Particle and metal emissions of diesel and gasoline engines - Are particle filters appropriate measures? A. Ulrich1, A. Wichser1, A. Hess1, 2, N. Heeb1, L. Emmenegger1,

J.Czerwinski3, M. Kasper4, J. Mooney5, A. Mayer6

1Empa, Swiss Federal Laboratories for Material Testing and Research, 8600 Dübendorf, Überlandstrasse 129, Switzerland 2EPFL École Polytechnique Fédérale de Lausanne, Switzerland 3AFHB, Abgasprüfstelle Biel, Gwerdtstr. 5, CH – 2560 Nidau, Switzerland 4ME, Matter Aerosol AG, Bremgarterstr. 62, CH – 5610 Wohlen, Switzerland 5585 Colgate Ave Wyckoff, NJ, USA 6TTM, Fohrhölzlistrasse 14b, CH – 5443 Niederrohrdorf, Switzerland Corrosponding author: andrea.ulrich@empa.ch

Introduction

Not only diesel, but also gasoline fueled internal combustion engines can emit particulate matter. The following figure compares different vehicle types in terms of particle number concentration (PN). The studied vehicles are listed below:

1. MPI gasoline = gasoline vehicle with multiport injection 2. DI gasoline = gasoline vehicle with direct injection 3. CNG = compressed natural gas vehicle 4. diesel = diesel vehicle without particle filter 5. DPF = diesel vehicle with diesel particle filter system (wall flow) 6. load = diesel vehicle with diesel particle filter system during the loading phase 7. reg = diesel vehicle with diesel particle filter system during regeneration phase

Figure 1: Particle number concentration (PN) of different vehicle types (adopted from Empa Report

2007 (Novatlantis) “Emissionsvergleich verschiedener Antriebsarten in aktuellen Personenwagen) [1]

1.E+11

1.E+12

1.E+13

1.E+14

MPIGasoline

DI Gasoline Diesel Diesel/DPFload

Diesel/DPFreg

CNG

Part

icle

Num

ber P

N [1

/km

]

PN reduction> 99 %

> 98 %

PN increase

The diesel vehicle equipped with particle filter system showed the lowest PN emissions which represent a filtration efficiency of over 99 % in the loading and over 98 % during the regeneration phase. Gasoline vehicles especially with direct injection show significantly higher PN emissions than those with multiport injection.

Figure 2: Particle number (PN) and particle mass concentration in emissions of two gasoline vehicles

adopted from VCD and Umwelthilfe Study „Auch neue Benziner brauchen strenge Grenzwerte - Testergebnisse: Benzinmotoren mit Direkteinspritzung“ [2]

Also a recently published study from Verkehrsclub Deutschland VCD and Umwelthilfe described similar observations for gasoline vehicles with direct injection and claimed stricter particle number restrictions also for gasoline vehicles (Figure 2). They carried out tests using different driving cycles.

A solid particle number emission limit of 6 × 1011 #/km becomes effective at the Euro 5b and 6 stage for all categories of diesel vehicles (compression injection) as well as for Euro 6 gasoline vehicles (positive injection). All vehicles tested in the studies presented in figure 1 and 2 significantly exceeded these PN limits.

Previous studies shown, that ultra-fine particulate emissions often contain metal oxides, which can originate from various sources such as engine wear, lubrication oil, fuel ashes, fuel additives or coatings from exhaust gas after-treatment systems. The main possible sources are summarized in the following table.

