A three-dimensional model of the atmospheric chemistry of E and Z-CF₃CH=CHCl (HCFO-1233(zd) (E/Z))

Using a 3-dimensional global atmospheric chemistry and transport model we investigated the atmospheric degradation of HCFO-1233zd(E), E-CF₃CH=CHCl, a commercially important, new hydrofluorocarbon replacement compound. Atmospheric degradation of E-CF₃CH=CHCl is initiated by reaction with OH radicals, which leads to several chemical oxidation products. Dissemination of these oxidation products to the environment is of concern due to the possible formation of trifluoroacetic acid (TFA) as a degradation product. The model indicates that the average global yield of TFA from atmospheric processing of E-CF₃CH=CHCl is approximately 2%. The annually averaged atmospheric lifetime of E-CF₃CH=CHCl was found to be approximately 36 days (12 days for Z-CF₃CH=CHCl). As E-CF₃CH=CHCl is short lived, by far the majority of its Cl atoms will be released and deposited in the lower atmosphere, and the impact on stratospheric ozone is insignificant. An Ozone Depletion Potential of 0.00030 was determined. The Photochemical Ozone Creation Potential was evaluated and a value of 3.6 determined. Finally, we derive a Global Warming Potential for E-CF₃CH=CHCl for a 100 year time horizon of <5. For comparison, data for the stereoismeric analogue, Z-CF₃CH=CHCl, was also obtained from the model.