How can more plastic be recycled? Better sorting of waste streams is the be-all and end-all. Packaging could then be turned into new plastic raw material. Researchers are working intensively on chemical or biotechnological processes for plastic recycling. However, most of them are not yet suitable for industrial use.
In principle, the aim of chemical recycling processes is to remove the material from Plastic packaging into original components such as polypropylene or polyethylene. With the „Monomers“ new plastics can be produced again.
These processes can also be used to „Plastic-rich waste streams“ that conventional mechanical recycling methods fail to process. That said Rainer Mantel, Managing Director of BKV GmbH, in March at the specialised press day of Plastics Europe Germany. He presented a study on chemical recycling processes. Mantel emphasised that chemical recycling is merely a building block for closing the carbon cycle.
Chemical plastics recycling to become suitable for industrial use
However, many processes are still many years away from industrial suitability, said Mantel. The most developed processes are the energy-intensive Gasification process, in which the plastics are strongly heated and then broken down by synthesis.
With Microwave radiation is again working with the Swiss company gr3n. When recycling plastics using this method, PET waste, which can also be unsorted, is broken down into ethylene glycol and terephthalic acid. gr3n is supported in its development by the „DEMETO“ consortium, which includes Coca-Cola.
The „ChemCycling“ project by a consortium led by BASF. The first pilot products have already been presented in the run-up to K 2019. Storopack showed insulating packaging made from „Styrofoam Ccycled“, Südpack a mozzarella pack with film from the ChemCycling project.
ChemCycling is based on the fact that mixed plastic waste is processed into pyrolysis oil. This is then used in the „SteamCracker“ into the elements ethylene and propylene at 850 degrees Celsius. At the end of last year, McKinsey certified that Pyrolysis process In view of the sharp rise in plastic waste volumes, the global market potential is estimated at 70 billion euros.
Enzymes even break down multi-layer materials
The bioenzymatic process works at significantly lower temperatures. Plastic recycling from the French company Carbios, which should be ready for industrial use in about four years. PET and polyester products from mixed waste streams - even multi-layer materials such as functional sportswear can be included - are broken down into their basic components. To do this, they are immersed in a 65 degree Celsius water bath for around 16 hours, which is followed by a Carbios specially optimised enzyme has been added. All that remains is water and non-treatable materials such as aluminium or paper.
Companies such as L'Oréal, Nestlé Waters, PepsiCo and Suntory Beverage & Food support Carbios in its development work.
