Maximising the Impact of Advanced Recycling: The Importance of Pre-, Post Treatment and Upgrading

With a majority of plastic production using fossil material, plastic waste recovery becomes a key factor to reduce exhaustion of such limited resource. Currently chemical recycling is the most promising way to efficiently utilize plastic waste resources in larger volumes. Some waste-streams can also be processed with mechanical recycling, which requires homogeneous feedstock, limiting the applicability of this approach to only a small waste fraction.

With advanced recycling technologies progressing, the recycling sector is undergoing a significant transformation, which is particularly driven by pre- and post-treatment technologies that improve the outcome of all recycling operations. These processes are essential for enhancing the efficiency and quality of recycling, addressing challenges across various waste streams. This includes plastics, textiles and electronics.

The importance of pre-treatment technologies

Chemical recycling technologies are the most promising path for the material recovery of plastic waste. However, 30% of such waste cannot be treated in this way due to the presence of contaminants or specific chemical elements. Pre-treatment processes are therefore crucial for preparing materials for recycling. This phase involves the identification, sorting, separating, washing, and preconditioning of material to generate fractions in consistent quality, minimize contamination or interfering substances and meet different feedstock requirements before entering the main recycling process.

Size reduction methods, such as shredding and grinding, enable to fulfil requirements on the physical properties (e.g. size or surface area). Additionally, washing techniques remove adhering dirt or impurities, while chemical pre-treatment can enhance material purity or its properties, making it more accessible for recycling.

Post-Treatment Innovations

Post-treatment technologies are critical for refining recycled materials. Advanced filtration, distillation and other fractionation techniques are being developed to purify products and adsorbents can be used to remove heteroatomic contaminants, ensuring that final products meet high quality standards. Innovations in purification processes are also crucial for monomers and polymers, particularly in the recycling of e.g. PET via solvolysis, where high purity levels are necessary for effective re-polymerization.

Examples of Pre- and Posttreatment Innovations in Recycling

Several innovative approaches highlight the potential of advanced pre- and post-treatment technologies in advanced recycling. These examples illustrate only a fraction of ongoing developments in the field:

1. Methods for pre- and post-treatment of feedstocks: Developed by Fraunhofer UMSICHT, this approach focuses on various innovative methods for treating plastic waste prior to chemical recycling. The research emphasizes novel techniques that enhance feedstock quality, thereby improving overall recycling outcomes.
2. Refinery upgrading to enable the scale-up of chemical recycling: Neste has made significant strides in upgrading liquefied waste plastic at its Porvoo refinery. With an investment of € 111 million, Neste aims to process 150,000 tons of liquefied waste plastic per year as part of Project PULSE. This project not only enhances the flexibility to process lower-quality plastics but also aims to scale up operations significantly by 2025. Latest effort enabled the company to double the amount of waste plastic processed during 2023.
3. Pioneering purity and transformative advances in chemical polymer recycling: Sulzer Chemtech has developed innovative purification processes that focus on removing contaminants from recycled polymer streams. This includes efficient bromine removal from polystyrene melts, which is essential for recycling EPS that often contains brominated flame retardants. Their advancements ensure the safety and purity of recycled materials while facilitating thermal depolymerization.

Conclusions

Advancements in pre- and post-treatment technologies are vital for improving the efficiency, quality, and scope of advanced recycling processes. The primary goal of recycling is to keep carbon within the technosphere by recovering valuable feedstock from waste materials. This not only reduces reliance on virgin resources but also minimizes greenhouse gas emissions associated with production processes.

In the future, digitalization and artificial intelligence (AI) are poised to play transformative roles in these processes. By integrating AI-driven analytics into sorting and processing systems, stakeholders can achieve greater precision in material separation and contaminant removal. Digital tools enable real-time monitoring and optimization of recycling operations, leading to enhanced (energy-)efficiency and reduced operational costs, and moving the industry closer to achieving a circular economy across various waste streams.

Advanced Recycling Conference 2024

For those interested in staying at the forefront of these developments, the Advanced Recycling Conference (ARC) 2024, scheduled for November 20-21, 2024, in Cologne, Germany, and online, will provide a comprehensive overview. The conference will showcase a range of solutions through dedicated sessions on advanced recycling technologies, highlighting innovations that shape the future of material recovery, such as extrusion, dissolution, enzymolysis, solvolysis, pyrolysis, thermal depolymerization, and gasification with Carbon Capture and Utilisation (CCU). Top experts from industry and research will address urgent issues such as E-waste valorization, PVC recycling, textile recycling, and utilizing advanced recycling methods for engineering thermoplastics.

For more information and registration, visit https://advanced-recycling.eu.