Detailed chemical modelling based on the Master Chemical Mechanism (MCM)
description
Transcript of Detailed chemical modelling based on the Master Chemical Mechanism (MCM)
O
O
OO
OO
OO
OO
O
O
O
O
O
OH
OO
O
O
OO
-pinene
pinonic acidpinonaldehyde
O
OO
stab.
O
OHO
acetone andother products
stab. 0%
OO
+ H2O
O
+ H2O
OO
50%
O
OHO
OH
87.5%12.5%
45%
- OH
- OH
60%40%
50%- OH- CO
+ O2
20%
55% + O2
80%
O
O
O
C9 acyl-oxy radical
formaldehydeO
OOO
RO2 or HO2 + O2
decomp.+ O2
O
O
decomp.
OH
- CO2
decomp.
OO
decomp.
isom.
pinic acid
+ O2
acetone, formaldehyde and other products
isom.
+ O2
+ O2 decomp.
20%O
O
OH
10-hydroxy-pinonic acid
OH80%RO2 or HO2
RO2
RO2
H2O2H2O
O3O3
OO
O
O
OH
O
OH
OO
OH
OO
OH
O
OH+ HO2
OHO
O
OHO
O
OO
OH
O
O
OHO
O
O
OH
O
O
O
O
O
O
O
O
O
OOO
OO
O
O
O
+ HO2+ HO2 + HO2
+ HO2
+ HO2
+ HO2
nitrate
nitrate
nitrate
H abstraction OH addition
1,4 addition1,2 addition
O2
O2
O2
O2
O2
NO
NO
NONO
NO
NO
O2
9.0%
16.0%
1.0%
1.0%
9.0%
24.7%7.0% 7.0%
21.0%
4.3%
'phenolic'
'peroxide-bicyclic'
'epoxy-oxy'
O2O2
O2
isom.
isom.
decomp.
decomp.decomp.
decomp.
Detailed chemical modelling based on the
Master Chemical Mechanism (MCM)
Mike JenkinEMMA GroupDepartment of Environmental Science and Technology [email protected]
Master Chemical Mechanism
Developed by a consortium of groups
• Imperial College London• Leeds• Meteorological Office• NETCEN (AEA Technology)
MCM: chemical processing of emissions
NOX nitrate
emissions
VOC
CH4
SO2
CO2, H2O
sulphate
MCM: chemical processing of emissions
NOX nitrate
emissions
Oxidant (O3, NO2, PAN)
VOC CO2, H2O
Secondary Organic Aerosol (SOA)
Degradation of CH4 and 124 non-methane VOC
ca. 4,500 chemical species ca. 12,500 chemical reactions
Non-methane VOC selected primarily on the basis of UK National Atmospheric Emissions Inventory (NAEI)
Provides a reasonable representation of major organic compounds emitted into the boundary layer in UK and other populated regions
Master Chemical Mechanism (MCM v3)
(http://chem.leeds.ac.uk)
22 alkanes (C1-C12) 16 alkenes (C2-C6) 2 dienes (C4-C5) 2 monoterpenes (C10) 1 alkyne (C2) 18 aromatics (C6-C11) 6 aldehydes (C1-C5)
10 ketones (C3-C6) 17 alcohols (C1-C6) 10 ethers (C2-C7) 8 esters (C2-C6) 3 carboxylic acids (C1-
C3) 2 other oxygenates
(C3) 8 chlorocarbons (C1-C2)
125 hydrocarbons, oxygenated and chlorinated VOC representative of a variety of important source sectors
e.g. road transport, solvent usage, biogenic
VOC degraded in MCM v3(http://chem.leeds.ac.uk)
Saunders et al., Atmos. Chem. Phys. 3, 161-180, 2003
Jenkin et al., Atmos. Chem. Phys. 3, 181-193, 2003
MCM scheme writing framework
VOC
second generationproducts
first generationproducts
CO2
OH, O3, NO3
OH, O3, NO3, h
emission
O
O
OO
OO
OO
OO
O
O
O
O
O
OH
OO
O
O
OO
-pinene
pinonic acidpinonaldehyde
O
OO
stab.
