There are lots of issues we don’t know concerning the ocean, probably the most unexplored a part of Earth, however there are two issues we do know: Water covers nearly 70 % of the planet, and the ocean is 96 % plus of that. And the ocean absorbs about 30 % of atmospheric carbon dioxide, a feat for which it doesn’t obtain a lot credit score.
How way more CO2 can the ocean swallow, with out harming delicate ecosystems and additional accelerating the acidification endangering coral reefs, mollusks and different sea life? A faculty of early-stage entrepreneurs is fishing for solutions, by each technological and organic means.
In mid-January, Los Angeles-based Captura — headed by well-known carbontech trade govt Steve Oldham, former CEO of direct air seize agency Captura — raised $12 million in Sequence A financing for its proposed answer, which it calls direct ocean seize. The spherical was led by the enterprise arm of oil firm Equinor, and in addition consists of backing from Aramco Ventures, the California Institute of Expertise (a.ok.a. Caltech), Future Planet Capital, Hitachi Ventures and mTerra Ventures.
Sure, it is a comparatively small spherical within the scheme of local weather tech enterprise moolah, however Captura is notable for different causes. It was a milestone winner final spring within the huge Carbon XPrize fronted by Elon Musk, together with roughly a dozen of the opposite rivals, plucked from the sphere of near 300 firms angling for the cash. Captura has additionally captured the eye of Frontier Local weather, a collaboration coordinated by Alphabet, Meta, McKinsey, Shopify and Stripe that’s investing $925 million in promising carbon elimination approaches. Frontier has signed a $500,000 prepurchase relationship with Captura to seize 508 tons of CO2, with the choice for a long-term offtake deal sooner or later, if the expertise delivers on sure pilot undertaking metrics.
Captura’s strategy makes use of electrochemistry to soak up CO2 from ocean water after which return the CO2-depleted water again into circulation, utilizing renewable vitality to energy the method, Oldham advised me. That decarbonized water is then accessible to soak up extra CO2, and the method is repeated — form of like dialysis on a human affected person.
“Our strategy is essentially completely different,” Oldham stated. “We don’t add something to the ocean, and we don’t take something from the ocean.” That’s, apart from the captured CO2, which Oldham stated can be utilized for feedstock by different firms, comparable to artificial fuels firms (suppose Lanzatech, though there’s no official deal there), or sequestered at a storage web site. The corporate is working with nonprofit Ocean Visions and just lately employed an oceanographer, who shall be accountable for ensuring Captura’s expertise is as protected for ocean ecosystems as its executives like to assert.
Oldham’s curiosity within the ocean as a carbon seize frontier is knowledgeable by his background with land-based choices, which he notes require huge quantities of capital, vitality and house. “The ocean is confirmed, it’s monumental, and it’s free.”
He touts Captura’s means to make use of current offshore infrastructure for its programs, comparable to desalination vegetation or oil rigs — and particularly in places the place there are current carbon sequestration and storage choices. Its pilot web site, off Newport Seaside, California, is able to slurping up 1 metric ton of CO2 yearly. The following-generation web site beneath building with the aforementioned monetary help shall be able to capturing 100 instances that capability. The fee for eradicating the CO2 shall be “nicely beneath” the $100-per-ton worth level that the Division of Power is encouraging with its grant funding. (Did I point out Captura additionally has DOE backing?)

Whereas Captura’s enterprise fashions are nonetheless beneath growth, the startup is exploring eventualities during which it might license its system to organizations with building and growth expertise, Oldham stated.
Joanna Klitzke, procurement and ecosystem technique lead with Frontier, stated one massive a part of the ocean’s enchantment as a carbon seize frontier is the truth that it doesn’t require using arable land — making it extra doubtlessly scalable. A part of Frontier’s particular curiosity in Captura stems from its curiosity in concurrently addressing ocean acidification — by eradicating CO2 to extra pure ranges. “We want a range of pictures on purpose,” Klitzke stated once we chatted concerning the fund’s curiosity in Captura.
The tide is popping
Captura’s electrochemical strategy represents considered one of six early-stage approaches to ocean carbon elimination outlined in a current report from World Assets Institute, starting from abiotic strategies (people who depend on the ocean’s bodily or chemical properties to take away CO2) to biotic strategies (people who rely upon photosynthesizing organisms to get the job completed). Listed below are six early approaches which have WRI’s explicit consideration:
- Electrochemical elimination
- Alkalinity enhancement
- Synthetic downwelling
- Nutrient fertilization
- Synthetic upwelling
- Seaweed cultivation
The WRI report mentions coastal wetland restoration however I’ve excluded it from the checklist above as a result of it is at a extra mature stage of growth. Ocean Visions, a technical adviser to XPrize for the ocean seize entrants, explains the idea behind many of those strategies at this useful resource.
So, except for Captura, what different early-stage firms are making waves and capturing funding? Listed below are a couple of that the GreenBiz crew is watching:
- Vesta: It’s experimenting with making use of olivine to coastlines, accelerating sequestration. The corporate is among the new local weather tech companies in Elemental Excelerator’s newest portfolio, disclosed in November.
- Planetary Tech: The agency calls its expertise an “antacid” for the ocean, and it’s one other of the XPrize milestone winners, backed with about $6.1 million once I final wrote about them in April.
- Operating Tide: Began as an oyster farm, the corporate hopes to develop kelp and sequester carbon by harvesting it and sinking it to the ocean flooring. It was among the many earliest firms producing buzz, however extra just lately the scientific group has raised considerations about its potential influence on ocean ecosystems.
- Atmocean: The corporate is creating a wave energy-powered system known as Ocean Floor Carbon Relocation that pumps carbon-saturated water from the floor down 400 to 500 meters and pulling up cool water and phytoplankton from these depths. (So, mixed downwelling and upwelling.) The thought is to sequester CO2 whereas restoring native ecosystems. CEO Phil Kithil advised me the corporate is planning its subsequent trial off the California coast within the spring.
- Lillianah Applied sciences: Technical founder Benjamin Slotnick, a geologist with experience within the carbon cycle, is engaged on this stealth startup’s plan to optimize the ocean’s current organic pump for managing CO2 sequestration utilizing microalgae, together with phytoplankton. Keep tuned for extra particulars on the strategy in a future article.
As with all the pieces associated to the ocean, we should tread calmly to make sure that any engineered approaches don’t tip the steadiness of marine ecosystems. What ocean carbon seize startups deserve our consideration? Alert me at [email protected].