presentation slides for chapter 11, part 1 of fundamentals of atmospheric modeling 2 nd edition
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Presentation Slides for Chapter 11, Part 1 of Fundamentals of Atmospheric Modeling 2 nd Edition. Mark Z. Jacobson Department of Civil & Environmental Engineering Stanford University Stanford, CA 94305-4020 [email protected] March 21, 2005. Types of Gases. Inorganic gases - PowerPoint PPT PresentationTRANSCRIPT
Presentation Slides for
Chapter 11, Part 1of
Fundamentals of Atmospheric Modeling 2nd Edition
Mark Z. JacobsonDepartment of Civil & Environmental Engineering
Stanford UniversityStanford, CA [email protected]
March 21, 2005
Types of GasesInorganic gases
Contain O, N, S, Cl, Br, and maybe H or C, but not both
Nitric oxide --Organic gases
Contain both H and C, but may also contain other atoms
Carbon dioxide --
Formaldehyde --
Acetone --
Peroxyacetylnitrate --
N O O C O
H C
O
H
H C
H
C
H
O
C
H
H
H
C C
O
O
H
H
H
O
N
O
O
HydrocarbonsOrganic gases that contain only hydrogen and carbon
Propane --
Alkanes - Carbons bonded by a single bond
Cyclobutane --
Ethene (ethylene) --
Cycloalkanes - A ring of alkanes
Alkenes - Carbons bonded by a double bond
H C
H
C
H
H
C
H
H
H
H
H2
C
H2
C CH2
CH2
C C
H
H
H
H
Hydrocarbons
Toluene --
Aromatics - Carbons that form a benzene ring
Isoprene --
Terpenes - Biogenic hydrocarbons
CH3
H
C C
H2
CCH
2
CH3
DefinitionsNon-methane hydrocarbons (NMHC)
Hydrocarbons, except for methane
Oxygenated hydrocarbonsHydrocarbons with oxygenated functional groups, such as aldehydes, ketones, alcohols, acids, and nitrates, added to them
Reactive organic gas (ROG)The sum of oxygenated and NMHC
Total organic gas (TOG)The sum of ROG and methane
Photostationary State Relationship(11.1)
(11.2)
(11.3)
NO + O3
NO2
+ O2
NO2
+ h ν NO + O λ < 420 νm
O + O2
+ M O3
+ M
d NO2[ ]dt =k1 NO[ ] O3[ ]−J NO2[ ]
O3[ ]=J NO2[ ]k1 NO[ ]
Time rate of change of nitrogen dioxide (11.4)
Steady state --> photostationary state relationship (11.5)
Photostationary State RelationshipExample 11.1:Estimate ozone mixing ratio when
pa = 1013 hPa T = 298 KNO = 5 pptv NO2 = 10 pptvk1 = 1.8x10-14 cm3 molec.-1 s-1 J = 0.01 s-1
Solution:[O3] = 1.1x1012 molec. cm-3
Nd = 2.46 x 1019 molec. cm-3
O3 = 44.7 ppbv
Other Reactions Affecting OzonePhotodissociation of ozone (11.6)
(11.7)
Conversion of excited to ground-state atomic oxygen (11.8)
O3
+ h νO
2 + O(
1
D ) λ < 310 νm
O3
+ h ν O2
+ O λ > 310 νm
O(1
D ) O
M
Hydroxyl Radical SourcesMajor (11.9)
Minor (11.10-13)
O(1
D ) + H2
O 2OH
HONO + h ν OH + NO λ < 400 νm
HNO3
+ h ν OH + NO2
λ < 335 νm
H2
O2
+ h ν 2OH λ < 355 νm
HO2
NO2
+ h ν
HO2
+ NO2
OH + NO3
λ < 330 νm
λ < 330 νm
Scavenging by Hydroxyl Radical(11.14-17)
OH + O3
HO2
+ O2
OH + H2
H2
O + H
OH + HO2
H2
O + O2
OH + H2
O2
HO2
+ H2
O
Scavenging by Hydroxyl Radical(11.19-23)
M
OH + NO2
HNO3
OH + SO2
HSO3
M
OH + CO H + CO2
OH + CH4
H2
O + CH3
Hydroperoxy Radical Production
