Taking away CO2 from the ocean is a groundbreaking carbon removal innovation holding massive potential. A startup pioneering “ocean-assisted” carbon removal called Heimdal announces it launched the world’s first ocean-assisted carbon removal plant located on the Island of Hawaii.
The startup has developed a process that can both permanently store CO2 and help reduce ocean acidification.
How Does The Technology Work?
Heimdal’s technology pumps saltwater into a machine that uses electricity to rearrange molecules in the water, removing acid. The acid it removes ends up in the form of hydrochloric acid. The de-acidified seawater is then returned to the ocean, where it will naturally capture CO2.
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As CEO of Heimdal, Erik Millar explains, the process removes carbonic acid from the water, which causes ocean acidification, and toward bicarbonate and carbonate. They are stable forms of mineralized carbon dioxide that make their way down to the ocean floor, where they are stored for more than 100,000 years.
By removing acid the process enhances the ocean’s natural ability to absorb carbon dioxide. The process also produces hydrogen and oxygen as by-products.
The ocean covers 70% of the Earth’s surface so it plays a large part in its environment. NASA scientists have estimated that the ocean absorbs one-quarter of the CO2 that humans create by burning fossil fuels.

It has already absorbed a third of the excess CO2 that is put in the atmosphere and 90% of the excess heat on the planet. When the CO2 dissolves, it acidifies the water, making it harder for marine life like corals and shellfish to form and survive.
Scientists have found that seawater’s acidity has already started dissolving the shells of young crabs. CO2 removal from the ocean can help locally to improve the pH of seawater.
Heimdal Pilot Plant
Currently, Heimdal launched a small pilot plant that can capture 36 tons of CO2 a year. It is connected to an existing desalination plant to save some costs as there is already a system in place that can pump water from the ocean.
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The plant in Hawaii runs on solar power which additionally saves on electricity costs. That version of the technology captures the CO2 from seawater at $475 per ton.
For the next project, the company has designed a plant to capture 5,000 tons of CO2 per year which drive down operations at a cost lower than $200 per ton of captured CO2. The next facility could be built either in Portugal, on the site of a decommissioned power plant, or in Dubai, where it would be colocated with another desalination plant.

“Carbon capture has only recently been able to take off because of this huge decrease in the cost of renewable green electricity in the past decade… So we’re running entirely on solar, and it’s cheaper than we could get from fossil fuel energy,” added Mr. Millar.
Is It Enough To Offset Emissions?
The CEO of Heimdal also shares the startup’s biggest challenge is to grow as quickly as required by IPCC to meet the need of humanity to remove 10 gigatons of CO2 from the atmosphere per year by 2050.
“It took Climeworks 13 years to build the world’s first current, largest [direct air capture] plant, at 4,000 tons per year… We don’t really have the time. We’re projecting that we’re going to be capturing 5 million tons per year within 3 years,” he adds.

Current carbon capture technology capacity takes away just around 40 million tons out of the atmosphere per year. That means carbon removal efforts – both from innovation and natural carbon sink projects would need to accelerate exponentially over the next couple of years to be able to meet the demand for CO2 reduction.
Groundbreaking innovation and widespread deployment of available technologies will have to be applied and quickly to remove large amounts of greenhouse gas emissions if humanity stands any chance of curbing climate change.