Background

Netherlands Circular 2050 aims for full circularity by 2050, with a focus on plastics; however, only 15% is currently recycled into high-end applications. The Circular Plastics Growth Fund aims to increase this percentage. Plastic recycling, both mechanical and chemical, generates microplastics. The European Commission is taking measures against the release of microplastics, and at the same time, the EC is determining the most appropriate measures to further reduce microplastic emissions into the environment. The EU has identified recycling as a potential source of microplastics. 1 Quantitative data on microplastics is crucial for the Netherlands’ recycling industry and policymakers. The project “Losses and Emissions in Plastic Recycling,” involving NTCP, ISPT, TNO, and Wetsus, has identified key processes that generate microplastics and effective mitigation methods such as dissolved air flotation. MiPlaR will build on this, focusing on the quantification and recovery of microplastics. In this project, we will explore multiple types of packaging plastics. The project aligns with UN SDGs 12 and 6, aiming to increase recycling rates, reduce emissions, and improve water quality by reducing pollution and untreated wastewater.

Goal of the project

As part of the MiPlaR project, our focus is on supporting the recycling industry both in the Netherlands and internationally to minimize losses and emissions resulting from the formation and release of microplastics. To achieve this, we aim to identify and quantify microplastics throughout the recycling chain, enabling: 

Reduction of microplastic generationin recycling processes for various sorted plastic packaging waste streams through: 

• understanding the properties (size, shape, density) of microplastics generated during the recycling process and their distribution throughout that process;
• optimizing process settings and implementing potential process design changes;
• adjusting the order of process steps;
• selecting better material (grade, processing conditions) and product (design) properties for specific packaging applications. 

Preventing microplastics from entering the environmentby: 

• recovering microplastics generated in recycling processes for reuse in other recycling processes;
• implementing water treatment methods to capture microplastics, including the smallest particles. 

Brief description of the activities

We will examine various unit operations and process designs in recycling, benchmarking typical packaging plastics for microplastic formation. NTCP will carry out this work at its modular, full-scale recycling facilities. Additionally, we will develop sampling and standardized analytical tools, building on our previous work in the LEmPlaR project (TNO, NTCP).

Our experimental work also examines the properties of materials, (product) design, and ink removal in relation to the formation of microplastics during recycling. 

After identifying the key unit operations that generate microplastics, we will develop mitigation strategies and conduct two types of trials to validate them: 

• Adjusting process parameters and settings of existing reprocessing equipment;
• Implementing design changes in equipment to reduce the formation of microplastics. 

We will develop rapid, in-line measurement (estimation) techniques for microplastics. 

The project will evaluate and benchmark conventional mechanical wastewater treatment processes for microplastic removal and wastewater quality. We will also identify and optimize candidate processes for microplastic removal and develop a proof-of-concept for a novel high-throughput filter (Wetsus).

Result

The main plastic packaging materials in the Netherlands are PP, PE, and PET. Our previous study established a detailed mass balance for the mechanical recycling of PP from household packaging waste, revealing that most losses occur in the form of microplastics. Using this study as a reference, we will provide benchmarks for HDPE, PET trays, and mixed plastics (DKR350/352, containing PE, PP, PET, PS, and PA) using state-of-the-art recycling processes. 

• Packaging printing involves polymeric ink binders that release microplastics during deinking. We will investigate the fate of inks in plastic recycling on a bench-scale basis, using direct printing on PP as a relevant example. 
• Following the benchmarking, we will explore potential mitigation measures and develop proofs of concept.
• The project will also result in standardized sampling methods for industrial use and analytical methods for inline or at-line application in recycling facilities. 
• Our findings will be shared with the recycling industry, policymakers, and the scientific community. We plan to publish several peer-reviewed articles.

Project partners

• NTCP, the Netherlands. Role: coordinator of a research institute with industrial-scale sorting and recycling facilities. NTCP will serve as both waste manager and recycler within the consortium.
• TNO, the Netherlands. Role: research institute with expertise in circular plastics and microplastics. TNO will serve as the recycler within the consortium.
• Verpact, the Netherlands. Role: producer responsibility organization for packaging.
• Van Dam Machine, the Netherlands. Role: provider of packaging printing machines.
• ISPT, the Netherlands. Role: network organization.
• HTP, Germany. Role: engineering firm specializing in waste management and processing.
• Wetsus, the Netherlands. Role: research institute with expertise in water treatment.
• Malvern Panalytical, Netherlands. Role: analytical equipment provider.
• SunChemical, Belgium. Role: ink manufacturer.
• Province of Friesland, the Netherlands. Role: provincial authority responsible for matters such as the environment in Friesland.
• Rijkswaterstaat, the Netherlands.Role: government agency with partial responsibility for water quality.