Efficient recycling and extended use of plastic-containing waste streams

The Fraunhofer flagship project “Waste4Future” sets new standards in waste management and the circular economy for plastics. Over the past four years, eight Fraunhofer Institutes have jointly developed solutions for more efficient use of waste containing plastics. Within the project, recycling methods, purification, sorting, formulations, and the processing of high-quality recyclates were significantly improved, and new recycling pathways opened up. The resulting recyclates can be used as basic material for new plastics, thus reducing dependence on fossil raw materials, such as oil and natural gas.

Research focus on chemical recycling

“Waste4Future” focused on six central fields of research: evaluation models, sensor technology, sorting technology, mechanical recycling, formulation development, and chemical recycling. Fraunhofer IKTS developed new possibilities for the chemical recycling of waste containing plastics. For this purpose, the Freiberg IKTS research group “Carbon Cycle Technologies” optimized pyrolysis and gasification technologies that enable the material utilization of plastic-containing residues from sorting. This also allows the plastic fractions to be converted into gaseous, liquid, and solid products, thus enabling material recycling. The technical and pilot plants that are used have capacities of up to 100 kg/h of feedstock. They offer the possibility to provide validation data on a large scale and thus ensure balancing under real conditions. Additionally, product samples can be manufactured under real life conditions for industrial partners.

New model approaches for optimized recycling processes

In addition, the IKTS team developed a new entropy model that enables comprehensive assessment of plastic-containing waste streams regarding their recycling potential. “We were able to show that gasification and pyrolysis can also be used to recycle plastic-containing waste streams that are no longer mechanically recyclable,” explains Dr. Jörg Kleeberg, head of the sub-project “Chemical Recycling” at Fraunhofer IKTS. “They offer great potential for increasing recycling rates and closing the carbon cycle.” Within the “Waste4Future” project, various chemical recycling process routes via pyrolysis and gasification were simulated in process chains. Subsequently, they were validated with experimental data on the basis of pilot-plant tests and serve as a reference for the comparison of the various recycling processes and their efficient transfer to industrial applications. Chemical and mechanical recycling were compared with the current state of energy recovery. The obtained data enable the assessment and optimization of various recycling paths and chemical processes. This can be used as a basis for developing new synthesis routes for the production of plastics and increasing the efficiency of existing processes.

Prospects for the circular economy and industry

The results of the Fraunhofer flagship project “Waste4Future” reveal a wide range of optimization opportunities for plastics recycling and the processing of recycled plastics. The participating Fraunhofer Institutes are thus providing crucial impulses for waste management and the chemical industry. With its expertise along the entire development chain of chemical recycling – from the laboratory to pilot scale – Fraunhofer IKTS made important contributions to the material utilization of plastic-containing waste in the project. Follow-up projects will further validate the findings and contribute to the establishment of sustainable raw material cycles.

About the Fraunhofer flagship project "Waste4Future": 

Project duration: 2021–2024

Participating Institutes:

• Fraunhofer Institute for High frequency Physics and Radar Techniques FHR
• Fraunhofer Institute for Ceramic Technologies and Systems IKTS
• Fraunhofer Institute for Microstructure of Materials and Systems IMWS
• Fraunhofer Institute for Optronics, System Technologies and Image Exploitation IOSB
• Fraunhofer Institute for Process Engineering and Packaging IVV
• Fraunhofer Research Institution for Materials Recycling and Resource Strategies IWKS
• Fraunhofer Institute for Nondestructive Testing IZFP
• Fraunhofer Institute for Structural Durability and System Reliability LBF