Particle Number Concentration in PN/km

PN Limit for Diesel Euro 5and Gasoline Euro 6

Particle Mass Concentration in g/km

«Auch neue Benziner brauchen strenge Grenzwerte - Testergebnisse: Benzinmotoren mitDirekteinspritzungVCD + Umwelthilfe

PN Limit for Diesel Euro 5b

Tab. 1: Possible sources for metals

1. Abrasion from piston ring, cylinder liner, valve cams, valves, bearings (e.g. Fe, Al, Cr, Ni, Cu, Pb ...) => abraded metal mass ca. 0.1 to 1 mg/km

2. Lubrication oil: e.g. Zn: 0.1 – 0.2 %, Ca: 0.5 %, B: 0.09 %. Mg: 0.002-0.004 %,... old vehicles: up to 1 % oil of fuel consumption

3. Fuel: several metals in traces, heavy metals (Pb, Mn,) have limits (e.g. in Germany BzBIG 1971: Pb <150 mg/kg fuel)

The metal content in most of the conventional on-road fuels is usually relatively low, whereas lubrication oils often contain much higher metal concentrations. Engine wear metals occur in all internal combustion engines. Metal compounds collected in lubrication oil can be re-entrained into the cylinder and then oxidized during combustion. Some metals might be vaporized and re-nuclide forming ultra-fine particles in a size range typically below 30 nm. These metal oxide particles can be present in the exhaust aerosol either as free metal oxide particles or attached to larger soot particles. The toxicological effect of nanoparticles was proved in several studies. Hence, these nanoparticulate emissions need to be avoided. Full wall-flow particle filter systems are effective measures to reduce particulate emissions and they are already well established in diesel engine technology. These filter technology might be also beneficial especially for direct injection gasoline engines.

Toxicological effects of nanoparticles

Particle emissions of diesel vehicles can cause acute and chronic harm at lung and cardiovascular system. The biological impact depends on the particles' ability to defeat the human body defense. Crucial factors are particle size and solubility. Almost insoluble particles are hazardous especially in small size ranges. Toxicological studies have shown increased toxicity of nanoparticles compared to micrometer particles of the same composition, which has raised concern about the impact on human health. Nanoparticles can enter alveoli in the lungs, pass biological barriers including placenta and blood–brain barrier, and enter cells. The high surface area and chemical composition of the nanoparticles (NPs) play an important role in biological activity and toxicology, but toxicology depends also on cell types. The binding of NPs to bacterial proteins can inhibit enzymatic activity. Epidemiological studies on ultrafine particles have shown increased cancer risk after long-term exposure of diesel vehicle drivers enhanced allergy tendency at traffic burdened sites and enhanced risk of heart attack.[3-16]_ENREF_1

Figure 3 shows that particles < 10 μm can intrude deep into the lung. Particles smaller than 100 nm show a high deposition rate in the alveoli, which increase with decreasing particle diameter. Tissue penetration from alveoli to the blood vessels, too, is highly dependent on particle size. Therefore, the particle dosage should be weighted with this size influence.

Fig. 3: Deposition of inhaled particles in the alveoli. The main particle sizes are: Diesel soot about 100 nm; SI soot about 50 nm and metal oxides about 10-15 nm.

Experimental

The vehicle characteristics as well as the sampling procedures and analysis are displayed in the following graphs and tables. Online particle analysis has been performed with SMPS. Size fractionated chemical analysis of nanoparticles in vehicle emissions were carried out by sampling with an electrical low pressure multi-stage impactor ELPI with subsequent acid digestion in a microwave system and chemical analysis with plasma mass spectrometry ICPMS. Further details can be found elsewhere.[16-27]

Particle deposition rates in the respiratory tract

particle diameter [nm]

1 10 100 1000 10000

depo

sitio

n ra

te [%

]

0

20

40

60

80

100

48% (10 nm)

54% (15 nm)

20%(100 nm)

total

nasal region

alveolar region

tracheobronchial region

100

80

60

40

20

0

Dep

ositi

on R

ate

in %

Particle Diameter in nm1 10 100 1000 10000

Metaloxides

Soot

Fig. 4: Test and sampling setup (A) for passenger cars and 2-wheelers (B) for diesel engine tests

