CARB Low NO<sub>X</sub> Stage 3 Program - Aftertreatment Evaluation and Down Selection

Abstract

<div class="section abstract"><div class="htmlview paragraph">With the conclusion of the California Air Resources Board (CARB) Stage 1 Ultra-Low NO<sub>X</sub> program, there continues to be a commitment for identifying potential pathways to demonstrate 0.02 g/hp-hr NO<sub>X</sub> emissions. The Stage 1 program focused on achieving the Ultra-Low NO<sub>X</sub> (ULN) levels utilizing a turbo-compound (TC) engine, which required the integration of novel catalyst technologies and a supplemental heat source. While the aftertreatment configuration provided a potential solution to meet the ULN target, a complicated approach was required to overcome challenges from low temperature exhaust. The Stage 3 program leverages a different engine architecture more representative of the broader heavy-duty industry to meet the Phase 2 Greenhouse Gas (GHG) targets and to simplify the ULN aftertreatment solution. The following work will discuss the aftertreatment technology evaluation, down selection criteria, and the emission results for the candidate ULN systems</div></div>