A new life for contaminated plastics

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Removing hazardous substances, valorizing side streams and applying ecodesign principles on material design to improve the sustainability and recycling rates of WEEE, ELV and C&DW waste plastics.

Published: 7. september 2022 12:41 - Last changed: 26. mai 2023 14:19


Norner Research AS is a partner of NONTOX a project funded by ECHorizon 2020-SC5. and the leader of the work package dealing with Upgrade of Plastics. The project is coordinated by VTT and partners from seven different European countries complement the consortium: STENA Metall Group (SE), Coolrec (NL), Relight (IT), Galea Polymers (ES), FRAUNHOFER IVV (DE), AIMPLAS (ES), IMDEA Energy Institute (ES), Relight (IT), ERION (IT), University of Campania “Luigi Vanvitelli” (IT), Aalto University (FI).

Waste handling panorama on WEEE, C&DW and ELV

The European plastic demand is of about 50 Mt (2018) of which 6.2% (~3.2 Mt) in Electrical and Electronics Equipment (EEE) sector; almost 20% (~10 Mt) in Construction sector; and 9.9% (~5Mt) in the Automotive sector1, Based on those volumes the plastic recycling targets are set to about 45% for Waste of Electrical and Electronic Equipment (WEEE), 30% for End-of-Life Vehicles (ELV) and 36% for Construction & Demolition Waste (C&DW).2, 3

A significant limitation for the recycling is the content of legacy hazardous substances (LHSs) such as brominated flame retardants (BFRs) and Persistent Organic Polutants (POPs) 4, 5, 6 and produce safe, high performance recycled plastics. Due to the content of LHSs a large proportion of this materials are used for energy recovery or landfilled in the absence of technically feasible, environmentally sustainable and cost-effective purification and recycling processes.

The challenge of NONTOX

NONTOX project takes a holistic approach in bid to increase the recycling rates of such plastics in a cost effective and sustainable way. Essentially, improving the whole value chain right from the start, where these waste streams are collected after the end of their life, until the very step where the recycled plastics are safely introduced back into the value chain.

The project aims to (i) optimise and demonstrate the efficacy of different technologies to extract LHSs and produce high quality recycled plastics; (ii) develop and improve techniques for efficient characterisation and pretreatment of hazardous plastic waste as well as (iii) increase the efficiency of downstream recycling technologies towards high performance upgraded plastics and by developing and demonstrating guidelines for each step of the plastic value chain. Moreover, (iv) the efficiency, sustainability and competitiveness of the entire system will be increased by the valorisation residues and non-target plastic waste, using thermocatalytic conversion. Finally, (v) life cycle assessment tools for the economic, social and environmental impacts will be implemented to evaluate the benefit of the technical solutions and boost the market uptake of plastic recycling technologies and of their recycled products.

Waste streams and handling 

Three input streams are the focus of NONTOX project: WEEE, ELV and C&DW (Figure 2). More specifically, BFRs are the most common HLSs in WEEE [5]. In ELV plastics (excl textiles) BFRs play a minor role, however PCBs and plasticizers are significant [6]. With respect to C&D waste, plasticizers and the BFRs are the main LHSs [5].

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» Figure 2: Polymer waste stream in the scope of NONTOX.

Mixed plastics streams or streams with less than 90% of a specific polymer type (mainly at density >1.1 g/ cm3)are specially enriched in BRFs. CreaSolv® (solvent recycling) is suitable to purify and separate these streams. Complementarily, plastics streams with high single plastic content and lower content of flame retardants (e.g. density < 1.1 kg/L) are addressed by the Extruclean ® (extrusion with supercritical CO2). Side steams of both processes as well as waste plastic streams not targeted by these fractions are treated with thermocatalytic conversion (TCC) processes in NONTOX (Figure1).

Material and product design

Increasing the recycling rates of plastics, improving the economy of the recycling process as well as the quality of the recyclates is also achievable by proper material and product design. NONTOX from the perspective of design for recycling and from recycling, works in the development of materials with recycled content and products designed to fit the nowadays commercially available and economically feasible separation by density to mitigate the formation of mixed plastic streams (Table 1) and demonstrate performance on materials with significant recyclate content. The work focuses on monomaterial products and self-reinforced composites with polyolefins, styrenics and polycarbonate matrices.

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» Figure 1: The NONTOX concept.

Density range (g/cm3) Major polymers in the stream
<1.0 PP, PE and versions with low levels of filler and reinforcing fibres
1.0-1.1 ABS (low Br), PS &HIPS (low Br), filled and reinforced polyolefins
1.1-1.25 ABS (high Br), PS &HIPS (high Br), PC, PC/ABS, PA, soft PVC, PMMA. Filled and reinforced polyolefins and styrenics
>1.25 Hard PVC and other high density and highly filled polymers

» Table 1: Density separation: Practical density ranges in NONTOX for separation in WEEE, ELV and C&DW. Figure 1: The NONTOX concept.

References

Polyolefins and styrenics are the most abundant polymer groups in the recycling streams, therefore is worth to design properly their next life with focus on density. In their density ranges, the recyclates show commonly levels below 2000 ppm Br. Considering the applicable EU regulations, these fractions are, in most of the cases, not considered hazardous and do not require decontamination prior to application. When the polyolefin-based compounds exceed density 1.0 g/ cm3, e.g. by the addition of fillers they become detrimental for the fraction of styrenics or become part of the fractions of mixed plastics above density 1.1g/ cm3. Therefore, designing with focus on density for both polyolefins and styrenics is a critical need to enhance the recyclability and mitigate the need of purification of all waste streams. 

[1] PlasticsEurope,”Plastics-the Facts 2019”. 2019.

[2] Deloitte, “Increased EU Plastics Recycling Targets: Environmental, Economic and Social Impact Assessment,“ 2015.

[3] E. Commission, “A European strategy for plastics in a circular economy,“ 2018.

[4] X. Yang, et al., “Pyrolysis and dehalogenation of plastics from waste electrical and electronic equipment (WEEE): A review,“ Elsevier, Bd. 33, pp. 462-473, 2013.

[5] S.Wagner, M. Schlummer, “Legacy additives in a circular economy of plastics: Current dilemma, policy analysis, and emerging countermeasures,“ Resources, conservation and recycling, Bd. 158, p. 104800, 2020.

[6] S. Cleres, G. Wolz, G. Lastennet, M. Schlummer und G. Golz, „Determination of polychlorinated biphenyls (PCB) and phthalates in waste polymer samples intended for mechanical recycling,“ Organohalogen compounds, Bd. 71, pp. 1184-1186. 

Based on

Removing hazardous substances to increase the recycling rates of WEEE, ELV and CDW plastics Vincenti N, Campadello L, Qureshi S, Schlummer M , Quiros S, Moreno J, Fermoso J, Barreto C, Taveau M, Ardolino F, Cardamone G, Arena U. Electronics Go Green 2020 Conference.

NNTOX

The project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No.820895. Find more about the project at: www.nontox-project.eu

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