Department of Chemistry, University of Copenhagen ojn@kiku.dk
1 www.cogci.dk

• Brug af nye kemiske stoffer
– Hvad er de atmosfæriske bekymringer
• Historie
• Miljømæssige effekter
• Konklusioner for HFO-1234yf
• Konklusioner generelt og fremtid
2

Safety low toxicity nonflammable
Environmental non-ozone depleting short atmospheric lifetime low global warming potential
Performance stability compatibility boiling/freezing point
3

Hvad bekymrer os generelt ved atmosfæriske udslip?
• 1. Skadelige emissioner og/eller skadelige nedbrydningsprodukter
– (lokal-regional-global- direkte påvirkning)
• 2. Forøgelse af ozon koncentrationen i troposfæren
– (lokal-regional-global)
• 3. Stratosfærisk ozon nedbrydning
– (global)
• 4. Ændring af jordens strålingsbalance = global opvarmning
– (global)
• Hvad er der fælles for disse fire bekymringer ?
• Der er kemi involveret
• “Skyldig – indtil det modsatte er bevist"
4

Atmospheric degradation of HFC-134a
CF3CFH2
OH.
H2O
CF3CFH.
CF3CFHOOH
HO2
OH
O2
NO2
CF3CFHO2
Decomp/h

CF3CFHOONO2 h

FO x
FCO x
NO h
 h

FNO
O
3 h
 aq
NO NO2 h

CF3CFHO
HCOF
CF3
O2
CF3O2
NO
NO
CF3O
NO2
RH R
O2
HO2
CF3COF aq h

CF3C(O)
CF3COOH
O2
?
CF3C(O)O2
NO
NO2
CF3C(O)O
CF3C(O)O2NO2
FNO
2 CF3OH HF+C(O)F2 5

• 1928 Thomas Midgeley opfandt CFCer (CF
2
Cl
2
)?
• 1930 Sidney Chapman ”opfandt” Chapman mekanismen som fører til ozonlaget
6

Dette og supersoniske fly ledte til …..
7

3
•1970-71 Paul Crutzen and Harold Johnston: ”katalyse” ?
•1970s James Lovelock: EC detektor og CFC målinger
Spørg: “Hvad sker der med …..?” – og få Nobel-prisen
“Hvad sker der med CFC-11 (CFCl
3
) og CFC-12 (CF
2
Cl
2
) …?”
8

3
•1970-71 Paul Crutzen and Harold Johnston: ”katalyse” ?
•1970s James Lovelock: EC detektor og CFC målinger
Spørg: “Hvad sker der med …..?” – og få Nobel-prisen
•
•
•
•
“Hvad sker der med CFC-11 (CFCl
3
) og CFC-12 (CF
2
Cl
2
) …?”
1974 Rowland and Molina: Stratosfærisk ozon nedbrydning
Cl + O
3
→ ClO + O
2
ClO + O → Cl +O
2
--------------------------
O + O
3
→ O
2
+ O
2
(Nature, 1974)
9

Det Antarktiske Ozon Hul - 1985
10

3
•
•
•
•
• 1970-71 Paul Crutzen and Harold Johnston: ”Catalysis” ?
• 1970s
• 1974
James Lovelock: EC detektor
Rowland og Molina: Ozon nedbrydning
Cl + O
3
→ ClO + O
2
ClO + O → Cl +O
2
--------------------------
O + O
3
→ O
2
+ O
2
Joe Farman: Publiserede ozon-hullet • 1985
• 1987
• 1990
• 1992
• 1995
Montreal protocol: 1. udgave
Montreal protocol: 2. udgave (London)
Montreal protocol: 3. udgave (København)
Nobelprisen til Rowland, Molina og Crutzen
11

