Closed-loop recycled plastics from end-of-life vehicles: Sensor-based sorting of automotive shredder residues and simulation of closed-loop rates

In the European Union, between 14 and 18% of current passenger cars are made of plastic materials. Despite all advantages that plastics bring to the production of vehicle components, there are also decisive disadvantages at the vehicle's end-of-life. Plastics end up as automotive shredder residues and are mainly utilized thermally as refuse-derived fuels. Mechanical recycling of automotive plastics from end-of-life vehicles is not common practice. We assessed the circularity potential of plastics in passenger cars through mechanical recycling of automotive shredder residues. We developed a sensor-based sorting process to separate polypropylene, polyamide, polycarbonate, and acrylonitrile butadiene styrene. Our process yields a 13.3% recovery rate for thermoplastics from end-of-life vehicles. 26.1% polypropylene, 31.2% polycarbonate, 5.3% acrylonitrile butadiene styrene, and 22.1% polyamide were recovered. We developed a dynamic simulation model to theoretically extrapolate those results and calculate the closed-loop recycled content of plastic in new cars from post-consumer end-of-life vehicle waste. We simulated total and polymer-specific closed-loop rates for six scenarios and performed a sensitivity analysis. In our MIX scenario, a closed-loop recycled content rate of 3.1-4.8% can be reached in 2035, based on our study setting. An environmental assessment shows that our developed sorting process results in 29.5% lower greenhouse gas emissions than the usual incineration of the automotive shredder residues sorted. Although additional efforts will be required to effectively close material loops for plastics in the automotive sector, our results indicate the technical potential of concentrating polymers from automotive shredder residue to contribute to meeting closed-loop recycled content quotas.