Effects of low- and high-oxidation DPFson genotoxic exhaust constituents
13th ETH-Conference on Combustion Generated NanoparticlesZürich, June 22. - 24. 2009
Effects of low- and high-oxidation DPFson genotoxic exhaust constituents
13th ETH-Conference on Combustion Generated NanoparticlesZürich, June 22. - 24. 2009
Trojan horse, Harbour of Canakkale, Turkey
What are the products of soot combustion and what are their health effects?
Effects of low- and high-oxidation DPFson genotoxic exhaust constituents
Diesel nanoparticles –Trojan horses for genotoxic compounds
Diesel exhaust contains dozens of carcinogenic, mutagenic, and hormone-like compounds
Nanoparticles penetrate cell membranes (alveoli, blood cells) acting as Trojan horses
Toxic nitrogen oxide emissions
Do DPFs detoxify diesel exhaust?
Problems:
Trojan horse, Harbour of Canakkale, Turkey
Secondary pollutants of catalytic converter systems
Toxic secondary pollutants - relevant examples
What else can a converter produce besides CO2 , H2 O, and N2 ?
Toxic secondary pollutants - relevant examples
Formation of PAHs in diesel particulate filters?Carcinogenic PAHs from soot combustion?
Nitration of PAHs in particulate traps?From harmless precursors to mutagenic Nitro-PAHs?
TWC-induced formation of ammonia TWCs – the most efficient DeNOx systems on road
Formation of PCDD/Fs in particulate traps?The DPF- an ideal reactor
What else can a converter produce besides CO2 , H2 O, and N2 ?
Formation of NO2 in diesel oxidation catalysts From a reducing to an oxidizing exhaust
Secondary pollutants of catalytic converter systems
No effects with respect to engine and vehicle legislation!
The NOx problem
Nitrogen oxides (NOx , NO, NO2 )
We have 2 filter families, one converts NO2 the other forms NO2 !
The NOx problem
Nitrogen oxides (NOx , NO, NO2 )
We have 2 filter families, one converts CO the other doesn’t!
Low- / high-oxidation potential DPFs
Carbon monoxide, hydrocarbons, fuel
We have 2 filter families, one converts CO the other doesn’t!
Low- / high-oxidation potential DPFs
Carbon monoxide, hydrocarbons, fuel
Both filter families convert HCs
Low- / high-oxidation potential DPFs
Carbon monoxide, hydrocarbons, fuel
Low- / high-oxidation potential DPFs
Carbon monoxide, hydrocarbons, fuel
Both filter families convert HCs
No significant effects on fuel consumption
Low- / high-oxidation potential DPFs
Carbon monoxide, hydrocarbons, fuel
High-ox filters, convert CO and NO forming NO2 , lox-DPFs don’t!
Low- / high-oxidation potential DPFs
Carbon monoxide, hydrocarbons, fuel
Toxic secondary pollutants - relevant examples
Formation of PAHs in diesel particulate filters?Carcinogenic PAHs from soot combustion?
Nitration of PAHs in particulate traps?From harmless precursors to mutagenic Nitro-PAHs?
TWC-induced formation of ammonia TWCs – the most efficient DeNOx systems on road
Formation of PCDD/Fs in particulate traps?The DPF- an ideal reactor
What else can a converter produce besides CO2 , H2 O, and N2 ?
Formation of NO2 in diesel oxidation catalysts From a reducing exhaust to an oxidizing exhaust
Secondary pollutants of catalytic converter systems
Genotoxic polycyclic aromatic hydrocarbons
Genotoxic PAHs in diesel exhaust
Carcinogenic PAH
1 2
5 6 7 8
1 1
111
1
3 4
11
Pyrene Fluoranthene Chrysene Benz(a)anthracene
Benzo[b]-fluoranthene
Benzo[k]-fluoranthene
Benzo[a]-pyrene
Indeno(1,2,3-cd)-pyrene
Six PAHs are carcinogenic according to the WHO
Carcinogenic PAH
1 2
5 6 7 8
1 1
111
1
3 4
11
Genotoxic polycyclic aromatic hydrocarbons
Pyrene Fluoranthene Chrysene Benz(a)anthracene
Benzo[b]-fluoranthene
Benzo[k]-fluoranthene
Benzo[a]-pyrene
Indeno(1,2,3-cd)-pyrene
Two are precursors for mutagenic nitro-PAHs
Carcinogenic PAH
1 2
5 6 7 8
1 1
111
1
3 4
11
Genotoxic polycyclic aromatic hydrocarbons
Pyrene Fluoranthene Chrysene Benz(a)anthracene
Benzo[b]-fluoranthene
Benzo[k]-fluoranthene
Benzo[a]-pyrene
Indeno(1,2,3-cd)-pyrene
Carcinogenesis from benzo(a)pyrene
Oxidative metabolic activation of benzo(a)pyrene by cytochrome P450 enzymes
Benzo(a)pyrene (BP) (+/-) 7,8 BP-oxide
O 78
(+/-) 7,8 BP-dihydrodiol
7
8HO
OH
(+) anti 7R,8S,9S,10R-BP- dihydrodiol-epoxide
78HO
OH
O
9
10
Stereoselective formation of benzo(a)pyrene-DNA-adducts
(+) anti 7R,8S,9S,10R-BP- dihydrodiol-epoxide
78HO
OH
O
9
10
(-) 10R trans-anti-[BP]-triol-N2-deoxy-guanosine-adduct
78HO
OH
9
10NHN
HO
NH
O
N
N
DNA
10NHN
HO
NH
O
N
N
DNA2
Carcinogenesis from benzo(a)pyrene
1
Volatility and reactivity affect filtration efficiency!
