CEO Loren Burnett sees a path to decarbonizing concrete via manufacturing with novel biotechnology.
“This whole thing started with a project with the Department of Defense, between the Department of Defense and four University of Colorado professors,” says Burnett of the genesis of Prometheus Materials.
The goal? “Was there a way they could add structure to sand, whether it was beach sand or desert-type sand?” says Burnett. “Troops can easily land on it and move across, without having to slog through sand.”

Concrete is too heavy to transport to remote battlefields. “They wanted to see if there was a way to use biology to create, essentially, a hardened structure in sandy environments,” says Burnett. “Over a five-year period, what the professors at University of Colorado came up with is this process of using algae — common microalgae you’d find in lakes, rivers, oceans, and fish tanks — to simulate a process called biomineralization.”
The algae creates calcium carbonate. “It’s a very similar process to what nature has used for millions of years to create seashells and coral reefs,” says Burnett.
There’s a key difference between Prometheus Materials’ process and nature: The former is faster, making it a viable means of creating bio-cement and bio-concrete. “Not only is it bio-concrete, but it is virtually zero-carbon bio-concrete,” notes Burnett.
Concrete currently accounts for a full 8 percent of CO2 emissions worldwide, and 9 percent of industrial water usage. “It’s horrible,” says Burnett. “We return virtually 100 percent of the water used in our process back to the Earth.”
The project was a success, and the U.S. Department of Defense provided funding for commercialization and hire “what they call an embedded entrepreneur,” says Burnett. “And that’s me. I’m an entrepreneur — this is the sixth company I’ve started.”

CU owns the intellectual property, and Prometheus Materials operates under a license from the university. “The four professors are co-inventors, co-founders, and advisors to the company,” says Burnett.
The company raised a Series A round of $8 million in 2022. “We have a pilot manufacturing facility where we are producing bio-cement, bio-concrete, and bio-concrete blocks,” says Burnett. “We have a biotech production facility where we’re actually producing the algae — we’re growing the algae and harvesting it, and stimulating the biomineralization process.”
The first product is a concrete masonry unit (CMU) that’s similar to a cinderblock. Beyond the algae, the manufacturing looks pretty similar to traditional precast production. “Bio-cement is mixed with sand and aggregate to make bio-concrete,” says Burnett. “The bio-concrete goes into mold, it’s consolidated . . . it’s de-molded, then those blocks go off and dry for a week — and you’ve got zero-carbon bio-concrete blocks.”
He continues, “This is not concrete and cement we’re making — this is a new material. It happens to have many of the characteristics of concrete and cement — and also some additional characteristics that concrete and cement don’t have, in a very positive way.”
For example, it offers superior insulation and acoustics. “If it’s used in certain ways, it can reduce not only your embodied carbon, but also operational carbon on an ongoing basis.”

Burnett says he expects the price tag “will follow the classic technology cost curve, where we start out a little bit higher, and then rapidly come down, and then create a new market price for a new product.”
After attaining ASTM certification in January, Prometheus Materials is launching production for both load-bearing and non-load-bearing CMUs in April 2023. “We’re producing what I call demonstration quantities,” says Burnett.
After closing a Series B, the company will move from its current 5,400-square-foot pilot plant to a 30,000- to 35,000-square-foot facility to scale to full production and prove out the products in the construction industry. “We’ll be producing four different types of precast bio-concrete products,” says Burnett, noting that bio-cement and bio-concrete mixes, slated to hit the market in 2025, will be next.
In the longer term, Prometheus Materials’ model involves licensing its technology to existing cement and concrete manufacturers. “We’ll provide the algae and biomineralization to licensees, and the licensees will use that to make bio-concrete and bio-concrete products,” says Burnett. “It’s getting out to those large manufacturers of cement, concrete, and concrete products. That’s how we will make a meaningful difference to the carbon footprint worldwide.”
“Our goal overall is, in time, to reduce CO2 emissions by a gigaton or more per year,” he adds. “Right now, there are about 53 gigatons of CO2 emitted globally per year — and that number’s increasing, not decreasing.”

Challenges: “Introducing a new product into the regulatory structure,” says Burnett. “It’s state by state, it’s city by city, it’s county by county — it’s just unbelievable. There’s no one framework. It’s very, very disparate.”
Opportunities: “Just looking out your window, almost everything you see is concrete,” notes Burnett. “It is the second-most-used material on Earth, second to only water. The numbers are almost irrelevant, it’s so large.”
And it’s only getting larger: “Total building space is forecast to double between now and 2060. That’s the equivalent of building a new New York City every month for the next 37 years. That’s a lot of concrete.”
Prometheus Materials’ pilot facility will provide small batches for demonstration projects at data centers and other structures. “The customers that we’re talking to are very, very focused on reducing embodied carbon in their organizations and in their construction, so they are very excited about what we are doing,” says Burnett.
Many other technologies can knock off as much as 30 percent from cement and concrete production and construction, he adds. “We reduce it by 90 to 100 percent. It’s a very different scenario for our product versus many of the other folks that are out there today.”
Needs: Capital to build a four-line production facility. “We are in the process of raising a Series B round of funding for about $35 million,” says Burnett. With the raise, the company will need to hire about 30 more employees in order to launch production at a new facility in the first half of 2024.