Constant Volum

e Sam

pling CVS

Air

Engine

T, p

Fuel supply

Partial DilutionTunnel

Air

Flow-proportional Sampling

catalyticDPF

VOC GC-FID

VOCOX LC-UV/VIS

PAH

n-PAH GC-HR-MS

PCDD/F

VGravimetry

ELPI

SMPS

NanoMet

ICP-MSMetals

V

V

Filter

PM Number/Surface

Sampling Parameter Methods

}Bag

Impinger

Dioxin Train

Mass

T, p

SizeDistribution

COCO2HCNONOxO2Opacity

NDIRNDIRFIDCLDCLDMagnosOpacity MeterM

ajor

com

pone

nts

Part

icul

ate

Mat

ter

Toxi

c tr

ace

com

pone

nts

Metals,Sulphur, Chlorine

ICP-MS, ICP-OES, XRF

Fuel

/ Lub

eoi

l

Tab. 2: Operation points for vehicle and diesel engine tests

Fig. 5: Used Test cycle ISO 8178/4 C1

Tab. 3: Characteristics of lubrication oils for cars and 2-wheelers

100 %

0.15

0.15

0.15

0.150.10

0.10

0.10

0.10

5

6

7

84

3

2

1

60 %

100 %

75 %

50 %

10 %

Load

Idling IntermediateRPM

RPM

Torq

ue

ISO 8178/4 C1-cycle for construction site engines

N. Heeb, EMPA Report 167985

100 %

0.15

0.15

0.15

0.150.10

0.10

0.10

0.10

5

6

7

84

3

2

1

60 %

100 %

75 %

50 %

10 %

Load

Idling IntermediateRPM

RPM

Torq

ue

ISO 8178/4 C1-cycle for construction site engines

N. Heeb, EMPA Report 167985

Tab. 4: Lubrication oil 15 W/40 and fuel for Liebherr D934S and D914T diesel engine

Fig. 6: CVS Background: Lab air and CVS tunnel only

Results

The investigation within this study focused on the particle emissions. Gaseous emissions are not reported. Sampling was carried out according to PMP Protocol at 300 °C. The particle mass emissions and their composition are summarized in table 5. Figure 7 shows the particle size distribution (measured by scanning mobility particle sizer SMPS) for Liebherr 924 engine without DPF and with DPF at the 8 tested operation points. At the point 8, i.e. idling at 800 RPM, the particle number concentration in the smaller size range is relatively low. A possible explanation for this fact might be the lower soot generation at idling point 8. Hence, possibly emitted metal species are emitted as free metal oxides, whereas at the other operating points the concentration of soot particles is much higher that the metals can be bounded to the soot particles like shown as an example in Fig. 8.

Fig. 7: Particle size distribution (SMPS) for Liebherr 924 engine (A) without DPF and (B) with DPF at 8 operation points (OP) according to test cycle ISO 8178/4 C1. OP 8 is idling at 800 RPM.

Sampling according to PMP Protocol: 300°C, Dilution Ratio DR=100

Low soot Free metal NPs OP 8

Fig. 8: SEM image of metal NPs, here cerium oxide, bound to soot particles

Tab 5: Particle mass emissions of filter samples for vehicles

If metal emissions lead to nanoparticulate emissions at very low size ranges, it was suspected that the phenomenon is also visible for petrol engines. The following graph shows the size distribution measured by SMPS for measurement of two cars and two 2 weelers. All measurements were carried out at two different steady-state conditions, i.e. at a constant speed of 50 km/h and at idling. The Renault R18 car has, both at the medium load point and at idling, relatively high particle emissions. A bimodal distribution was observed at part load. For the Honda 450 CWR Motorbike modality of the size distribution is clearly evident and the emissions are relatively high. Also the 1-cylinder/4-stroke scooter engine of the Piaggio Scooter showed significant particle emissions at 50 km/h which were even higher than for the Honda motorbike. However, the bimodal distribution is less evident. The .particle emission at idling operation was lower than expected. The second car Nissan Qashqai, which was of newer engine technique showed relatively low particle emissions which hardly exceed the background, neither at 50 km/h nor at idling. Further investigations on metal oxide emissions of different vehicle types have been already published [16, 18, 19, 27].

