| abstract |
Through the addition of tertiary air and a reduction of secondary air, NOx emissions from a waste-to-energy (WTE) boiler may be reduced. The tertiary air is added to the WTE at a distance from the secondary air, in a boiler region of relatively lower temperatures. A secondary NOx reduction system, such as a selective non-catalytic reduction (SNCR) system using ammonia or urea, may also be added to the boiler with tertiary air to achieve desirable high levels of NOx reductions. The SNCR additives are introduced to the WTE boiler proximate to the tertiary air. |