Covestro develops innovative recycling technologies
From mechanical remanufacturing to raw material recycling and beyond
Far too much plastic still ends up in the trash. Although the recycling rate has increased in recent years, it is still only 14 percent worldwide. Used plastics are a valuable resource in this respect. Covestro wants to align itself comprehensively with circularity and help make it the global guiding principle. To achieve this, the company develops innovative technologies to reuse plastics and return them to the value cycle – often in close cooperation with partners.
The goal of a new collaboration with the Zurich-based bag company FREITAG is the unlimited recycling of truck tarps, based on thermoplastic polyurethanes (TPUs) from Covestro. At the end of their useful life, the tarps are to be recycled mainly chemically and used for new tarps or other products. It is important for the success of the project that the tarps are similarly robust, durable and water-repellent as the previous products. FREITAG expects it to be a few years before bags made from the tarps are mass-produced, but plans to put a first prototype on a truck as early as this year.
Sorting of plastics by type
At the K 2022 trade show, Covestro will present these and a number of other developments for the unmixed recycling of used plastics. The company’s focus to date has been on proven mechanical recycling, in which the plastic is chemically preserved, and more recent chemical recycling processes, in which the polymer molecules are broken down chemically. Other technologies of such raw material reprocessing – specifically enzymatic and pyrolytic – are under development.
Mechanical recycling is particularly suitable for polycarbonates. Numerous corresponding products from Covestro are already on the market, including polycarbonate blends for IT applications with up to 75 percent recycled material – besides products based on mass balanced raw materials. To facilitate recycling, the company is increasingly relying on monomaterial solutions for end products that feature simplified material separation. In addition, new plastic products are designed from the outset to be easier to recycle at the end of their useful life.
Chemical recycling on the rise
Polyurethanes (PU) and other thermoset products usually cannot be mechanically recycled. Chemical processes are the obvious choice here. Covestro has developed an innovative technology for recovering both core raw materials PU mattress foam as part of a research project with partners. These are polyols and the isocyanate TDI, which are used in the production of mattress foam. The precursor is recovered from the TDI, and both raw materials can be reused for the production of new foam after reprocessing. The results achieved to date are being tested in a pilot plant at the Leverkusen site. Covestro has now introduced the Evocycle® brand name for the project.
To drive the project forward and close recycling cycles, Covestro is cooperating with partners from the chemical and recycling industries. Together with Interseroh, an ALBA Group company, opportunities are to be developed for the collection and processing of the recyclables so that they can ultimately be supplied to Covestro for chemical recycling. Covestro is pursuing a similar goal in its cooperation with the French environmental protection organization Eco-mobilier, which specializes in the collection and recycling of old furniture.
Used PU rigid foams, which provided efficient thermal insulation for buildings and refrigeration equipment, should also be able to be broken down into their constituent parts again by means of chemolysis or even pyrolysis. This is the goal of the CIRCULAR FOAM research project with 22 industrial partners from nine countries, coordinated by Covestro. Over the next four years, experts from science, industry, and society want to develop a comprehensive solution model for the waste management and recycling of such foams.
Here, too, the aim is to recover both raw materials originally used – polyols and an amine used as a precursor for the isocyanate MDI. If the material cycle is successfully closed, up to one million metric tons of waste, 2.9 million metric tons of CO2 emissions and 150 million euros in incineration costs could be saved in Europe every year from 2040.
