Method and apparatus for reducing the nitrogen oxides in flue gas
AssigneeSiemens Aktiengesellschaft
InventorsRalf Sigling, Franz Lankes
Life of this patent
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Abstract
Combustion systems have a combustion apparatus, heating surfaces downstream of the combustion apparatus in a flue gas stream, and a deNO.sub.x catalyst. A method for reducing nitrogen oxides in the flue gas of the combustion systems includes selectively assigning the deNO.sub.x catalyst to a position inside and a position outside the flue gas stream as a function of a nitrogen oxide concentration or of a selected energy carrier. An apparatus for reducing nitrogen oxides in the flue gas of the combustion system includes a device for selectively assigning the deNO.sub.x catalyst to a position inside and a position outside a line through which the flue gas flows.
Claims20
In a method for reducing nitrogen oxides in flue gas of combustion systems having a combustion apparatus, heating surfaces downstream of the combustion apparatus in a flue gas stream, and wherein the nitrogen oxides in the flue gas are reduced by exposing the flue gas stream to a denitrification catalyst, the improvement which comprises:
- selectively assigning the denitrification catalyst to a position essentially completely inside and a position essentially completely outside the flue gas stream as a function of a nitrogen oxide concentration.
In a method for reducing nitrogen oxides in flue gas generated by combusting a selected energy carrier in combustion systems having a combustion apparatus, heating surfaces downstream of the combustion apparatus in a flue gas stream, and wherein the nitrogen oxides in the flue gas are reduced by exposing the flue gas stream to a denitrification catalyst, the improvement which comprises:
- selectively assigning the denitrification catalyst to a position essentially completely inside and a position essentially completely outside the flue gas stream as a function of the selected energy carrier.
In a combustion system in which a flue gas is generated by combustion of a selected energy carrier, the combustion system including a flue gas channel through which the flue gas flows,
- an apparatus for reducing nitrogen oxides in the flue gas of the combustion system, the apparatus comprising:
- a denitrification catalyst for reducing nitrogen oxides in the flue gas, and
- means for selectively assigning said denitrification catalyst to a position essentially completely inside and a position essentially completely outside the flue gas channel as a function of a parameter selected from the group consisting of a nitrogen oxide concentration in the flue gas and the selected energy carrier.
In a combustion system in which a flue gas is generated by combustion of a selected energy carrier, the combustion system including a flue gas channel through which the flue gas flows,
- an apparatus for reducing nitrogen oxides in the flue gas of the combustion system, the apparatus essentially consisting of:
- a denitrification catalyst for reducing nitrogen oxides in the flue gas, and
- means for selectively exposing said denitrification catalyst to essentially all of the flue gas flowing through the flue gas channel and preventing the flue gas from flowing through
- said denitrification catalyst as a function of a parameter selected from the group consisting of a nitrogen oxide concentration in the flue gas and the selected energy carrier.
Dependencies are inferred from the claim text.