Atmospheric degradation and global warming potentials of three perfluoroalkenes

• Published in: Atmospheric environment (1994) Vol. 35; no. 24; pp. 4113 - 4123
• Main Authors: Acerboni, G., Beukes, J.A., Jensen, N.R., Hjorth, J., Myhre, G., Nielsen, C.J., Sundet, J.K.
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01.08.2001; Elsevier Science
• Subjects: Applied sciences; Atmospheric lifetimes; Atmospheric pollution; Chemical composition and interactions. Ionic interactions and processes; Earth, ocean, space; Exact sciences and technology; External geophysics; Global modelling; Infrared absorption cross sections; Meteorology; OH radical; Perfluoroalkenes; Pollutants physicochemistry study: properties, effects, reactions, transport and distribution; Pollution; Radiative forcing; Perfluoroalkenes; Atmospheric lifetimes; Global modelling; Radiative forcing; OH radical; Infrared absorption cross sections; Organic perhalocompound; Chemical degradation; Fluorocarbon; Lifetime; Atmospheric chemistry; Radiative properties; Ethylene(tetrafluoro); Air pollution; Radiative transfer; Fluorine Organic compounds; Kinetics; Forcing; Rate constant; Degradation product; Molecule radical reaction; Gaseous phase reaction
• ISSN: 1352-2310; 1873-2844
• DOI: 10.1016/S1352-2310(01)00209-6

The vapour phase reactions of perfluoropropene, CF 3CFCF 2, and perfluorobuta-1,3-diene, CF 2CFCFCF 2, with OH, NO 3 and O 3 were studied at 298±4 K and 740±5 Torr using long-path FT-IR detection. The reactions with ozone are very slow, k CF 3CFCF 2+O 3 =(6.2±1.5)×10 −22 and k CF 2CFCFCF 2+O 3 =(6.5±0.2)×10 −21 cm 3 molecules −1 s −1, and upper limits of 3×10 −15 cm 3 molecules −1 s −1 are reported for the NO 3 reaction rate coefficients. The OH reaction rate coefficients were determined as k CF 3CFCF 2+OH =(2.6±0.7)×10 −12 and k CF 2CFCFCF 2+OH =(1.1±0.3)×10 −11 cm 3 molecules −1 s −1; perfluoropropene gave a nearly quantitative yield of CF 3CFO and CF 2O as organic products, while perfluorobuta-1,3-diene gave from 130% to 170% of CF 2O. A chemistry transport model was applied to calculate the atmospheric distributions and lifetimes of the perfluoroalkenes; the global and yearly averaged lifetimes were calculated as 1.9 day for C 2F 4 and C 4F 6 and 6 days for C 3F 6. Quantitative infrared cross-sections of perfluoroethene, perfluoropropene, and perfluorobuta-1,3-diene have been obtained at 298 K in the region 100–2600 cm −1. Radiative forcing calculations have been performed for these gases assuming either constant vertical profiles or the distribution derived from the chemistry transport model. The results show that the Global Warming Potentials are totally negligible for these compounds.