Chemical reactivity and aerosol
forming potential of anthropic
Volatile Organic Compounds
from chemical structure to properties
JF Doussin, M. Scarfogliero, L. Chiappini, B.Picquet-Varrault, E. Perraudin
« VOC in the urban atmosphere of Europe – sources, transformation and impacts »
Wroclaw, Poland, 25-26 Sept. 2007 - JF Doussin
• VOCs are a blend of hundreds of volatile organic
compounds some of which are chemically reactive,
• VOCs are emitted from a variety of sources,
–
–
–
–
motor vehicles,
chemical plants, refineries, other industries,
consumer and commercial products,
architectural coatings …
• Anthropic VOCs emmission are changing with the
increasing use of new products, alternatives
fuels/solvents, new industrial processes…
Because of this diversity, it is necessary to be able to
draw rules to link chemical structure and
atmospheric effects
« VOC in the urban atmosphere of Europe – sources, transformation and impacts »
Wroclaw, Poland, 25-26 Sept. 2007 - JF Doussin
Plan
• Oxidizing capacity of the atmosphere
• how fast they are removed ?
• how many photo-oxidant are produced ?
• Secondary aerosol formation
« VOC in the urban atmosphere of Europe – sources, transformation and impacts »
Wroclaw, Poland, 25-26 Sept. 2007 - JF Doussin
Atmospheric Oxidation of the VOCs
NOx
Ozone production ?
Secondary products ?
Aerosols production
VOC
VOC +
+ OH
OH →
→ products
products
VOC
VOC +
+ OO33 →
→ products
products
VOC
VOC +
+ NO
NO33 →
→ products
products
« VOC in the urban atmosphere of Europe – sources, transformation and impacts »
Wroclaw, Poland, 25-26 Sept. 2007 - JF Doussin
Nitrate Radical (NO3 )
NO3 sources :
NO2 + O3 → NO3 + O2
NO3 + NO2 N2O5
HNO3 + OH → NO3 + H2O
Puits de NO3 :
NO3 + hν → NO2 + O3P
NO3 + hν → NO + O2
NO3 + NO → 2 NO2
N2O5 + H2O → 2 HNO3 (het.)
⇒ Daytime lifetime : few seconds only !!!
Geyer et al,
JGR, 2003
(Ground
measurement,
« VOC in the urban atmosphere of Europe – sources, transformation and impactsHouston,
»
Texas)
Wroclaw, Poland, 25-26 Sept. 2007 - JF Doussin
NO3 induce a night-time chemistry…
composé
τNO3
τOH
τO3
at night
([OH]= 2.106
[O3] = 30 ppb
[NO3]= 10 ppt molécules.cm-3)
3-methylpentane
Acetaldéhyde
2-methylbutanal
23 days
18 days
1,7 days
1 days
10 hours
4 hours
755 years
-
Pentene
Trans-2-butene
6-methyl-5-hepten-2-one
Acétate de cis-3-héxényl
α-pinene
β-pinene
2-carene
3 days
3 hours
9 min.
4,5 hours
11 min.
27 min.
4 min.
4,5 hours
14 min.
53 min.
2 hours
3 hours
2 hours
2 hours
1,7 days
42 min.
1 hours
7 hours
5 hours
1,1 days
2 hours
« VOC in the urban atmosphere of Europe – sources, transformation and impacts »
Wroclaw, Poland, 25-26 Sept. 2007 - JF Doussin
… but NO3 can also be a daytime oxidant
τNO3
daytime
τOH
τO3
[NO3]= 0,2 ppt
[OH]= 0.1ppt
[O3] = 30 ppb
3,2 years
2,5 years
0.25 years
1 day
10 hours
4 hours
755 years
-
Pentene
Trans-2-butene
152 days
6,3 days
4,5 hours
14 min
1,7 days
42 min
6-methyl-5-hepten-2-one
8 hours
53 min
1 hours
Acétate de cis-3-héxényl
α-pinene
β-pinene
2-carene
10 days
9 hours
23 hours
3 hours
2 hours
3 hours
2 hours
2 hours
7 hours
5 hours
1,1 days
2 hours
compounds
3-methylpentane
Acétaldehyde
2-methylbutanal
« VOC in the urban atmosphere of Europe – sources, transformation and impacts »
Wroclaw, Poland, 25-26 Sept. 2007 - JF Doussin
What about new compounds ?
