Power plant and method for operation

The power plant has a gas turbine unit (1) with at least one compressor (101), at least one downstream combustion chamber (102), at least one further downstream turbine (103) and a heat exchanger equipment (202) arranged in the flue gas path on the primary side and in a working gaseous fluid flow path on the secondary side. A flue gas cleaning catalyzer (205) is arranged in the flue gas path of the gas turbine group downstream of at least a first part of the heat exchanger equipment. An independent claim is also included for the following: (a) a method of operating an inventive system.