Particle Emissions from Light-Duty Vehicles during Cold-Cold Start

Emissions of particulate matter associated with the use of light-duty vehicles are an increasingly important topic, with more and more political attention focused on this issue. Now that direct injection Diesel engines feature DPFs, particle emissions from other engine types operating on other fuels are also of great interest. This paper discusses the phenomenon in general, briefly reviews worldwide legislation and emissions limits and presents the results of a laboratory test programme measuring the particle emissions from a range of vehicles. The experimental programme showed that the engine/fuel type has a greater impact on particle emissions than the test conditions.

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Determinants of rear-of-wheel and tire-road wear particle emissions by light-duty vehicles using on-road and test track experiments

Atmospheric Pollution Research ◽

10.1016/j.apr.2020.12.014 ◽

2020 ◽

Author(s):

A. Beji ◽

K. Deboudt ◽

S. Khardi ◽

B. Muresan ◽

L. Lumière

Keyword(s):

Wear Particle ◽

Particle Emissions ◽

Test Track ◽

Light Duty ◽

Light Duty Vehicles

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Technical note: Emission factors, chemical composition and morphology of particles emitted from Euro 5 diesel and gasoline light duty vehicles during transient cycles

10.5194/acp-2020-842 ◽

2020 ◽

Author(s):

Evangelia Kostenidou ◽

Alvaro Martinez-Valiente ◽

Badr R'Mili ◽

Baptiste Marques ◽

Brice Temime-Roussel ◽

...

Keyword(s):

Chemical Composition ◽

Diesel Particulate Filter ◽

Chemical Reactivity ◽

Cold Start ◽

Emission Factors ◽

Technical Note ◽

Particulate Filter ◽

Diesel Particulate ◽

Light Duty ◽

Light Duty Vehicles

Abstract. Changes in engine technologies and after-treatment devices can profoundly alter the chemical composition of the emitted pollutants. To investigate these effects, we characterized the chemical composition of particles emitted from three diesel and four gasoline Euro 5 light duty vehicles on a chassis dynamometer facility. Black carbon (BC) was the dominant emitted species with emission factors (EFs) varying from 0.2 to 7.1 mg km−1 for gasoline cars and 0.003 to 0.08 mg km−1 for diesel cars. For gasoline cars, the organic matter (OM) EFs varied from 5 to 103 µg km−1 for direct injection (GDI) vehicles, and from 1 to 8 µg km−1 for port fuel injection (PFI) vehicles, while for the diesel cars it ranged between 0.15 and 65 µg km−1. Cold-start cycles and more specifically the first minutes of the cycle, contributed the largest fraction of the PM including BC, OM and Polycyclic Aromatic Hydrocarbons (PAHs). More than 40 PAHs, including methylated, nitro, oxygenated and amino PAHs were identified and quantified in both diesel and gasoline exhaust particles using an Aerodyne High Resolution Time-of-Flight Aerosol Mass Spectrometry (HR-ToF-AMS). The PAHs emissions from the GDI technology were a factor of 4 higher compared to the vehicles equipped with a PFI system during the cold start cycle, while the nitro-PAHs fraction was much more appreciable in the GDI emissions. For two of the three diesel vehicles the PAHs emissions were close to the detection limit, but for one, which presented an after-treatment device failure, the average PAHs EF was 2.04 µg km−1. Emissions of nanoparticles (below 30 nm), mainly composed by ammonium bisulfate, were measured during the passive regeneration of the catalyzed diesel particulate filter (CDPF) vehicle. TEM images confirmed the presence of ubiquitous nanometric metal inclusions into soot particles emitted from the diesel vehicle equipped with a fuel borne catalyst – diesel particulate filter (FBC-DPF). XPS analysis of the particles emitted by the PFI car revealed both the presence of heavy elements (Ti, Zn, Ca, Si, P, Cl), and disordered soot surface with a significant concentration of carbon radical defects having possible consequences on both chemical reactivity and particle toxicity. Our findings show that different after-treatment technologies have an important effect on the level and the chemical composition of the emitted particles. In addition, this research highlights the importance of the particle filter devices condition and their regular checking.

