Method and device for operating a gas turbine comprising a fossile fuel combustion chamber

The method involves dividing the exhaust gas (9) from the gas turbine into first and second partial flows (11,13), mixing the first partial flow with combustion air (15), feeding the resulting mixture (17) back to the combustion chamber and feeding the second partial flow to a carbon dioxide separation system (21). The exhaust gas is cooled before being divided and resulting water is carried away. AN Independent claim is also included for the following: (a) an arrangement for operating a gas turbine with a fossil-fired combustion chamber.