On the Chemical Pathways Influencing the Effective Global Warming Potential of Commercial Hydrofluoroolefin Gases

Abstract

The enforcement of a global hydrofluorocarbon (HFC) refrigerant phase down led to the introduction of hydrofluoroolefins (HFOs) as a low Global Warming Potential (GWP) substitute, given their low atmospheric lifetime. However, to this date it is not fully clear the long‐term atmospheric fate of HFOs primary degradation products: trifluoro acetaldehyde (TFE), trifluoro acetyl fluoride (TFF), and trifluoroacetic acid (TFA). It particularly concerns the possibility of forming HFC‐23, a potent global warming agent. Although the atmospheric reaction networks of TFE, TFF, and TFA have a fair level of complexity, the relevant atmospheric chemical pathways are well characterized in the literature, enabling a comprehensive hazard assessment of HFC‐23 formation as a secondary HFO breakdown product in diverse scenarios. A lower bound of the HFOs effective GWP in a baseline scenario is found above regulatory thresholds. While further research is crucial to refine climate risk assessments, the existing evidence suggests a non‐negligible climate hazard associated with HFOs.

The global threat from the irreversible accumulation of trifluoroacetic acid (TFA)

“…Further, destructive techniques for concentrated TFA may lead to harmful byproducts. At high temperatures (> 170°C) and certain conditions, TFA can be converted to the potent greenhouse gas fluoroform (CF3H) 60 , which may be relevant in the context of heating or burning organic matter or RO brine concentrates containing TFA.…”