APPARATUS, SYSTEM, AND METHOD FOR REDUCING NOX EMISSIONS ON AN SCR CATALYST

摘要

According to one representative embodiment, an apparatus (130) for reducing NOx emissions in an engine exhaust gas stream of an engine system (10) having a selective catalytic reduction (SCR) system (150) with an SCR catalyst (152) positioned downstream of a reductant injector (192) includes a NOx reduction target module (300) and a reductant module (330). The NOx reduction target module is configured to determine a NOx reduction requirement (304). The reductant module is configured to determine the amount of reductant added to the exhaust gas stream to achieve the NOx reduction requirement. The amount of reductant added to the exhaust gas stream is a function of at least one ammonia storage characteristic of the SCR catalyst, at least one reductant-to-ammonia conversion characteristic, and a conversion capability of an AMOX catalyst (160) in exhaust receiving communication with the SCR catalyst.