CARB Low NOX Stage 3 Program - Aftertreatment Evaluation and Down Selection
With the conclusion of the California Air Resources Board (CARB) Stage 1 Ultra-Low NOX program, there continues to be a commitment for identifying potential pathways to demonstrate 0.02 g/bhp-hr NOX emissions. The Stage 1 program focused on achieving the Ultra-Low NOX (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 GHG targets and to simplify the ULN aftertreatment solution.