A system for producing electricity, the system comprising - a chemical recovery boiler adapted to supply superheated steam to a steam turbine driving a generator , the chemical recovery boiler comprising o a first flue gas discharge channel adapted to discharge the flue gases of the chemical recovery boiler and o a first heat exchanger arrangement arranged in the first flue gas discharge channel and adapted to recover thermal energy from the flue gases of the chemical recovery boiler ; - a lime kiln adapted to oxidize calcium carbonate (CaCO 3 ) of lime mud to produce lime (CaO), the lime kiln comprising o a second flue gas discharge channel adapted to discharge the flue gases of the lime kiln and o a second heat exchanger arrangement arranged in the second flue gas channel and adapted to recover thermal energy from the flue gases of the lime kiln ; and - a circulation for heat transfer medium, characterized in that - the circulation comprises o the first heat exchanger arrangement , o the second heat exchanger arrangement , and o a pipeline adapted to convey at least some of the heat transfer medium between the first heat exchanger arrangement and the second heat exchanger arrangement , and - the system is configured to provide feed water of the chemical recovery boiler with thermal energy originating from flue gases of the lime kiln via a line of the circulation for heat transfer medium. - a chemical recovery boiler adapted to supply superheated steam to a steam turbine driving a generator , the chemical recovery boiler comprising o a first flue gas discharge channel adapted to discharge the flue gases of the chemical recovery boiler and o a first heat exchanger arrangement arranged in the first flue gas discharge channel and adapted to recover thermal energy from the flue gases of the chemical recovery boiler ; o a first flue gas discharge channel adapted to discharge the flue gases of the chemical recovery boiler and o a first heat exchanger arrangement arranged in the first flue gas discharge channel and adapted to recover thermal energy from the flue gases of the chemical recovery boiler ; - a lime kiln adapted to oxidize calcium carbonate (CaCO 3 ) of lime mud to produce lime (CaO), the lime kiln comprising o a second flue gas discharge channel adapted to discharge the flue gases of the lime kiln and o a second heat exchanger arrangement arranged in the second flue gas channel and adapted to recover thermal energy from the flue gases of the lime kiln ; and o a second flue gas discharge channel adapted to discharge the flue gases of the lime kiln and o a second heat exchanger arrangement arranged in the second flue gas channel and adapted to recover thermal energy from the flue gases of the lime kiln ; and - a circulation for heat transfer medium, characterized in that - the circulation comprises o the first heat exchanger arrangement , o the second heat exchanger arrangement , and o a pipeline adapted to convey at least some of the heat transfer medium between the first heat exchanger arrangement and the second heat exchanger arrangement , and - the system is configured to provide feed water of the chemical recovery boiler with thermal energy originating from flue gases of the lime kiln via a line of the circulation for heat transfer medium. o the first heat exchanger arrangement , o the second heat exchanger arrangement , and o a pipeline adapted to convey at least some of the heat transfer medium between the first heat exchanger arrangement and the second heat exchanger arrangement , and - the system is configured to provide feed water of the chemical recovery boiler with thermal energy originating from flue gases of the lime kiln via a line of the circulation for heat transfer medium. - the system is configured to provide feed water of the chemical recovery boiler with thermal energy originating from flue gases of the lime kiln via a line of the circulation for heat transfer medium. <EOS>