February 13, 2024
At the beginning of 2024, Professors Bonten from the University of Stuttgart and Endres from IKK – Hannover Institute discuss current developments in the plastics industry and circular economy in an exclusive interview.
Insight into the research and expertise of the two professors provides an outlook on what to expect in these crucial areas in 2024. We highlight the topics shaping the industry, from regulatory and technological upheavals to economic trends. It becomes clear that a more sustainable approach to plastics is essential, with innovative solutions such as biogenic carbons, recycling, and CO2 utilization being key. Future regulations and standards will continue to drive the industry forward and promote the use of recycled plastics. The interview was conducted by the online magazine Circular Technology (CT) and is reproduced below in its original text.
CT: What developments and innovations do you expect in 2024 in the field of plastics and the circular economy, particularly concerning new technologies or processes?
The industry is aware and active: Processes and procedures in all areas of plastic recycling will continue to evolve. This applies to pre-treatment and preparation strategies, as well as to various mechanical, solvent-based, and chemical recycling processes. Moreover, recycling methods will be combined to increase efficiency and enhance output quality. Examples include the use of twin-screw extruders for removing residual solvents through degassing or pre-melting before solvent use. Targeted depolymerization in the twin-screw extruder is also possible.
CT: What challenges and trends do you foresee for 2024 regarding the handling of plastic waste and promoting a sustainable circular economy?
The EU's circular economy and plastic recycling guidelines are increasingly addressing sectors beyond packaging. This broadens the input streams for recycling to include products from the automotive, electrical and electronics, textile, construction, and even medical sectors. For recycling, this means not only typical packaging materials like PE, PP, PS, and PET but also increasingly technical and composite plastics based on PA, ABS, PC, and others will need to be reused.
CT: Can you predict which long-term changes and strategic approaches in the plastic sector and circular economy will gain importance in 2024, and how will these influence the industry's transformation?
The entire plastics industry is in motion, and securing high-quality, clean, and pure input streams for recycling, both in the pre-consumer and increasingly in the post-consumer sector due to recycling regulations, is becoming crucial for industry players. This leads to new alliances, joint ventures, and integrated company structures both downstream and upstream.
CT: What current developments and trends do you foresee in 2024 in the field of plastics and the circular economy, particularly concerning the research activities of IKT and IKK?
Further development of recycling processes to improve recycled material quality:
Research activities at IKK focus on developing input-specific pre-treatment strategies and integrating analytics into mechanical recycling processes using state-of-the-art recycling facilities. The term "strategy" is deliberately chosen here, as there are almost no adapted pre-treatment strategies (cleaning and shredding methods, identification and separation technologies, definition of separation criteria, sequence of process steps and parameters) for products outside the packaging sector. A clear example we are working on in this context is automotive shredder light fraction. At what stage should shredding occur, and what is the optimal particle size? Where, how, and how often should washing be done (cold or hot wash, use of surfactants)? When and where should density-based separation occur, and with which density cut-off? Where does it make the most sense to separate shredder components by colour or polymer type? Similar questions arise for nearly all other plastic input streams regarding recycling-optimized pre-treatment strategies.
An equally important research focus at IKK is the further development of mechanical recycling processes themselves. Various approaches are being innovated to maximize the quality of recycled materials during the process. The core process usually involves modular, cascaded recycling plants with high technical flexibility and extensive in-line cleaning technology (rinsing gases, supercritical CO2 as stripping gas, melt filter cascades) and inline analytics (colour and viscosity measurement and control, analysis of melt composition and emissions) to measure, control, and regulate the quality of recycled material during the recycling process.
Parallel to researching efficient pre-treatment strategies and innovating recycling processes, IKK also continuously conducts technical, economic, and ecological assessments of the resulting materials and processes and estimates scalability. The goal is to produce efficient, sustainable, and high-quality recycled materials, even from difficult-to-recycle input streams, with a proper ecological assessment of different recycling processes and products being a scientific challenge.
Research on the behaviour of plastics and bioplastics in the environment:
IKK also researches the persistence of plastics and the aquatic degradation behaviour of bioplastics under various environmental conditions.
Keeping material from sustainable sources in the loop longer:
IKT, with its large processing technology centre, traditionally works in the field of gentle remelting, or mechanical recycling. Polycarbonates are successfully mechanically recycled to be reused in food contact applications. Bioplastics, known to be less thermally stable, are systematically tested for recyclability and specifically stabilized. Before the recyclability of bioplastics becomes necessary, reducing material use remains the preferred step.
In Stuttgart, work is also being done to enable biobased and biodegradable materials for established processing technologies, such as foaming. Extensive know-how on reactive extrusion has been developed over long-term research projects, which allows for the targeted adjustment of bioplastics' foamability. Biobased lightweight materials can be produced not only by foaming but also through biobased fibre composites. Here, novel matrix materials and fibre materials are being studied. Additionally, various biobased plastics are tested for their long-term durability and continuous use in automotive and electrical applications.
Through a successful circular economy, uncontrolled plastic entry into the environment can be reduced. However, IKT also considers the consequences if this is not fully achieved. Therefore, new methods for identifying and quantifying plastics in the environment are being developed. It is still not fully understood how quickly different plastics degrade in the environment and what ageing processes play a crucial role. The knowledge generated from these questions is used to develop more sustainable plastic solutions, where the entry of plastics into the environment cannot be avoided. For instance, one research project investigates the initial creation of a biobased (and partially biodegradable) synthetic turf system with the same sporting and functional properties as conventional sports fields. Holistic life cycle assessments of the projects are always conducted to ensure increased sustainability.
CT: Considering the dynamic changes in the plastics and circular economy sector, what long-term perspectives and challenges do you foresee for 2024 and beyond, particularly concerning the activities of IKT and IKK?
Plastics are indispensable for daily life, our standard of living, and future megatrends. At the same time, we cannot continue to handle plastics and plastic products in a (linear) manner as we have done since the discovery of plastics over 100 years ago. There are several approaches for more sustainable handling of plastics. These include using biogenic carbon sources at the feedstock level, i.e., natural raw materials or organic by-products and waste, recycling plastics, i.e., petrochemical or biogenic carbon in various end-of-life scenarios, or using CO2 as a carbon source to even reverse the greenhouse effect. Researching, developing, and ecologically evaluating these different measures can and must provide the basis for depoliticizing and making fact-based political decisions in plastics and plastic circular economy.
CT: What significant changes do you expect in legislation and regulatory frameworks for the plastics industry in 2024, and how might these changes affect business models and practices in the industry?
In addition to quotas for specific sectors, products, or materials, the sustainability assessment of various circular measures and (newly developed) standards and norms for recycled plastics are gaining importance for legislation and recycling value chains. Long-term, beyond 2024, a Europe-wide product tax based on product-specific life cycle assessments will financially favour the most sustainable materials – and here, recycled plastics will perform excellently.
You can access the original interview here.
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