• Vinyl ethers
(new solvents, motor oil additives, manufacturing of coatings,
synthesis intermediates…)
• Unsaturated acetates
(new fumigants, synthesis intermediates,
monomer for polymer production, emission from new fuel use…)
Only few kinetics and mechanistic studies
Need for data to rationalize our
understanding of the gas phase chemistry of
new oxigenated compounds
« VOC in the urban atmosphere of Europe – sources, transformation and impacts »
Wroclaw, Poland, 25-26 Sept. 2007 - JF Doussin
Kinetic and mechanistic studies of the NO3 induced
oxidation scheme
• Use of simulation
chambers
• Relative and absolute
studies
• Products and
pathways
identification
« VOC in the urban atmosphere of Europe – sources, transformation and impacts »
Wroclaw, Poland, 25-26 Sept. 2007 - JF Doussin
A serie of vinyl ether …
• A homogeneous serie of vinyl ether
O
methyl vinyl ether
O
ethyl vinyl ether
O
propyl vinyl ether
O
butyl vinyl ether
• Some studies
(Thiault 2002, Klotz et al. 2004, Zhou, 2006)
« VOC in the urban atmosphere of Europe – sources, transformation and impacts »
Wroclaw, Poland, 25-26 Sept. 2007 - JF Doussin
Vinyl ether experiment
3
Concentrations (ppm)
MVE
isoprène
N2O5
2
1
0
4000
6000
8000
10000
t (sec.)
12000
14000
« VOC in the urban atmosphere of Europe – sources, transformation and impacts »
Wroclaw, Poland, 25-26 Sept. 2007 - JF Doussin
16000
Kinetics
Composé
MVE
k (∗∗)
(∗
∗)
7,6 ± 0,4
6,1 ± 1,1
O
kmoyen
7,2 ± 2,9
6,3 ± 0,5
EVE
15,1 ± 3,3
O
13,8 ± 1,5
13,1 ± 5,3
14,5 ± 2,5
PVE
(∗
∗)
4,68
(Grosjean et al., 1992)
(Estimation)
17 ± 13
(Pfrang et al., 2006)
14.0 ± 3.5
(Zhou et al., 2006)
13,3 ± 1,8
12,8 ± 1,6
O
Autres travaux
12,4 ± 2,0
13,3 ± 5,9
18.5 ± 5.3
(Zhou et al., 2006)
17,0 ± 7,3
21.0 ± 5.4
(Zhou et al. 2006)
15,1 ± 1,7
BVE
15,8 ± 1,8
O
18,9 ± 1,6
16,5 ± 1,4
(∗) : 10-13 cm3.molecule-1.s-1
Scarfogliero et al, 2006
Journal of Physical Chemistry A
« VOC in the urban atmosphere of Europe – sources, transformation and impacts »
Wroclaw, Poland, 25-26 Sept. 2007 - JF Doussin
Products Identification from FTIR monitoring
PVE alone
RONO2 + ROONO2
5 min after N2O5
injection
Formaldehyde
ROONO2
RONO2
Propyl Formate
1 hour after
N2O5 injection
3300 3200 3100 3000 2900 2800 2700 2600
σ (cm-1)
1500 1400 1300 1200 1100 1000 900 800 700
σ (cm-1)
« VOC in the urban atmosphere of Europe – sources, transformation and impacts »
Wroclaw, Poland, 25-26 Sept. 2007 - JF Doussin
Chemical Scheme
O2NO
H
RO
OH
O2NO
H
R-C(O)-R' + O2
H
OONO2
H
H
RO
H
+
HO2
H
C
RO
ONO2
H
H
HO
H
RO
ONO2
H
H
H
ONOO
2
RO
ONO2
H
H
R-C(O)-R' + O2
+ O2
R-CHO2.-R'
O2NO
NO2
H
RO
O2NO
O
NO3
H
C
H
H
OO.
