Can This Ocean-Based Carbon Power Plant Help Save the World? Some Scientists Are Raising Red Flags

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On a stretch of waterfront in western Singapore, a startup is building a factory to transform carbon dioxide of air and seawater in the same material as the shells, in a process that will also produce “green” hydrogen – a highly praised clean fuel.

The collection of low-rise buildings starting to take shape in Tuas will become the “largest” ocean-based carbon dioxide removal plant in the world when it is completed later this year, according to Equatic, the startup behind it, which was derived from the University of California. In Los Angeles.

The idea is that the plant extracts water from the ocean, shoots it with an electrical current, and passes air through it to produce a series of chemical reactions to capture and store carbon dioxide as minerals, which can be put back into the sea or used. in land.

It’s a compelling vision of a potential solution to the worsening climate crisis that has fueled unprecedented heat It is devastating extreme weather. Efforts to control global warming remain extremely out of the wayand many scientists are now warning that in addition to rapidly reducing fossil fuels, the world will also need to remove the carbon pollution that humans have already released into the atmosphere.

This Singapore plant is one example of a series of recent projects that look at the oceans, which already absorb almost 30% of the pollution caused by the warming of the planet, as a tool to do this. Other projects include spreading iron particles in the ocean to stimulate CO2-absorbing phytoplankton, sinking algae at depth to trap carbon, and spraying particles into marine clouds to reflect some of the sun’s energy.

But carbon removal projects are controversial, criticized for being expensive, unproven at scale, and a distraction from fossil fuel-cutting policies. And when they involve the oceans – complex ecosystems already under enormous pressure from global warming – the criticism could get even louder.

There are “huge knowledge gaps” when it comes to ocean geoengineering in general, said Jean-Pierre Gatusso, an ocean scientist at Sorbonne University in France. “I’m very concerned that science is lagging behind industry,” he told CNN.

How it works

Equatic’s technology, which has been tested in small pilot projects in Los Angeles and Singapore, requires three main ingredients: seawater, rocks and electricity.

It works like this: the plant pumps seawater and passes an electric current through it, separating it into four components: two liquids, one acidic and one alkaline, and two gases, hydrogen and oxygen.

The acidic water will be mixed with crushed rocks so that the pH returns to the same levels as seawater and then sent back to the ocean.

The fans will pump air through the alkaline stream, which causes the carbon dioxide to form solid calcium carbonate, the material from which the shells are formed, which will resemble fine sand as well as dissolved bicarbonate.

Solid and dissolved minerals, which Equatic says can trap carbon to at least 10,000 years, will be returned to the ocean or used on land. Seawater will also be returned to the sea, ready to absorb more carbon dioxide from the atmosphere.

No processing happens 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 are doing perfectly.” This includes the electricity the plant uses, as well as the amount of carbon stored.

The $20 million facility will be fully operational by the end of the year and will be capable of removing 3,650 metric tons of carbon dioxide annually, said Edward Sanders, chief operating officer of Equatic, which has partnered with Singapore’s National Water Agency. to build the plant. This amount is equivalent to removing around 870 medium-sized passenger cars from the roads.

The ambition is to increase removal to up to 100,000 metric tons of CO2 per year by the end of 2026, and then to millions of metric tons over the next few decades, Sanders told CNN. The plant can be replicated almost anywhere, he said, stacked in modules “like Lego blocks.”

As the plant grows, they will need to ensure there are no negative impacts, Sant told CNN. “There’s a big difference if you do it on the scale of one ton, versus one million tonnes, versus one billion tonnes. 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 during the process.

Equatic has already signed a deal 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, deputy director of the climate and energy program at the Center for International Environmental Law, criticized the use of “speculative technology” at a time when “climate change is already destroying our oceans”.

Processing large amounts of seawater can 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 it would take thousands of such plants to make any significant impact on the global climate.”

The impacts would need to be monitored closely, said James Niffenegger, a researcher at the National Renewable Energy Laboratory who wrote a report on removing carbon from the oceans. “Artificial water movement on this scale will be enormous,” he told CNN.

The process could also upset the delicate balance of ocean chemistry, Niffenegger said. While there is a lot of research into the negative impacts of ocean acidification, there is much less about what might happen if the ocean becomes more alkaline.

There are indications that the impacts may be low, he added, but “we won’t be able to understand the potential of this solution until we actually start implementing this kind of thing.”

Then there are energy needs – as the world moves away from fossil fuels, the demand for clean energy increases exponentially. “Moving seawater would require large amounts of renewable energy that would be better used to replace fossil fuels in the first place,” Fuhr said.

It’s a point shared by Gatusso, who said that “justice must be considered when precious electricity is used to remove carbon, rather than supplying it to populations in need.”

Equatic said it filters seawater to ensure marine life does not enter the system and that water discharged back into the ocean will have the same composition as normal seawater and comply with Singapore’s environmental guidelines.

The company also said that producing hydrogen, which could be used to power the process, means its overall energy use is lower than other carbon removal methods.

Equatic’s project encapsulates a broader debate between those who fear that the rush into geoengineering could wreak untold damage on ecosystems, versus those who believe the climate crisis is so acute that the technology must be an option.

It’s clear which side Equatic is on.

“Inaction is not a climate strategy,” said Sant of UCLA, adding that it is vital to be able to make decisions with uncertainty. “If we really want to mitigate the trajectory of climate change,” Sant said, “we need to be willing to act, and act quickly and at scale.”

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