Covestro: Chemical recycling of polycarbonate reaches a major milestone

Covestro has developed an innovative process for recycling polycarbonate. In this process, plastics are converted back into their monomers (precursors of plastics) so that they can be put back into the production process as alternative raw materials. At Covestro in Leverkusen, Germany, the technical implementation of chemical recycling has already started as a pilot. On the road to industrial scale, the process is still being optimized and is in a further development stage.

Dr. Thorsten Dreier, Chief Technology Officer of Covestro: “As manufacturers of plastics such as polycarbonate, we naturally have a responsibility to dispose of these important materials, including at the end of their product life. The strength of Covestro is: we know How our products are designed so that targeted research into recycling solutions is possible. The chemical recycling of polycarbonate is one example where our R&D colleagues demonstrate the possibility of closed loops in the future with this recycling process. We End-of-life plastic needs to be closed as a resource and reused as an alternative raw material.”

Plastics can replace major fossil raw materials in production through recycling. Comprehensive recycling thus contributes to climate neutrality and the protection of natural resources and the environment. The physical recycling of polycarbonate has become an important part of Covestro’s recycling strategy. Physical recycling is used as long as the waste stream is sufficiently pure and the recovered polycarbonate is suitable for future applications.

Chemical recycling and physical recycling go hand in hand – chemical recycling converts plastic components back into monomers. These monomers can be isolated and used as raw materials for future plastics. As a result, larger waste streams that are not suitable for physical recycling processes can be recycled using chemical recycling methods, producing plastics of the highest quality. Covestro is actively developing chemical recycling technologies.

Chemical decomposition directly enables polycarbonate recycling to close the loop

The newly developed process, driven by an international team, is a special chemical dissolution process for polycarbonate. Markus Dugal, Head of Process Technology at Covestro, explains: “Pre-sorted waste streams containing more than 50 percent polycarbonate products can be recycled in this way. This has been demonstrated for various polycarbonate-containing plastics. This was successfully demonstrated in the waste stream. With the help of chemical decomposition, the precursors of polycarbonate can go directly into the cycle. This makes the recycling process highly sustainable”.

Recycled products can be used directly as raw materials

The recovered products are polycarbonate precursors that can be mass balanced and reused as raw material for the production of polycarbonate without further processing. Lily Wang, head of the Engineering Plastics business entity at Covestro: “This high-quality recycled raw material is required for applications with high quality requirements. For example, it can be used in the automotive industry for safety, optical clarity or aesthetics Applications with special requirements, as well as products in everyday life, such as consumer electronics.”

will invest millions of euros

After successful laboratory development, the next stage of development, the technical implementation of the continuous process, has started. The pilot plant, which is currently in the planning stage, will be used to gather the experience needed for further industrial scale-up. Covestro will invest several million euros in this effort over the next few years. A pilot plant will be built in Leverkusen, Germany.

At the same time, Covestro is further promoting an innovative recycling process for polycarbonate in its research laboratories. These include chemical decomposition alternatives, recycling processes that use enzymes to break down plastics, and smart pyrolysis processes. Promising alternatives can also be tested in pilot plants.

Plastics are key to sustainable growth and a green future. To ensure that plastic products do not become waste at the end of their useful life, they must be reused as alternative raw materials. Innovative recycling is one of the four major areas that Covestro is actively promoting on the path of circular economy. As with chemical recycling, Covestro is strengthening research into recycling methods with an open technological approach and is actively promoting these innovative methods.