Fuel tanks, airbag covers, or radiator grilles – many components in cars are made of plastics. They need to meet stringent safety, heat resistance, and quality requirements. This is why plastic automotive components that are subject to particularly high levels of stress can, to date, only be manufactured from materials of virgin material quality, which mechanically recycled plastics usually do not achieve. Additionally, mixed plastic waste is often not available for mechanical recycling.

For this reason, the THINKTANK Industrial Resource Strategies at the Karlsruhe Institute of Technology (KIT) launched a pilot project for Chemical Recycling together with Audi at the end of 2020. Within the scope of the project, tests were carried out to determine the extent to which mixed automotive plastic fractions can be fed back into a resource-friendly cycle via Chemical Recycling.

Under the leadership of Prof. Dr. Dieter Stapf from the KIT Institute of Technical Chemistry and Dr. Rebekka Volk from the KIT Institute of Industrial Management and Industrial Production (IIP), scientists investigated the technical feasibility of the process as well as its cost-effectiveness and its impact on the environment.

The results show that Chemical Recycling can be used to process the mixed plastic waste from automotive manufacturing into pyrolysis oil, which can replace petroleum as a chemical raw material.

This means materials made from it exhibit the same high quality as virgin materials and plastics made from pyrolysis oil can be reused in automotive manufacturing to produce plastic components that are subject to high levels of stress.

Chemical Recycling pilot project of Audi and KIT aimed at recycling mixed automotive plastic waste successfully completed.

Audi is one of the first automakers to test this recycling method in a pilot project with automotive plastic waste. Audi intends to intensify its research together with its partner KIT. As such, the partners plan to test its industrialization potential in a follow-on project. This would allow fossil resources to be used for longer and reduce the use of additional fossil resources.

“An initial assessment shows that Chemical Recycling may be superior to energy recovery from both a financial and environmental perspective. An initial comparison of the figures shows that the costs for Chemical Recycling are on par with the prices that have to be paid for energy recovery. Furthermore, Chemical Recycling offers the opportunity to recycle much of the carbon and reuse it in the production of new plastic components,” explained Dr. Rebekka Volk from IIP.

As a result, carbon dioxide emissions from Chemical Recycling are significantly lower than from the current energy recovery process – which benefits the climate. Complementing mechanical recycling, pyrolysis also converts mixed waste plastics and composites into a liquid chemical feedstock while separating out unwanted constituents.

After a purification step, this pyrolysis oil can be processed into new plastic using conventional industrial processes, thus replacing primary raw materials from fossil energy sources, such as petroleum. This conserves resources and energy.

As per Philipp Eder, project manager for Chemical Recycling in the supply chain at Audi, “Audi wants to use intelligent methods to proactively shape the market for secondary raw materials and take responsibility in line with our mission of achieving a competitive edge through the use of innovative technologies.”

Audi has identified Chemical Recycling as an opportunity and has set out to successively increase the amount of recycled plastic in its models. Up to now, Audi has primarily used recycled single-variety plastics.

A current example is the use of PET in the Audi A3. PET is a plastic that consists of a single-variety chemical compound. These materials are easier to process than mixed plastics. The A3, for example, is available with three different fabric covers for the car seats that contain up to 89 percent recycled material.

The new Audi Q4 e-tron electric SUV also contains components with recycled content – including mounting brackets, wheel arch liners, fender covers, floor paneling, and wheel spoilers. A total of 27 components contain recycled material. But in the future, mixed high-performance plastics produced via Chemical Recycling could also be added.

Fuel tanks, airbag covers, or radiator grilles – many components in cars are made of plastics. They need to meet stringent safety, heat resistance, and quality requirements. This is why plastic automotive components that are subject to particularly high levels of stress can, to date, only be manufactured from materials of virgin material quality, which mechanically recycled plastics usually do not achieve. Additionally, mixed plastic waste is often not available for mechanical recycling.

For this reason, the THINKTANK Industrial Resource Strategies at the Karlsruhe Institute of Technology (KIT) launched a pilot project for Chemical Recycling together with Audi at the end of 2020. Within the scope of the project, tests were carried out to determine the extent to which mixed automotive plastic fractions can be fed back into a resource-friendly cycle via Chemical Recycling.

Under the leadership of Prof. Dr. Dieter Stapf from the KIT Institute of Technical Chemistry and Dr. Rebekka Volk from the KIT Institute of Industrial Management and Industrial Production (IIP), scientists investigated the technical feasibility of the process as well as its cost-effectiveness and its impact on the environment.

The results show that Chemical Recycling can be used to process the mixed plastic waste from automotive manufacturing into pyrolysis oil, which can replace petroleum as a chemical raw material.

This means materials made from it exhibit the same high quality as virgin materials and plastics made from pyrolysis oil can be reused in automotive manufacturing to produce plastic components that are subject to high levels of stress.

Chemical Recycling pilot project of Audi and KIT aimed at recycling mixed automotive plastic waste successfully completed.

Audi is one of the first automakers to test this recycling method in a pilot project with automotive plastic waste. Audi intends to intensify its research together with its partner KIT. As such, the partners plan to test its industrialization potential in a follow-on project. This would allow fossil resources to be used for longer and reduce the use of additional fossil resources.

“An initial assessment shows that Chemical Recycling may be superior to energy recovery from both a financial and environmental perspective. An initial comparison of the figures shows that the costs for Chemical Recycling are on par with the prices that have to be paid for energy recovery. Furthermore, Chemical Recycling offers the opportunity to recycle much of the carbon and reuse it in the production of new plastic components,” explained Dr. Rebekka Volk from IIP.

As a result, carbon dioxide emissions from Chemical Recycling are significantly lower than from the current energy recovery process – which benefits the climate. Complementing mechanical recycling, pyrolysis also converts mixed waste plastics and composites into a liquid chemical feedstock while separating out unwanted constituents.

After a purification step, this pyrolysis oil can be processed into new plastic using conventional industrial processes, thus replacing primary raw materials from fossil energy sources, such as petroleum. This conserves resources and energy.

As per Philipp Eder, project manager for Chemical Recycling in the supply chain at Audi, “Audi wants to use intelligent methods to proactively shape the market for secondary raw materials and take responsibility in line with our mission of achieving a competitive edge through the use of innovative technologies.”

Audi has identified Chemical Recycling as an opportunity and has set out to successively increase the amount of recycled plastic in its models. Up to now, Audi has primarily used recycled single-variety plastics.

A current example is the use of PET in the Audi A3. PET is a plastic that consists of a single-variety chemical compound. These materials are easier to process than mixed plastics. The A3, for example, is available with three different fabric covers for the car seats that contain up to 89 percent recycled material.

The new Audi Q4 e-tron electric SUV also contains components with recycled content – including mounting brackets, wheel arch liners, fender covers, floor paneling, and wheel spoilers. A total of 27 components contain recycled material. But in the future, mixed high-performance plastics produced via Chemical Recycling could also be added.