(11.27)
(11.28)
M
H + O2
HO2
HO2
NO2
HO2
+ NO2
M
Hydroperoxy Radical LossHyrdoxyl radical reactions in presence of NO (11.29)
(11.30)
(11.31)
(NO > 10 pptv)
(NO 3-10 pptv)
(NO < 3 pptv)
M
H O2
+ NO OH + NO2
HO2
+ NO2
HO2
NO2
HO2 +
O3
OH + 2O2
HO2
+ HO2
H2
O2
+ O2
Nighttime Nitrogen ChemistryProduction of nitrate radical (11.32)
Dinitrogen pentoxide formation / decomposition (11.33)
NO2
+ O3
NO3
+ O2
M
NO2
+ NO3
N2
O5
Nighttime Nitrogen ChemistryDinitrogen pentoxide reaction, photolysis (11.34)
Nitrate radical photolysis (lifetime of minutes) (11.35)
(11.36)
N2
O5
+ H2
O(aq) 2HNO3
(aq)
N2
O5
+ h ν NO2
+ NO3
λ < 385 νm
NO3
+ h ν
NO2
+ O
NO + O2
410 νm < λ < 670 νm
590 νm < λ < 630 νm
Ozone From Carbon Monoxide
(11.37-41) CO + OH CO2
+ H
M
H + O2
HO2
NO + HO2
NO2
+ OH
NO2
+ h ν NO + O λ < 420 νm
O + O2
+ M O3
+ M
Ozone Formation From Methane(11.42)
(11.43)
CH4
+ OH CH3
+ H2
O
+ O2
, M
C
H
H
H
Methyl
radical
C
H
H
H
O
O
Methylperoxy
radical
H
C O
H
H
Methoxy
radical
O2
NO2
+ NO
+ HO2
H C
H
O
H
O H
Methyl
hydroperoxide
H C
O
H
Formaldehyde
+ O2
HO2
(11.40)
(11.41)
NO2
+ h ν NO + O λ < 420 νm
O + O2
+ M O3
+ M
Methyl Hydroperoxide Decomposition(11.44)
H C
O
H
Formaldehyde
+ O2
HO2
H
C O
HOH
Methoxy
radical
H C
H
O
H
O H
+ h ν
C
H
H
H
O
O
Methyλperoxy
radiaλ
Methyλ
hydroperoxide
λ < 360 νm
H
+ OH
H2
O
Ethane Oxidation
Methylperoxy radical production and loss (11.45)
Ethane
H C
H
C
H
H
H
H C
H
C
H
H
H
Ethyl radical
H
H C
H
C
H
O
H
H
O
Ethylperoxy radical
+ O2
, M
+ OH
H2
O
Ethane Oxidation(11.46)
H C
H
C
H
O
H
H
O
Ethylperoxy radical
H C
H
C
H
H
H
Ethoxy radical
O
NO2
+ NO
Acetaldehyde
H C
H
C
H
O
H
+ O2
HO2
+ NO2
M
H C
H
C
H
H
O
H
Ethylperoxynitric acid
O
N
O
O
Propane OxidationMethylperoxy radical production and loss (11.47)
+ O2
, M
H C
H
C
H
H
C
H
H
H H C
H
C
H
H
C
H
H
Propane n -Propyl radical
H H
H C
H
C
H
H
C
H
H
O
H
n -Propylperoxy radical
O
+ OH
H2
O
NO2
+ NO
H C
H
C
H
H
H
n -Propoxy radical
C
H
H
O H C
H
C
H
O
C
H
H
H
Acetone
+ O2
HO2
Formaldehyde/Acetaldehyde PhotolysisFormaldehyde (11.48)
Acetaldehyde (11.49)
Eormyl radical (11.50)
H C
O
H
Formaldehyde
+ h ν
+ H
Formyλ
radiaλ
CO + H2
λ < 334 νm
λ < 370 νm
C
HO
+ h ν
C
H
H
H
CH C
H
C
H
Aetaλdehyde Methyλ radiaλ Formyλ radiaλ
+
O
H
O
H
λ < 325 νm
Formyl
radical
C
O
H
CO
+ O2
HO2
Formaldehyde/Acetaldehyde ReactionFormaldehyde (11.51)
Acetaldehyde (11.52)
CH C
Formaldehyde Formyl radical
O
H
O
H
+ OH
H2
O
C C
O
H
H
H
H
Acetaldehyde Acetyl radical
C C
OH
H
H
Peroxyacetyl
radical
C C
O
O
H
H
H
O
+ OH
H2
O
+ O2
, M
Formaldehyde/Acetaldehyde ReactionPAN formation (11.53)
Peroxyacetyl
radical
C C
O
O
H
H
H
O
Acetyloxy radical
C C
O
O
H
H
H
Peroxyacetyl nitrate
C C
O
O
H
H
H
O
N
O
O
NO2
+ NO
+ NO2
, M
Acetone Photolysis(11.55)
H C
H
C
H
O
C
H
H
H
Acetone
+ h νC
H
H
H
Methyλ radiaλ
+
Aetyλ radiaλ
C C
OH
H
H
Sulfur PhotochemistryBiogenic sulfur
H2S -- hydrogen sulfideCH3SH -- methyl sulfideCH3SCH3 -- dimethyl sulfide (DMS)CH3SSCH3 -- methyl disulfide