O
OHO
acetone andother products
stab. 0%
OO
+ H2O
O
+ H2O
OO
50%
O
OHO
OH
87.5%12.5%
45%
- OH
- OH
60%40%
50%- OH- CO
+ O2
20%
55% + O2
80%
O
O
O
C9 acyl-oxy radical
formaldehydeO
OOO
RO2 or HO2 + O2
decomp.+ O2
O
O
decomp.
OH
- CO2
decomp.
OO
decomp.
isom.
pinic acid
+ O2
acetone, formaldehyde and other products
isom.
+ O2
+ O2 decomp.
20%O
O
OH
10-hydroxy-pinonic acid
OH80%RO2 or HO2
RO2
RO2
H2O2H2O
O3O3
OO
O
O
OH
O
OH
OO
OH
OO
OH
O
OH+ HO2
OHO
O
OHO
O
OO
OH
O
O
OHO
O
O
OH
O
O
O
O
O
O
O
O
O
OOO
OO
O
O
O
+ HO2+ HO2 + HO2
+ HO2
+ HO2
+ HO2
nitrate
nitrate
nitrate
H abstraction OH addition
1,4 addition1,2 addition
O2
O2
O2
O2
O2
NO
NO
NONO
NO
NO
O2
9.0%
16.0%
1.0%
1.0%
9.0%
24.7%7.0% 7.0%
21.0%
4.3%
'phenolic'
'peroxide-bicyclic'
'epoxy-oxy'
O2O2
O2
isom.
isom.
decomp.
decomp.decomp.
decomp.
Applications of the MCM
Calculation of organic species distribution for comparison with and supplementation of field measurements
alkanes
alkenes/dienes
aromatics
carbonyls
ethers
esters
acids
alkynes
chlorocarbons
Emitted VOC Products
Majority of emitted VOC will be oxidised to:
aldehydes (C1- C?)
ketones (C3- C?)
nitrates (C1- C?)
PAN(s) (C2- C?)
hydroperoxides
alcohols
esters
carboxylic acids
percarboxylic acids
bi- and multi-functional products (esp. hydroxy-carbonyls and nitrates and dicarbonyls)
Trajectories to Silwood Park, 28 July – 3 August 1999
N
28/729/7
30/731/7
1/82/8
3/8
Ozone at Silwood Park, 28 July – 3 August 1999(EU PRIME campaign)
0
20
40
60
80
100
120
140
28/07/9900:00
29/07/9900:00
30/07/9900:00
31/07/9900:00
01/08/9900:00
02/08/9900:00
03/08/9900:00
04/08/9900:00
Mix
ing
ra
tio
(p
pb
v)
Silwood Park
51.41oN 0.65
oW
Ozone
3610.3
182.453.9 41.5 24.3 11.0 35.0
1226.2
0
1000
2000
3000
4000
form
aldeh
yde
acet
aldeh
yde
propan
al
butanal
i-buta
nal
penta
nal
hexan
al
benza
ldeh
yde
mix
ing
ra
tio
(p
ptv
)
aldehydes
2639.4
1035.7
22.6144.4 159.0
3.3 12.6 46.3 4.7 55.6
0
1000
2000
3000
acet
one
butanone
2-pen
tanone
3-pen
tanone
3-m
ethyl
-2-b
utanone
2-hex
anone
3-hex
anone
4-m
ethyl
-2-p
enta
none
3,3-
dimet
hyl-2
-buta
none
cycl
ohexan
one
mix
ing
ra
tio
(p
ptv
)
ketones
O
O
OO
OO
OO
OO
O
O
O
O
O
OH
OO
O
O
OO
-pinene
pinonic acidpinonaldehyde
O
OO
stab.
O
OHO
acetone andother products
stab. 0%
OO
+ H2O
O
+ H2O
OO
50%
O
OHO
OH
87.5%12.5%
45%
- OH
- OH
60%40%
50%- OH- CO
+ O2
20%
55% + O2
80%
O
O
O
C9 acyl-oxy radical
formaldehydeO
OOO
RO2 or HO2 + O2
decomp.+ O2
O
O
decomp.
OH
- CO2
decomp.
OO
decomp.
isom.
pinic acid
+ O2
acetone, formaldehyde and other products
isom.
+ O2
+ O2 decomp.
