steam turbine and a cooler/condenser. A division module is provided at a division point, via which downstream the heat recovery steam generator the combustion gas is cooled and dehumidified in the cooler/condenser and then divided into a first combustion gas flow and a second combustion gas flow. A second condenser is provided for receiving the second combustion gas flow to separate contained carbon dioxide from contained water by condensation of the water. The cogeneration plant further includes a heater and a compressor for receiving the first combustion gas flow, which is heated, compressed and partly extracted to by-pass the combustor for cooling of the gas turbine before it enters the combustor and mix with the flow of oxygen and fuel to be burned in the gas turbine.