Industrial-scale production of microalgae: From factory fume to fish feed

At the Finnfjord AS ferrosilicon plant in Northern Norway CO₂-rich emission gases and heat surplus are utilized in a circular loop through photobioreactors for large-scale production of microalgae. Finnfjord AS emits 300 000 tons of CO₂ per year that can potentially be converted by microalgae to 100-150 000 tons of biomass. The produced microalgae biomass can function as sustainable raw material for fish feed enabling a further expansion of the salmon production with a simultaneous reduction of the carbon footprint. Through the Green platform AlgOpti and the knowledge project AlgScaleUP we are developing the technology and biological foundation to achieve efficient growth in industrial-scale bioreactors. Important tasks within the project include identifying cold-water adapted microalgae suitable for production in very large volume vertical photobioreactors (VLVVPBR), determining the optimal addition and distribution of factory flue gas, and developing a novel energy efficient lighting concept enabling the light to be homogenously distributed throughout the tank. A 300 000 L pilot-scale photobioreactor are used to gather the knowledge necessary to establish the design criteria for a tank in the million L-scale