With the current much-needed shift towards the circular economy, there is a steadily increasing interest in the recycling of fishing nets. End-of-life fishing nets can be composed of a variety of mixed materials making them difficult to recycle. Nonetheless, a lot of research is being done to find ways to ‘close the loop’ for fishing gear. Seeing as KIMO administers the Green Deal Fisheries for a Clean Sea in the Netherlands, we were invited to deliver a presentation at the MARELITT Baltic Workshop “Recycling of Lost Fishing Gear” on April 11-13 in Stralsund, Germany. The workshop was organized by the World Wildlife Fund and dealt with both lost fishing nets and end-of-life nets. The workshop included the following topics
- Harbour reception facilities
Collection of end-of-life and lost fishing gear
- Pre-processing of nets for recycling
What needs to be done to prepare nets for different recycling schemes
- Thermal recycling methods
Hydrolysis & pyrolysis for contaminated lost fishing gear
- Material recycling plastics from the Sea
Which materials can be used and how can consumer products be created from lost nets?
Particpants were interested in the Green Deal approach and the Dutch working method. The presentation was well received. Participants were impressed by the success of Fishing for Litter and were keen to learn about the active collaboration between different entrepreneurs, organisations and authorities to address the challenges in the fishing waste sector. There was particular interest in the use of dedicated big bags for galley waste and the unique approach to dealing with dolly rope waste. It is collaboration that makes Fishing for Litter and the Green Deal Fishing for a Clean Sea a success.
Recycling fishing nets
During the workshop, many interesting possibilities for the recycling of fishing nets were presented. Collection takes place in different ways: for example, the government of Norway organizes annual expeditions to dredge up abandoned, lost or discarded nets and various parties work together with the Global Ghost Gear Initiative. The nets are contaminated with sediment, chemicals and metals. This does not, however, appear to present a problem when it comes to processing the nets. Shredders have been developed by various companies such as Vecoplan AG that can shred the material. These companies can also clean the material. By using different methods, the ‘organic’ (i.e. everything made from oil) can then be separated from the inorganic (for example sand and metal).
Thereafter you have three options: 1) pyrolysis, 2) creating plastic pellets and 3) hydrolysis. In the first, the shredded netting is heated to 400-600° C. The molten material can then be pressed into shape or poured into a mould. Impurities such as rubber particles can, however cause bubbles to form in the liquid. The higher the temperature, the more fluid the material becomes. However, at higher temperatures, the yield decreases and one ends up with more waste than reusable oil. The liquid can also be used to make plastic pellets which serve as source material for the creation of new plastic products.
With hydrolysis all material is sublimated (i.e. “gasified”). For this the shredded netting does not have to be cleaned first. First, all oxygen is removed from the material, then the temperature is raised to above 1100° C. The resulting gas is cooled and inorganic material settles. Then the gas passes through two systems through which heavy metals, halogen, salt, chlorine and sulfur are filtered out of the gas. What remains is clean ‘Syngas‘. This system was presented by Thies von Appen from CleanCarbonConversion. The installation is modular and can be transported by road.
The participants of the conference came from all over Europe and in particular the countries around the Baltic Sea. Companies and organisations from the United Kingdom, France and Spain were also present. The amount of presentations showed the diversity of initiatives in Europe to collect and recycle fishing nets. It was especially good to have three Fishing for Litter coordinators present: Xoan Lueiro from CETMAR (Galicia), Nils Möllmann from NABU (Germany) and Jan Joris Midavaine from KIMO (Netherlands and Belgium). Fishing for Litter will no doubt have a big role to play in moving net recycling forward in the coming years.
There’s no one simple solution when it comes to fishing net recycling and, as an industry it is still in its infancy but it is good to see the level of commitment from a diversity of stakeholders in the fishing industry. We’re closing in on closing the loop.