Critical Minerals Bottleneck Solved By Weed (Make That Seaweed)

Sign up for CleanTechnica’s Weekly Substack for Zach and Scott’s in-depth analyses and high level summaries, sign up for our daily newsletter, and/or follow us on Google News!

---

Wheeling, dealing, and geopoliticking aside, the solution to the US critical minerals supply chain is sitting right there, just beyond the nation’s copious shorelines. Valuable minerals, metals, and rare earths can be extracted from seaweed, and researchers have figured out how to make the extraction process work on a commercial level. That sounds like a free lunch, but is there any such thing as a free lunch?

Harvesting Critical Minerals From Seaweed: It’s Complicated

The idea of extracting minerals and metals from plants — phytomining — has been kicking around the pages of CleanTechnica for a while now. Harvesting nickel for EV batteries from plants is one promising example to emerge.

Plants are always taking minerals up from the soil, so opportunities for phytomining opportunities abound, at least in theory. The tricky part is to find, or develop, hyperaccumulators, meaning plant species that have a superior ability to concentrate critical minerals. Even so, the sheer bulk and weight of the biomass needed for commercial-scale phytomining can present daunting challenges, and land use conflicts present additional obstacles.

Extracting critical minerals from seaweed instead of land-based crops can offer a more economical pathway, partly by streamlining harvest and transportation systems, and partly by reducing if not eliminating the fertilizers, pesticides, and other inputs needed for industrial scale farming on land.

There being no such thing as a free lunch, the impacts of new industrial-scale seaweed farming operations on the marine environment could limit the availability of suitable sites. Conflicts with other commercial fishing, recreation, shipping, and defense will add further restrictions.

Farming Seaweed For Critical Minerals

Despite the obstacles, the prize of mining-free access to critical minerals right at the nation’s doorstep is a tantalizing one. The Energy Department’s Pacific Northwest National Laboratory was tasked with assessing the technical feasibility of seaweed-based bio-mining and issued a report on the topic in 2023.

“The ocean is a vast reserve of mineralogical wealth including rare earth elements (REEs) and platinum group metal (PGMs),” PNNL noted. “These elements, categorized as “critical minerals”, are used in telecommunication devices, lasers, LED lighting, turbine generators, electric car motors, jet engine alloys, and many other applications.”

Steven Ashby, PNNL director of the US Department of Energy Pacific Northwest National Laboratory, also provided a handy recap of the opportunity at hand. “A spoonful of seawater contains not just salt, but every element in the periodic table,” Ashby noted. “Even though they are found in low concentrations—only parts per trillion—oceans are perhaps the largest single source of rare earth elements on the planet.”

Seaweed can act as an efficient, natural concentrator, with some strains achieving levels a million times more than the surrounding seawater. Further processing can increase those concentrations considerably. Producing biofuel from seaweed was an initial motivation for the PNNL research, and the team found that that the bulky solids left over from the fuel-producing process are rich in rare earth elements, with a concentration of about 10 million times more than seawater.

Maybe There Is A Free Lunch After All

Research at PNNL also indicates that farming seaweed for critical minerals might not be so fraught with environmental impacts after all. Ashby noted that the outflow from the lab’s seaweed tanks was less acidic because the algae were taking up carbon along with nitrogen and phosphorus. A seaweed farm could potentially help prevent algae blooms in at-risk regions.

As for commercial development, biofuel production represents an additional value stream that could help offset the cost of extracting critical minerals. An ammonia- and potassium-rich liquid is another byproduct, leading to the potential for tapping into the fertilizer market.

The Energy Department’s ARPA-E office, which supports transformative early stage technologies, has been funding the PNNL research along with other algal mining projects over the past 10 years, with a focus on mineral extraction and biofuel production under the whole-of-plant economic model.

Last year, ARPA-E provided additional funding to PNNL, supporting the launch of a new initiative in partnership with Virginia Tech and the startup Blue Evolution, with a focus on carbon sequestration as well as fuel, critical minerals, and other products.

Blue Evolution also adds a social benefit angle to the effort, leveraging its existing relationships with indigenous communities around the world. “We are creating more than a mining solution; we are fostering a sustainable industry that prioritizes environmental health and community prosperity,” explains Blue Evolution CEO Beau Perry.

Critical Minerals From Seaweed: Just Around The Corner

Earlier this week, Blue Evolution took aim at the marketplace with the launch of its new Orca Minerals branch, billing it as “the first U.S.-based platform to deliver regenerative biomining of critical minerals using cultivated seaweed.” The new venture deploys a modular seaweed farming system that can be used for both offshore and onshore cultivation.

“Our work with Pacific Northwest National Laboratory uncovered something we hadn’t seen before—rare earth elements and platinum group metals in our seaweed,” explains Perry.

“It’s what led us to launch Orca Minerals—a focused platform built to advance regenerative mineral recovery at scale,” he added.

In addition to the partnership with PNNL and Virginia Tech, researchers from other academic institutions are also continuing to collaborate on the project goals, listed as:

Use seaweed to optimally absorb minerals from seawater

Refine extraction techniques to efficiently recover those minerals

Ensure economic viability in local and global supply chains

Can be implemented both offshore and in controlled onshore environments

Separately, Orca is also developing systems to track and monetize the benefits of seaweed farming as a natural carbon capture, utilization, and storage system.

The next steps include developing an onshore facility for growing seaweed strains optimized for hyperaccumulation. Blue Evolution already has a head start through its existing cultivation of red, green, and brown species in Alaska and Mexico.

If all goes according to plan, Orca anticipates a working prototype up and running in 2027, with commercial production to follow in 2028.

As the research end of the project continues, PNNL is already anticipating the payoff. “In our partnership with Blue Evolution, we’ll explore scalable, non-extractive and sustainable solutions that may one day complement or even reduce the need for traditional mining,” notes Dr. Michael Huesemann, who leads the Algae Research Team at PNNL.

Photo (cropped): “Researchers at PNNL are exploring how to use algae to tap into the vast reserve of mineralogical wealth in the oceans and domestically produce critical minerals such as scandium and yttrium from seawater” (Photo by Andrea Starr | Pacific Northwest National Laboratory).