Chemical recycling of mixed plastic waste is both technically feasible and environmentally and financially promising, according to new research from Audi and Karlsruhe Institute of Technology (KIT). The researchers have invented a way to turn mixed plastic waste from automotive manufacturing into pyrolysis oil, which could replace petroleum as a raw material for the production of new plastic parts for cars. Together with partners from the chemical industry and KIT, Audi is now researching ways to industrialize the recycling process.
Many car parts are made of plastics, including fuel tanks, air bag covers or radiator grilles. These parts must meet stringent requirements for safety, heat resistance and quality. As a result, plastic parts that are subject to high levels of stress are typically made from “virgin” materials; mechanically recycled plastics usually cannot meet performance requirements. Additionally, mixed plastic waste is often not available for mechanical recycling.
To solve this problem, KIT and Audi launched a pilot project for chemical recycling in 2020. Tests were carried out to determine the extent to which mixed automotive plastic could be fed back into a resource-friendly cycle via chemical recycling. The project was led by Dieter Stapf, Ph.D., of the KIT Institute of Technical Chemistry, and Rebekka Volk, Ph.D., of the KIT Institute of Industrial Management and Industrial Production.