A bold new effort to siphon carbon dioxide from the Pacific Ocean as a way to combat climate change is being backed by fossil fuel giants and big tech. But the fledgling technology, called Direct Ocean Capture (DOC), still has a long way to go to prove it works — and that it won’t cause any new problems.
Caltech researchers founded startup Captura, which just announced a new project today. Captura was founded in 2021 and won Elon Musk’s $1 million XPrize the following year. Now, with funding from the largest gas utility in the United States, Captura has built its largest pilot project to date in the Port of Los Angeles.
The idea is that filtering carbon dioxide out of seawater will allow the oceans to absorb more of the greenhouse gas
The idea is that filtering carbon dioxide out of seawater will allow the oceans to absorb more of the greenhouse gas, keeping it out of the atmosphere where it will warm the planet. The world’s oceans have absorbed nearly a third of human greenhouse gas emissions since the Industrial Revolution. Without this help, climate change will be much worse than it already is – with global warming already fueling more extreme weather disasters and threatening to wipe some coastal communities off the map.
The ocean’s carbon dioxide absorption powers, as well as Captura technology, are based on a principle called Henry’s Law. It’s the same force that makes a drink flat after you open a bottle of beer or a can of soda. Carbon dioxide wants to flow from where there is a higher concentration of it to where there is a lower gas concentration so that there is an equilibrium. When fossil fuels increased the concentration of carbon dioxide in the atmosphere, the oceans began to absorb more of the gas.
Captura technology aims to enhance this process by drawing carbon dioxide out of seawater. First, it has to draw ocean water into the biodegradable organic carbon plant. Then, you separate about half a percent of that water and put it through a process called electrolysis. This is a fancy way of saying they give off electrolytes from water to rearrange molecules into an acid and a base. When the acid is returned to the rest of the sea water, it reacts with carbon to release carbon dioxide.
Captura can then capture this gas to store it away somewhere or sell it as a product. Acidic water (which also happens to be a symptom of climate change) is very harmful to marine life, so Captura adds the base to the water before releasing it back into the ocean. Now that the water is deficient in carbon dioxide, it can then draw more carbon dioxide out of the atmosphere.
Captura launched its first pilot in Newport Beach, California this past August. It unveiled a new pilot project today that’s about 100 times larger at a public and private research facility called AltaSea in the Port of Los Angeles. The project should be able to remove about 100 tons of carbon dioxide from the ocean annually. In the grand scheme of things, that’s still minuscule—the equivalent of taking about 22 cars off the road for a year.
The goal is to test how the technology works in the real world and check to see if it has any unwanted side effects. “We want to make sure our impact on ocean waters is as good as we think it is,” says Steve Oldham, CEO of Captura.
“We want to make sure that our impact on ocean waters is as benign as we think it is.”
Some conservation groups are already wary of the technology. Captura plans to filter the water to prevent marine animals from being swept away by the plant’s biodegradable organic carbon. Whether these filters are good enough to keep out plankton is a concern for Shay Wolfe, director of climate sciences at the Center for Biological Diversity who has a background in ecology and oceanography. Plankton forms the base of the entire marine food web, which means that many other animals depend on microorganisms for food. Then there are concerns about adding more industrial activity and noise pollution to already stressed marine ecosystems.
What happens to the CO2 Captura capture at the Port of Los Angeles is still up in the air. For now, Oldham says Captura will likely sell the gas to other companies for use as an ingredient in commercial products such as concrete or carbon fibre. In the long term, he envisions building commercial DOC plants atop retired offshore oil and gas platforms where the carbon dioxide captured could be pumped under the sea floor for permanent sequestration.
This possibility worries Wolfe, too. “This is a major concern because oil and gas wells have a poor track record of leaks and blowouts,” she says the edge. “It is inevitable that the carbon dioxide pumped under high pressure will leak underground at some point.”
She is also skeptical of technology as a climate solution because of the Captura funders. Southern California Gas, which prides itself as the largest gas utility in the country, is a major financier of the project in the Port of Los Angeles. Among Captura’s backers are oil and gas giants Aramco and Equinor.
“Across the board, the biggest supporters (of decarbonisation) are the fossil fuel industry and partners. It ends up being industry fraud or distracting industry from real climate action, which rapidly reduces fossil fuel extraction and use,” says Wolf.
Before joining Captura in 2022, Oldham was the CEO of another startup called Carbon Engineering which is partnering with oil giant Occidental to develop projects that filter carbon dioxide from the air. Occidental plans to release some of the carbon dioxide into the oil fields to pay off hard-to-reach reserves in order to sell what it calls “net zero” oil.
“I have absolutely no qualms about spending my personal time trying to make this technology a reality, because it will be necessary,” says Oldham. the edge From his work on Captura. He points to a UN climate report that includes decarbonization as potential pathways to achieving the global climate goals set out in the Paris Agreement.
However, proponents of decarbonization warn that it is not a substitute for preventing greenhouse gas emissions through a clean energy transition. Decarbonization is most useful for addressing emissions from sectors that cannot easily be run with renewable energy, such as steel mills that typically use coal to heat furnaces to very high temperatures.
Yet all kinds of companies, Big Tech in particular, are turning to technologies that seek to filter carbon dioxide from the air and water to offset some of their emissions. Captura has a contract with Frontier, an initiative launched last year by Stripe, Alphabet, Meta, Shopify and McKinsey to make it easier for other companies to offset emissions with emerging carbon removal technologies. Through Frontier, Captura aims to sell carbon credits that are tons of carbon dioxide taken from the ocean. The credits will likely come from another pilot plant that the startup plans to build next year.