Polypropylene and high-density polyethylene parts
Vicente Vert Belenguer, PhD, Technical Coordinator of the LIFE CIRC-ELV Project, AIMPLAS, discusses how the project aims to recover plastics from ELVs during the dismantling stage.
TheEnd-of-Life Vehicle (ELV) Directive (DIRECTIVE 2000/53/EC) has been under revision since 2020. A new, reviewed text is expected to be ready by the end of 2022. Some reports were produced in 2020 to evaluate the ELV Directive. Different surveys and open consultations were distributed in 2021 to define the new text. These documents included a common recommendation to dedicate more effort to increasing the recycling of materials besides metals from ELVs. This is due to the fact that the presence of plastics in ELVs is expected to continue increasing in the coming years.
This European concern about recovering and recycling plastic was reinforced by the establishment of the Circular Plastics Alliance (CPA), which has set the target of recycling 10 million tonnes of plastics from different sectors, including the automotive industry, as well as construction, packaging, agriculture and electric/electronics. A dedicated working group for the automotive industry has been working hard to provide insights into recycled plastics based on the source (ELVs) and the destination (automotive parts) of these recycled plastics. Public papers released by the CPA suggest using similar approaches. The fact is that recovering plastics from ELVs is crucial because the amount of plastic content in end-of-life vehicles is steadily increasing.
The LIFE CIRC-ELV Project (Boosting Circular Economy of Plastics from End-of-Life Vehicles through Recycling into High Added-Value Applications) started in 2018 with the aim of creating a techno-economically feasible process for recovering selected plastics from ELVs at the authorized treatment facility (ATF) stage. Specific targets included bumpers made of polypropylene (PP) and fuel tanks made of high-density polyethylene (HDPE). This European LIFE project was planned and started years before the ELV Directive was reviewed and the CPA was created. Now, in 2021, the objective of the LIFE CIRC-ELV Project has once again become a hot topic.
Great effort was previously spent sorting mixed types of plastics in the final steps of the ELV waste management process. After the depollution of ELVs at ATFs, plastics could still be found in the depolluted hulk. The hulk was then shredded, and metals were recovered. Finally, any plastics ended up mixed into the remaining automotive shredder residue (ASR). Post-shredder technologies (PST) were then used to recover each type of plastic from the mixture.
One aim of the LIFE CIRC-ELV Project was to collect large plastic parts at the ATF stage to establish an optimized route and methodology for removing and dismantling bumpers and fuel tanks from depolluted ELVs. The methodology was optimized by INDRA and validated by DESGUACE CORTÉS.
INDRA applied industry expertise and its own proprietary know-how to optimize the depolluting method used by DESGUACE CORTÉS and certain French ATFs. Depending on the country and the size of the ATF, different solutions can be applied.
One of the planned project outcomes described different ways to dismantle and sort plastics from bumpers and fuel tanks. Depending on the ATF facilities and location, dismantling bumpers and fuel tanks will be manual or mechanically assisted. A dedicated station for removing parts/components other than the plastics of interest (polypropylene and high-density polyethylene) is tailor-made based on the ATF type. Once these parts are cleaned, they are reduced in size to be sent to the recycler/compounder to produce recycled plastics.
For DESGUACE CORTÉS, the model was validated by the destructive dismantling of bumpers and fuel tanks. A new dedicated space was created for a sorting station to clean bumpers and fuel tanks, and these are being sent to the recycler/waste manager in pressed bales.
Although bumpers are non-hazardous waste, fuel tanks are considered hazardous. This means that the waste manager must be authorized to handle this waste; a common occurrence as these safety protocols apply to workers and waste managers.
Once these plastics are optimally extracted from ELVs at the ATF, they are further treated for use as recycled plastics. Processing tests for transforming bumpers and fuels tanks into recyclates and recycled plastics were conducted by AIMPLAS and ISOLAGO.
Recyclates are the plastics obtained after shredding, washing, cleaning, purifying and sorting the plastics from bumpers and fuel tanks; this is a conventional procedure at plastics recycling companies.
Shredded plastics undergo water washing with detergents and cleaning agents:
When bumpers and fuel tanks enter the recycling plant in separate streams, first, they are shredded (if they have not already been shredded at the ATF). Then the water washing process takes place, which further purifies the plastic stream; any plastic or metal parts still in the bumpers and fuel tanks with densities greater than water will sink to the bottom of the cleaning tank. PP and HDPE will float on the surface and can be channelled to a purer stream. Finally, drying and additional size reduction processes are carried out, so the recyclates are ready for further processing.
To produce, recover, or custom make recyclates with the desired properties for the intended use, recyclates must go through a compounding process in which they are mixed with additives and virgin plastics, as necessary. This helps prepare the recycled plastic pellets to be ready for the final application.
The LIFE CIRC-ELV Project demonstrated that these recyclates can make up from 25% to 30% of the final product. SIGIT and ISOLAGO validated these claims by producing parts for the automotive and construction industries. Specifically, SIGIT produced injection moulded wheel liners made of recycled PP from bumpers, and ISOLAGO produced pipes made of recycled HDPE and fittings made of recycled PP.
Final functional products can contain up to 30% recyclates.
The project is now entering the most exciting phase. Both techno-economic assessment and replicability/transferability is being overseen by SIGRAUTO. A preliminary internal economic assessment helped DESGUACE CORTÉS decide to recover 100% of the bumpers of the nearly 11,000 ELVs that enter the ATF every year. This will have an impact by keeping close to 20,000 bumpers out of landfills a year and will result in the recovery of 100 tonnes of PP from ELVs that can be put back on the market as recycled plastics and components.
The feasibility of reusing fuel tanks is still being evaluated. However, promising technical results have been found: they can be successfully converted into corrugated pipes of up to 400 mm in diameter.
The LIFE CIRC-ELV Project provided a base for these plastics collected from end-of-life vehicles at the ATF stage to deal with the continuous increase of plastic parts in new vehicles. The LIFE CIRC-ELV approach will help:
- Achieve the recycling targets arising from the new ELV DIRECTIVE.
- Increase the use of recycled plastics in the automotive and construction industries in keeping with the commitment of the Circular Plastics Alliance.
- Put plastics from ELVs back on the market.
- Keep these recycled plastics in the loop of the circular economy.