Perfluorinated polymers - such as the well known polytetrafluoroethylene PTFE (trade name: Teflon^®) - are non-sticking and resistant to heat and chemicals. Therefore they are essential not only for frying but also in the semiconductor industry, as a coating for seals or as material for cable insulation in electrical engineering. Since fluoropolymers are among the most stable organic compounds, their waste or products have been previously either landfilled or incinerated. The University of Bayreuth, the Research Institute InVerTec e.V. and the company Dyneon GmbH succeeded in developing a recycling process for fluoropolymers separated by material types and thus close the gap in the cycle for materials and component substances.

Depolymerization by flash pyrolysis

Fluoropolymers are depolymerized by flash pyrolysis, that is to split them into recyclable monomers. Optimized process conditions recover the gaseous monomers tetrafluoroethylene and hexafluoropropene by up to 93 per cent by weight. For the partially fluorinated polymers, ethylene-propylene copolymer (FEP) and ethylene-PPVE copolymer (PFA), the recycling rate was 86 respectively 77 percent by weight.

The new method allows to save large quantities of energy and avoid unwanted by-products. Even a return system has been designed. Dyneon currently plans to build a pilot plant for the recycling of 500 tons per year of perfluorinated polymers.

Project Operation:
Universität Bayreuth
Lehrstuhl für Werkstoffverarbeitung
Universitätsstraße 30
95447 Bayreuth
Telefon    0921|55-7201
monika.willert-porada@uni-bayreuth.de
www.lswv.de

Cooperation Partner:
INVERTEC Institut für Innovative Verfahrenstechnik e. V., Bayreuth
info@invertec-ev.de
www.invertec-ev.de
Dyneon GmbH, Burgkirchen
dyneon.europe@mmm.com
www.dyneon.eu

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