The extraction of high-quality secondary raw materials from waste coming from production and daily consumption is essential for the development of sustainable economic growth, which is to become increasingly independent of resource consumption. Certain material flows, such as plastics made of PET, can already be separated efficiently and automatically and fed to further processing. However, as technology advances, new materials and manufacturing processes are being developed that make it more difficult to separate materials. In particular, shredder light fractions, e.g. mixed plastic residues from vehicles, still pose a challenge for conventional recycling plants. In 2015, around 542,000 tonnes of shredder light fraction were produced, 92,000 tonnes of which from the recycling of end-of-life vehicles. Of these, around 33% were thermally recycled in 2015 (source: German Federal Environment Agency). So far, it has not been possible to separate the plastics efficiently enough so that recycling would be economically worthwhile.

This is precisely where the Fraunhofer Project Group Materials Recycling and Resource Strategies IWKS comes in. Researchers in the Urban Mining department see large potential for improving conventional technologies by evaluating sensor data in real time. "Material flows are subject to constant change. Our modular sorting system already offers a high degree of flexibility. By using and, above all, linking sensor data in real time, we can manage material flows faster and more efficiently in the future," explains Dr. Katrin Bokelmann, head of Urban Mining at the Project Group IWKS. The researchers' idea is to use artificial intelligence to evaluate the data supplied by the sensors. This will enable the individual modules of the sorting system to be independently adapted to the optimum result during the sorting process. The aim is to automate the separation of complex materials such as shredder light fractions and therefore make them available for further processing in a highly efficient manner. “Currently, these plastic fractions are mostly used for thermal recycling. This has two disadvantages: On the one hand, the plastics are lost in a sustainable material cycle and, on the other hand, only a limited amount of these materials can be recycled in the incineration plants without causing any damage to the plants," Dr. Bokelmann continues. "We see a high demand in the market to find a solution for the industry. Digitization opens up promising ways for us to make better and more efficient use of the potential of waste streams." Concrete projects are already being planned.

The Fraunhofer Project Group IWKS can be found at the Solids & Recycling-Technik 2018 trade fair from November 7-8 in Dortmund in Hall 7, Stand X08 A. Dr. Gert Homm will also be giving a lecture at the trade fair entitled "Circular Management of Valuable Materials: New Concepts and Technologies with Concrete Examples” at the WFZruhr e.V. workshop on November 7, starting at 1:30 pm. Registration and further information at https://wfz-ruhr.de/index.php?id=3.