FLUE GAS DENITRIFICATION METHOD AND FLUE GAS DENITRIFICATION SYSTEM SUITABLE FOR CARRYING OUT THE METHOD, FOR INTEGRATION INTO A POWER PLANT THAT PRODUCES FLUE GAS

摘要

The invention relates to a flue gas denitrification method in which a raw flue gas mass flow (121) of a boiler or steam generator (11) of a power plant (100), which boiler or steam generator is fired with carbon-containing fuel, which raw flue gas mass flow flows in a flue gas channel (120), is dentrified on the flue gas outlet side of the boiler or steam generator (110) in a flue gas denitrification reactor (210), more particularly a selective catalytic flue gas denitrification reactor, wherein reductant (221), more particularly reductant (221) comprising ammonia or urea, is introduced and/or injected, on the flue gas outlet side of the boiler or steam generator (110) and upstream of the flue gas denitrification reactor (210) in the flue gas flow direction (R), into the raw flue gas mass flow (121) flowing in the flue gas channel (120) by means of a reductant feed (240). The invention aims to provide a solution that allows flue gas and reductant to be well mixed in a way that conserves operating means, more particularly without additional consumption of operating means and without additional system components. This is achieved in that the reductant (221) is introduced and/or injected as a constituent of a preheated combustion-air partial flow (231) into the raw flue gas mass flow (121) flowing in the flue gas channel (120), the combustion-air partial flow (231) being branched off from one or more air-preheating units (130, 130'), which are arranged in a combustion air channel (140) supplying combustion air (141) to the boiler or steam generator (110), or being branched off downstream of said one or more air-preheating units (130, 130') in the air flow direction (L) from a preheated combustion air flow (142).