275
270
265
260
255
250
245
240
235
230
1990
CFC-11
1995 2000
3.0
2.5
1990
220
200
180
160
140
120
100
80
1990
140
120
100
80
60
40
20
0
1990
5.0
4.5
4.0
3.5
CH3CCl3
1995
Halon1211
2000
1995
HCFC-22
1995
2000
2000
2005
2005
2005
2005
550
540
530
520
510
500
490
2010
480
1990
110
105
100
95
90
2010
85
1990
3.5
3.0
2.5
2.0
CFC-12
1995
CCl4
1995
Halon1301
2000
2000
2005
2005
2010
1.5
1990
25
20
1995
HCFC-141b
2000
15
10
5
2010
0
1990 1995 2000
2005
2005
85
80
75
70
2010
65
1990
10.0
CFC-113
1995 2000 2005
9.0
8.0
7.0
CH3Br
2010
6.0
1990
0.6
0.5
0.4
0.3
0.2
0.1
2010
0.0
1990
25
20
1995
Halon2402
1995
HCFC-142b
2000
2000
15
10
5
2010
0
1990 1995 2000
12
2005
2005
HCFC-124
2005
2010
2010
2010
2010

• Freon-12, CFC-12, CF
2
Cl
2 blev erstattet
• Hvad kan man gøre for ikke at få Cl i stratosfæren?
• Nedsætte levetiden
• HCFC-22, CHFCl
2 og andre
• Fjerne chlor
• HFC-134a, CF
3
CFH
2 og andre
13

Hvad bestemmer levetiden af halogenerede forbindelser i atmosfæren?
• De fotolyseres ikke i den nederste del af atmosfæren
( l max typisk ≤ 200 nm)
• Regner ikke ud da de har lav opløselighed i vand
• De fjernes ved reaktion med OH hvis de har et H atom,
• som kan abstraheres:
CF
3
• +
H
2
O CF
3
H + •OH
•Indsætte H atomer
•Indsætte æter-bindinger: –O-
•Indsætte dobbeltbindinger 14

• CFC - chlorofluorocarbons
• HCFC – hydrochlorofluorocarbons (↓O
3
)
• HFC – hydrofluorocarbons (↓O
3
)
• HFE – hydrofluoroethers (↓O
3
)
• HFO – hydrofluoroolefin – ( pas på navnet ) ( ↓GWP)
• ?
• ?
15

Environmental effects of CFCs and alternatives formel
CFC-12
HCFC-22
HFC-134a
HFC-143a
HFE-143
CF
2
Cl
2
CHClF
2
CF
3
CFH
2
CF
3
CH
3
CF
3
OCH
3
HFO-1234yf CF
3
CF=CH
2 levetid
100 år
12 år
14 år
52 år
4.3 år
11 dage
ODP
0
0
0
1
0.05
0
GWP
10890
1810
1430
4470
756
4
POCP
~0
~0
7
~0
~0
0.1
TOXICS
None
None
15% TFA
None
None
100% TFA
Nu er det klima som styrer udviklingen
– GWP<150
16

17
IPCC/TEAP, 2005

1.
En gas der absorberer infrarød stråling
2. En gas der lever længe nok i atmosfæren
3.
Der skal være en vis mængde for at der er en effekt:
• CO
2
, CH
4
, halogenerede gasser (freoner), N
2
O, O
3
, H
2
O ?
18

19
IPCC/TEAP, 2005

1.
En gas der absorberer infrarød stråling
2. En gas der lever længe nok i atmosfæren
3.
Der skal være en vis mængde for at der er en effekt:
• CO
2
, CH
4
, halogenerede gasser (freoner), N
2
O, O
3
, H
2
O ?
20

Environmental effects of CFCs and alternatives formel
CFC-12
HCFC-22
HFC-134a
HFC-143a
HFE-143
CF
2
Cl
2
CHClF
2
CF
3
CFH
2
CF
3
CH
3
CF
3
OCH
3
HFO-1234yf CF
3
CF=CH
2 levetid
100 år
12 år
14 år
52 år
4.3 år
11 dage
ODP
0
0
0
1
0.05
0
GWP
10890
1810
1430
4470
756
4
POCP TOXICS
~0
~0
7
~0
~0
0.1
None vs
15% TFA
Kyoto?
None
None
100% TFA
Der er to andre miljømæssige bekymringer man skal være opmærksom på:
1.
Troposfæriske ozon
2.
Skadelige nedbrydningsprodukter – trifluoreddikesyre - TFA
21