H
NO3
O2NO
H
RO
+
+ O2
R-CHO2.-R'
O2NO
H
RO
H
RO
H
+ O2
H
RO
H
.OO
RO
ONO2
H
H
NO3
NO2 + O2
H
O
H
H
.O
RO
NO2
NO2 + O2
ONO2
H
H
+ O2
O
RO
H
R-O-CHO
+
ONO2
H
H
HO2
+
HCHO
+
NO2
« VOC in the urban atmosphere of Europe – sources, transformation and impacts »
Wroclaw, Poland, 25-26 Sept. 2007 - JF Doussin
Products study experiments
méthyl vinyl ether
formaldehyde
formate de méthyle
0,8
concentrations (ppm) )
concentration (ppm)
1,0
0,6
0,4
0,2
0,0
1,0
0,8
0,6
nitrates organiques
(unités arbitraires)
0,4
0,2
0,0
0
30
60
90
120
150
180
0
30
tem ps (m inutes )
10
N2O5
acide ntrique
0,8
0,6
0,4
0,2
0,0
0
30
60
90
90
120
150
180
150
180
tem ps (m inutes )
concentrations (ppm) O2])
concentrations (ppm)
1,0
60
120
150
NO
8
NO2
6
4
2
0
180
tem ps (m inutes )
0
30
60
90
120
tem ps (m inutes )
NO injection at the end to destroy peroxynitrates
« VOC in the urban atmosphere of Europe – sources, transformation and impacts »
Wroclaw, Poland, 25-26 Sept. 2007 - JF Doussin
Products study experiments : Yield
0,5
0,5
formaldéhyde
0,4
0,3
0,2
y = 0,39x + 0,03
R2 = 0,99
0,1
concentrations (ppm)
concentrations (ppm)
méthyl formate
0,0
0,3
0,2
y = 0,41x + 0,02
R2 = 0,99
0,1
0,0
0,0
1,2
0,2
0,4
- ∆ [MVE] (ppm)
0,6
0,8
0,0
0,2
0,4
- ∆ [MVE] (ppm)
0,6
0,8
0,6
0,8
1,2
péroxynitrates
1,0
concentrations (unités
arbitraires)
concentrations (unités
arbitraires)
0,4
0,8
0,6
0,4
0,2
0,0
nitrates organiques
1,0
0,8
0,6
0,4
0,2
0,0
0,0
0,2
0,4
- ∆ [MVE] (ppm)
0,6
0,8
0,0
0,2
0,4
- ∆ [MVE] (ppm)
« VOC in the urban atmosphere of Europe – sources, transformation and impacts »
Wroclaw, Poland, 25-26 Sept. 2007 - JF Doussin
Products Yields
vinyl
ether
Primary yield (%)
final yield (%)
HCHO
alkyl
formate
HCHO
alkyl
formate
methyl
46 ± 9
45 ±9
52 ± 14
53 ± 9
ethyl
54 ± 14
46 ± 8
68 ±13
60 ±7
propyl
51 ±16
45 ± 15
50 ±16
48 ± 6
butyl
44 ± 8
44 ± 7
47 ± 8
50 ± 4
« VOC in the urban atmosphere of Europe – sources, transformation and impacts »
Wroclaw, Poland, 25-26 Sept. 2007 - JF Doussin
X 100
Kinetics
Alkyle
Alkenes (a)
Vinyl ethers (a)
group
(R-CH=CH2)
(R-O-CH=CH2)
CH3
(9,5 ± 0,8).10-15 (b)
(7,2 ± 1,5).10-13
C2H5
(13,5 ± 4,1).10-15 (c)
(13,1 ± 2,7).10-13
C3H7
(15 ± 5).10-15 (d)
(13,3 ± 3,0).10-13
C4H9
(18 ± 7).10-15 (d)
(17,0 ± 3,7).10-13
« VOC in the urban atmosphere of Europe – sources, transformation and impacts »
Wroclaw, Poland, 25-26 Sept. 2007 - JF Doussin
2,00E-010
1,80E-012
k NO3
1,60E-012
k OH
??