Fig. 8: Particle distribution (SMPS) at 50 km/h and idle for cars: (A) Renault R18 and (B) Nissang Quahqai motorbikes: (A) Honda 450 and (B) Scooter Piaggio

Mechanism

In figure 9 a schematic of possible reactions in the exhaust gas are given. Metals, present in the exhaust can be adsorbed to other particles e.g. soot, but in absence of this particles also nucleate with itself. Therefore, a lower soot generation at idling point 8 like in figure 7 might lead to a higher amount of self-nucleation and is therefore emitted as metal species (metal oxides). A particle filter enables to lower this emissions significantly.

Fig. 9: Schematic mechanisms of emission and particle formation in exhaust (partly adopted from Schneider et al.) [26]

Conclusion

Emissions of metal oxide particles can occur for all types of internal combustion engines. Even if clean fuels are used, lubrication oil remains as a potential source for metal oxide particles. Full-wall-flow particle filter systems have shown high filtration efficiency in diesel exhaust gas after-treatment. However, this study demonstrated that they can be also useful to remove metal oxide emissions from other engine types. An effective filtration of metal particles is important to reduce toxic potential of nanosized particles and metals. Hence, filtration technology is promising not only for diesel engines (soot filtration) but for all types of combustion engines. The filtration efficiency for metals should be further investigated in future projects.

Acknowledgements:

The authors like to thank the Swiss Federal Office for Environment BAFU, the VERT Assoziation and our industry partners for support.

References

(1) C. Bach et al: Empa Report 2007 (Novatlantis) “Emissionsvergleich verschiedener Antriebsarten in aktuellen Personenwagen. - Untersuchung der Emissionen von aktuellen Personenwagen mit konventionellen und direkteingespritzten Benzinmotoren, Dieselmotoren mit und ohne Partikelfilter, sowie Erdgasmotoren. (Empa Final Report for Novatlantis and Bundesamt für Umwelt BAFU,).

(2) Studie des Verkehrsclubs Deutschland VCD und der Umwelthilfe «Auch neue Benziner brauchen strenge Grenzwerte - Testergebnisse: Benzinmotoren mit Direkteinspritzung

(3) Kasper M. et al. PM10-TEQ, Approach to a Health-Oriented Descriptor of Particulate Air Pollution,. 11th ETH Conference on Combustion Generated Nanoparticles, August 2007 (2007).

(4) Rothen-Rutishauser, B. M., Kiama, S. C. & Gehr, P. A three-dimensional cellular model of the human respiratory tract to study the interaction with particles. American Journal of Respiratory Cell and Molecular Biology 32, 281-289 (2005).

Vehicle Emissions

(5) Wick, P., Manser, P., Spohn, P. & Bruinink, A. In vitro evaluation of possible adverse effects of nanosized materials. Physica Status Solidi (B) Basic Research 243, 3556-3560 (2006).

(6) Rothen-Rutishauser, B., Muehlfeld, C., Blank, F., Musso, C. & Gehr, P. Translocation of particles and inflammatory responses after exposure to fine particles and nanoparticles in an epithelial airway model. Particle and Fibre Toxicology 4 (2007).

(7) Wick, P. et al. The degree and kind of agglomeration affect carbon nanotube cytotoxicity. Toxicology Letters 168, 121-131 (2007).

(8) Wick, P. et al. Barrier Capacity of Human Placenta for Nanosized Materials. Environmental Health Perspectives 118, 432-436 (2010).

(9) Krystek, P., Ulrich, A., Garcia, C. C., Manohar, S. & Ritsema, R. Application of plasma spectrometry for the analysis of engineered nanoparticles in suspensions and products. Journal of Analytical Atomic Spectrometry (2011).

