Worn sneakers go pure fiber


Recycling PET bottles has become standard. The raw material (used PET bottles) is typically cleaned with hot alkaline water, some additives, and is then mechanically recycled in a multi-step process. Afterwards, process losses (which can amount to 30%) are filled up with fossil PET. The resulting material can be reused for PET packaging or other PET applications. However, the share of PET bottles in total PET waste is small: overall much more PET is found in non-bottle packaging and non-food applications. Recycling these materials is difficult because the starting material is a composite or is not coming from closed loops and thus heavily contaminated with unwanted substances, most prominently by dyes. Here, chemical recycling processes contribute synergistically to mechanical recycling. If not developed, this waste material has no value, hence access to this feedstock will remain limited and not organized.


The idea is to support a growing collection of raw material fractions for PET recycling by offering a chemical recycling process technology, which allows the expansion of waste sorting from bottle to mixed waste fractions. The collected waste is cleaned and mechanically treated first, e. g. by removing surface contaminations or zippers from clothes. After these steps, a proprietary chemical sorting process using Alkoxide technology from Evonik further cleans the material, having at its core a chemical depolymerization of PET into its monomers. After cleaning of the monomers, their repolymerization yields fossil-like PET which ultimately allows the replacement of fossil PET in the fill-up of losses in mechanically recycled PET.

Together with partners Evonik is working on a process that will make it possible to spin a new pure fiber or to blow a new bottle from soiled PET waste in the future.


Evonik and partners currently are in the process of upscaling for a pilot plant operation. Core objective is the operation of a seamless process from mixed waste to 100% chemically recycled PET for the most demanding applications.


Our partners in this process are technology and market leaders in the respective value chain element. Further partnerships are developed with start-up’s which develop new and cutting-edge process elements for a circular future.


Would you like to dive even deeper into the subject? You can satisfy your thirst for knowledge on the websites of our department. Or get in touch with our team of experts: in Adrian Blum, you will find an experienced contact person.