Will Euro 6 reduce the NOx emissions of new diesel cars? – Insights from on-road tests with Portable Emissions Measurement Systems (PEMS)

Weiss, Martin; Bonnel, Pierre; Kühlwein, J.; Alessio, Provenza; Lambrecht, Udo; Alessandrini, Stefano; Massimo, Carriero; Colombo, R.; Fausto, Forni; Gaston, Lanappe; Lijour, Philippe Le; Manfredi, Urbano; Moureau, François; Sculati, Mirco

doi:10.1016/j.atmosenv.2012.08.056

Cited by 212 publications

(102 citation statements)

References 7 publications

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“…28) couple at the urban scale there are a number of issues regarding the role of an increase in the NO 2 : NO emission ratio caused by an increase in the share of diesel vehicles in Europe and the role that may play in ozone formation (Weiss et al, 2012;Carslaw et al, 2011;Carslaw, 2005). Further, there are questions as to what extent spatially (along roadsides, across urban areas, regionally) primary NO 2 emissions affect ozone concentrations (see e.g.…”

Section: Atmosmentioning

confidence: 99%

Tropospheric ozone and its precursors from the urban to the global scale from air quality to short-lived climate forcer

et al. 2015

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Abstract. Ozone holds a certain fascination in atmospheric science. It is ubiquitous in the atmosphere, central to tropospheric oxidation chemistry, yet harmful to human and ecosystem health as well as being an important greenhouse gas. It is not emitted into the atmosphere but is a byproduct of the very oxidation chemistry it largely initiates. Much effort is focused on the reduction of surface levels of ozone owing to its health and vegetation impacts, but recent efforts to achieve reductions in exposure at a country scale have proved difficult to achieve owing to increases in background ozone at the zonal hemispheric scale. There is also a growing realisation that the role of ozone as a short-lived climate pollutant could be important in integrated air quality climate change mitigation. This review examines current understanding of the processes regulating tropospheric ozone at global to local scales from both measurements and models. It takes the view that knowledge across the scales is important for dealing with air quality and climate change in a synergistic manner. The review shows that there remain a number of clear challenges for ozone such as explaining surface trends, incorporating new chemical understanding, ozone-climate coupling, and a better assessment of impacts. There is a clear and present need to treat ozone across the range of scales, a transboundary issue, but with an emphasis on the hemispheric scales. New observational opportunities are offered both by satellites and small sensors that bridge the scales.

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Section: Atmosmentioning

confidence: 99%

Tropospheric ozone and its precursors from the urban to the global scale from air quality to short-lived climate forcer

et al. 2015

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“…In a different approach, real-world emissions from diesel cars and cars with spark-ignition engines are measured by Portable Emission Measurement Systems (PEMS) (Weiss et al 2011;Kousoulidou et al 2013;Ntziachristos et al 2016). Several PEMS studies have shown that the Euro emission standards are frequently exceeded, especially the latest standard Euro 6 (Weiss et al 2012;Franco et al 2014;O'Driscoll et al 2016). Almost all of the tested diesel vehicles exceeded the emission limits by at least a factor of 2 and up a factor of 22.…”

