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Hawaiian start-up pioneers world’s first ‘ocean-assisted’ carbon capture plant

While the majority of carbon capture efforts are focused on air pollution, the current version of this ‘ocean-assisted’ tech can capture CO2 at a cost of $475 per ton – which is cheaper than any land project to date.

Along a remote stretch of Hawaiian coastline, a geoengineering start-up is pioneering ‘ocean-assisted’ carbon removal – which can both sequester emissions and help to reduce ocean acidification.

Now, as you’re no doubt already aware, the ocean is brilliant for storing carbon emissions and slowing the immediate warming of our climate. In-fact, around 140bn tons of CO2 are concealed within deep sea reserves, peatlands, and seagrass every year. Nuts, right?

While this is obviously a good thing, there is a significant drawback which has prevented researchers from running away with ocean-based carbon capture projects: ocean acidity.

When emissions enter the water and are absorbed as natural bicarbonates, chemical reactions break the gas down into hydrogen ions which increase the surrounding PH level. This has been proven to damage low dwelling marine animals as well as coral and algae.

In the Pacific Ocean, scientists have reported that ocean acidity levels have dissolved the shells of young crabs, for example.

Therefore, if we’re to deliberately coax more carbon into the sea, the resulting rise in acidity is something we need to be prepared for and ready to counter.

One company that appears to have solved the conundrum on a local scale, is Hawaii based Heimdal.

This start-up has developed a machine that can take existing sea water and rearrange its molecules to remove acid using an electrical charge.

Once removed, the acid can be sold in its hydrochloric form while the neutralised water is returned to the ocean where it will naturally capture CO2.

‘When the excess acidity is removed from the ocean, it shifts how CO2 exists back to how it was pre-Industrial Revolution,’ says CEO Erik Millar. He’s referring to the transformation of carbonic acid to stable mineral carbon that will be stored on the ocean floor for a millennium.

Credit: Heimdal

The operation in Hawaii is something of a pilot with a view to eventually building larger facilities in Portugal and Dubai. It’s connected to a pre-existing desalination plant, which helps to save on the costs of pumping water, and its own technologies all run on solar power.

The current version of the tech can capture CO2 at a cost of $475 per ton, which is lower than any existing air capture enterprise globally. More importantly though, it has given investors confidence in the concept of ocean carbon capture and electrolysis.

According to the team, the next plant is being designed to capture 5,000 tons of CO2 per year and will operate at a cost lower than $200 per ton of emissions.

In the grand scheme of things, the IPCC states that we need to remove around six billion tons of carbon a year by 2050 to avoid devastating climate impacts.

Meanwhile, the climate capture industry is only in its infancy, meaning that projects are one successful pilot away from potentially taking off in a big way. Let’s hope things pan out that way here.

As for Heimdal’s internal goals, Millar declares: ‘We’re projecting that we’re going to be capturing 5 million tons per year within three years.’ Impressive stuff.