Breakthrough in the recycling of polyurethane soft foam waste

Polyurethane foam is one of the most important plastic products in the world and can be used in many fields, but waste recycling is a major challenge currently facing the polyurethane industry. In this regard, the PUReSmart project funded by the European Union gathered 9 partners from 6 countries to find innovative methods and technical paths to solve this problem.

At present, the project has been successfully concluded. The polyurethane flexible foam waste recycling solution proposed by it has significantly improved the recycling efficiency and recycling effect, and is expected to completely change the traditional mattress production and recycling system.

Smart Sorting Technology Helps Sorting Waste

Although the polyurethane industry is very concerned about waste recycling, just a few years ago, there was no good solution for the disposal of waste mattresses, about 60% ended up in landfill, and the remaining 40% was incinerated. With the joint efforts of all parties, especially the EU PUReSmart, which combined intelligent mechanical recycling technology and developed chemical decomposition technology, successfully developed an innovative process for chemical decomposition of waste polyurethane, which can realize the complete recycling of polyurethane soft foam. This technology is more conducive to promoting carbon emission reduction in the polyurethane industry and promoting the development of the industry in line with its environmental goals.

It is reported that the European Union's "Horizon 2020" research and innovation program has provided 6 million euros in funding for the PUReSmart project over four years. The goal of the project is to recycle more than 90% of polyurethane waste and convert it into new and reusable products.

4 years ago, when PUReSmart set out to find a way to transform the traditional model of polyurethane production-application-waste into a circular economy model, the project put forward a practical idea from the beginning: polyurethane recycling should start from solids that are beneficial to subsequent chemical decomposition The mechanical sorting process begins. Subsequently, PUReSmart is committed to developing intelligent classification technology, identifying and sorting various polyurethane flexible foams into various types of materials that do not use raw materials, and decomposing them into basic chemical components.

Practice has proved that this idea is effective. Redwave first proposed a solution using near-infrared sensors to detect sorted polyurethane waste in order to better reuse polyurethane soft foam. Near-infrared reflectance spectroscopy has been used in the detection and classification of various thermoplastics such as PET and PE, and is now being used for the first time to sort polyurethane foam.

It is understood that the R&D team of Redwave has developed a reliable solution for polyurethane waste sorting, including all aspects of sorting polyurethane soft foam waste. Redwave's sorting equipment can identify and classify 20 to 30 different types of polyurethane, such as MDI-based polyurethane foam, traditional polyurethane foam, high resilience roll paper foam, and flexible polyurethane foam containing additives such as flame retardants. At present, relevant companies are still upgrading the waste polyurethane material sorting system to make the downstream chemical decomposition process easier.

Subsequent research and development of chemical decomposition technology is accelerated

While clarifying the idea of ​​optimizing the identification and sorting of waste in the early stage, PUReSmart is also accelerating the technical research and development and industrialization test of subsequent chemical decomposition. In recent months, Recticel Engineered Foams, a member company of the PUReSmart consortium, has carried out various experiments to regenerate polyurethane foam from recycled polyols and isocyanates obtained from Covestro's pilot plant in Leverkusen, Germany.

Unlike other chemical processes for recycling flexible polyurethane foam, this process does not use polyols produced from fossil sources, and only requires the addition of ethylene glycol and an additive to pre-sorted waste foam raw materials. During the chemical decomposition process, the waste flexible foam can be decomposed into high-purity and high-yield polyols and toluenediamine (TDA, the precursor of TDI). After reprocessing, the polyurethane raw materials produced by these decompositions can be reused to produce new flexible polyurethane foams as needed.

Covestro "tests" the sustainable cycle of polyurethane flexible foam

Covestro has been trying to promote this work since 2019, launching a pilot plant in Leverkusen, Germany in 2021, and has achieved positive results in the laboratory. Experiments have proved that the two main raw materials of mattress polyurethane soft foam can be recycled by chemical means to achieve high quality and purity. So far, they have produced new flexible foam samples with fully recyclably produced polyols and TDI respectively. If the trial goes well, the company plans to build a larger recycling facility to further validate the technology.

This innovation enables the sustainable recycling of flexible polyurethane foam and reduces CO2 emissions. Covestro and Recticel are pleased with the results achieved. Bart Haelterman, Director of Research and Development at Recticel, said: "We have successfully developed technology to chemically recycle these products, turning polyurethane into high-quality recycled material. This is the first time that polyurethane foam has truly enabled a circular economy."

Based on the innovation of the PUReSmart project, Covestro is cooperating with companies in the waste management industry to promote the industrialization of flexible foam recycling. Christine Mendoza-Frohn, Head of Sales Performance Materials at Covestro said:���Our aim is to convert waste into valuable raw materials and, together with our partners, integrate the principles of the circular economy into the company value chain. The company therefore makes innovative recycling a priority. Covestro's innovative recycling process for flexible polyurethane foam waste, named Evocycle CQ, continues to promote the chemical decomposition of polyurethane mattress foam and demonstrates our willingness to further invest in this technology. "

CQ, which stands for "circular intelligence," is a smarter approach to more sustainable materials and solutions, according to Covestro. Customers can easily distinguish products based on alternative raw materials from those based on fossil raw materials by the CQ label in the product name. Covestro wants to drive a circular economy in the polyurethane mattress industry by converting waste into valuable resources, reducing the use of fossil fuels and significantly reducing carbon emissions.

To achieve this goal, there are still many problems to be solved, especially in terms of scale-up, and the efficient and economical supply of waste soft foam mattresses is crucial. The first step is to collect a large number of discarded soft foam mattresses, and the second is to disassemble them into individual components, such as springs, textiles and foams, etc., and pre-sort them according to the purity and density of the foam. This requires polyurethane companies to strengthen close cooperation with business partners. Currently, Covestro has cooperated with Interzero and Ecomaison (formerly Eco-mobilier) in this regard.