A method for retrofitting a fossil-fueled power station is provided. The power station includes a multi-housing stream turbine with a carbon dioxide separation device. As per the method, a suction capability of the steam turbine is adapted for an operation of the carbon dioxide separation device to a process steam to be removed. The carbon dioxide separation device is connected via a process steam line to an intermediate superheating line. Further, an auxiliary condenser is connected to the carbon dioxide separation device. On failure or deliberate switching off of the carbon dioxide separation device surplus process steam is condensed in the auxiliary condenser.