When we talk about the energy transition, one term is increasingly associated with it: rare earths. This refers to several metals such as neodymium, cerium, ytterbium or scandium, which usually occur together in the underground. Until now, they have been obtained from mined ores using complex separation processes. Rare earth metals are crucial, among other things, for renewable energy technologies, such as the construction of powerful wind turbines, electric motors or energy-saving lamps.
Researchers at the University of Alaska Fairbanks are now researching a more sustainable alternative for extracting these raw materials. They want to find out whether algae near a rich rare earth deposit in southeast Alaska absorbs these metals. They are focusing on algae in the waters near Bokan Mountain.
The key question was whether underwater plants like the bull kelp shown here can enrich rare earths in a concentration that is economically lucrative. Lead researcher Schery Umanzor explains that the algae act like sponges, accumulating the elements in higher concentrations than in water. Preliminary studies have already shown that the marcoalgae can actually absorb rare earths. However, it is still unknown in which concentrations the metals are found and how complex it would be to subsequently extract the metals.
In the first year of their project, the team first examines wild algae populations and determines the amounts of rare earths that are absorbed by the plants. Only when these results are promising will Umanzor and his colleagues also want to explore the potential of algae farms with different types of algae and growth conditions.
Umanzor is convinced of the potential of the idea. However, he also emphasizes the relevance of scale, because a small farm would probably not work. The extraction of metals from algae must be part of a large commercial enterprise in order to be economically viable. Since the researchers will be collecting and analyzing their algae samples from March 2024, it will still take a while until the first results are available.