Atmospheric Lifetimes and Global Warming Potentials of CF₃CH₂CH₂OH and CF₃(CH₂)₂CH₂OH

Abstract

A comprehensive study of several atmospheric degradation routes for two hydrofluoroalcohols, CF(3)(CH(2))(x=1,2)CH(2)OH, is presented. The gas-phase kinetics of their reactions with hydroxyl radicals (OH) and chlorine (Cl) atoms are investigated by absolute and relative techniques, respectively. The room-temperature rate coefficients (±σ, in cm(3) molecule(-1) s(-1)) k(OH) and k(Cl), are respectively (9.7±1.1)×10(-13) and (1.60±0.45)×10(-11) for CF(3)CH(2)CH(2)OH, and (2.62±0.32)×10(-12) and (8.71±0.24)×10(-11) for CF(3)(CH(2))(2)CH(2)OH. Average lifetimes of CF(3)CH(2)CH(2)OH and CF(3)(CH(2))(2)CH(2)OH due to the OH and Cl reactions are estimated to be 12 and 4 days, and greater than 20 and 4 years, respectively. Also, the IR and UV absorption cross sections of CF(3)(CH(2))(x=1,2)CH(2)OH are determined in the spectral ranges of 500-4000 cm(-1) and 200-310 nm. Photolysis of CF(3)(CH(2))(x=1,2)CH(2)OH in the actinic region (λ≥290 nm) is negligible compared to their homogeneous removal. Additionally, computational IR spectra are consistent with the experimental ones, thus giving high confidence in the obtained results. The lifetimes of CF(3)(CH(2))(x=1,2)CH(2)OH and IR spectra reported herein allow the calculation of the direct global warming potential of these hydrofluoroalcohols. The contribution of CF(3)(CH(2))(x)CH(2)OH to radiative forcing of climate change will be negligible.

Kinetics of Reactions of CHF2CF2CH2OH with Cl Atoms and CHF2CF2CHO with OH Radicals and Atmospheric Degradation Pathways of CHF2CF2CH2OH: A Theoretical Investigation

“…However, in the coastal region where chlorine concentration increases, the atmospheric lifetime decreases to 0.41 years. Similar observations have been made for other HFA molecules like CF 3 CH 2 CH 2 OH and CF 3 (CH 2 ) 2 CH 2 OH by Jiménez et al . Nevertheless, the very low atmospheric lifetime of this HFA molecule compared to CFCs ascertains that the molecule is very short‐lived and hence expected to have very low contribution to Global Warming Potential (GWP).…”

Global warming potentials and radiative efficiencies of halocarbons and related compounds: A comprehensive review

“…[234] Previous experimental studies of 3,3,3-trifluoropropan-1-ol have reported values for RE in the range of 0.17-0.20 W m À2 ppb À1 (mean: 0.19 W m À2 ppb À1 ) [Jimenez et al, 2010;Sellevåg et al, 2007]. We have used absorption cross sections from Jimenez et al [2010], Sellevåg et al [2007] and Waterland et al [2005] and calculated the same RE of 0.02 W m À2 ppb À1 for all three spectra.…”

“…[234] Previous experimental studies of 3,3,3-trifluoropropan-1-ol have reported values for RE in the range of 0.17-0.20 W m À2 ppb À1 (mean: 0.19 W m À2 ppb À1 ) [Jimenez et al, 2010;Sellevåg et al, 2007]. We have used absorption cross sections from Jimenez et al [2010], Sellevåg et al [2007] and Waterland et al [2005] and calculated the same RE of 0.02 W m À2 ppb À1 for all three spectra. Our calculated instantaneous REs of 0.21 W m À2 ppb À1 and 0.17 W m À2 ppb À1 using spectra from Jimenez et al [2010] and Sellevåg et al [2007], respectively, compare well with the previously published REs (which did not account for stratospheric temperature adjustment and lifetime correction).…”

“…We have used absorption cross sections from Jimenez et al [2010], Sellevåg et al [2007] and Waterland et al [2005] and calculated the same RE of 0.02 W m À2 ppb À1 for all three spectra. Our calculated instantaneous REs of 0.21 W m À2 ppb À1 and 0.17 W m À2 ppb À1 using spectra from Jimenez et al [2010] and Sellevåg et al [2007], respectively, compare well with the previously published REs (which did not account for stratospheric temperature adjustment and lifetime correction). The lifetime of 12.0 days is taken from Jimenez et al [2010].…”

Rate Coefficient for the Reaction of Cl Atoms with cis-3-Hexene at 296 ± 2 K

“…In fact, GWPs for short-lived compounds have been reported recently. [36][37][38][39] The plot of the cross-sections (cm 2 molecule -1 cm -1 ) as a function of wavenumber (cm -1 ) of the cis-3-hexene is shown in Figure 6. .…”