Fortschritte im Recycling und Abfallmanagement

Recycling of flame retarded waste polystyrene foams (EPS and XPS) to PS granules free of hexabromocyclododecane (HBCDD)

Abstract

Martin Schlummer, Andreas Mäurer, Swetlana Wagner, Arthur Berrang, Tanja Fell and Fabian Knappich

Expanded and extruded polystyrene (EPS and XPS) belong to the most often used insulation materials and with respect to this application-both material have been equipped with the brominated flame retardant hexabromocyclododecane (HBCDD) for more than 50 years. After HBCDD had been identified as a substance of very high concern, it was set under control of the Stockholm Convention and the European Reach legislation. In consequence, the use of HBCDD in insulation materials is currently phased out and waste insulation material made of HBCDD equipped EPS or XPS cannot further be subjected to state-of-the art mechanical recycling. However, as the majority of the formerly produced HBCDD equipped EPS and XPS is still in use as insulation material, more sophisticated recycling approaches are currently investigated. This study investigates a solvent based recycling process, which dissolves polystyrene from insulation waste and eliminates not only insoluble waste components but also co-dissolved HBCDD. The study investigates the efficiency of HBCDD removal as well as mechanical properties of recycled PS produced by this process.