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Effects of low temperature on the cold start gaseous emissions from light duty vehicles fuelled by ethanol-blended gasoline

Applied Energy ◽

10.1016/j.apenergy.2012.08.010 ◽

2013 ◽

Vol 102 ◽

pp. 44-54 ◽

Cited By ~ 93

Author(s):

M. Clairotte ◽

T.W. Adam ◽

A.A. Zardini ◽

U. Manfredi ◽

G. Martini ◽

...

Keyword(s):

Low Temperature ◽

Cold Start ◽

Gaseous Emissions ◽

Light Duty ◽

Light Duty Vehicles

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Emission Factors Derived from 13 Euro 6b Light-Duty Vehicles Based on Laboratory and On-Road Measurements

Atmosphere ◽

10.3390/atmos10050243 ◽

2019 ◽

Vol 10 (5) ◽

pp. 243 ◽

Cited By ~ 23

Author(s):

Victor Valverde ◽

Bernat Mora ◽

Michaël Clairotte ◽

Jelica Pavlovic ◽

Ricardo Suarez-Bertoa ◽

...

Keyword(s):

Co2 Emissions ◽

Particle Number ◽

Cold Start ◽

Emission Factors ◽

Testing Procedures ◽

Diesel Vehicles ◽

Type Approval ◽

Light Duty ◽

Gasoline Vehicles ◽

Light Duty Vehicles

Tailpipe emissions of a pool of 13 Euro 6b light-duty vehicles (eight diesel and five gasoline-powered) were measured over an extensive experimental campaign that included laboratory (chassis dynamometer), and on-road tests (using a portable emissions measurement system). The New European Driving Cycle (NEDC) and the Worldwide harmonised Light-duty vehicles Test Cycle (WLTC) were driven in the laboratory following standard and extended testing procedures (such as low temperatures, use of auxiliaries, modified speed trace). On-road tests were conducted in real traffic conditions, within and outside the boundary conditions of the regulated European Real-Driving Emissions (RDE) test. Nitrogen oxides (NOX), particle number (PN), carbon monoxide (CO), total hydrocarbons (HC), and carbon dioxide (CO2) emission factors were developed considering the whole cycles, their sub-cycles, and the first 300 s of each test to assess the cold start effect. Despite complying with the NEDC type approval NOX limit, diesel vehicles emitted, on average, over the WLTC and the RDE 2.1 and 6.7 times more than the standard limit, respectively. Diesel vehicles equipped with only a Lean NOX trap (LNT) averaged six and two times more emissions over the WLTC and the RDE, respectively, than diesel vehicles equipped with a selective catalytic reduction (SCR) catalyst. Gasoline vehicles with direct injection (GDI) emitted eight times more NOX than those with port fuel injection (PFI) on RDE tests. Large NOX emissions on the urban section were also recorded for GDIs (122 mg/km). Diesel particle filters were mounted on all diesel vehicles, resulting in low particle number emission (~1010 #/km) over all testing conditions including low temperature and high dynamicity. GDIs (~1012 #/km) and PFIs (~1011 #/km) had PN emissions that were, on average, two and one order of magnitude higher than for diesel vehicles, respectively, with significant contribution from the cold start. PFIs yielded high CO emission factors under high load operation reaching on average 2.2 g/km and 3.8 g/km on WLTC extra-high and RDE motorway, respectively. The average on-road CO2 emissions were ~33% and 41% higher than the declared CO2 emissions at type-approval for diesel and gasoline vehicles, respectively. The use of auxiliaries (AC and lights on) over the NEDC led to an increase of ~20% of CO2 emissions for both diesel and gasoline vehicles. Results for NOX, CO and CO2 were used to derive average on-road emission factors that are in good agreement with the emission factors proposed by the EMEP/EEA guidebook.

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