Environmental effects of CFCs and alternatives formel
CFC-12
HCFC-22
HFC-134a
HFC-143a
HFE-143
CF
2
Cl
2
CHClF
2
CF
3
CFH
2
CF
3
CH
3
CF
3
OCH
3
HFO-1234yf CF
3
CF=CH
2 levetid
100 år
12 år
14 år
52 år
4.3 år
11 dage
ODP
0
0
0
1
0.05
0
GWP
10890
1810
1430
4470
756
4
POCP
~0
~0
7
~0
~0
0.1
TOXICS
None
None
15% TFA
None
None
100% TFA
22

23

•Den atmosfæriske nedbrydning af HFO-1234yf, CF
3 kortlagt
CF=CH
2 er
•Ingen virkning på det stratosfæriske ozonlag.
•Levetiden i atmosfæren er 11 dage som medfører at GWP er 4.
•Photochemical Ozone Creation Potential (POCP) for HFO-
1234yf er 7. Betyder at CF luftforurening.
3
CF=CH
2 bidrager ikke til fotokemisk
•Atmosfærisk nedbrydning af HFO-1234yf, CF
3
CF
3
C(O)F som hydrolyserer til CF
CF=CH
2 danner,
3
C(O)OH (trifluoreddikesyre,
TFA) i et udbytte på 100%. Der forventes ikke signifikant miljømæssig effekt fra TFA fra det forventede forbrug af
CF
3
CF=CH
2
.
24

• Atm. levetider og GWP for halogenerede forbindelser dækker et stort område
• Det er muligt at lave nye halogenerede forbindelser med langt mindre klimaeffekt end tidligere anvendte forbindelser.
• Bidraget til den menneskabte ændring af strålingsbalancen fra halogenerede forbindelser kan bringes tæt på nul.
• HFO-1234yf og andre vil blive brugt i fremtiden
• Udgifterne vil være en lille del af de samlede udgifter
• Der bliver brug for mange alternativer mange anvendelser
• Vi er med til at udvikle nye stoffer og vi bestemmer der nedbrydning i atmosfæren og dermed deres miljøpåvirkning
25

Mads
Meshkat
Tim Ole John
Mike
26

27

5.
6.
7.
1. Temperature control: a. Insulation b. Heat exchanger c. Fan
2. Lamps
3. Quartz tube
4. White optics: a. Large mirror b. Smaller mirror
5. Bruker IFS 66v/s
6. Transfer optics
7. Detector (InSb/MCT)
4a.
1a.
UV-A UV-C
3.
1b.
2.
1c.
4b.
Sun lamps 28
Slide by Matthew S. Johnson

Other ways of lowering the atmospheric lifetime
Insert a double bond
Compound
CF
3
CF=CF
2
Mads
CF
3
CH=CFH
Roar
CF
3
CF=CH
2
Meshkat
CF
3
CH=CH
2
Anne
CH
3
CH=CH
2 everybody k
Cl
(2.7 ± 0.3) x 10 -
11 k
OH
(2.4 ± 0.2) x 10 -
12 k
O3
< 3 x 10 -21
(4.7 ± 0.2) x 10 -
11
(9.3
± 0.5) x 10 -13 (2.8 ± ) x 10 -21
(6.9 ± ) x 10 -11 (1.06 ± ) x 10 -12 (6.6 ± ) x 10 -20
τ
18 d
14 d
11 d
(9.0
± 1.1) x 10 -11 (1.4 ± 0.3) x 10 -
12
2.4 x 10 -10 2.6 x 10 -11
(3.5
± 0.3) x 10 -19 8.5 d
1.0 x 10 -17 10 h
GWP
6
6
4 n.d.
n.d.?
29

30
IPCC/TEAP, 2005

31
IPCC/TEAP, 2005

32
IPCC/TEAP, 2005

33
IPCC/TEAP, 2005

34
IPCC/TEAP, 2005

35
IPCC 2001

1. The intensity and position of infrared absorption
2. The atmospheric lifetime (near term)
3. The amount released
EU law will be: GWP
100y
< 150
What can we do something about for the halogenated compounds?
36