Volcanic sulfurCS2 -- carbon disulfideOCS -- carbonyl sulfideSO2 -- sulfur dioxideH2S -- hydrogen sulfide
Sulfur PhotochemistrySulfuric acid formation from sulfur dioxide (11.74)
S
OO
O
S
HO O
O
S
O O
+ OH, M+ H
2O
Sulfur
dioxide
Bisulfite Sulfur
trioxide
Sulfuric
acid
S
O
OH
O OH
+ O2
HO2
DMS Abstraction PathwaySulfur dioxide production from dimethyl sulfide (DMS) (11.56)
+ O2
H C
H
S
H
C
H
H
H H C
H
S
H
C
H
H
H C
H
S
H
C
H
H
O
O
Dimethyl sulfide (DMS) DMS radical DMS peroxy radical
+ OH
H2
O
H C
H
S
H
C
H
H
O H C
H
S
H
+
H C
O
H
DMS oxy radical Methanethiolate
radical
Formaldehyde
M
NO2
+ NO
DMS Abstraction PathwayMethanethiolate radical reaction (11.57)
H C
H
S
H
H C
H
S
H
O
O
Methanethiolate
radical
Excited methanethiolate
peroxy radical
*
H C
H
S
H
O
O
Methanethiolate oxy
radical
Methanethiolate
peroxy radical
M
H C
H
S
H
O
+ O2
, M
NO2
+ NO
DMS Abstraction PathwayMethanethiolate oxy radical reaction (11.58)
H C
H
H
Methyl
radical
H C
H
S
H
O
+
H C
H
S
H
O
O
S O
Sulfur monoxide
Methanethiolate
peroxy radical
Methanethiolate oxy
radical
M
+ O3
O2
DMS Abstraction PathwaySulfur dioxide production from sulfur oxide (11.59)
Sulfur dioxide production from sulfur oxide (11.60)
S
OO
OSulfur
monoxide
S O
Sulfur
dioxide
+ O2
S
OO
H C
H
H
+H C
H
S
H
O
O
Methyl radical Sulfur dioxideMethanethiolate
peroxy radical
M
DMS Addition PathwayMethanethiolate oxy radical reaction (11.61)
H C
H
S
H
C
H
H
H
+ OH
Dimethyl sulfide (DMS)
H C
H
S
H
C
H
H
H
OH
H C
H
H
H C
H
S
H
O
H
O
S C
O
C
H
H
H
H
H
H
+
Dimethyl sulfone (DMSO2
)
Methanesulfenic
acid
Methyl
radical
DMS-OH adduct
M
+ OH, 2O2
2 HO2
DMS Addition PathwayMethanesulfenic acid oxidation (11.62)
Methanethiolate oxy
radical
H C
H
S
H
O
H
Methanesulfenic
acid
H C
H
S
H
O
+ OH
H2
O
DMDS ReactionOH addition (11.63)
Photolysis (11.64)
H C
H
S
H
S C
H
H
H H C
H
S
H
O
H
H C
H
S
H
+
Dimethyl disulfide (DMDS) Methanesulfenic
acid
Methanethiolate
radical
+ OH
H C
H
S
H
S C
H
H
H H C
H
S
H
2
Dimethyl disulfide (DMDS) Methanethiolate
radical
+ h ν
Biogenic SulfurHydrogen sulfide oxidation (11.65)
Hydrogen sulfide radical reaction (11.66)
Sulfur dioxide production from sulfur oxide (11.59)
S
HH
S
H
Hydrogen
sulfide
Hydrogen
sulfide radical
+ OH
H2
O
+ O2
S
H
OH
Hydrogen
sulfide radical
Sulfur
monoxide
S O
S
OO
OSulfur
monoxide
S O
Sulfur
dioxide
+ O2
Volcanic SulfurSulfur monoxide production from carbonyl sulfide (11.68)
(11.69)
(11.70)
+ OHO C S
S
H
Hydrogen sulfide
radical
+ CO2
Carbonyl
sulfide
Carbonyl
sulfide
O C S +
Carbon
monoxide
Atomic
sulfur
+ h ν λ < 260 νmCO S
O
+ O2
Sulfur
monoxide
S O
Atomic
sulfur
S
Volcanic SulfurSulfur oxide production from carbon disulfide (11.71)
(11.72)
(11.73)
+ OHS C S
S
H
O C S+
Carbon
disulfide
Hydrogen sulfide
radical
Carbonyl
sulfide
S C S +C S
Carbon
disulfide
Carbon
monosulfide
Atomic
sulfur
+ h ν S λ < 340 νm
+ O2C S
Carbon
monosulfide
+ OO C S
Carbonyl
sulfide
Urban PhotochemistryOzone production in smog (11.75-8)
