Environmental risks of new-generation fluorocarbons in replacement of potent greenhouse gases

Abstract

This article aimed to address two categories of environment friendly fluorocarbons (i.e., hydrofluoroethers and hydrofluoro-olefins), which are used as replacements for potent greenhouse gases like hydrochlorofluorocarbons (HCFC) and hydrofluorocarbons (HFC). In the work, the author will introduce the new-generation fluorocarbons on the basis of their excellent data on the environmental properties (e.g., atmospheric lifetime and global warming potential) and safety (e.g., flammability and exposure limit/level). Further, the values of photochemical ozone creation potential (POCP) for these fluorocarbons and some HFC compounds are estimated using the Wallington method and the rate constant data for the reaction of OH radical, showing that their POCP values are largely lower than those of common hydrocarbons. Based on the molecular structure and possible fate mechanism, these fluorocarbons and their decomposition products (especially in trifluoroacetic acid and fluoride) may pose adversely environmental risks, including flammability and fluoride hazards. Currently, hydrofluoroethers (HFE) such as HFE-7000 (C3H7OCH3), and hydrofluoro-olefins (HFO), including HFO-1234yf (CH2 = CFCF3) and HFO-1234ze (CHF = CHCF3), are considered as the probable candidates to replace HCFC and HFC.