(10) Limbach, L. K. et al. Exposure of Engineered Nanoparticles to Human Lung Epithelial Cells:  Influence of Chemical Composition and Catalytic Activity on Oxidative Stress. Environmental Science & Technology 41, 4158-4163 (2007).

(11) Karlsson, H. L., Gustafsson, J., Cronholm, P. & Möller, L. Size-dependent toxicity of metal oxide particles--A comparison between nano- and micrometer size. Toxicology Letters 188, 112-118, doi:10.1016/j.toxlet.2009.03.014 (2009).

(12) Jeng, H. A. & Swanson, J. Toxicity of metal oxide nanoparticles in mammalian cells. Journal of environmental science and health. Part A, Toxic/hazardous substances & environmental engineering 41, 2699-2711 (2006).

(13) Hinds William C. Aerosol Technology, Properties, Behavior, and Measurement of Airborne Particles. (John Wiley & Sons, , 1989).

(14) Gehr, P. & J, H. Particle-Lungs Interactions. Vol. http://books.google.ch/books?id=YA94Ic8r_G8C&printsec=frontcover#v=onepage&q&f=false (Marcel Dekker, Inc., 2005).

(15) Oberdörster, G., Oberdörster, E. & Oberdörster, J. Nanotoxicology: An Emerging Discipline Evolving from Studies of Ultrafine Particles. Environ Health Perspect. 113, 823–839. (2005).

(16) Ulrich, A. & Wichser, A. Analysis of additive metals in fuel and emission aerosols of diesel vehicles with and without particle traps. Analytical and Bioanalytical Chemistry 377, 71-81 (2003).

(17) J. Czerwinski et al: SAE Paper 2005-01-1100. (18) A.Mayer et al; SAE 2007-01-1112 (19) Mayer, A. C., Ulrich, A., Czerwinski, J. & Mooney, J. J. Metal-Oxide Particles in Combustion Engine Exhaust. SAE

Technical Paper 2010-01-0792, doi:10.4271/2010-01-0792 (2010). (20) Heeb, N. V. et al. Secondary Emissions Risk Assessment of Diesel Particulate Traps for Heavy Duty

Applications. doi:10.4271/2005-26-014 (2005). 329-338. (21) N.V. Heeb, et al., Environ Sci Techn 2008, 42(10); 3773-3779. (22) Mayer et al, SAE 2010-01-0792. (23) N.V. Heeb, et al. Env. Sci. Tech. 44 (3), 2010, 1078 - 1084. (24) N.V. Heeb, et al. Atm. Env. 45, 2011. 3203-3209 (25) Ulrich, A., Mayer, A., M.;, K., Wichser, A. & Czerwinski, J. Emissions of metal-oxide particles from IC engines and

vehicles. Proceedings of teh PTNSS Congress 2011 (2011) (26) J. Schneider et al. Environ. Sci. Technol. 2005, 39, 6153-6161 (27) Mayer et al, SAE 2012-01-0841.

Particle size distribution (SMPS) for Liebherr 924 engine (A) without DPF and (B) with DPF at 8 operation points Point 8 is idling at 800 RPM.

Particle mass emissions of filter samples for vehicles Particle distribution (SMPS) at 50 km/h and idle for cars: (A) Renault R18 and (B) Nissang Quahqai motorbikes: (A) Honda 450 and (B) Scooter Piaggio

Particle and metal emissions of diesel and gasoline engines Are particle filters appropriate measures? A. Ulrich1, A. Wichser1, A. Hess1,2, N. Heeb1, L. Emmenegger1 J.Czerwinski3, M. Kasper4, J. Mooney5, A. Mayer6

1Empa, Swiss Federal Laboratories for Material Testing and Research, 8600 Dübendorf, Überlandstrasse 129, Switzerland 2EPFL École Polytechnique Fédérale de Lausanne, Switzerland 3AFHB, Abgasprüfstelle Biel, Gwerdtstr. 5, CH – 2560 Nidau, Switzerland 4ME, Matter Aerosol AG, Bremgarterstr. 62, CH – 5610 Wohlen, Switzerland 5585 Colgate Ave Wyckoff, NJ, USA 6TTM, Fohrhölzlistrasse 14b, CH – 5443 Niederrohrdorf, Switzerland

