Hydrothermal Treatment
Hydrothermal recycling of PFSA membranes
InVerTec has developed a hydrothermal recycling process for perfluorosulfonic acid (PFSA) ionomer membranes, enabling the recovery of valuable polymer materials from membrane waste and other PFSA-containing feedstocks.
Unlike conventional thermal recycling approaches that decompose polymer structures, this process enables the selective redispersion of PFSA ionomers while preserving their polymer structure. The recovered ionomer dispersions can subsequently undergo purification and further processing, providing opportunities for material recovery and reuse.
Technical Spotlight: Selective Ionomer Recovery Through Hydrothermal Redispersion
The technology is based on the treatment of PFSA-containing materials in an aqueous alkaline medium under elevated temperatures and pressures. Under controlled hydrothermal conditions, the ionomer is separated from the original membrane structure and transferred into a liquid dispersion. The process can be adapted to different membrane compositions and feedstock characteristics by adjusting operating parameters such as temperature, treatment time, and alkaline concentration.
Project Highlights
InVerTec has investigated and optimized this recycling process through laboratory and pilot-scale experiments, focusing on:
- Ionomer Recovery: Selective redispersion of PFSA materials while preserving the polymer structure.
- Process Optimization: Investigation of temperature, treatment time, alkaline concentration, and feedstock composition.
- Recovery Efficiency: Demonstrated ionomer redispersion yields exceeding 90% under optimized experimental conditions.
- Feedstock Flexibility: Investigation of different PFSA membrane materials and compositions.
- Process Scale-Up: Successful transfer of the process from laboratory-scale experiments to a 500 L pilot-scale reactor.
These results demonstrate the potential of hydrothermal redispersion as an alternative recycling route for PFSA-containing materials, supporting the recovery of valuable ionomers and the development of more resource-efficient polymer recycling technologies.