Replacement of Ozone-Depleting Compounds with hydrofluorocarbons (HFCs) – no Cl!
CFC-11
CFC-12
CFC-113
CCl
3
F
CCl
2
F
2
CCl
2
FCClF
2
CFC-115 CF
3
CF
2
Cl halon 1301 CF
3
Br halon 1211 CBrClF
2
Also GHG
HFC-23 CF
3
H
HFC-125 CF
3
CF
2
H
HFC-134a CF
3
Slide by John Owens (3M)
CF
2
H
HFC-227ea CF
3
CFHCF
3
HFC-236fa CF
3
CH
2
CF
3
HFC-365mfc CF
3
CH
2
CF
2
CH
3

Compound
CF
4
(PFC-14)
CHF
3
(HFC-23)
CH
2
F
2
(HFC-32)
CH
3
F (HFC-41)
Atm.
GWP (IPCC2007)
Lifetime (yrs) (100 yr)
50000
270
7,390
14,800
4.9
3.7
675
140
CF
3
CF
3
(PFC-116)
CF
3
CHF
2
(HFC-125)
CF
3
CH
2
F (HFC-134a)
CF
3
CH
3
(HFC-143a)
CHF
2
CH
3
(HFC-152a)
CH
2
FCH
3
(HFC-161)
CF
3
CHFCF
3
(HFC-227ea)
CH
2
FCF
2
CHF
2
(HFC-245ca)
10000
29
14
52
1.4
0.25
34.2
6.6
CF
3
CH
2
CF
2
CH
3
(HFC-365mfc) 8.6
CF
3
CHFCHFC
2
F
5
(HFC-43-10mee) 15.9
12,200
3,500
1,430
4,470
124
10
3,220
720
794
38
1,640 Slide by John Owens (3M)

Atmospheric degradation of HFC-134a
CF3CFH2
OH.
H2O
CF3CFH.
CF3CFHOOH
HO2
OH
O2
NO2
CF3CFHO2
Decomp/h

CF3CFHOONO2 h

FO x
FCO x
NO h

FNO
O
3 h h

 aq
NO NO2
O2
CF3CFHO
HO2
HCOF h

CF3
O2
CF3COF aq h

CF3C(O)
CF3COOH
O2
CF3O2
CF3C(O)O2
NO
NO2
CF3C(O)O
NO
NO
CF3O
NO2
RH R
CF3C(O)O2NO2
FNO
2 CF3OH HF+C(O)F2 39

Potential replacements for CFCs and perfluorocarbons.
Perfluoropolyether (PFPE)
F
3
C
O
F F
O O
F F F F
CF
3
Hydrofluoropolyether (HFPE)
F
2
HC
O
F F
O O
F F F F
CHF
2
Hydrofluoroether (HFE)
F H
F O
F F F F
F F
F H
F
F F
F
3
C O
F F F F
Slide by John Owens (3M)
40

Effect of Ether Oxygen on Atmospheric Lifetime
Compound
CH
3
CF
3
(HFC-143a)
CH
3
OCF
3
(HFE-143a)
CF
3
CFHCF
3
(HFC-227ea)
CF
3
CFHOCF
3
(HFE-227ea)
CF
3
CH
2
CF
3
(HFC-236fa)
CF
3
CH
2
OCF
3
(HFE-236fa)
CF
3
CH
2
CHF
2
(HFC-245fa)
CF
3
CH
2
OCHF
2
(HFE-245fa2)
Atm.
GWP
Lifetime (yrs) (100 Yr ITH)
52
4.3
4,470
756
34.2
11
240
3.7
7.6
4.9
3,220
1,500
9,810
470
1,030
659
GWP still too high!
alkane ether
41
Slide by John Owens (3M)

R f
O R h n-C
4
F
9
- OCH
3 i-C
4
F
9
- OCH
3 n-C
4
F
9
- OC
2
H
5 i-C
4
F
9
- OC
2
H
5
C
4
F
9
-O-(CH
2
)
3
-O-C
4
F
9 k
OH

