Atmospheric chemistry of HFC-134a: Kinetics of the decomposition of the alkoxy radical CF3CFHO

Møgelberg, Trine E.; Sehested, Jens; Wallington, Timothy J.; Nielsen, Ole John

doi:10.1002/(sici)1097-4601(1997)29:3<209::aid-kin8>3.0.co;2-y

Cited by 18 publications

(14 citation statements)

References 30 publications

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“…The reaction of HFO-1234yf with OH (Reaction 1) is the rate-limiting step in its atmospheric degradation in both low and high NO x (= NO + NO 2 ) conditions. Subsequent reactions (with O 2 ) leading to the formation of CF 3 C(O)F occur instantaneously compared to the initial addition of OH to HFO-1234yf [Maricq et al, 1992;Møgelberg et al, 1997;Nielsen et al, 2007;Hurley et al, 2008;Papadimitriou et al, 2011;Kaiser and Wallington, 2012]. HFO-1234yf is also degraded in reactions with ozone (O 3 ) and chlorine (Cl) which are not considered in this work.…”

Section: Gas and Aqueous Phase Chemistrymentioning

confidence: 99%

Deposition and rainwater concentrations of trifluoroacetic acid in the United States from the use of HFO‐1234yf

et al. 2014

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Currently, HFC‐134a (1,1,1,2‐tetrafluoroethane) is the most common refrigerant in automobile air conditioners. This high global warming potential substance (100 year GWP of 1370) will likely be phased out and replaced with HFO‐1234yf (2,3,3,3‐tetrafluoropropene) that has a 100 year GWP of 4. HFO‐1234yf will be oxidized to produce trifluoroacetic acid (TFA) in clouds. TFA, a mildly toxic substance with detrimental effects on some aquatic organisms at high concentrations (≥100μgL−1), would be transported by rain to the surface and enter bodies of water. We investigated the dry and wet deposition of TFA from HFO‐1234yf over the contiguous USA using the Advanced Research Weather Research and Forecasting model (ARW) with interactive chemical, aerosol, and cloud processes (WRF/Chem) model. Special focus was placed on emissions from three continental USA regions with different meteorological characteristics. WRF/Chem simulated meteorology, cloud processes, gas and aqueous phase chemistry, and dry and wet deposition between May and September 2006. The model reproduced well the multimonth total sulfate wet deposition (4% bias) and its spatial variability (r = 0.86) observed by the National Atmospheric Deposition Program. HFO‐1234yf emissions were obtained by assuming the number of automobile air conditioners to remain unchanged, and substituting HFO‐1234yf, mole‐per‐mole for HFC‐134a. Our estimates of current HFC‐134a emissions were in agreement with field data. Average TFA rainwater concentration was 0.89μgL−1, with peak values of 7.8μgL−1, for the May–September 2006 period over the contiguous USA. TFA rainwater concentrations over the dry western USA were often significantly higher, but wet‐deposited TFA amounts remained relatively low at such locations.

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Section: Gas and Aqueous Phase Chemistrymentioning

confidence: 99%

Deposition and rainwater concentrations of trifluoroacetic acid in the United States from the use of HFO‐1234yf

et al. 2014

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“…Long chain perfluorinated oxy radicals yield COF 2 and a perfluorinated alkyl radical with one carbon less and the reaction sequence is repeated until the CF 3 radical is formed in the final step [13][14][15][16]:…”

Section: General Mechanisms Of Atmospheric Degradation Of Cfc Replacementioning

confidence: 99%

Fluorocarbon oxy and peroxy radicals

Ahsen¹,

Willner²,

Argüello

2004

Journal of Fluorine Chemistry

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“…The value of k4 measured here is entirely consistent with the high-pressure limiting rate constants for reactions between other halogenated peroxy radicals and NO,, which lie in the range (4.5-8.9) x lo-', cm3 molecule-' s-1. 2,9,15 Kinetics of the Reactions of F and CI Atoms with CFJCF~CFH~. Before the products arising from the C1 atom initiated oxidation of CF3CF$XH2 were investigated, a series of relative rate experiments were performed using the FTIR setup to investigate the kinetics of the reactions of F and C1 atoms with CF~CF~CFHZ.…”

Section: Kinetics Of Thementioning

confidence: 99%

Atmospheric Chemistry of HFC-236cb: Spectrokinetic Investigation of the CF3CF2CFHO2 Radical, Its Reaction with NO and NO2, and the Fate of the CF3CF2CFHO Radical

Møgelberg¹,

Feilberg²,

Giessing³

et al. 1995

J. Phys. Chem.

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A pulse radiolysis technique was used to study the UV absorption spectrum of CF3CF2CFH02 radicals (at 250 nm CT = (175 f 36) x lo-,' cm2 molecule-'). The observed bimolecular rate constant for the self reaction of CF3CF2CFH02 radicals was k130b\ = (5.2 f 1.4) x lo-', cm3 molecule-' s-I. Rate constants for reactions of CF3CF2CFH02 radicals with NO and NO, were k3 > 8 x lo-', and k4 = (6.3 k 0.7) x lo-'? cm3 molecule-' s-l, respectively. Using a FTIR spectrometerkmog chamber technique it was shown that, under atmospheric conditions, reaction with 0 2 and decomposition via C-C bond scission are competing loss mechanisms for CF3CFKFHO radicals. A lower limit of lo5 s-' was deduced for the rate of decomposition of CF3CF2CFHO radicals via C-C bond scission at 296 K in 1 bar of SF6 diluent. It is estimated that in the atmosphere approximately 98% of CF3CF2CFHO radicals will undergo decomposition into C2Fj radicals and HC(0)F and 2% will react with 0 2 to give C,F5C(O)F. As part of this work relative rate methods were used to measure rate constants of (1.3 f 0.3) x lo-'' and (1.5 i 0.3) x cm3 molecule-' s-' for the reactions of C F~C F~C F H Z with F and C1 atoms, respectively.

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Atmospheric chemistry of HFC-134a: Kinetics of the decomposition of the alkoxy radical CF3CFHO

Cited by 18 publications

References 30 publications

Deposition and rainwater concentrations of trifluoroacetic acid in the United States from the use of HFO‐1234yf

Deposition and rainwater concentrations of trifluoroacetic acid in the United States from the use of HFO‐1234yf

Fluorocarbon oxy and peroxy radicals

Atmospheric Chemistry of HFC-236cb: Spectrokinetic Investigation of the CF3CF2CFHO2 Radical, Its Reaction with NO and NO2, and the Fate of the CF3CF2CFHO Radical

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