Assessment of Gaseous and Particulate Emissions of a Euro 6d-Temp Diesel Vehicle Driven >1300 km Including Six Diesel Particulate Filter Regenerations

Abstract

Diesel-fueled vehicles have classically had high particulate and NOx emissions. The introduction of Diesel Particulate Filters (DPFs) and Selective Catalytic Reduction for NOx (SCR) systems have decreased the Particle Number (PN) and NOx emissions, respectively, to very low levels. However, there are concerns regarding the emissions released during the periodic DPF regenerations, which are necessary to clean the filters. The absolute emission levels and the frequency of the regenerations determine the contribution of regenerations, but where they happen (city or highway) is also important due to different contributions to human exposure. In this study, we measured regulated and non-regulated emissions of a Euro 6d-temp vehicle both in the laboratory and on the road. PN and NOx emissions were similar in the laboratory and on-the road, ranging around 1010 p/km and 50 mg/km, respectively. Six regeneration events took place during the 1300 km driven, with an average distance between regeneration events of only 200 km. During regeneration events, the laboratory limits for PN and NOx, although not applicable, were exceeded in one of the two measured events. However, the on-road emissions were below the applicable not-to-exceed limits when regenerations occurred. The weighted PN and NOx emissions over the regeneration distance were approximately two times below the applicable limits. The N2O emissions were <14 mg/km and NH3 at instrument background level (<1 ppm), reaching 8 ppm only during regeneration. The results of this study indicate that due to the short interval between regenerations, studies of diesel vehicles should report the emissions during regeneration events.

Comparisons of Laboratory and On-Road Type-Approval Cycles with Idling Emissions. Implications for Periodical Technical Inspection (PTI) Sensors

“… Tailpipe studies: Laboratory studies that compared PMP systems at the tailpipe and the dilution tunnel [ 28 , 36 ]. Emissions monitoring: Laboratory and on-road assessment of various vehicles [ 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 ]. Unpublished data: Internal data of older vehicles (non DPF diesel vehicles, or GDIs emitting >6 × 10 12 p/km).…”

“…Emissions monitoring: Laboratory and on-road assessment of various vehicles [ 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 ].…”

Overview of Vehicle Exhaust Particle Number Regulations

“…However, SPN emissions during regeneration events and immediately after are very high and can bring the weighted emissions close to the current limit. Thus, filtration efficiencies and regeneration strategies need to be carefully assessed for future regulation [72][73][74][75][76][77].…”

Gasoline Direct Injection Engine Emissions of OC and EC: Laboratory Comparisons with Port Fuel Injection Engine

“…Gasoline vehicle engines are generally known to emit less black carbon (BC) and total particle mass than those in diesel vehicles (Gordon et al, 2014). However, equipping diesel vehicles with diesel particle filters (DPF) has significantly reduced particle emissions, which has been shown in the laboratory test (Valverde and Giechaskiel, 2020) and on-road measurements (Preble et al, 2015;Chao et al, 2020). To further improve air quality, it is thus increasing important to focus on reducing emissions from gasoline vehicles.…”