초록 ▼

A system and method are disclosed for lowering NOx levels in flue gases of a fluidized bed reactor using selective non-catalytic reduction. A reactor is connected to a separator by a duct, and a reactant is introduced into the duct for decreasing NOx levels in the flue gases passing from the reactor

A system and method are disclosed for lowering NOx levels in flue gases of a fluidized bed reactor using selective non-catalytic reduction. A reactor is connected to a separator by a duct, and a reactant is introduced into the duct for decreasing NOx levels in the flue gases passing from the reactor, through the duct, and into the separator. The reactant, such as ammonia or urea, is selectively injected into a gaseous-rich region of the duct, near an upper, inner portion of the duct, so that a high degree of mixing of the reactant with flue gases is achieved while maintaining a low degree of mixing of the reactant with the particulate materials. The point of injection of the reactant into the duct is also at a location nearer to the reactor than to the separator to provide for increased residence time. In this manner, the reactant is used efficiently while obtaining the desired lowering of NOx levels in the flue gases.

대표청구항 ▼

A combustion method for decreasing NOx emissions, the method comprising the steps of: introducing fuel particles into an enclosure; combusting the fuel particles material in the enclosure; introducing an oxygen-containing, fluidizing gas into the enclosure to support combustion of the fuel particles

A combustion method for decreasing NOx emissions, the method comprising the steps of: introducing fuel particles into an enclosure; combusting the fuel particles material in the enclosure; introducing an oxygen-containing, fluidizing gas into the enclosure to support combustion of the fuel particles and to fluidize the fuel particles so that the fluidizing gas combines with gaseous products of combustion to form flue gases that entrain a portion of the fuel particles and pass upwardly through the enclosure; providing a duct in an upper portion of the enclosure in gas flow communication with the enclosure, the duct having an upper portion, a lower portion, and two side portions; locating the duct relative to the enclosure so, as the flue gases pass through the duct, they tend to pass closer to one side portion thereof than the other side portion; and so, as the fuel particles pass through the duct, they tend to pass closer to the other side portion than the one side portion; and injecting a reactant into the duct nearer to the one side portion than to the other side portion for decreasing NOx, levels in the flue gases passing through the duct.