1,80E-010
1,60E-010
1,40E-012
1,40E-010
1,20E-012
1,20E-010
1,00E-012
1,00E-010
8,00E-013
8,00E-011
6,00E-013
6,00E-011
4,00E-013
4,00E-011
3
-1
-1
k (cm molecule s )
2,00E-012
2,00E-013
O
O
O
O
0,00E+000
2,00E-011
0,00E+000
Methyl
Ethyl
Propyl
Butyl
Alkyl group
Electron donor (mesomeric and inductive) effects increase
the reactivity of the double bond
« VOC in the urban atmosphere of Europe – sources, transformation and impacts »
Wroclaw, Poland, 25-26 Sept. 2007 - JF Doussin
A serie of unsaturated acetates …
• A homogeneous serie
O
O
Vinyl acetate
O
O
Isopropenyl acetate
O
O
• Very few studies
Allyl acetate
(Grosjean et al. 1992 (SAR))
« VOC in the urban atmosphere of Europe – sources, transformation and impacts »
Wroclaw, Poland, 25-26 Sept. 2007 - JF Doussin
kacetate + NO3
O
O
O
(115
O
±8)x10-15
cm3.molecule-1.s-1
O
ONO 2
C
δ+ δ
O
ONO 2
× 10
O
O
O
(11.4 ±1)x10-15 cm3.molecule-1.s-1
O
O
ONO 2
C
÷ 10
O
O
O
(1.0 ±0.6)x10-15 cm3.molecule-1.s-1
O
C
ONO 2
« VOC in the urban atmosphere of Europe – sources, transformation and impacts »
Wroclaw, Poland, 25-26 Sept. 2007 - JF Doussin
δ+ δ
O
ONO 2
Atmospheric Lifetimes
τNO3
τNO3
τOH
τO3
[NO3] = 50 ppt
(polluted)
[NO3] = 2 ppt
(rural)
[OH] = 2×106
moléc.cm-3
Methyl vinyl ether
20 min
8 hours
3 hours (a)
Ethyl vinyl ether
9 min
4 hours
2 hours (a)
Propyl vinyl ether
10 min
4 hours
1.5 hours (a)
Butyl vinyl ether
8 min
3 hours
1.5 hours (a)
Vinyl Acetate
20 hours
21 days
3 hours (b) 70 hours (c)
Isopropényle Acetate
2 hours
2 days
2 hours (e)
-
Allyl Acétate
7 days
160 days
5 hours (f)
-
[O3] = 50 ppb
1 hours (a)
a : Thiault et al., 2002, b: Grosjean et al., 1992, c: Grosjean et al., 1998, d: Fantechi et al., 1998, e:
Ferrari 1995, f: Picquet 2000
•Vinyl Ethers very reactive with NO3
•Acetate lifetime can vary over a wide range with NO3
« VOC in the urban atmosphere of Europe – sources, transformation and impacts »
but
not really with OH
Wroclaw, Poland, 25-26 Sept. 2007 - JF Doussin
Secondary aerosol formation
• Organic material contributes from 10 to 90% to total fine
aerosol mass
• SOA formed by gas-to-particle conversion of oxidation products
of VOC.
• Complexe mixtures (dicarboxylic acids, ketoacids, polyols …)
• Environmental effects :
direct and indirect radiative forcing
visibility reducing
toxicity
Good knowledge of their formation processes
and chemical composition is needed !
« VOC in the urban atmosphere of Europe – sources, transformation and impacts »
Wroclaw, Poland, 25-26 Sept. 2007 - JF Doussin
SOA from Aromatic compounds
•
Intensively emitted by anthropogenic sources
• Known to be precursors of SOA (Odum et al., 1997, Forstner et al. 1997)
•Two target compounds : 2-methyl Styrene and Indene
polymer combustion,
biomass burning, cigarette
smoke
•Strong similarities in chemical structures
•Only one kinetic study (Kwok et al., 1996) – no mechanistic study
« VOC in the urban atmosphere of Europe – sources, transformation and impacts »
Wroclaw, Poland, 25-26 Sept. 2007 - JF Doussin
SOA production from indene and Me-Styrene :
comparative study
• Production of SOA in simulation chamber…
•… from ozonolysis reaction …
• … under dry conditions.
