New NERC grant to study the breakdown of next-generation refrigerant gases in the atmosphere

School of Chemistry researchers Dr Kieran Stanley, Dr Maria de los Angeles Garavagno, Professor Andrew Orr-Ewing, Professor Dudley Shallcross, Dr Angelina Wenger and Dr Anwar Khan have been awarded a grant from the Natural Environment Research Council (NERC) to study the environmental fates of a new generation of fluorocarbon gases being used as replacements for hydrofluorocarbons (HFCs) and chlorofluorocarbons (CFCs) in refrigeration, and as propellant and foam-blowing gases.

The HFCs and CFCs are long-lived and potent greenhouse gases, and the CFCs also deplete stratospheric ozone. The replacement compounds are hydrofluoroolefins (HFOs) containing a C=C bond that is vulnerable to attack by OH and ozone in the lower atmosphere. However, led by discoveries in Bristol and elsewhere, concern is growing about the products of this oxidation chemistry which include CF3H and CF4, both of which are greenhouse gases, as well as trifluoracetic acid (TFA, a persistent environmental pollutant).

The new NERC project, entitled "Quantifying the production of environmentally damaging compounds from atmospheric oxidation of hydrofluoroolefins" will use a simulation chamber in the School's Atmospheric Chemistry Research Group laboratory to quantify the yields of products such as CF3H and CF4 from this oxidation chemistry for various different HFOs and related compounds. The outcomes will be included in atmospheric chemistry models to assess the environmental and climate consequences of greater use of HFOs.