Recycling of polyurethane foam mattresses using chemical recovery

Every year, Belgians discard one million mattresses that end up in landfills and incinerators. The EU wants to recycle and reuse at least 55% of household waste, including mattresses, by 2025, while Belgium has decided to start mandatory recycling gradually in 2021. In this context, we can better understand the interest of the research project carried out by polyurethane foam producer Recticel and Covestro over the last four years: in collaboration with KU Leuven, Ghent University and recycling partners, they have developed a process to recreate new polyurethane foam from old mattresses.

This type of foam is used to "fill" most of the mattresses sold around the world, competing with polyether foam and latex. Their new technology has a double advantage over other existing recycling methods in that it allows for continuous recycling of all foams and eliminates the need to recreate new "fossil" plastic components, creating a completely circular process

How does it work? You must first collect the mattresses, sort them and then disassemble them by separating the different polyurethane (PU) families. These foams are then chemically broken down by breaking down polyols on the one hand and toluene diisocyanate (TDA) on the other, the latter being the raw material for toluene diisocyanate (TDI). Polyols (PPG,PTMEG) and toluene diisocyanate are the basic raw materials for two types of polyurethane foams.Another raw material is MDI. The pilot plant set up by

Covestro in Leverkusen, Germany, proved that there is a way to do this with high purity and high throughput.

The TDA is processed into TDI in a pilot plant through post-processing, which makes it possible to remanufacture polyurethane foams, Recticel and Covestro explained in a press release, "The process does not use fossil-sourced polyols, only pre-sorted mattress waste foam, ethylene glycol and additives. After reprocessing, they can be reused as often as needed for the production of new flexible polyurethane foams."

With funding from Europe's Horizon 2020 program, the project called "PUReSMART" has been a success. The project's sponsors are already talking about recycling about 220,000 tons of polyurethane foam per year from waste processing centers to supply plants like Recticel, thereby reducing the carbon footprint by "at least 30 percent" and creating 20 jobs for each 6,000-ton batch of recycling.

All that remains is to repeat the same thing on a larger scale, but it hasn't been won yet. Karin Clauberg, project manager at Covestro, said, "We hope to achieve this within this decade, but no decisions have been made yet because the issue of access to these materials is still to be resolved."

Bart Haelterman, Recticel's director of research and development, said, "Belgium, the Netherlands and France have already set up collection systems for used mattresses. But other member states should follow suit and collect throughout Europe if we want to get sufficient quantities." This is not currently the case, with the result that most mattresses continue to go to incinerators. In the case of Covestro, Recticel and their partners such as RedWave, Weylchem or Ecoinnovazione, they are ready to go further once this problem is solved.

Baert Haelterman adds, "We expanded into other polyurethane products, such as car seats and furniture, but they will prove more difficult to disassemble. However, this will increase production by a factor of two or more."

Coincidentally, a few days ago, the French group Veolia and Recyc-Matelas Europe announced that they have developed a complete mattress recycling solution: based in Sombreffe, their joint division uses an automated sorting process that can process 500,000 mattresses per year before reusing them in other industries, such as insulation, sports mats, seat pads, etc. Unlike the recycling methods used by Recticel and Covestro, these two companies use mechanical recycling, rather than chemical recycling.