MechChem Africa November-December 2020

⎪ Environmental management and cleaning technologies ⎪

MoPo: Recycling polystyrene into raw-materials

VTT has secured funding and established partnership for its multi-technological recycling for polystyrene (MoPo) project that aims to develop collection, handling, mechanical and chemical processing techniques to recirculate waste polystyrene, including expanded polystyrene, into pure polystyrene or styrene monomers. T he bulk of collected expanded poly- styrene (EPS) and other polystyrene waste still ends up incinerated. In its two-year MoPo project, VTT with

its partners will, therefore, explore how re- cycling of polystyrene could be substantially increasedby reshaping its collection andhan- dling. The goal is to convert waste into pure polystyrene or styrene monomers used in other plastics and chemicals. The global polystyrene market was worth some €36-billion last year, and the market is expected to grow by 10% per year over the next few years. At the same time, there’s a need to reduce the use of fossil raw materi- als, such as crude oil. This is why recycling of crude-oil-based polystyrene will inevitably become increasingly important. Polystyrene is typically used in its hard form in containers, such as yogurt pots, and as a foam, known as expandable polystyrene (EPS) when insulating or damping properties are needed. Both types can be mechanically recycled, which means they can be moulded intonewpolystyrene products bymelting the material.Theamountofcollectedpolystyrene waste is, however, quite small in Finland, so it usually ends up incinerated. The collection of EPS is especially challenging, as EPS takes up a lot of space for its weight and crumbles and stains easily. “In the newMoPo project, our target is to offer a technically and economically feasible solution to the recycling of polystyrenewaste inEurope.Wewillexplorethestateofpolysty- rene production, consumption and recycling inFinlandand in selectedEuropeancountries. Wewill also develop a logistics model for col- VTT offers solutions for the whole value chain in a circular economy of plas- tics. VTT helps plastics producers to rede- sign their materials to enable circularity, recyclers to develop their technologies to increase recycling rates and improve recyclate quality, and brand owners to pro- vide new and sustainable offerings. The cornerstones of VTT’s multi-tech-

The collection of EPS is especially challenging, as EPS takes up a lot of space for its weight and crumbles and stains easily.

lecting polystyrene waste and methods for its mechanical and chemical recycling,” says Muhammad SaadQureshi, senior scientist at VTT and leader of the MoPo project. Turning polystyrene into styrene As not all polystyrene waste is suited for mechanical recycling, thermochemical recy- cling methods will be developed in the MoPo project as well. In thermochemical recycling polystyrene is pyrolysed, that is, heated in the absence of oxygen, which causes it to disintegrate into shorter polymer chains and, ultimately, into styrene monomers. The resulting pyrolysis oil, upon purification, can replace oil fractions when producing, for example, aromatics, latex, polystyrene and carbonblack. Amethodwill alsobedeveloped to allow safe utilisation of polystyrene waste containingflameretardantsandotherhazard - ous components. nology approach include: • Ecodesign: Developing reuse oppor- tunities for plastics applications and redesigning or replacing plastics that are difficult to recycle. • Sorting and mechanical recycling: Improving recyclate quality and in- creasing recycle rates with intelligent sorting and recycling systems.

The MoPo project led by VTT has a total budget of EUR €964 000, which will be cov- ered by Business Finland, VTT and research and business partners: Aalto University, L&T, HSY, Finnfoam, PS Processing, CH-Polymers, Pohjanmaan Hyötyjätekuljetus and Suomen Uusiomuovi. “Together with our partners we can develop the whole value chain involved in polystyrene recycling. We expect that the project will substantially increase recycling opportunities andcreatenewbusinesses.Our goal is to lead theway inpolystyrene recycling across Europe,” Qureshi says. During the project, participants will dem- onstrate various processes such as separate collection of polystyrene waste, handling of polystyrenewastewithanewkindofextruder developed at VTT, andmechanical and chemi- cal recycling of polystyrene waste. www.vttresearch.com

VTT’s approach to plastic in the circular economy

• Reduce fossil feedstock: Developing renewable bio- and CO 2 -based polymers without competing with the food manufacturing chain. • Chemical recycling: Developing robust thermochemical recycling and depolymerisation technologies towards producing monomers and oligomers. q

November-December 2020 • MechChem Africa ¦ 37