NO + ROG * NO2
+ ROG **
NO + O3
NO2
+ O2
NO2
+ h ν NO + O λ < 420 νm
O + O2
+ M O3
+ M
0 0.5 1 1.5 2
0
0.05
0.1
0.15
0.2
0.25
ROG (ppmC)
NO
x
(g) (ppmv)
0.4
0.32
0.24
0.16
0.08 = O
3
(g), ppmv
Ozone Isopleth
Fig. 11.1Contours are ozone (ppmv)
NO
x (pp
mv)
0.24
0.08
0.32
0.16
Sea Breeze
Fig. 11.2
0
1
2
3
4
5
6
7
0 6 12 18 24 30 36 42 48 54 60 66 72
Wind speed (m s
-1
)
Hour of day
Day 1 Day 2
Day 3
Win
d sp
eed
(m s-1
)
Source/Receptor Regions in Los Angeles
0
0.1
0.2
0.3
0 6 12 18 24
Volume mixing ratio (ppmv)
Hour of day
O
3
NO
2NO
Central Los Angeles
August 28, 1987
Vol
ume
mix
ing
ratio
(ppm
v)
Fig. 11.2
0
0.1
0.2
0.3
0 6 12 18 7224
Volume mixing ratio (ppmv)
Hour of day
O
3
NO
2
NO
San Bernardino
August 28, 1987
Vol
ume
mix
ing
ratio
(ppm
v)
Daily Los Angeles Emission (1987)
Table 11.2
Gas Emission (tons/day) Percent of totalCarbon monoxide 9796 69.3
Nitric oxide 754Nitrogen dioxide 129Nitrous acid 6.5
Total NOx+HONO 889.5 6.3Sulfur dioxide 109Sulfur trioxide 4.5
Total SOx(g) 113.5 0.8Alkanes 1399Alkenes 313Aldehydes 108Ketones 29Alcohols 33Aromatics 500Hemiterpenes 47
Total ROGs 2429 27.2Methane 904 6.4
Total emission 14,132 100
Percent Emission by SourceNitric oxide from combustion (11.79)
N N O O N O+ 2+ heat
Table 11.4
Source Category CO(g) NOx(g) SOx(g) ROG Stationary 2 24 38 50Mobile 98 76 62 50Total 100 100 100 100
Organic Gases Emitted in Greatest Abundance in Los Angeles (1987)
Table 11.3
1. Methane2. Toluene3. Pentane4. Butane5. Ethane6. Ethylene7. Octane8. Xylene
9. Heptane10. Propylene11. Chloroethylene12. Acetylene13. Hexane14. Propane15. Benzene
Most Important Gases in Smog in Terms of Ozone Reactivity and Abundance
Table 11.6
1. m- and p-Xylene2. Ethene3. Acetaldehyde4. Toluene5. Formaldehyde6. i-Penane7. Propene8. o-Xylene9. Butane10. Methylcyclopentane
Lifetimes of ROGs Against Loss in Urban Air
Table 11.5
ROG Species Phot. OH HO2 O NO3 O3 n-Butane --- 22 h 1000 y 18 y 29 d 650 ytrans-2-butene --- 52 m 4 y 6.3 d 4 m 17 mAcetylene --- 3 d --- 2.5 y --- 200 dFormaldehyde 7 h 6 h 1.8 h 2.5 y 2 d 3200 yAcetone 23 d 9.6 d --- --- --- ---Ethanol --- 19 h --- --- --- ---Toluene --- 9 h --- 6 y 33 d 200 dIsoprene --- 34 m --- 4 d 5 m 4.6 h
OH Sources in Polluted AirEarly morning source (11.80)
Mid-morning source (11.81)
(11.82)
(11.83)
λ < 400 nmOH + NOHONO + h ν
HCHO + h ν λ < 334 νmH + HCO
M
H + O2
HO2
HCO + O2
HO2
+ CO
(11.84)NO + HO
2NO
2 + OH
Hydroxyl Rad. Sources in Polluted Air
Afternoon source (11.88)
(11.86)
O3
+ h ν O2
+ O(1
D ) λ < 310 νm
O(1
D ) + H2
O 2 OH
Alkene Reaction With Hydroxyl Radical
Ethene oxidation (11.87)
C C
H
H
H
H
Ethene
C C
H
H
H
H
Ethanyl radical
OH
C C
H
H
H
H
Ethanolperoxy
radical
OH
O
O
C C
H
H
H
H
Ethanoloxy
radical
OH
O
+ OH, M + O2
, M
NO2
+ NO
Alkene Reaction With Hydroxyl Radical
Ethanoloxy radical oxidation (11.88)
Formaldehyde
C O
H
H
C C
H
H
H
H
Ethanoloxy
radical
OH
O
C C
H
H
O
H
OH
Glycol aldehyde
72% 2
28%
+ O2
HO2