Circular potassium fertilizer from waste after production of ingredients for fish feed and straw ash

Nutrients like potassium and phosphorus enable organisms to survive and grow, making them essential in bioprocesses. There are many nutrient-rich waste streams from bioindustries which are landfilled due to hazardous contaminants (heavy metals); or are underused without fully exploiting their nutrient value. Two examples are incinerated substrates after production of fish feed ingredients via fermentation, and straw ash.

These contain significant amounts of potassium, above 20%. This project will set the basis for the first regional industrial implementation of a circular solution for clean and safe potassium fertilizers. EasyMining’s technology for recycling potassium will be optimized for these wastes to produce heavy-metal free potassium sulfate salts.

In cooperations with several partners across the value chain, we intend to do a feasibility study for building the first circular potassium solution for bioindustries in Sweden and the Nordics. Included are agricultural field trials with the recycled fertilizers to confirm the equivalence to their commercial counterparts, and a life cycle assessment. Successful implementation will have positive economic and societal impacts, but foremost environmental and climate benefits. Europe relies heavily on importing nutrients, and Sweden has flagged future access to nutrients as critical. Since most potassium mined is for fertilizer production, its recovery from bioindustry waste will significantly boost circularity in this sector.