(GWP)
(cm 3 molecules -1 s -1 ) (years)
1.20 x 10 -14 4.7 (~404)
1.54 x 10
6.4 x 10
7.7 x 10
-14
-14
-14
1.44 x 10 -13
3.7 (~404)
0.9 (~
0.7 (~
57
57
0.4 (n.d.)
)
)
CF
3
CF
3
CF
O
F
F
F
CF
3
CF
CF
3
O
CH
2
CH
3
F
F
5.93 x 10 -14 1.0 ( 55 )
42
Slide partly by John Owens (3M)

3
2
T.J. Wallington 1 , M.D. Hurley 1 , M.P.S. Andersen 2 ,
M.S. Javadi 3 , O.J. Nielsen 3
3
1 Ford Motor Company, USA
2 University of California, Irvine, USA
University of Copenhagen, Denmark
43

• CFC-12 (CF
2
Cl
2
) replaced by HFC-134a
(CH
2
FCF
3
) in 90s.
• HFC-134a has GWP
100 of 1430
• Regulations developed by the European
Union require refrigerants with GWPs<150 for all new vehicles by 2017.
• HFO-1234yf (CF
3
CF=CH
2
) under consideration as replacement for R-134a.
44

Ford Smog Chamber
Experimental study of kinetics of reactions with
OH radicals, Cl atoms, O
3
.
Measurement of products of
OH radical and Cl atom initiated oxidation.
IR spectrum, radiative efficiency, and global warming potential.
Trifluoroacetic acid formation and impacts.
(delete)
45

Cl + CF
3
Cl + C
2
H
CF=CH
2
4
→ products (1)
→ products
(2)
Cl + C
2
H
2
→ products (3)
Linear least squares analysis gives k
1
/k
2
= 0.76
± 0.04 and k
1
/k
3
= 1.38
±0.06.
Using k
2
= (9.29
0.34) x 10 -11
± 0.51) x 10 -11 and k
3
= (5.07 ± gives k
1
= (7.06 ± 0.54) x 10 -11 and (7.00 ± 0.56) x 10 -11 cm 3 molecule -1 s -1 .
Hence k
1
= (7.03
±0.59) x 10 -11 k k (Cl + CF
3 k
(Cl + CH
(Cl + CF
3
3
CH=CH
CH=CH
2
CF=CF
2
2
) = 2.4 x 10 -10
) = (9.07 ± 1.08) x 10
) = (2.7 ± 0.3) x 10 -11
-11
Reaction with Cl atoms not major atmospheric loss of CF
3
CF=CH
2
.
46

47

Pseudo first order decays of
CF
3
CF=CH
2 experiments.
observed in all
Second order plot gives k =(2.77 ± 0.21) x 10 -21 cm 3 molecule -1 s -1 .
Combining with [O
3
] = 35 ppb gives lifetime of 13 years with respect to reaction with O
3
.
48

IR spectrum, radiative efficiency, and GWP
Integrated IR absorption cross section
(800 –2000 cm -1 ) =
(1.63 ± 0.09) x 10 -16 cm molecule -1
Instantaneous cloudy-sky radiative efficiency estimated using method of
Pinnock et al. to be 0.22 W m -2 ppb -1 .
Global warming potential (100 year time horizon) = 4.
49

OH radical initiated oxidation gives
CF
3
C(O)F in a molar yield of 91
± 6%.
Atmospheric fate of CF
3
C(O)F is hydrolysis to give CF
3
C(O)OH
(trifluoroacetic acid).
Oxidation of CF
3
CF=CH
2 gives trifluoroacetic acid in yield close to 100%.
50