Not only diesel, but also gasoline fueled internal combustion engines can emit particulate matter. Especially for direct injection technology an increase in particulate emission was observed. Previous studies shown, that ultra-fine particulate emissions often contain metal oxides, which can originate from various sources such as engine wear, lubrication oil, fuel ashes, fuel additives or coatings from exhaust gas after-treatment systems. The metal content in most of the conventional on-road fuels is relatively low, whereas lubrication oils often contain much higher metal concentrations. Engine wear metals occur in all internal combustion engines. Metal compounds collected in lubrication oil can be re-entrained into the cylinder and then oxidized during combustion. Some metals might be vaporized and re-nuclide forming ultra-fine particles in a size range typically below 30 nm. These metal oxide particles can be present in the exhaust aerosol either as free metal oxide particles or attached to larger soot particles. The toxicological effect of nanoparticles was proved in several studies. Hence, these nanoparticulate emissions need to be avoided. Full wall-flow particle filter systems are effective measures to reduce particulate emissions and they are already well established in diesel engine technology. These filter technology might be also beneficial especially for direct injection gasoline engines.

1. Abrasion from piston ring, cylinder liner, valve cams, valves, bearings (e.g. Fe, Al, Cr, Ni, Cu, Pb ...) => abraded metal mass ca. 0.1 to 1 mg/km

2. Lubrication oil: e.g. Zn: 0.1 – 0.2 %, Ca: 0.5 %, B: 0.09 %. Mg: 0.002-0.004 %,... old vehicles: up to 1 % oil of fuel consumption

3. Fuel: several metals in traces, heavy metals (Pb, Mn,) have limits (e.g. in Germany BzBIG 1971: Pb <150 mg/kg fuel)

Materials Sci ence & Technolog y

Text

Conclusion Literature: A. Ulrich et al, Anal Bioanal Chem, 2003, 377, 7181. J. Czerwinski et al: SAE Paper 2005-01-1100. A. Mayer et al; SAE 2007-01-1112 C. Bach et al: Empa Report 2007 (Novatlantis) “Emissionsvergleich verschiedener Antriebsarten in aktuellen Personenwagen. N.V. Heeb, et al., SAE Paper 2005-26-014, 329-338. N.V. Heeb, et al., Environ Sci Techn 2008, 42(10); 3773-3779. A. Mayer et al, SAE 2010-01-0792. N.V. Heeb, et al. Env. Sci. Tech. 44 (3), 2010, 1078 - 1084. N.V. Heeb, et al. Atm. Env. 45, 2011. 3203-3209 A. Ulrich et al. Proceedings of PTNSS Congress 2011, June 2011 J. Schneider et al. Environ. Sci. Technol. 2005, 39, 6153-6161 A. Mayer et al, SAE 2012-01-0841.

Presented at: 16th Conference on Combustion Generated Nanoparticles 2012, 24.6.2012 – 27.6.2012 in Zürich, Switzerland

Comparison of Vehicles Emissions Gasoline Vehicles

Emissions of metal oxide particles can occur for all types of internal combustion engines. Even if clean fuels are used, lubrication oil remains as a potential source for metal oxide particles. Full-wall-flow particle filter systems have shown high filtration efficiency in diesel exhaust gas after-treatment. However, this study demonstrated that they can be also useful to remove metal oxide emissions from other engine types. An effective filtration of metal particles is important to reduce toxic potential of nanosized particles and metals. Hence, filtration technology is promising not only for diesel engines (soot filtration) but for all types of combustion engines. The filtration efficiency for metals should be further investigated in future projects.

