Norwegian fish poop can replace Russian gas and phosphorus
Every year, thousands of tonnes of sludge from Norwegian fish farms leak straight into the ocean. Now new technology puts this waste to use, both as a major source of energy and to produce the nutrient phosphorus, which Europe is importing from Russia. The Havbruk project give the Nordic region a new, global multi-billion industry, while enabling expanded fish farming without harming the coastal environment.
– Circular solutions for fish-farm waste means a lower climate impact, less pressure on the marine environment in the fjords and more fish, while making Europe less dependent on importing energy and nutrients. This way we contribute to mitigating both the climate crisis and the global food crisis, says Vidar Svenning Olsen, CEO of Ragn-Sells Norway.
In 2022, the export value of Norwegian fish farming was over 100 billion NOK (about 10 billion euros). But the successful industry has a major challenge: the fish faeces and waste feed sink through the netpens and are flushed into the sea. This sludge, packed with nutrients such as phosphorus and nitrogen, can affect the coastal environment, and the opportunity to make use of the highly valuable nutrients is lost.
The ARAL initiative, a business network in which Ragn-Sells participate, has the potential to solve both problems at once – and others to boot.
– If we are serious about building a sustainable society, we have to start using the materials we already have, over and over again. This is especially true for raw materials that are increasingly difficult to source, such as phosphorus, which is needed in both agriculture and livestock breeding, says Pär Larshans, Director of Sustainability at Ragn-Sells Group.
The sludge is taken care of
As a first step, the sludge is collected at the bottom of the netting instead of sinking straight through it. Next, the sludge is filtered and transported to facilities that separate out more water. Ongoing work aims to also capture the nitrogen at this stage, another valuable fertiliser component. The sludge is then used to produce energy-rich biogas. Finally, after incineration, more than 90 percent of the phosphorus in the ashes from the burnt sludge can be extracted using technology developed by Ragn-Sells innovation company EasyMining.
Once the phosphorus is used in new fish feed, the loop is closed. Each time around, large amounts of energy are produced.
– The amount of phosphorus released into the ocean from fish farms in Norway every year would be enough to supply every Swedish farmer with phosphorus fertiliser. We look forward to rigging more and more facilities with our system, putting an end to this harmful waste of resources, says Vidar Svenning Olsen.