Off-Road Low NOx Demonstration Stage 2
This study is part of a continuing effort aimed at demonstrating the capability of diesel emission control technologies to reach low nitrogen oxide (NOx) levels on an off-road diesel engine. The study objective is to demonstrate the feasibility of technologies to reach tailpipe NOx emission reductions of up to 90% from the current Tier 4 Final standards, and particulate matter (PM) emission reductions of at least 75% from the current Tier 4 Final standards.
Two different systems are being developed to meet these targets, the first of which is intended to meet the target NOx and PM levels with no impact on greenhouse gas (GHG) emissions. The second system is intended to meet the target NOx and PM levels while also demonstrating a 5% to 8.6% improvement in carbon dioxide (CO2) emissions, and remaining GHG neutral with respect to nitrous oxide (N2O) and methane (CH4). The demonstration is targeted primarily at off-road engines rated between 56 kilowatts (kW) and 560 kW. The off-road Low NOx demonstration reported here builds on previous extensive studies to demonstrate Low NOx technologies for on-road engines, the Stage 3 Low NOx Demonstration study, as well as the previous Off-Road Low NOx Demonstration Stage 1 that was intended to lay the groundwork for the current study. The emission control systems demonstrated in this study showed good promise in being able to reach levels 25% to 50% below the 90% NOx emission reduction target levels with technologies suitable for implementation in production, allowing for a significant potential compliance margin.