Impact on climate change
Degradation is initiated by reaction with OH radicals (Orkin et al., 1997; Nielsen et al. 2007, Papadimitriou et al.2008)
We estimate an atmospheric lifetime of approximately 11 days and a GWP of approximately 4.
Papadimitriou et al. (2008) estimated an atmospheric lifetime of approximately 12 days and a GWP of < 4.4.
Atmospheric lifetime and GWP of HFO-1234yf are well established. No significant contribution to radiative forcing of climate change.
References
O.J. Nielsen, M.S. Javadi, M.P. Sulbaek Andersen, M.D. Hurley, T.J. Wallington, R. Singh, Chem. Phys. Lett., 439, 18 (2007); V. L. Orkin, R.
E. Huie and M. J. Kurylo, J. Phys. Chem. A, 1997, 101, 9118 –9124; V.C. Papadimitriou, R.K. Talukdar, R.W. Portman, A.R. Ravishankara,
J.B. Burkholder, Phys. Chem. Chem. Phys., 10, 808 (2008).
51

Impact on Stratospheric Ozone
HFO-1234yf does not contain chlorine or bromine and hence will not contribute to the well established Cl- and
Br-based catalytic ozone destruction cycles.
Papadimitriou et al. (2008) concluded that ozone-depletion potential for HFO1234yf is “nearly zero”.
References
V.C. Papadimitriou, R.K. Talukdar, R.W. Portman, A.R. Ravishankara, J.B. Burkholder, Phys. Chem. Chem. Phys., 10, 808
(2008).
52

Impact on Tropospheric Ozone
CF
3
CF=CH
2 reacts with OH radicals with rate constant of approximately
1.1 x 10 -12 cm 3 molecule -1 s -1 at 298 K. The peroxy radicals formed will oxidize NO
2 which will photolyze and contribute to ozone formation. Using method of Jenkin (1998) the photochemical ozone creation potential
(POCP) for CF
CF
3
CF=CH
2
3
CF=CH
2 can be estimated to be 7. The POCP for lies between those for methane and ethane. CF
3
CF=CH not expected to make a significant contribution to tropospheric ozone
2 formation.
is
Derwent, R.G., M.E. Jenkin, S.M. Saunders, and M.J. Pilling, Atmos. Environ ., 32, 2429
–2441, 1998. Hayman, G.D., and R.G. Derwent, Environ. Sci. Technol.
, 31, 327-336, 1997; Jenkin, M.E., Photochemical Ozone and PAN Creation
Potentials: Rationalisation and Methods of Estimation , AEA Technology plc, Report AEAT-4182/ 20150/003, 1998 53

Impact of trifluoroacetic acid
Atmospheric oxidation of CF
3
CF=CH
2 gives CF
3
C(O)OH (TFA).
Tang et al. conclude “no significant risk is anticipated from TFA produced by atmospheric degradation of the present and future production of HFCs and HCFCs as there is a 1000fold difference between the PNEC (Predicted No Effect Concentration) and the PEC
(Predicted Environmental Concentration)”. Based on risk assessment of CF
3
C(O)OH by
Tang et al. (1988) and analysis by WMO (2006), Hurley et al. conclude that “the products of the atmospheric oxidation of CF
3
CF=CH
2 have negligible environmental impact”.
It has been shown that trifluoroacetic acid is ubiquitous in precipitation and ocean water even in remote areas (Berg et al., 2000; Frank et al., 2002; Scott et al, 2005, 2006; Von
Sydow et al. 2000). Contribution of CF
3
CF=CH
2 expected to be negligible.
References
Berg. M., S.R. Müller, J. Mühlemann, A. Wiedmer, and R.P. Scharzenbach, Environ. Sci. Technol.
34, 2675-2683, 2000;
M.D. Hurley, T.J. Wallington, M.S. Javadi, O.J. Nielsen, Chem. Phys. Lett., 450, 263 (2008); X. Tang, S. Madronich, T.
J. Wallington, D. Calamari, , J. Photochem. Photobiol., B 46, 83, (1998); WMO, Scientific Assessment of Stratospheric
Ozone: 2006, World Meteorological Organization, Geneva (2007); Frank, H., E.H. Christoph, O. Holm-Hansen, J.L.
Bullister, Environ. Sci. Technol.
36, 12-15, 2002. Scott, B.F., C. Spencer, S.A. Mabury, and D.C.G. Muir, Environ. Sci.
Technol ., 40, 7167-7174, 2006; Scott, B.F., R.W. Macdonald, K. Kannan, A. Fisk, A. Witter, N, Yamashita, L. Durham,
C. Spencer, D.C.G. Muir, Environ. Sci. Technol.
, 39, 6555-6560, 2005; Von Sydow, L.M., A.B. Grimvall, H.B. Borén, K.
Laniewski, and A.T. Nielsen, Environ. Sci. Technol.
, 34, 3115-3118, 2000.
54