Metal NPs bound to soot

Soot generation at idling point 8 is relatively low => free metal oxides

Contact: andrea.ulrich@empa.ch

1.E+11

1.E+12

1.E+13

1.E+14

MPIGasoline

DI Gasoline Diesel Diesel/DPFload

Diesel/DPFreg

CNG

Part

icle

Num

ber P

N [1

/km

]

PN reduction> 99 %

> 98 %

PN increase

Schematic mechanisms of emission and particle formation in exhaust (partly adopted from Schneider et al.)

Particle Number Concentration in PN/km

PN Limit for Diesel Euro 5 and Gasoline Euro 6

Particle Mass Concentration in g/km

Sources for Metal Emissions

«Auch neue Benziner brauchen strenge Grenzwerte - Testergebnisse: Benzinmotoren mit Direkteinspritzung VCD + Umwelthilfe

Vehicle Renault R18 Honda 450 CBR Nissan Qashqai Piaggio Diesel

Cycle 50 km/h Idling 50 km/h Idling 50 km/h Idling 50 km/h Idling Idling

Ntotal

Nash

Nsoot

Dash

Dsoot

[P/cm3]

[P/cm3]

[P/cm3]

[nm]

[nm]

4.1 107

3.8 107

3.1 106

7.9

69.6

7.1 107

7.1 107

7.1 104

24.4

131.6

2.2 106

n.d.

n.d.

n.d.

n.d.

6.8 106

6.8 106

3.7 104

12.7

25.6

9.1 103

n.d.

n.d.

n.d.

n.d.

1.8 103

n.d.

n.d.

n.d.

n.d.

3.6 107

n.d.

n.d.

n.d.

n.d.

6.2 103

n.d.

n.d.

n.d.

n.d.

1.5 107

1.4 107

8.6 105

11.8

48.1

0

5

10

15

20

25

30

35

40

45

Na

Mg Al Si P S Cl K Ca Ti V Cr Mn Fe Co Ni

Cu Zn Rb Sr Y Zr Nb

Mo Sn Sb Ba La Ce Pt Pb

Mas

s Con

cent

ratio

n in

g/1

00 g

(%)

Soot 1Soot 2Soot 3Soot 4Soot 5

Metals in ash and soot collected in 5 different DPFs

(DPF 4 and 5 were operated with CeO2 regeneration fuel additive)

OP 8 = idle Sampling: 300°C, Dilution Ratio DR=100

Low soot Free metal NPs

Particle deposition rates in the respiratory tract

particle diameter [nm]

1 10 100 1000 10000

depo

sitio

n ra

te [%

]

0

20

40

60

80

100

48% (10 nm)

54% (15 nm)

20%(100 nm)

total

nasal region

alveolar region

tracheobronchial region

100

80

60

40

20

0

Dep

ositi

on R

ate

in %

Particle Diameter in nm1 10 100 1000 10000

Metaloxides

Soot

Toxicity

Emissions Diesel PN for Diesel engine (Test cycle ISO 8178/4 C1 from VERT VSET (SN 277 206)

Deposition of particles in respiratory tract

Mechanism

Idle with / without particle filter (PF) Filtration efficiency > 99.9%

PN

con

cent

ratio

n dN

/ d

log

DP

[cm

-3]

Efficiency of a particle filter

without PF with PF

PN Emissions of Petrol Engines NEDC = New European driving cycle for cars Euro 3-C2 = European driving cycle for bikes Euro 3-C1 = European driving cycle for scooters

Acknowledgements: Bafu for financial support; VERT Association

PN Limit for Diesel Euro 5b

DPF 1 DPF 2 DPF 3 DPF 4 DPF 5

Particle number concentration (PN) of different vehicle types adopted from Empa Report 2007 (Novatlantis) “Emissionsvergleich verschiedener Antriebsarten in aktuellen Personenwagen MPI = multiport injection / DI = direct injection / CNG = compressed natural gas DPF = diesel particle filter (wall flow) / load = loading phase / reg = regeneration phase