A New Process with Great Potential

Chemical recycling is particularly relevant for plastic products that cannot be mechanically recycled at all or only with great effort – for example, if they are heavily contaminated or consist of several types of plastics that are difficult to separate.

Covestro is working intensively with partners to further develop nascent chemical recycling and establish it in the market.

Two types are currently particularly important for Covestro.

In chemolysis, plastics are broken down into their original building blocks through targeted chemical reactions. These molecules are first isolated and purified and can then be processed into plastics again just like virgin material.

Covestro uses chemolysis, among other things, for recycling soft polyurethane foam. In this process, old mattress foam is broken down into its main chemical components. From these, new, high-quality and high-performance foam can be produced. We are testing this new process, which forms the core of our planned platform technology called Evocycle^® CQ, in a pilot plant at our Leverkusen site.

In addition, Covestro has developed a process for the chemolysis of polycarbonate. Pre-sorted waste streams containing more than 50 percent of this high-performance plastic can be recycled in this way. The recyclates can then be used to produce new polycarbonates for applications in the automotive sector or consumer electronics.

In smart pyrolysis, plastics are heated in the absence of oxygen and in the presence of a catalyst so that they do not burn, but instead break down into smaller high-quality molecules. These are separated by distillation so that they can be further processed like chemical raw materials in chemical plants.

Covestro, for example, has co-developed a process in which smart pyrolysis enables the recovery of aniline from rigid polyurethane foam. Rigid foams are used for insulating buildings and refrigeration equipment. The recycled high-purity aniline can be used to produce the foam component MDI at the quality level of virgin material. Compared to MDI from conventional, fossil-based production routes, the material has a CO₂ footprint that is up to 40 percent lower.

Covestro developed the new process in the EU-funded project Circular Foam and scaled it up together with the Fraunhofer Institute for Environmental, Safety, and Energy Technology (UMSICHT). It is scheduled to be tested in a pilot plant from 2028.