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Sustainable Polyester Recycling Implementation & Technology
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Sustainable Polyester Recycling Implementation & Technology

SPRINT

Sustainable Polyester Recycling Implementation & Technology
Project leader
CuRe Technology B.V.
Duration
September 2023 till November 2026
Domains
Engineering and Technology

Within the SPRINT project, we are developing an advanced chemical recycling process for PETtogether with CuRe Technology B.V.. We are working to improve and scale up this process in order to apply it on an industrial scale. 

Within this chemical recycling process, we polymerize PET via oligomers. Instead of mechanical recycling (where plastic is physically melted and reshaped), in this process the PET is chemically broken down into smaller units called oligomers. These oligomers are then re-polymerized (assembled) into recycled PET (rPET). This process can be more efficient and produce higher quality recycled material than mechanical recycling. The goal is to scale up the process from a pilot scale (TRL6), to an operational scale (TRL7). In addition to scaling up, we also focus on improving specific steps in the recycling process and automating existing processes. We aim for greater efficiency and consistency in production. Ultimately, our goal is to achieve a TRL-level 8.

Reason for the project

By 2050, the Netherlands must be a circular economy. Products will no longer be landfilled or incinerated, but all materials will be reused. Many plastics, such as polyester (PET), are now mainly recycled mechanically. As a result, the quality of the material deteriorates and the product is only suitable for low-grade applications. CuRe Technology has developed a form of chemical recycling, in which PET is chemically broken down into smaller fragments (oligomers) that are repolymerized immediately afterwards. This means that the material that was first broken down into its basic components (monomers or oligomers) is reassembled into polymers.

The quality of the plastic is retained within this process and the material can be used in high-value applications, such as in food packaging. The technological feasibility of this technique has been demonstrated in a pilot setup capable of processing 20 kg/h of polyester waste in a continuous operation.

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Mechanisch Recyclelab Leeuwarden

Our goal

Our goal is to realize the most energy-efficient polyester recycling technology at industrial production scale in Emmen. We want to scale up the pilot setup more than 100 times to a plant capable of making 25,000 kg of rPET.

What problem does our project solve?

Although previous studies have shown that there are no fundamental objections to further scaling up the technology, there is still a final sprint to make this realization possible in detail. In addition to partial scaling up of some components of the system, efforts are also being made on automation, in-line process control and setting up a QMS (Quality Management System).

Three northern knowledge institutions (University of Groningen, Hanze University of Applied Sciences and NHL Stenden University of Applied Sciences) are contributing by investigating the properties of the oligomer mixture and developing innovative methods of purification. This promises to eventually provide the industrial knowledge needed (TRL3-6) to facilitate the scale-up process. This, together with the previously developed basic design of the pilot setup, provides the basis for efficient construction and commissioning of the plant.

Cooperating partners

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Logo Cure
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NHL Stenden logo grid
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Hanze Hogeschool logo 1
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University of Groningen

Who is the project team

CuRe Technology B.V. wants to realize worldwide the first circular plant for the production of rPET specialties by means of chemical recycling where the quality, flexibility and sustainability of the rPET is of the highest importance.

From the Faculty of Science & Engineering of the University of Groningen, the Green Chemical Reaction Engineering Department of Prof. Dr. H.J. (Erik) Heeres is involved. His department specializes in thermochemical biomass conversion, environmentally friendly catalysts and chemical technology.

The Biobased Economy knowledge center of Hanze University of Applied Sciences Groningen aims to contribute to a biobased economy, using the strengths of the Northern Netherlands region. Attached to the knowledge center is the Zernike Advanced Processing (ZAP) facility. This is an innovative learning working environment in which applied research and education is carried out in cooperation with industry. The aim is to strengthen human capital and innovations.

NHL Stenden is a higher education institution with campuses in the Northern Netherlands and abroad. From the campuses in Emmen and Leeuwarden, applied research is carried out within the lectureship Circular Plastics
 

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Circular Plastics Sprint item

Professorship Circular Plastics

This project falls under the professorship Circular Plastics. Plastics are unique and versatile materials that help us stay healthy, safe and warm. From a heart catheter and car seatbelt to cavity wall insulation, a world without plastics is hard to imagine....

How is this project team tackling it?

The activities within this project can be divided into three parts. 

  • Scaling up of the production process
  • Improvement of process steps
  • Automation of existing processes

In order to achieve the project objectives in an effective and efficient manner, we strive for a clear project structure and organization.

Scaling up production process

For scaling up the production process, we identify several points of interest. This includes scaling up portions of the equipment as well as the design of individual components for the demonstration plant. Currently there is a continuous pilot plant for depolymerization and purification with a production capacity of 20 kg/hour. We want to scale up to a plant 100 times larger. So the current plant needs to be scaled up. This includes scaling up portions of the equipment, as well as the design (engineering) of individual components (such as filters and pumps) for the demonstration plant. And a new extruder must be purchased. An extruder is a device specifically designed to deliver a plastic in molten form to a mold through labor. Other steps also need to be taken in the scale-up process. Ultimately, the goal is to achieve a TRL-level 8.

Improvement of process steps

The second is the improvement of process steps. Here we are going to work on optimizing some parts of the process. The goal is to make these parts ready for further upscaling. This concerns the different mates of contamination of the polyester supply streams. The accumulated experience with CuRe Technology's pilot line shows that impurities can greatly affect the results of the process. High levels of fouling have a negative impact on machine tool life. The mixture is passed through a column of activated carbon after depolymerization. Given the cost of activated carbon, regeneration is desirable. For this to be applicable on a large scale, an arrangement must be developed with several columns in a carousel.

A post-doc researcher at the RUG is conducting research on developing and testing alternative forms of purification, including testing fillings other than activated carbon. The second part of this post-doc research is focused on understanding and controlling the particle size of the mixture after depolymerization (this is a chemical decomposition reaction in which a polymer is broken down into a monomer or mixture of monomers). Finally, alternative purifications of the oligomeric mixture are still being investigated. Consider crystallization. If successful, this could provide a way out to increase purity and quality while avoiding purification by adsorption and filtration.

Automation of existing processes

Automation of existing processes is the third component of this project. In the current production process, certain operations are performed manually. This creates relatively high down-time of the plant and off-spec production. The automation must be tested in the pilot plant in order to then be used optimally in the large plant.

In view of the application in food packaging material, an inventory of (upcoming changes) in legislation and possible adaptations to it is necessary. In anticipation of this, it is desirable that analyses that are currently carried out externally can take place on site. NHL Stenden (Agora, Leeuwarden) has experience with various analysis methods to determine the quality of oligomers and polymers. They can advise CuRe Technology on how this can be captured in a quality management system.

Made possible in part by these parties

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Sustainable Development Goals

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