By 2030, the European Union (EU) wants all plastic packaging to be reusable, or recycled in a cost-effective manner. By the same year, half of all plastics waste generated in Europe should be recycled — aided by a four-fold increase in sorting and recycling capacity from a 2015 baseline. This is the goal of its European Plastics Strategy. In response, Europe’s leading trade and academic organizations issued a 29-page report highlighting three main challenges to creating a genuine circular plastics economy in the region.
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In “Plastics Strategic Research and Innovation Agenda in a Circular Economy,” the Technology Platform for Sustainable Chemistry (SusChem); the European Chemical Industry Council (Cefic); trade associations PlasticsEurope and European Plastics Converters (EuPC); and industry-driven collaboration the European Composites, Plastics and Polymer Processing Platform (ECP4) argue that research into plastic design, recycling and alternative feedstocks is needed.
“The Plastics industry is committed to increasing the resource efficiency of its production processes and face the challenge of closing the circularity loop. The new Research and Innovation Agenda gives fresh impetus on the strongest way to drive progress along plastics value chains by means of collaboration,” says SusChem chairman Markus Steilemann.
The first of the three challenges is the design of plastics themselves and the products in which they’re used.
The report indicates during manufacturing and use, delamination and matrix cracking that can’t be repaired with existing technologies can occur, leading to high scrap rates of up to 20–30% depending on a part’s complexity.
Different solutions exist to address these specific challenges including self-healing polymers based on thermally reversible Diels-Alder reactions, disulphide-thiol exchange reactions, and repair polymers based on dynamic hardeners.
The report notes it’s possible to develop more accurate and effective detection signals to trigger the healing process when needed. It also suggests considering other innovative activities, such as increasing the exchange reaction speed through use of linkers to develop more accurate and effective detection signals and the optimization of novel repairing technologies based on reshuffling of chemical bonds by applying heat and pressure.
A need to improve aging performance under external conditions such as extreme temperature, pressure, UV exposure, humidity and mechanical stress also exists.
“Different approaches have been developed like the addition of additives in the plastic or composites matrix and their well-controlled application in relevant areas throughout the matrix structure. To control these improvements at the nano-reinforcement and polymeric matrix interface, there is a need to improve chemical compatibility and dispersion stability as well as increasing mixing efficiency as necessary,” says the report.
The second issue is recycling. Here, the authors focus on a number of different technologies, with advanced thermochemical recycling processes prominent.
One is the combination of solvolysis with a microwave energy system. This would decrease energy consumption and speed the solvolysis process. “The microwave technology should be especially increased in the presence of impurities,” note the authors.
Another is gasification, possibly combined with biological and chemical post-treatment. The syngas produced could serve as a raw material for chemicals and materials production, and in cogeneration projects.
Other technologies considered include integrated cascading catalytic pyrolysis, synthetic biological processes to depolymerize plastics back to monomers, and co-pyrolysis of plastic wastes with other wastes such as cotton and organic materials with high aromatics content to obtain new chemical intermediates.
The third and final issue highlighted is alternative feedstocks.
Here, the report looks at technologies to convert carbon dioxide (or carbon monoxide from gaseous industrial effluents) into polymers or chemical building blocks which then can be turned into polymers.
The specific challenge identified here is getting cost-competitive access to carbon dioxide. This will rely on energy-efficient and cost-effective purification of gaseous industrial effluents to reach the purity required for the carbon dioxide-to-chemicals conversion process. New capture and purification technologies must complement and optimize state-of-the art technologies, note the authors, who go on to emphasize the importance of smart design and new materials on emerging membrane separation technologies.
SusChem and its partners hope the report will inspire both an increase in the number of collaborative projects and full implementation by EU member states of the technologies and strategies proposed within it.
Seán Ottewell is Chemical Processing's Editor at Large. You can email him at [email protected].
