Ultra-low NOx and PN with integrated emission control systems for light-duty gasoline and heavy-duty diesel vehicles

Abstract

Public data shows Euro 6d and Euro VI-D vehicles overall have low on-road emissions. But there remain areas where higher emissions occur for both light- and heavy-duty. Two ultra-low emission demonstrator vehicles were built to investigate further emission reductions through an integrated approach of emission control technologies. On a gasoline car, a close-coupled three-way catalyst (TWC) is put in combination with an underfloor catalysed gasoline particulate filter (cGPF), second TWC and ammonia slip catalyst (ASC). The work focuses on further reducing the initial cold-start emissions by using a ccTWC substrate with maximised surface area in combination with early closed-loop lambda control activation. The emission control system is integrated within a 48V mild-hybrid powertrain. On a diesel truck, the system integrates a close-coupled DOC, a catalysed DPF, dual-SCR system (one in a close-coupled position before the DPF), with twin AdBlue® dosing. Both SCR catalysts contain an ammonia slip catalyst. The innovative system layout allows ultra-low NOx emissions in even the most challenging low-load and urban driving conditions including cold-start. Pollutant emissions were evaluated for both vehicles over a broad range of operating conditions, with tests in the lab and on the road. Results show ultra-low pollutant emissions are achieved for all regulated pollutant emissions, while controlling the currently non-regulated emissions (PN10, NH3 and N2O are measured with a prototype PEMS). The demonstrator vehicles show efforts to further reduce the impact of internal combustion engines on air quality. The impact on climate change is reduced in the case the vehicle operates on a sustainable renewable fuel.