Impact of Aftertreatment Device and Driving Conditions on Black Carbon, Ultrafine Particle and NOx Emissions for Euro 5 Diesel and Gasoline Vehicles

Abstract

Ultrafine particle, black carbon and NOx emissions from Diesel and gasoline passenger cars have been investigated in this work, as well as influences of aftertreatment device and driving conditions (the cold start, urban, rural and motorway conditions…) on emissions. Experiments have been carried out on chassis dynamometer bench with Artemis urban, road and motorway driving cycles and NEDC (New European Driving Cycle). Exhaust from Euro 5 Diesel vehicles equipped with additive and catalysed particle filter and Euro 5 gasoline vehicle with direct injection system has been taken directly from the tailpipe and diluted by Constant Volume Sampler (CVS). Tested gasoline DI vehicle emits 25% more CO2 than Diesel vehicles for all Artemis and NEDC driving conditions. It emits 2 to 200 times more PN and BC and 5 to 150 times less NOx than Diesel vehicles. Additive DPF vehicles emit 2 times more NO2 for urban conditions (175 mg/km), comparing to Diesel catalysed DPF (80 mg/km). No significant differences have been observed between additive and catalysed DPF for CO2 and NOx emissions. The cold start induces 10 to 20% more CO2 emissions for all tested vehicles. It induces 3 to 20 times higher PN emission with a great uncertainty. For NOx and NO2, the cold start induces about 40 to 60% less emissions for additive DPF Diesel vehicles. No significant impact has been observed for gasoline and catalysed DPF Diesel vehicles. DPF regeneration was observed for Artemis motorway driving cycles, with an increase of 100 -200 times more PN emission than standard filter operation mode.

Exhaust emissions of particulate matter from light-duty vehicles – an overview and the current situation

“…That being said, the total proportion of idle time is not the only factor: the timing and number of engine restarts and the warm-up penalty caused by engine shutdown at idle also influence the relative PM and PN results; this applies whether the Stop&Start system is active or inactive. The magnitude of the emissions from vehicle 1 are reasonably similar to those reported elsewhere [7,15]. Importantly, when Stop&Start was turned on, the vehicle met the Euro 6 PN limit over the WLTC, despite (presumably) not being calibrated to that cycle.…”

“…Anderson et al [3] subjected two Euro 6 diesel vehicles to a range of chassis dyno tests, reporting that PM emissions were always under 1 mg/km; PN emissions varied between test cycles and inertia settings with higher PN emissions over the NEDC than the WLTC. Cédric et al [7] tested several Euro 5 Diesel-DPF and DISI vehicles over multiple driving cycles and reported that cold start was responsible for both a high proportion of PN results and a high proportion of the uncertainty associated with those results. Wei et al [27] also report finding cold start and high load during the first 200 seconds to be a massive contributor to particulate emissions (measured as PM in their study).…”

European Regulatory Framework and Particulate Matter Emissions of Gasoline Light-Duty Vehicles: A Review

“…Figure 7: As Figure 6. Figure A1: Total PN [93,95,104,105,108,109,150,158,[161][162][163]170,195,204,212,226,248,[271][272][273][274]…”

Euro 6 Unregulated Pollutant Characterization and Statistical Analysis of After-Treatment Device and Driving-Condition Impact on Recent Passenger-Car Emissions

“…Various aftertreatment devices (such as the diesel oxidation catalyst (DOC), the diesel particulate filter (DPF), the selective catalytic reduction (SCR), or NO X trap and the three-way catalyst (TWC)) are being used to bring the pollutant emissions below regulatory levels. − Although these technologies make it possible to significantly reduce regulated compound emissions, they affect some emissions of pollutants. Catalyzed or additive DPF reduce particle mass emission, with efficiency near 100%, but they might induce an increase of fine and ultrafine particle emissions and affect NO 2 , volatile organic compounds, PAH, BTEX, and black carbon (BC) emissions. − The actual impacts of these after-treatment technologies on unregulated pollutant emissions are not fully known. ,− The recent study by Louis et al showed that catalyzed DPF vehicles emitted about 3 to 10 times more carbonyl compounds and particles than additive DPF vehicles, respectively, during urban driving cycles, while additive DPF vehicles emitted 2 and 5 times more BTEX and carbonyl compounds during motorway driving cycles.…”