CFCs replacements: Reactivity and atmospheric lifetimes of a series of Hydrofluoroolefins towards OH radicals and Cl atoms

Degradation mechanism of 2-fluoropropene by Cl atoms: experimental and theoretical products distribution studies

“…Using the experimental kinetic results obtained in our laboratory, we reported previously an atmospheric lifetime of 7 days for the 2-fluoropropene degradation by Cl atoms. 53,54 Concurrently, Gour et al 14 reported τ Cl = 10.8 days from their theoretical work.…”

“…It is well documented that in general OH radical is considered the most important tropospheric oxidant during daytime, with atmospheric lifetimes (in days) of τ OH = 0.8, 53 and τ OH = 0.3. 54 Although, other oxidants, including O 3 , NO 3 radicals, and Cl atoms, can contribute also to the degradation of alkenes depending on the atmospheric conditions and the structure of the alkene. 52,55 In particular, oxidation reactions by Cl atoms are important sinks of VOCs in coastal areas and in the marine boundary layer, where the Cl atoms concentration peaks at dawn, Cl degradation could be relevant loss process, in order of days.…”

“…With the atmospheric lifetimes reported of 2FP of few days is expected, to react close to its emission sources and have an impact at the local level. For this reason Rivela et al , 54 estimated POCPs using the modeling method reported by Jenkin et al 58 This method estimates the photochemical ozone creation potential of VOCs relative to that of ethane assigned the value 100. The estimated POCP value for 2-FP was 13, where in comparison with the reference ethane, 2FP has a small contribution to the tropospheric ozone formation.…”

FTIR product study of the Cl-initiated oxidation products of CFC replacements: (E/Z)-1,2,3,3,3-pentafluoropropene and hexafluoroisobutylene

“… 10,11,31 It is also known that ozonolysis reactions generally represent a minor or insignificant atmospheric loss for halo-olefins. 32 The atmospheric lifetimes of both compounds were calculated in previous studies, and the values obtained were τ OH = 4 and τ Cl = 51 days for PFP and τ OH = 18 and τ Cl = 66 days for HFIB by Tovar et al 28 Moreover, the values obtained by Rivela et al 29 were τ OH = 2 and τ Cl = 18 days for PFP, and τ OH = 9 and τ Cl = 33 days for HFIB. Therefore, it is expected that HFOs will react close to their emission sources and have a local impact due to their short lifetimes.…”

Fluorocarbon Refrigerants and their Syntheses: Past to Present

“…A recent report by Blanco et al estimates the tropospheric lifetimes of 1,2,3,3,3-pentafluoropropene (HFO-1225ye) to be 2 or 18 days with either [OH • ] or [Cl • ] (respectively) as the oxidant. 745 Another report by Burkholder et al examined the atmospheric degradation pathways for 2,3,3,3-tetrafluoropropene (HFO-1234yf) and 1225ye by [Cl • ], and O 2 , demonstrating the formation of trifluoroacetyl fluoride, formyl chloride, formyl fluoride, and formaldehyde as downstream products. 746 Specifically, 1234yf was designed as a replacement for 134a, approximating the latter in thermophysical properties.…”