During the first year of the project, an up to date review of the technical and patent literature and industry trends around the recycling of MultiCycle’s target multi-materials has validated the opportunities identified for the MultiCycle process concept, and the CreaSolv® selective material recovery technology at its heart. Whilst regulatory pressure to establish higher recycling targets will drive development of the recycling sector in the coming years, current options for the MultiCycle target materials are limited: both multi-material/multi-layer flexible packaging and reinforced plastics in End of Life Vehicles (ELV) are predominantly sent for fuel/energy recovery.
Capitalizing on pre-existing small pilot facilities and experience gained by Fraunhofer IVV, the MultiCycle technical team has been able to lay strong foundations in the project’s first year to smoothly up-scale to a Technology Readiness Level (TRL) 7 prototype industrial demonstration later in the project. Critical process parameters for stable plant operation have been identified, along with candidate process monitoring systems, and insight gained into input material requirements such as which components of a motor vehicle can be used within the framework of the project to increase the recycling quota of end of life vehicles.
To those ends technical work is well underway to obtain and evaluate a wide selection of waste material streams representing the variety of material types which the MultiCycle pilot plant might be expected to handle, and to identify from this a broad window of suitable waste stream requirements within which economic and practical processing could take place. Reaching into the relevant supply and value chains, the project partners have secured numerous samples of both industrial scrap and post-consumer wastes, including all the major classes of thermoplastics encountered in flexible packaging, inclusing single polymer and multiple component later materials, and similar exemplars of carbon and glass reinforced plastic composites from the automotive sector. Both laboratory characterization and experimentation on a small-scale batch CreaSolv® pilot plant at Fraunhofer IVV is being used to parameterize the MultiCycle process, and to inform the design of a 25 kg/h scale, continuous pilot plant, including suitable monitoring systems for plastic waste composition tracking and process control being developed by IRIS Technology Group.
The MultiCycle process is designed to accept a diverse range of industrial scrap and post-consumer plastic and composite wastes.
Automated monitoring of waste composition and PAT platform for process optimization
IRIS has been testing a number of innovative parallel techniques for identifying the composition of the input complex materials for the Creasolv® process. In contrast to standard mechanical recycling, where the quality of reprocessed material can be jeopardized by the risk of inclusion of foreign polymer fractions, the Creasolv® process is tolerant to multimaterials. It is possible however to optimize its set up based on batch by batch compositional data for the feed stock to be recycled, and ensure that any disruptive materials are avoided.
Material recycling from mixed waste plastics is based on sophisticated process chains combining different sorting steps like screening, wind sifting, NIR (Near-infrared) spectroscopic sorting, electromagnetic removal of metals and others. Currently available sorting technologies cannot fully solve the challenge which MultiCycle has tackled. They are effective for rigid packaging, like bottles, but are not tailored for laminated or composite materials. The latter, in fact, are very rarely automatically sorted.
Against this background, IRIS has therefore tested a variety of molecular and atomistic spectroscopic techniques coupled with advanced data processing algorithms when needed. For packaging materials, NIR spectroscopy, and NIR hyperspectral imaging (HSI) are commonly used in several sorting stages by waste management facilities, but they are generally calibrated only to identify monomaterials. Tailoring its proprietary Hypera HSI solutions, several cameras at different wave ranges have been tested by IRIS with particular attention being dedicated to the development of models to identify as many fractions of combined polymers as possible.
A combination of direct imaging (left) and HSI monitoring (right) of various mono- and multilayer films shows the ability to identify single and combined materials. Further improvements are ongoing.
For automotive materials, the main challenges lies in the identification of the thermoplastic matrices and the glass or carbon fibres in end of life parts. Since these are very often black they prevent the use of standard techniques like NIR. Different methods have been tested and calibrated to identify the main polymers and fibres targeted for recovery in the project. Since this fraction is currently not individually recycled but generally ground with other light fractions from end of life vehicles, the protocol to collect and define in which step to control the composition of the parts is also being defined in collaboration with project partner GBP Metal.
A versatile hardware and software prototype combining the different selected techniques is currently being built. The Process Analytical Technologies platform will be equipped with artificial intelligence models to make informed decisions on the process (e.g. selection of the optimal process parameters and which fractions are worth recovering). It will be installed in the Multicycle pilot plant at a LOEMI facility during the second quarter of next year, where it will support the production of a significant amount of secondary raw materials for the subsequent validation stages of the project.
CreaSolv® trademark registered by CreaCycle GmbH.
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