1
6.0 x 10-4 Pa 1.2 x 10-3 Pa 8.5 x 10-7 Pa
Carcinogenic PAHs
2.8 x 10-5 Pa
Genotoxic PAHs
Toxic secondary pollutants - relevant examples
Formation of PAHs in diesel particulate filters?Carcinogenic PAHs from soot combustion?
Nitration of PAHs in particulate traps?From harmless precursors to mutagenic Nitro-PAHs?
TWC-induced formation of ammonia TWCs – the most efficient DeNOx systems on road
Formation of PCDD/Fs in particulate traps?The DPF- an ideal reactor
What else can a converter produce besides CO2 , H2 O, and N2 ?
Formation of NO2 in diesel oxidation catalysts From a reducing exhaust to an oxidizing exhaust
Secondary pollutants of catalytic converter systems
Is nitration of PAHs in NOx-rich diesel exhaust an issue?
pyrene
The DPF – a chemical reactor
Nitration of PAHs
pyrene 1-nitropyrene
In one step from a harmless precursor to a mutagen?
The DPF – a chemical reactor
Nitration of PAHs
Genotoxic Nitro-PAHs
DPF-induced nitration of PAHs
Formation of 1-nitronaphthalene but conversion of 2-nitronaphthalene
NO O
1O
N
O
23.2 x 10-2 Pa
Genotoxic Nitro-PAHs
DPF-induced nitration of PAHs
Formation of 1-nitronaphthalene but conversion of 2-nitronaphthalene
NO O
1O
N
O
23.2 x 10-2 Pa
For comparison
1.2 x 10-3 Pa
Genotoxic Nitro-PAHs
DPF-induced nitration of PAHs
Formation of 9-nitrophenanthrene but some conversion of 3-nitrophenanthrene
9N
O
O
O
NO3
Genotoxic Nitro-PAHs
DPF-induced nitration of PAHs
Nitration is regioselective – peri-positions are more reactive.
NO O
19
NO
O
ON
O
2
O
NO3
Genotoxic Nitro-PAHs
What about less volatile Nitro-PAHs?
NO O
9
4
O
NO
16
3
O
N
O1
ON
ODPF-induced nitration of PAHs
Substantial variation among DPFs, but similar nitration chemistry
NO O
19
NO
O
ON
O
2
O
NO3
Genotoxic Nitro-PAHs
DPF-induced nitration of PAHs
Formation and release of 1-nitronaphthalene and 9-nitrophenanthrene is frequent
NO O
19
NO
O
ON
O
2
O
NO3
Genotoxic Nitro-PAHs
DPF-induced nitration of PAHs
Do DPFs detoxify diesel exhaust?
Trojan horse, Harbour of Canakkale, Turkey
Effects of low- and high-oxidation DPFson genotoxic exhaust constituents
Its a long way from diesel soot to CO2 and H2 O!
Results:
Conclusion:
Current DPF technology lowersemissions of genotoxic compoundsSome nitro-PAHs are formed de novo, others areconverted
VERT®-approved DPF are efficient sinks for soot nanoparticles and genotoxic compoundswith moderate risks for secondary poisoning
Some DPFs form NO2, others convert it
DPFs to not abate the NOx problem, some evenenhance it!
Effects of low- and high-oxidation DPFson genotoxic exhaust constituents
Wall-flow DPFs eliminate solid nanoparticles
About 7 m3 exhaust (3 min operation of a 3.0 L Euro-3 engine (100 kW)
Effects of low- and high-oxidation DPFson genotoxic exhaust constituents
Today, wall-flow DPFs are best available technology to detoxify diesel exhaust. Are combined DPF-DeNOx systems the future?
Effects of low- and high-oxidation DPFson genotoxic exhaust constituents
Thanks: VERT team: Andreas Mayer, TTM, NiederrohrdorfJan Czerwinski, Sandro Napoli, Tobias Neubert, Thomas Hilfiker, Jean-Luc Petermann, Yan Zimmerli, Uni. Appl. Sci., Biel.Markus Kasper, Adrian Hess, Thomas Mosimann, Matter Engineering, WohlenHans Jaeckle, Urs Debrunner, Oliver Schumm, Intertek Caleb Brett, Schlieren.
Empa colleagues: Brigitte Buchmann, Thomas Bührer, Anna-Maria Forss, Urs Gfeller,Maria Guecheva, Peter Graf, Roland Graf, Erika Guyer, Regula Haag, Peter Honnegger,Judith Kobler, Martin Kohler, Peter Lienemann, Alfred Mack, Peter Mattrel, Martin Mohr, Joachim Mohn, Christof Moor, Peter Schmid, Cornelia Seiler, Andreas Paul, Heinz Vonmont, Thomas Walter, Max Wolfensberger, Daniela Wenger, Adrian Wichser,Markus Zennegg, Kerstin Zeyer.
Governement: Giovanni D’Urbano, Max Wyser, Gerhard Leutert, Martin Schiess, Swiss Fed. Office for Environment, Bern
Filter- & catalyst manufacturers: >30 different diesel particulate filter systems
Traugott Sandmeyer (1854-1922)
Effects of low- and high-oxidation DPFson genotoxic exhaust constituents