Application of Combustion Modification Technologies to Achieve NOx Emissions Less than 0.15 lb/MMBtu on Pulverized Coal Fired Boilers

摘要

Coal-fired power plants must generate power at competitive prices while reducing NOx emissions to low levels. Combustion modification technologies, such as low-NOx burners, overfire air, and reburning can significantly reduce NOx emissions. These technologies can be effectively integrated along with post-combustion control technologies, such as selective non-catalytic reduction (SNCR). By layering NOx emissions control technologies, plants can achieve low NOx levels at a fraction of the cost of Selective Catalytic Reduction (SCR). This paper presents the layering concept as well as performance results of a layered NOx control system applied to coal-fired utility boilers. Results are shown from two coal-fired boilers integrating low-NOx burners, overfire air, reburning and SNCR. The application of advanced computational modeling techniques to optimize system design and integration are discussed. The results demonstrate that NOx emissions levels less than 0.15 lb/MMBtu can be achieved with minimal impacts on boiler performance.