by Editor’s Note: CNN Films’ “Carbon Blue: Nature’s Hidden Power” takes viewers from the mangroves of Vietnam to the salt marshes of France to explore a powerful new ally in the battle to slow climate change. It airs at 9 pm ET/PT on Sunday, April 21.
On a slice of the seafront in western Singapore, a firm has started building a plant to convert carbon dioxide from the air and seawater into the same material as sea shells, in a process that also produces “green” hydrogen – a clean fuel fully hyped. .
According to Equatic, the start-up behind it spun out of the University of California, the cluster of low-slung buildings that are starting to take shape in Tuas will be the carbon dioxide removal center. carbon “world’s largest” when it is completed later this year. at Los Angeles.
The idea is that the plant will draw water from the ocean, electrify it and run air through it to produce a series of chemical reactions to capture and store carbon dioxide as minerals, which can be put back in the sea or use. on land.
It’s a compelling vision of a possible solution to a worsening climate crisis fueled by unprecedented heat and extreme weather. Efforts to reverse global warming are still in full swing, and many scientists are now warning that, in addition to rapidly depleting fossil fuels, the world will have to remove carbon pollution that humans have already pumped into the atmosphere.
This Singapore plant is one example of a series of recent projects looking at the oceans, which already absorb nearly 30% of humanity’s planet-warming pollution, as a tool to do this. Other projects include pouring iron particles into the ocean to stimulate CO2-absorbing phytoplankton, soaking algae into the depths to lock in carbon and spraying particles into marine clouds to reflect some of the sun’s energy.
But carbon sequestration projects are controversial, criticized for being expensive, unproven at scale and evading policies to cut fossil fuels. And when it comes to the oceans – complex ecosystems already under enormous pressure from global warming – criticism can become even louder.
There are “huge knowledge gaps” about ocean geoengineering in general, said Jean-Pierre Gatusso, an ocean scientist at France’s Sorbonne University. “I’m very concerned that the science is lagging behind the industry,” he told CNN.
How it works
Equatic’s technology, which has been tested in small pilot projects in LA and Singapore, requires three main ingredients: seawater, rocks and electricity.
It works like this: The plant pumps in seawater and runs an electric current through it, separating it into four components: two liquids, one acid and one alkaline, and two gases, hydrogen and oxygen.
The acidic water will be mixed with crushed rocks to bring the pH back to the same levels as seawater and then returned to the ocean.
A fan will pump air through the alkaline stream, causing carbon dioxide to form solid calcium carbonate, the material seashells are made of, which will look like fine sand, as well as dissolved bicarbonate.
The solid and dissolved minerals, which Equatic says can lock in carbon for at least 10,000 years, will either be returned to the ocean or used on land. The seawater will also be sent back into the sea, ready to absorb more carbon dioxide from the atmosphere.
None of the processing takes place in the open ocean, said Gaurav Sant, founder of Equatic and professor of sustainability at UCLA, “this is important because it allows you to measure everything you’re doing perfectly.” This includes the electricity used by the plant as well as the amount of carbon locked up.
The $20 million facility will be fully operational by the end of the year and capable of removing 3,650 metric tons of carbon dioxide annually, said Edward Sanders, chief operating officer of Equatic, which is partnering with Singapore’s National Water Agency to build the plant. construction. That amount is equivalent to taking around 870 average passenger cars off the road.
The ambition is to scale up to 100,000 metric tons of CO2 removal per year by the end of 2026, and from there to millions of metric tons over the coming years, Sanders told CNN. The plant can be replicated pretty much anywhere, he said, and is stacked in modules “like lego blocks.”
As the plant expands, they will have to make sure there are no negative impacts, Sant told CNN. “There’s a big difference whether you do this on the scale of one ton, compared to a million tons, compared to a billion tons. You need to measure, you need to monitor, you need to adapt.”
The initial costs are high but the company says it plans to make money by selling carbon credits to polluters to offset their pollution, as well as selling the hydrogen produced in the process.
Equatic has already signed an agreement with Boeing to sell it 2,100 metric tons of hydrogen, which it plans to use to create green fuel, and to finance the removal of 62,000 metric tons of CO2.
Fragile oceans
For some critics, however, the risks far outweigh the benefits.
Lili Fuhr, director of the fossil economy program at the Center for International Environmental Law, criticized the use of “speculative technology” at a time when “climate change is already killing our oceans.”
Processing large amounts of seawater could kill marine life, Fuhr told CNN. “We already know that power plants kill fish larvae and other marine life. Equatic would process much more seawater per plant than a power plant,” she told CNN, “And thousands of such plants would be needed to have any meaningful impact on the global climate.”
The impacts need to be closely monitored, said James Niffenegger, a researcher at the National Renewable Energy Laboratory, who wrote a report on ocean carbon removal. “Artificial movement of water on this scale will be massive,” he told CNN.
The process could also disrupt the delicate balance of ocean chemistry, Niffenegger said. While there is plenty of research on the negative impacts of ocean acidification, there is much less on what would happen if the ocean became more alkaline.
There are indications that the impacts may be low, he said, but “we won’t be able to understand the potential of this solution until we start deploying this kind of thing”.
Then there are the energy needs — as the world moves away from fossil fuels, the demand for clean energy is increasing exponentially. “Moving seawater required a lot of renewable energy that would have been better used to displace fossil fuels in the first place,” Fuhr said.
It’s a point made by Gatusso, who said “justice must be taken into account when valuable electricity is used to remove carbon rather than providing it to populations in need.”
Equatic said it filters the seawater to ensure that marine life does not enter the system, and that the water released back into the ocean will have the same composition as normal seawater and meet environmental guidelines Singapore.
The company also said that the production of hydrogen, which could be used to power the process, means that its overall energy use is lower than other methods of carbon removal.
The Equatic project encompasses a wider debate among those who fear that rushing into geoengineering would significantly damage ecosystems, compared to those who believe that the climate crisis is so acute that this technology must be an option .
It’s clear which side Equatic is on.
“Inaction is not a climate strategy,” UCLA’s Sant said, adding that being able to make decisions with uncertainty is critical. “If we’re serious about mitigating the path of climate change,” Sant said, “we have to be willing to move, and move at scale quickly.”
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