Decomposition of fluoropolymers by their mineralization in subcritical water

Recycling and the end of life assessment of fluoropolymers: recent developments, challenges and future trends

“…Furthermore, these authors examined the formation of CaF 2 154,155 from the reaction solutions to close the loop on the fluorine element, given that CaF 2 is the source for all the fluorinated compounds. This strategy was further extended to the mineralisation of various copolymers such as ETFE (efficiently mineralised in sc water at 380 1C in the presence of an excess amount of O 2 150 or a lower temperature in the presence of H 2 O 2 ), 151 VDF-containing copolymers, 154 poly(VDF-ter-HFP-ter-TFE) fluoroelastomer 152 and perfluorosulfonic acid (PFSA) membranes 149 (usually involved in ion-exchange polymer membranes, PEMFC, chloro-alkali process to produce chlorine and sodium hydroxide from brine, desalination for drinkable waters, etc. ).…”

“…Although the mineralisation of low molar mass-PFASs has been reported, 148 to the best of our knowledge, the only strategy involving that of FPs has been well-established at the Kanagawa University. Hori's team is currently studying the mineralisation process of various FPs by subcritical water 149 ( i.e. , superheated water) as high-pressure liquid water in the temperature range of 100 °C and its critical temperature, 374 °C (while supercritical (sc) water is defined as water at temperature and pressure higher than the critical point: 374 °C and 22.1 MPa, respectively).…”

“…Although the mineralisation of low molar mass-PFASs has been reported, 148 to the best of our knowledge, the only strategy involving that of FPs has been wellestablished at the Kanagawa University. Hori's team is currently studying the mineralisation process of various FPs by subcritical water 149 (i.e., superheated water) as high-pressure liquid water in the temperature range of 100 1C and its critical temperature, 374 1C (while supercritical (sc) water is defined as water at temperature and pressure higher than the critical point: 374 1C and 22.1 MPa, respectively). [149][150][151][152][153][154][155] Given that under these conditions, the water displays high diffusivity, low viscosity and ability to hydrolyze many organic compounds including biomass, reactions using subcritical or sc water are considered environmentally benign in chemical engineering with the aim of developing a technique for the recycling of fluorine element.…”

“…Hori's team is currently studying the mineralisation process of various FPs by subcritical water 149 (i.e., superheated water) as high-pressure liquid water in the temperature range of 100 1C and its critical temperature, 374 1C (while supercritical (sc) water is defined as water at temperature and pressure higher than the critical point: 374 1C and 22.1 MPa, respectively). [149][150][151][152][153][154][155] Given that under these conditions, the water displays high diffusivity, low viscosity and ability to hydrolyze many organic compounds including biomass, reactions using subcritical or sc water are considered environmentally benign in chemical engineering with the aim of developing a technique for the recycling of fluorine element.…”

Efficient Mineralization of Lithium Bis(pentafluoroethanesulfonyl)imide and Related Electrolyte Fluorochemicals Using Superheated Water

“…Reaction using this water is recognized as an environmentally benign technique because it has been shown to have a smaller environmental impact than pyrolysis in the recycling of nonmetallic component from electronic waste . In addition, it allows generating value-added compounds. − Furthermore, unlike with pyrolysis of fluorinated compounds, even if harmful COF 2 is generated during the treatment, it is easily decomposed by hydrolysis to CO 2 and HF . Of course, lowering the operation temperature and pressure are desirable in view of saving energy.…”