Not all items are created equally and not all materials lend themselves as readily to recycling as others. Items such as glass and metals are relatively easy to re-use if treated the right way, but some items present a whole new set of problems and logistical challenges that make them much harder to re-use in a manufacturing cycling.

Plastics, or more specifically, automotive plastics are a perfect case in point. Because of the quality control requirements they must meet for safety and durability purposes, automotive plastics have to be made using petroleum-based materials which makes them more difficult to recycle. Where you have plastics of the same type, these can often be mechanically recycled, which essentially means cutting them up and melting them down to be reformed, but mixed plastics are not so straightforward.

So, as part of the brand’s ongoing efforts to make improvements in efficiency and environmental impacts, Audi and the Karlsruhe Institute for Technology (KIT) have established a pilot project for chemical recycling designed to feed mixed plastic fractions back into a resource-conserving circular system. 

Audi has already enjoyed considerable success with its Aluminium Closed Loop that sees off cut and waste aluminium being absorbed back into the system and re-used. Working with its suppliers, Audi managed to recover aluminium waste and improve it to new-product quality level, avoiding some 150,000 tonnes of CO2 on the environmental balance sheet in 2019 alone. 

So too this plastic initiative is seeking to do much the same thing, and seeing plastics absorbed back into the system, increasing the proportion of sustainably of manufactured components in vehicles.

Partnering with KIT, Audi is initially testing the technical feasibility of chemical recycling and evaluating whether it is financially feasible and of course its environmental impacts. The KIT team is led by Professor Dieter Stapf (PhD) at the Institute for Technical Chemistry (ITC) and Dr Rebekka Volk at the Institute for Industrial Production (IIP), with Audi providing items such as fuel tanks, wheel trim parts and radiator grilles from Audi models returning from the German dealership network for use in the evaluation process. 

These plastic components are processed into pyrolysis oil using the chemical recycling method, with the resulting oil quality corresponding to that of petroleum products. This means that materials made from it are of the same standard as new ones, which in turn means that components made from pyrolysis oil can be used again in vehicles. 

Audi is one of the first vehicle manufacturers to test this recycling method in a pilot project with plastics from vehicle production. Already the brand has achieved tremendous success with similar initiates such as the utilisation of PET plastic polymer. The fine thread produced from recycled plastic bottles now forms up to 89 percent of seats covers available in the new Audi A3, providing an attractive upholstery choice that uses significant amounts of recycled material.

“Our goal is to manufacture the seat cover completely from the same type of material so that it can be recycled. We’re not far from achieving this goal,” says Ute Grönheim, who looks after textile materials development at Audi. 

Ultimately, energy and material savings will become an integral part of every manufacturing process at Audi and future vehicles will in turn be easier to recycle at the end of their lives, creating a positive flow-on effect. Every little bit counts and the cumulative effect will make a positive impact on the future.