20%O
O
OH
10-hydroxy-pinonic acid
OH80%RO2 or HO2
RO2
RO2
H2O2H2O
O3O3
OO
O
O
OH
O
OH
OO
OH
OO
OH
O
OH+ HO2
OHO
O
OHO
O
OO
OH
O
O
OHO
O
O
OH
O
O
O
O
O
O
O
O
O
OOO
OO
O
O
O
+ HO2+ HO2 + HO2
+ HO2
+ HO2
+ HO2
nitrate
nitrate
nitrate
H abstraction OH addition
1,4 addition1,2 addition
O2
O2
O2
O2
O2
NO
NO
NONO
NO
NO
O2
9.0%
16.0%
1.0%
1.0%
9.0%
24.7%7.0% 7.0%
21.0%
4.3%
'phenolic'
'peroxide-bicyclic'
'epoxy-oxy'
O2O2
O2
isom.
isom.
decomp.
decomp.decomp.
decomp.
Applications of the MCM
Assessment of comparative importance of:Free radical sources:
O3 + hSpeciated alkenes + O3
Speciated carbonyls + hHONO + hFree radical
sinks:OH + NO2 HNO3
HO2 + HO2 H2O2 + O2
RO2 + NO RONO2
RO2 + HO2 ROOH + O2Assessment of oxidant formation associated
with different VOCs/VOC source sectors
O
O
OO
OO
OO
OO
O
O
O
O
O
OH
OO
O
O
OO
-pinene
pinonic acidpinonaldehyde
O
OO
stab.
O
OHO
acetone andother products
stab. 0%
OO
+ H2O
O
+ H2O
OO
50%
O
OHO
OH
87.5%12.5%
45%
- OH
- OH
60%40%
50%- OH- CO
+ O2
20%
55% + O2
80%
O
O
O
C9 acyl-oxy radical
formaldehydeO
OOO
RO2 or HO2 + O2
decomp.+ O2
O
O
decomp.
OH
- CO2
decomp.
OO
decomp.
isom.
pinic acid
+ O2
acetone, formaldehyde and other products
isom.
+ O2
+ O2 decomp.
20%O
O
OH
10-hydroxy-pinonic acid
OH80%RO2 or HO2
RO2
RO2
H2O2H2O
O3O3
OO
O
O
OH
O
OH
OO
OH
OO
OH
O
OH+ HO2
OHO
O
OHO
O
OO
OH
O
O
OHO
O
O
OH
O
O
O
O
O
O
O
O
O
OOO
OO
O
O
O
+ HO2+ HO2 + HO2
+ HO2
+ HO2
+ HO2
nitrate
nitrate
nitrate
H abstraction OH addition
1,4 addition1,2 addition
O2
O2
O2
O2
O2
NO
NO
NONO
NO
NO
O2
9.0%
16.0%
1.0%
1.0%
9.0%
24.7%7.0% 7.0%
21.0%
4.3%
'phenolic'
'peroxide-bicyclic'
'epoxy-oxy'
O2O2
O2
isom.
isom.
decomp.
decomp.decomp.
decomp.
Reduced mechanism
Common Representative Intermediates
Mechanism (CRI v1)
CRI v1
121 VOC
250 species
570 reactions
Jenkin et al., Atmospheric Environment, 36, 4725-4734, 2002
O
O
OO
OO
OO
OO
O
O
O
O
O
OH
OO
O
O
OO
-pinene
pinonic acidpinonaldehyde
O
OO
stab.
O
OHO
acetone andother products
stab. 0%
OO
+ H2O
O
+ H2O
OO
50%
O
OHO
OH
87.5%12.5%
45%
- OH
- OH
60%40%
50%- OH- CO
+ O2
20%
55% + O2
80%
O
O
O
C9 acyl-oxy radical
formaldehydeO
OOO
RO2 or HO2 + O2
decomp.+ O2
O
O
decomp.
OH
- CO2
decomp.
OO
decomp.
isom.
pinic acid
+ O2
acetone, formaldehyde and other products
isom.
+ O2
+ O2 decomp.
