TNO, the Netherlands Organisation for Applied Scientific Research, continues to advance dissolution-based plastics recycling.
In the past years, the research centre has developed what it calls the TNO Möbius dissolution process. The physical recycling technique allows for the selective dissolution of certain polymers under superheated conditions. The technology uses a low-boiling solvent at an elevated temperature and pressure, facilitating the dissolution of the polymers. Compared with other dissolution processes, TNO’s has the potential to save energy by evaporating the solvent at a low temperature, typically below 120 C. Moreover, the use of a low-boiling solvent makes it possible to recover polymers with a low solvent content.
“We found the energy consumption and cost in the dissolution process is largely in solvent recovery and polymer drying,” TNO senior scientist Mark Roelands said in a statement about the technology’s developments. “A low boiling temperature makes it easier to evaporate and recover our solvent, speeding up the process. As well as this, we achieve a polymer solution with a low viscosity, which enables the use of conventional separation technologies.”
In the past year, TNO started working on phase 2.0 of TNO Möbius. The team designed the technology to process Acrylonitrile Butadiene Styrene (ABS) from Waste from Electrical and Electronic Equipment (WEEE).
Together with Elix Polymers, a Spain-based manufacturer of ABS resin and derivates, the Dutch research organisation has been working on removing the polymer, antimony trioxide, and brominated flame retardants from WEEE.
“As a not-for-profit organisation, it’s not about competing, but collaborating – bringing our expertise together towards a common goal,” Roelands said. “Elix already has an ABS plant and provided the domain knowledge of ABS at the start of the project. At TNO we have the expertise and the facilities in the field of dissolution and decontamination.
“By working together, we were able to recover ABS – amongst other things – that was recompounded with fresh ABS by Electrolux to produce a washing machine part. That’s a great value-chain project example – all the way from the waste collector to the end-user, and including the virgin-grade producer, too,” the researcher added.
The next step for the technology is opening a pilot ABS dissolution-based recycling plant, Roelands revealed. TNO plans to open the facility in June 2024 in the western Netherlands.
“As well as looking at removing pigments and flame retardants we want to look at removing the rubber particles in ABS, for example, so we can replace them with fresh ones and rejuvenate the ABS,” Roelands explained.
The project will be key to further advance the technology towards commercialisation.