Ineos Styrolution advances PS chemical recycling 

The ResolVe project, which was launched in 2017 to study the chemical recycling of polystyrene has borne fruit: Ineos Styrolution has announced in a 22 Sept statement that it has proof of concept of closed-loop recycling, thus establishing the recyclability of polystyrene. 
 
The technology converts waste polystyrene back to pure styrene via a depolymerisation process. The monomer then goes through a polymerisation process, which produces polystyrene identical to virgin PS in terms of quality, said the company statement. 
 
“Polystyrene is one of very few polymers that can be converted back into its specific monomer,” said Ineos Styrolution, adding that the material’s technical properties, such as low ceiling temperature, enable recycling under conditions that can be achieved in a twin-screw extruder. 
 
The key questions covered in the ResolVe project included the yield of styrenics in the chemical recycling process and the impact of non-styrenic waste contaminations.
 
While the recycling process is sensitive to PET contamination, it is hardly impacted by contamination with polyolefins of up to 10%, according to the project results.
 
With these findings, Styrolution will now head to the next phase of the project, i.e. the pilot phase. In addition, the results will prepare the ground for scaling the process for industrial use, and offer guidance to waste sorters.
 
“The ResolVe project gives us an insight into chemical recycling. As a result, we can clearly say: Polystyrene is indeed made for recycling,” said Norbert Niessner, director global R&D/intellectual property at Ineos Styrolution.
 
Details of the findings were presented at the Bayreuth Polymer Symposium, held 22-24 Sept, in Bayreuth, Germany.
 
Funded by the German federal ministry for education, BMBF, project ResolVe is jointly executed by Ineos Styrolution and Neue Materialien GmbH Bayreuth as well as with two institutes of the University of Aachen (RWTH).