Atmospheric chemistry of C4F9OC2H5 (HFE-7200), C4F9OCH3 (HFE-7100), C3F7OCH3 (HFE-7000) and C3F7CH2OH: temperature dependence of the kinetics of their reactions with OH radicals, atmospheric lifetimes and global warming potentials

The atmospheric chemistry of several gases used in industrial applications, C4F9OC2H5 (HFE-7200), C4F9OCH3 (HFE-7100), C3F7OCH3 (HFE-7000) and C3F7CH2OH, has been studied. The discharge flow technique coupled with mass-spectrometric detection has been used to study the kinetics of their reactions with OH radicals as a function of temperature. The infrared spectra of the compounds have also been measured. The following Arrhenius expressions for the reactions were determined (in units of cm(3) molecule(-1) s(-1)): k(OH + HFE-7200) = (6.9(-1.7)(+2.3)) x 10(-11) exp(-(2030 +/- 190)/T); k(OH + HFE-7100) = (2.8(-1.5)(+3.2)) x 10(-11) exp(-(2200 +/- 490)/T); k(OH + HFE-7000) = (2.0(-0.7)(+1.2)) x 10(-11) exp(-(2130 +/- 290)/T); and k(OH + C3F7CH2OH) = (1.4(-0.2)(+0.3)) x 10(-11) exp(-(1460 +/- 120)/T). From the infrared spectra, radiative forcing efficiencies were determined and compared with earlier estimates in the literature. These were combined with the kinetic data to estimate 100-year time horizon global warming potentials relative to CO2 of 69, 337, 499 and 36 for HFE-7200, HFE-7100, HFE-7000 and CF3CF2CF2CH2OH, respectively.