Section: Introductionmentioning

confidence: 99%

Real-world vehicle emissions as measured by in situ analysis of exhaust plumes

Peitzmeier

Loschke

Wiedenhaus

et al. 2017

Environ Sci Pollut Res

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We conducted a 60-day roadside measurement campaign on a busy street in Münster, Germany, during summer 2016. We used gas and particle concentration measurements with high temporal resolution (10 Hz) to quantify both the emission ratios of nitrogen oxides per carbon dioxide (NO x /CO 2 ) for over 70,000 individual exhaust plumes as well as the emission ratios for size-resolved particle numbers per carbon dioxide (d(PN CO 2 −1 )/dlogD) for about 10,000plumes. The real-world fleet passing by the measurement station consisted of passenger cars (85%), buses (5.9%), light duty commercial vehicles (5.7%), trucks (1.7%), and motorcycles (1.6%). The median measured NO x /CO 2 ratio was 3.33 g kg −1 . The median measured PN/CO 2 emission ratio for particles with diameters between 0.03 and 10 μm was 5.6 × 10 14 kg −1 . We compared our results with the Handbook Emission Factors for Road Transport (HBEFA) and the Euro 5 and Euro 6 emission standards by employing traffic counts, assuming the diesel-to-gasoline ratios of vehicles according to registration statistics, and estimating that stop-and-go traffic occurred 65% of the time. Using a conservative estimate, our median ratios exceeded the HBEFA data by more than 65% for NO x /CO and by a factor of about 100 for PN/CO 2. Furthermore, our median NO x emission per kilometer travelled (NO x km −1 ) exceeded the Euro 5 emission limit for diesel cars by a factor of 3 and exceeded the Euro 6 limit by almost a factor of 7. Additionally, our median particle number emission (PN km −1 ) exceeded the Euro 5 and Euro 6 limits of diesel cars by a factor of almost 150. These results confirm the presumption that the emissions of a real-world traffic fleet comprehensively exceed the legal limits. Very likely, the widespread presence of defeat devices in vehicle emission control systems plays a major role in this discrepancy. This has a strong impact on the apparent inability of authorities to comply with the legal limits of the NO 2 concentrations in urban air.

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“…The data above the Euro 6 level were confined to the 4 -29 km/h mean velocity region and would not be seen on an RDE cycle as these low mean velocities are omitted from the RDE cycles. This is why RDE journeys with gasoline vehicles and lambda 1 TWCs all show no real world effects with the NOx emissions below Euro 6 levels [18][19][20]33].…”

Section: No X Emissionsmentioning

confidence: 99%

“…Diesel vehicles are mainly responsible as prior to Euro 6 there was no catalytic deNOx technology and higher engine out NOx emissons than for SI vehicles was allowed. However, even for Euro 6 diesel vehicles with deNOx catalysts real world NOx emissions are substantially greater than on the NEDC [18][19][20]33]. This is because Diesel engines have lower exhaust temperatures at the low power of congested traffic and often will be below the 200 o C light off temperature of most deNOx catalytic systems.…”

Section: No X Emissionsmentioning

confidence: 99%

“…With deNOx catalysts for Euro 6 diesel vehicles the regulated NOx emissions are the same as for Euro 4 SI emissions. However, real world measurement of Euro 6 vehicle emissions [18][19][20]33] have shown a major problem of much higher missions than certified, for the reasons discussed above. Both spark ignition and Diesel engines have problems of high emissions at the low powers used in congested low speed driving as shown in this work and in the work of Hadavi et al [7] for diesels on the same congested road.…”

Section: No X Emissionsmentioning

confidence: 99%

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Real World Driving: Emissions in Highly Congested Traffic

Khalfan¹,

Andrews²,

Li³

2017

SAE Technical Paper Series

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The emissions from vehicles in real world driving are of current concern, as they are often higher than on legislated test cycles and this may explain why air quality in cities has not improved in proportion to the reduction in automotive emissions. This has led to the Real Driving Emissions (RDE) legislation in Europe. RDE involves journeys of about 90km with roughly equal proportion of urban, rural and motorway driving. However, air quality exceedances occur in cities with urban congested traffic driving as the main source of the emissions that deteriorate the air quality. Thus the emissions measured on RDE journeys may not be relevant to air quality in cities. A Temet FTIR and Horiba exhaust mass flow measurement system was used for the mass emissions measurements in a Euro 4 SI vehicle. A 5km urban journey on a very congested road was undertaken 29 times at various times so that different traffic congestion was encountered. Each journey was split into ten sections in order that the location and traffic conditions of the highest emissions could be determined. It was found that low speed stop-start traffic has much higher emissions than for freely moving traffic and most of the higher emissions on the longer 5km journeys occurred in relatively short sections of slow moving stop/start traffic. The journey used passed a roadside air quality monitor that exceeded the EU NO2 and PM standards on an annual basis and it was located by the most congested part of the route, where the traffic emissions are shown in this work to be at their highest.

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Will Euro 6 reduce the NOx emissions of new diesel cars? – Insights from on-road tests with Portable Emissions Measurement Systems (PEMS)

Cited by 212 publications

References 7 publications

Tropospheric ozone and its precursors from the urban to the global scale from air quality to short-lived climate forcer

Tropospheric ozone and its precursors from the urban to the global scale from air quality to short-lived climate forcer

Real-world vehicle emissions as measured by in situ analysis of exhaust plumes

Real World Driving: Emissions in Highly Congested Traffic

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