CARB Low NOX Stage 3 Program - Aftertreatment Evaluation and Down Selection 2020-01-1402
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. The following work will discuss the aftertreatment technology evaluation, down selection criteria, and the emission results of the final demonstration aftertreatment system for a heavy-duty on-highway ULN application. As part of these efforts, the demonstration system was subjected to accelerated hydrothermal and chemical aging exposure utilizing the Diesel Aftertreatment Accelerated Aging Cycles (DAAAC) protocol. The accelerated aging methodology and aging impact will also be presented to provide catalyst deterioration insights.
Bryan Zavala, Christopher Sharp, Gary Neely, Sandesh Rao