How the Ocean Could Be the Answer to Efficient and Effective Carbon Removal

The world’s CO2 emissions hit a record high in 2021, leading to a slowdown in food harvests, extreme weather, and the mass extinction of coral reefs. Which is why some startups are developing methods to harness the ocean and use it to remove carbon at a more rapid rate.

Last week Pasadena-based Captura inked a deal with the Port of Los Angeles in May that will see it install its largest ocean carbon removal system ever. Capable of capturing 100 tons of carbon, Captura’s thesis is that we already have the largest possible carbon remover on the planet—the ocean. Their goal, according to CEO Steve Oldham, is to “use the ocean as a mechanism to remove carbon from the air.”

Captura launched in 2021 and began a smaller pilot program in Newport Beach in August 2022. It won a $1 million XPRIZE award last April and has raised $12 million to date, from backers including Caltech and some international funders, including Saudi Arabian fund Aramco Ventures, Norwegian VC Equinor Ventures and London-based Future Planet Capital. Oldham wouldn’t disclose future funding plans, but noted that the project is a costly endeavor and said he expects Captura to raise more capital in the near future.

A rendering of Captura's proposed at-sea carbon removal plant. Photo: Captura

Right now Captura’s projects are based on the shore, but Oldham said he envisions a future where the company maintains huge carbon removal plants on the ocean. “The advantage of using the ocean for carbon removal is it exists, and it's massive,” Oldham explained. “There’s the opportunity to build very large centers of carbon removal on the ocean, using ocean-based renewable electricity: solar power, wind power, and wave power.”

In addition, Oldham said the partnership with AltaSea (the Port’s 35-acre research facility) comes with the advantage of there being existing infrastructure. “What's nice about AltaSea is it’s an enclosed location, you're right next to the water on a barge, and you're able to pull and process the ocean water, take out its CO2, and then assess the ocean water coming out of our process,” he said. The first rounds of testing at AltaSea should begin by this June or July and will focus on making sure the system has minimal negative impacts on the ocean.

Oldham said he envisions a time when Captura can take over abandoned oil barges and repurpose them to be ocean carbon removal centers.

Currently, one of Captura’s backers is SoCalGas, the largest gas utility in the state. Which, Oldham admits, isn't exactly divesting from fossil fuels completely. But, “as a startup company, getting the funding to build your first system or two is extremely challenging. [SoCalGas] got very interested in our technology, understood the potential of using the ocean at lower cost and at a larger scale,” Oldham said. “This allows us to demonstrate this technology at quite a good scale.”