•
Chemical/Physical
analysis …
Particles number and size monitored by SMPS (TSI 3022A/3081)
… in gas phase : long-path FTIR
… in particulate phase : sampling on glass-fiber filters +
Supercritical Fluid extraction with BSTFA + direct coupling with
GC/MS (SFE-GC-MS)
« VOC in the urban atmosphere of Europe – sources, transformation and impacts »
Wroclaw, Poland, 25-26 Sept. 2007 - JF Doussin
SOA production from indene and Me-Styrene :
comparative study
2-méthylstyrène
Ozone
4000
Aérosols
3000
Y = 0.07
2000
1000
Indène
2500
-3
Concentrations ( µg m )
-3
Concentrations ( µg m )
5000
Ozone
2000
Aérosols
1500
Y = 0.17
1000
500
0
0
0
1000 2000 3000 4000 5000 600
0
7000
Time (s)
0
1000
2000
3000
Time (s)
« VOC in the urban atmosphere of Europe – sources, transformation and impacts »
Wroclaw, Poland, 25-26 Sept. 2007 - JF Doussin
4000
5000
SOA production from indene and Me-Styrene :
comparative study
Indene: distribution en taille
3
Millions
Millions
MeStyrene: distribution en taille
2.5
0.8
0.7
1.5
1
0.5
dN/dlogD
Nombre dN/dlogd
2
dN/dlogD
Nombre dN/dlogd
0.6
0.4
0.3
0.2
0.5
0.1
0
0
0
50
100
150
200
250
Diamètre
(nm)
diametre (nm)
0
100
200
300
Diametre
(nm)
Diamètre
« VOC in the urban atmosphere of Europe – sources, transformation and impacts »
Wroclaw, Poland, 25-26 Sept. 2007 - JF Doussin
400
(nm)
500
Composition of SOA produced from Me-Styrene
ozonolysis
H
HO
O
HO
O
H
O
O
O
H
O
HO
OH
O
OH
18
Ions: 73+75+117+147
19
20
Time (mn)
21
22
Total Ions
« VOC in the urban atmosphere of Europe – sources, transformation and impacts »
Wroclaw, Poland, 25-26 Sept. 2007 - JF Doussin
23
Composition of SOA produced from Indene
ozonolysis
O
H
O
O
O
OH
O
H
O
O
OH
H
16
O
OH
H
H
10
H
O
OH
O
12
OH
O
H
OH
14
OH
H
O
O
O
O
O
O
O
OH
H
O
O
OH
H
O
OH
O
HO
O
8
6
4
2
0
15
16
17
18
19
20
21
22
23
24
Time
(mn)
« VOC in the urban atmosphere of Europe
– sources,
transformation and impacts »
Wroclaw, Poland, 25-26 Sept. 2007 - JF Doussin
Composition of SOA produced from Me-Styrene
ozonolysis
« VOC in the urban atmosphere of Europe – sources, transformation and impacts »
Wroclaw, Poland, 25-26 Sept. 2007 - JF Doussin
Composition of SOA produced from Indene
ozonolysis
« VOC in the urban atmosphere of Europe – sources, transformation and impacts »
Wroclaw, Poland, 25-26 Sept. 2007 - JF Doussin
SOA production from indene and Me-Styrene :
comparative results
Me-Styrene
Indene
Rate Constant with O3
(molec-1.cm3.s-1)
(1.5±0.3)x10-17
(14±2)x10-17
Mass yield (%)
7%
17 %
Aerosol Mass (mg.m-3)
310
850
Max size (nm)
100
250
Analyzed SOA (%)
54 ±17 %
36 ±7 %
Mono-functionnal
Poly-functionnal
Structure
Typical identified
species
HO
O
O
O
H
O
H
H
O
H
O
OH
OH
O
OH
« VOC in the urban atmosphere of Europe – sources, transformation and impacts »
Wroclaw, Poland, 25-26 Sept. 2007 - JF Doussin
SOA production from indene and Me-Styrene :
comparative results
Indene ozonolysis forms more particles (in mass)
2-méthylstyrène
Indène
O O
O
• Because it leads
to more polar compounds
O
+ O3
O
O
O3 +
• Because
of the endocyclic double bond
C
O
H
O
HC
O
O
+
O
H
C
O
O
H
O
• Because of the hydroperoxide channel
Hydroperoxide pathway
Di-carboxylic acids
« VOC in the urban atmosphere of Europe – sources, transformation and impacts »
Wroclaw, Poland, 25-26 Sept. 2007 - JF Doussin
Conclusion
•Small change in the structure may induce large effects on
the impacts of the considered VOC
•Simple structure analysis rules can be used to roughtly
forecast the reactivity/impact of new VOCs : ex use of allyl acetate
may be an alternative to vinyl acetate at local scale
•These rules may be useful for the building of StructureActivity Relationship
« VOC in the urban atmosphere of Europe – sources, transformation and impacts »
Wroclaw, Poland, 25-26 Sept. 2007 - JF Doussin
Acknowledgment
MOST
«Multiphase Chemistry of
Oxygenated Species in the
Troposphere »
Introp
EVK2-. 2001-00114
French Ministry of
Environment
« VOC in the urban atmosphere of Europe – sources, transformation and impacts »
Wroclaw, Poland, 25-26 Sept. 2007 - JF Doussin