The invention pertains to a power plant including a gas turbine, a heat recovery boiler arrangement with at least a boiler inlet, and an outlet side with a first exit connected to a stack and a second exit connected to a flue gas recirculation, which connects the second exit to the compressor inlet of the gas turbine. The heat recovery boiler arrangement includes a first boiler flue gas path from the boiler inlet to the first boiler exit, and a separate second boiler flue gas path from the boiler inlet to the second boiler exit. Additionally, a supplementary firing and a subsequent catalytic NOx converter are arranged in the first boiler flue gas path. Besides the power plant a method to operate such a power plant is an object of the invention.