Table 1-6. Direct Global Warming Potentials (mass basis) for gases that have adequately characterized lifetimes.
Industrial designation or common name Chemical formula Lifetim e
(years)

Carbon dioxide
Methane
Nitrous oxide
Chlorofluorocarbons
CO
2
CH
4
N
2
O
12.0
114
CFC-11
CFC-12
CFC-13
CFC-113
CFC-114
CFC-115
CCl
CCl
CClF
CCl
3
2
2
CClF
CClF
F
F
3
FCClF
2
2
2
CClF
CF
3
2
2
45
100
640
85
300
Hydrochlorofluorocarbons
HCFC-21 CHCl
2
F
1700
1.7
HCFC-22
HCFC-123
HCFC-124
HCFC-141b
CHClF
CHCl
CHClFCF
CH
3
2
2
CF
CCl
2
3
3
F
12.0
1.3
5.8
9.3
HCFC-142b
HCFC-225ca
HCFC-225cb
Hydrofluorocarbons
HFC-23
HFC-32
HFC-41
HFC-125
CH
CHCl
CHClFCF
CHF
CH
CH
3
2
3
CHF
CClF
3
F
F
2
2
2
CF
CF
2
2
3
2
CF
3
CClF
2
17.9
1.9
5.8
270
4.9
2.4
29
ODP
0.043
0.017
0.017
<1.5x10
-5
HFC-134
HFC-134a
HFC-143
HFC-143a
HFC-152
HFC-152a
HFC-227ea
HFC-236cb
CHF
2
CHF
2
CH
2
FCF
3
CH
2
FCHF
2
CH
3
CF
3
CH
2
FCH
2
F
CH
3
CHF
2
CF
3
CHFCF
3
CH
2
FCF
2
CF
3
9.6
14.0
3.5
52
0.60
1.4
34.2
13.6
0.85
0.40
.0.034
0.012
0.026
0.086
1
0.82
0.90
0
HFC-236ea
HFC-236fa
HFC-245ca
HFC-245fa
HFC-365mfc
HFC-43-10mee
CHF
CF
CH
3
2
2
CHFCF
CH
2
FCF
CF
2
3
CHF
CHF
2
CH
2
CF
3
3
2
CH
3
CF
2
CH
2
CF
3
10.7
240
6.2
7.6
8.6
CF
3
CHFCHFCF
2
CF
3
15.9
Fully fluorinated
Sulfur hexafluoride
Trifluoromethylsulfurpentafluoride
FC-14
FC-116
FC-218
FC-31-10
FC-318
FC-41-12
FC-51-14
Halogenated alcohols ethers
SF
SF
CF
C
C
C
2
3
4
F
F
F c-C
C
C
5
6
6
5
4
F
F
6
8
10
4
CF
F
12
14
8
3
3200
800
50000
10000
2600
2600
3200
4100
3200
2270
120
586
12240
543
90
3450
1090
1320
347
4400
52
122
3660
1320
1350
9650
682
1020
782
1610
14190
6030
9880
7250
148
1780
76
599
713
GWP
(100 years)
1
23.
d
300
4680
10720
22450
17500
5820
12010
8690
8710
10090
9010
9140
55

Hvorfor interesserer man sig for F-forbindelser?
CH
4
9%
2005 Globale GHG Emissioner
% Bidrag på CO
2 basis
N
2
O
6%
FCs
2%
Ændring siden 1990
CO
2
83%
CO
2
CH
4
+1.6%
-18%
N
2
O -20%
FCs +19%
HFCs +154%
PFCs -45%
SF
6
-62%
56

