A Hawaii-based startup called Heimdal is developing a new "ocean-assisted" carbon removal method that can permanently store CO2 at the same time as reducing ocean acidification, a FastCompany report reveals.
The company pumps saltwater into a machine that applies electricity to rearrange the molecules in the water and reduce the acidity.
The acid is removed in the form of hydrochloric acid, which can be stored and sold separately. The process also produces hydrogen and oxygen as byproducts, which can also be stored. The water, meanwhile, is returned to the ocean, where it will help to capture CO2.
"When the excess acidity is removed from the ocean, it shifts how CO2 exists back to how it was pre-Industrial Revolution," Erik Millar, co-CEO of Heimdal, explained to FastCompany in an interview. "This moves it away from being carbonic acid, which causes ocean acidification, and toward bicarbonate and carbonate. These 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."
Removing CO2 from the atmosphere is an oceanic task
The ocean absorbs a huge amount of CO2, though the more CO2 it contains, the slower that process becomes as the world's oceans become saturated — the ocean has absorbed a third of the excess CO2 humans have released into the atmosphere.
Last year, University of California Los Angeles (UCLA) researchers announced they were launching a new startup called Seachange based on a similar concept to the one used by Heimdal. Their process converts CO2 in ocean water into a material similar to seashells, allowing it to be permanently stored. Similarly, the process was designed to enable the ocean to absorb more CO2 from the atmosphere.
Heimdal has launched a solar-powered pilot plant using the infrastructure of an existing desalination plant that already has the capacity to pump a large amount of seawater. The company says its technology can currently capture CO2 at a cost of $475 per ton and the pilot plant can capture 36 tons of CO2 a year. Its next plant will be designed to capture 5,000 tons of CO2 per year and it will operate at a lower cost of $200 per ton. Heimdal aims to build that next facility either in Portugal or Dubai.
Carbon removal technology is very much in the early stages of development, and economics may be a major problem. The UCLA researchers behind Seachange last year said that it would take roughly 1,800 of their carbon removal plants, called sCS2, to remove 10 billion metric tons of carbon dioxide each year, which would cost trillions of dollars. The latest IPCC report suggests that, alongside efforts to reduce emissions, the world will have to remove roughly six billion tons of CO2 per year by 2050 to avoid the worst effects of climate change.