One of the key options for dealing with the growing volumes of end of life construction PS foam waste streams in the decades to come is the closed-loop recycling of PS foam waste. The PolyStyreneLoop project has been assessing the economic feasibility of such a process.
pilot scale proven and tested physio-chemical recycling process
The PolyStyreneLoop concept uses the CreaSolv® Technology; allowing for the recycling of construction PS foam and waste and destruction of HBCD, while recovering the bromine in line with the POP regulations from the Basel Convention. The CreaSolv® Technology is a development of the Fraunhofer Institute in co-operation with the CreaCycle GmbH. CreaSolv® is a registered trademark of CreaCycle GmbH.
The project is supported by the EU through the LIFE Financial instrument Environmental and Governance Program LIFE 16/ENV/NL/000271
Expanded plastics like polystyrene will be collected, cleaned and compacted at or nearby their place of origin, thus achieving a optimal freight density: a transport cost reduction compared to other current collection systems. The compacted plastic is further processed and recycled in the demoplant in Terneuzen.
During the process in the demonstration plant the XPS /EPS foam and the substance of concern HBCD are dissolved, enabling the separation of the two. By adding a second liquid the polystyrene precipitates leaving the HBCD in the solvent solution. This solvent is then vaporized and HBCD remains as a sludge. The solvent in the process is in close-loop for re-use. HBCD stays chemically unchanged and will be subsequently destructed. The polystyrene can be further re-used.
The process runs in a closed-loop circuit in which the relatively small volume of impurities are separated and concentrated. The volume of solvent used is small (<1wt%) in relation to the treated PS foam. With its optimal energy balance it performs very well in environmental impact assessment studies.