20%O
O
OH
10-hydroxy-pinonic acid
OH80%RO2 or HO2
RO2
RO2
H2O2H2O
O3O3
OO
O
O
OH
O
OH
OO
OH
OO
OH
O
OH+ HO2
OHO
O
OHO
O
OO
OH
O
O
OHO
O
O
OH
O
O
O
O
O
O
O
O
O
OOO
OO
O
O
O
+ HO2+ HO2 + HO2
+ HO2
+ HO2
+ HO2
nitrate
nitrate
nitrate
H abstraction OH addition
1,4 addition1,2 addition
O2
O2
O2
O2
O2
NO
NO
NONO
NO
NO
O2
9.0%
16.0%
1.0%
1.0%
9.0%
24.7%7.0% 7.0%
21.0%
4.3%
'phenolic'
'peroxide-bicyclic'
'epoxy-oxy'
O2O2
O2
isom.
isom.
decomp.
decomp.decomp.
decomp.
Reduced mechanism
Common Representative Intermediates
Mechanism (CRI v1)
CRI v1
121 VOC
250 species
570 reactions
VOC CO2, H2O
Jenkin et al., Atmospheric Environment, 36, 4725-4734, 2002
O
O
OO
OO
OO
OO
O
O
O
O
O
OH
OO
O
O
OO
-pinene
pinonic acidpinonaldehyde
O
OO
stab.
O
OHO
acetone andother products
stab. 0%
OO
+ H2O
O
+ H2O
OO
50%
O
OHO
OH
87.5%12.5%
45%
- OH
- OH
60%40%
50%- OH- CO
+ O2
20%
55% + O2
80%
O
O
O
C9 acyl-oxy radical
formaldehydeO
OOO
RO2 or HO2 + O2
decomp.+ O2
O
O
decomp.
OH
- CO2
decomp.
OO
decomp.
isom.
pinic acid
+ O2
acetone, formaldehyde and other products
isom.
+ O2
+ O2 decomp.
20%O
O
OH
10-hydroxy-pinonic acid
OH80%RO2 or HO2
RO2
RO2
H2O2H2O
O3O3
OO
O
O
OH
O
OH
OO
OH
OO
OH
O
OH+ HO2
OHO
O
OHO
O
OO
OH
O
O
OHO
O
O
OH
O
O
O
O
O
O
O
O
O
OOO
OO
O
O
O
+ HO2+ HO2 + HO2
+ HO2
+ HO2
+ HO2
nitrate
nitrate
nitrate
H abstraction OH addition
1,4 addition1,2 addition
O2
O2
O2
O2
O2
NO
NO
NONO
NO
NO
O2
9.0%
16.0%
1.0%
1.0%
9.0%
24.7%7.0% 7.0%
21.0%
4.3%
'phenolic'
'peroxide-bicyclic'
'epoxy-oxy'
O2O2
O2
isom.
isom.
decomp.
decomp.decomp.
decomp.
Reduced mechanism
Common Representative Intermediates
Mechanism (CRI v1)
CRI v1
121 VOC
250 species
570 reactions
VOC CO2, H2O
Jenkin et al., Atmospheric Environment, 36, 4725-4734, 2002
O3 O3 O3 O3
O
O
OO
OO
OO
OO
O
O
O
O
O
OH
OO
O
O
OO
-pinene
pinonic acidpinonaldehyde
O
OO
stab.
O
OHO
acetone andother products
stab. 0%
OO
+ H2O
O
+ H2O
OO
50%
O
OHO
OH
87.5%12.5%
45%
- OH
- OH
60%40%
50%- OH- CO
+ O2
20%
55% + O2
80%
O
O
O
C9 acyl-oxy radical
formaldehydeO
OOO
RO2 or HO2 + O2
decomp.+ O2
O
O
decomp.
OH
- CO2
decomp.
OO
decomp.
isom.
pinic acid
+ O2
acetone, formaldehyde and other products
isom.
+ O2
+ O2 decomp.