Halogenerede forbindelser i atmosfæren
57
IPCC 2007

HFC134a at Mace Head
BAU and reduced emissions
58
IPCC/TEAP, 2005

Forbindelse
CF
4
(PFC-14)
CHF
3
(HFC-23)
CH
2
F
2
(HFC-32)
CH
3
F (HFC-41)
CF
3
CF
3
(PFC-116)
CF
3
CHF
2
(HFC-125)
CF
3
CH
2
F (HFC-134a)
CF
3
CH
3
(HFC-143a)
CHF
2
CH
3
(HFC-152a)
CH
2
FCH
3
(HFC-161)
Atm. Levetid (år) GWP
100
50000 7,390
270 14,800
4.9
3.7
675
140
10000
29
14
52
1.4
0.25
12,200
3,500
1,430
4,470
124
10
GWP<150
59

Hvad betyder en æter-gruppe for levetiden?
Forbindelse
CH
3
CF
3
(HFC-143a)
CH
3
OCF
3
(HFE-143a)
Atm. Levetid (år)
GWP
100
52 4,470
4.3
756
CF
3
CFHCF
3
(HFC-227ea)
CF
3
CFHOCF
3
34.2
(HFE-227ea) 11
CF
3
CH
2
CF
3
(HFC-236fa)
CF
3
CH
2
OCF
3
(HFE-236fa)
240
3.7
3220
1500
9810
470
CF
3
CH
2
CHF
2
(HFC-245fa) 7.6
1030
CF
3
CH
2
OCHF
2
(HFE-245fa) 4.9
659
60

•
R f
O R h
• n-C
4
F
9
- OCH
3
• i-C
4
F
9
- OCH
3
• n-C
4
F
9
- OC
2
H
5
• i-C
4
F
9
- OC
2
H
5
Atm. Levetid (år)
• C
4
F
9
-O-(CH
2
)
3
-O-C
4
F
9
0.4
•
•
CF
3
CF
3
CF
O
F
F
F
CF
3
CF
CF
3
O
CH
2
CH
3
F
F
4.7
3.7
0.9
0.7
1.0
GWP
404
404
57
57 ikke bestemt
55
61
100

•
• CF
3
CX=CYZ Atm. Levetid ( dage ) GWP
100
•
CF
3
CF=CF
2
(interessant) 18
•
CF
3
CH=CFH 14
•
CF
3
CF=CH
2
(HFO1234yf) 11
•
CF
3
CH=CH
2
8.5
6
6
4 ikke bestemt
62

The Montreal Protocol have reduced net GWP-weighted emissions from
ODSs in 2010 by 5-6 times the reduction target of the first commitment period (2008-2012) of the Kyoto Protocol.
The Montreal Protocol will have reduced net GWP-weighted emissions from ODSs in 2010 by about 11 Gt CO
2
-eq yr -1 .
• Greenhouse gases: CO
2
, CH
4
, N
2
O, HFCs, PFCs, SF
6
63
G. Velders et al.
, PNAS, 2007

2004-2007: 30% increase in global CO
2 emissions.
-weighted HCFC
2007: HCFC emissions were 2.6% of fossil-fuel and cement related
CO
2 emissions (30 Gt/yr)
64
Montzka et al. GRL 2008

3
• 1970-71 P. Crutzen and H. Johnston: ”katalyse” ?
• X + O
3
→ XO + O
• XO + O → X + O
2
2
• --------------------------
• O + O
3
→ 2O
2
X = H, OH, NO, NO
2
, F, Cl, Br, (og andet ?)
65

Ole John Nielsen
• 1954 Født, gift og har 2 børn på 20 og 22 år
• 1973 Begyndte at læse kemi og fysik på KU
• 1974 Vigtigt atmosfærekemisk år
• 1978 Færdig som cand scient og læste videre (PhD) på RISØ
• 1978-95 på 96-99 på Forskningscenter RISØ
• 1995-96 Ford’s Forskningscenter i Aachen, Tyskland
• 1999-? Professor på Kemisk Institut på KU (det bedste)
Mit speciale er nedbrydning af stoffer i atmosfæren (hvor hurtigt og hvordan og hvorfor)
IPCC – Intergovernmental Panel of Climate Change
Nobels Fredspris 2007
66