ENHANCEMENT OF CONVENTIONAL SCR AND SNCR PROCESSES WITH AMMONIA DESTRUCTION CATALYST

摘要

An apparatus and method for achieving increased NO x removal efficiency fro m an emissions control portion of a fossil fuel fired boiler while controlling ammonia slip provides excess levels of ammonia above those levels conventionally employed in SCR and/or SNCR applications. The apparatus and methods comprise, in part, use o f a NO x reduction system comprising at least one selective catalytic reduction syste m which receives ammonia in higher amounts than conventional practice from an upstre am ammonia injection point, and an ammonia reduction system positioned downstre am of one or more ammonia injection points and the NO x reduction system. The exce ss ammonia achieves increased NO x removal, while the ammonia reduction system contains at least one ammonia destruction catalyst which permits the NO x reduction system to be operated at an increased NO x removal efficiency without a corresponding increase in ammonia slip.