20%O
O
OH
10-hydroxy-pinonic acid
OH80%RO2 or HO2
RO2
RO2
H2O2H2O
O3O3
OO
O
O
OH
O
OH
OO
OH
OO
OH
O
OH+ HO2
OHO
O
OHO
O
OO
OH
O
O
OHO
O
O
OH
O
O
O
O
O
O
O
O
O
OOO
OO
O
O
O
+ HO2+ HO2 + HO2
+ HO2
+ HO2
+ HO2
nitrate
nitrate
nitrate
H abstraction OH addition
1,4 addition1,2 addition
O2
O2
O2
O2
O2
NO
NO
NONO
NO
NO
O2
9.0%
16.0%
1.0%
1.0%
9.0%
24.7%7.0% 7.0%
21.0%
4.3%
'phenolic'
'peroxide-bicyclic'
'epoxy-oxy'
O2O2
O2
isom.
isom.
decomp.
decomp.decomp.
decomp.
CRI vs MCM
0
5
10
15
20
25
30
0 20 40 60 80 100 120Time along trajectory (hours)
Mix
ing
ra
tio (
pp
bv)
NO2
NO
0.00
0.10
0.20
0.30
0.40
0.50
0.60
0.70
0 20 40 60 80 100 120Time along trajectory (hours)
Mix
ing
ra
tio (
pp
tv)
OH
0
5
10
15
20
25
30
35
40
45
50
0 20 40 60 80 100 120Time along trajectory (hours)
Mix
ing
ra
tio (
pp
tv) HO2 + RO2
0
20
40
60
80
100
120
140
160
0 20 40 60 80 100 120Time along trajectory (hours)
Mix
ing
ra
tio (
pp
bv)
O3
dM
dlo
gD
a (g
m-3
)
Aerodynamic Diameter (nm)
4
3
2
1
02 3 4 5 6 7 8 9
1002 3 4 5 6 7 8 9
10002 3
Manchester in Summer
1.5
1.0
0.5
0.02 3 4 5 6 7 8 9
1002 3 4 5 6 7 8 9
10002 3
SASUA3 - Edinburgh
Urban
2.0
1.5
1.0
0.5
0.02 3 4 5 6 7 8 9
1002 3 4 5 6 7 8 9
10002 3
Pacific2001: Sumas Site
2.5
2.0
1.5
1.0
0.5
0.02 3 4 5 6 7 8 9
1002 3 4 5 6 7 8 9
10002 3
Pacific2001: Langley Site
3
2
1
0
2 3 4 5 6 7 8 9100
2 3 4 5 6 7 8 91000
2 3
Pacific2001: Slocan Park
Urban
Urban
Rural
Semi Rural
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0.02 3 4 5 6 7 8 9
1002 3 4 5 6 7 8 9
10002 3
Manchester in winter
Organics Sulphate Nitrate
Urban
Importance of organics in aerosols (slide from Hugh Coe, UMIST)
VOC
second generationproducts
first generationproducts
CO2
OH, O3, NO3
OH, O3, NO3, h
emission
VOC
second generationproducts
first generationproducts
CO2
first generationproducts
second generationproducts
OH, O3, NO3
OH, O3, NO3, h
emission condensedphase
gas phase
monoterpenes
second generationproducts
first generationproducts
CO2
C5-C7 multi-oxygenated
species(probably
WSOC)
OH, O3, NO3
OH, O3, NO3, h
emission condensedphase
gas phase
O
O
OH
O
O
OH
OH
OH
O
O
OH
O
O
OH
e.g.
aromatics
second generationproducts
first generationproducts
CO2
OH, O3, NO3
OH, O3, NO3, h
emission condensedphase
gas phase
OH
NO2
ONO2
O
O
OHOH
O
HOO
OH
(probably WSOC)
e.g.
X (g)
gas phase
X (a)
Equilibriumpartitioning
kin
kout
[X](a)/[X](g) = kin[OA]/kout
= Kp [OA]
organicaerosol, OA
European Photoreactor (EUPHORE)Valencia, Spain
0
2
4
6
8
10
12
10:00 12:00 14:00 16:00
NO
, N
O2 (
pp
b)
0
20
40
60
80
100
120
-p
inen
e ,
ozo
ne
(pp
b)
27-Sep-00 Chamber A
0
4
8
12
16
20
24
10:00 12:00 14:00 16:00
Aer
oso
l mas
s (
g m
-3)
27-Sep-00 Chamber A
Photo-oxidation of -pinene/NOX
EU OSOA campaign at EUPHORE