Low temperature destruction of gas-phase per- and polyfluoroalkyl substances using an alumina-based catalyst
Citation:
Shields, E. AND M. Wallace. Low temperature destruction of gas-phase per- and polyfluoroalkyl substances using an alumina-based catalyst. Environmental Science & Technology Letters. American Chemical Society, Washington, DC, , 0, (2023). https://doi.org/10.1080/10962247.2023.2210103
Impact/Purpose:
Per- and polyfluoroalkyl substances (PFAS) pose a major health and environmental problem. Methods are needed to ensure that PFAS are not released into the environment during their use or disposal. Alumina-based catalysts have been used for the abatement of small perfluorocarbons emitted during the silicon etching process. Here an alumina-based catalyst was tested to determine if these catalysts may facilitate the destruction of gas phase PFAS. The catalyst was challenged with two nonionic surfactants with eight fluorinated carbons, 8:2 fluorotelomer alcohol and N-Ethyl-N-(2-hydroxyethyl)perfluorooctylsulfonamide. The catalyst helped decrease the temperatures needed for the destruction of the parent PFAS relative to a thermal only treatment. Temperatures of 200 °C were sufficient to destroy the parent PFAS using the catalyst, although a significant number of fluorinated products of incomplete destruction (PIDs) were observed. The PIDs were about no longer observed by 500 °C with catalyst treatment. Alumina-based catalysts are a promising PFAS pollution control technology that could eliminate both perfluorocarbons and longer chain PFAS from gas streams. This information may be of interest to those who need to control PFAS emissions, such as other EPA offices, States, and PFAS manufacturers and users.
Description:
Emissions from PFAS users and treatment methods pose a threat to human health and the environment. Methods are needed to destroy PFAS by breaking all the strong carbon fluorine bonds. Here an alumina based catalyst developed for the electronics industry to destroy perfluorocarbons was investigated to determine if the catalyst is effective at destroying vaporized long chain PFAS. Two nonionic fluorinated surfactants were studied and found to be destroyed by 500 C. The hard to destroy perfluorocarbons can be destroyed by 700 C, so at temperatures that the catalyst is normally used at it appears that all the carbon fluorine bonds should be broken. This type of catalyst is promising, but more studies are needed to fully determine if it is an effective and efficient means to curtail PFAS emissions.
URLs/Downloads:
DOI: Low temperature destruction of gas-phase per- and polyfluoroalkyl substances using an alumina-based catalyst