Nice review, but if DAC is storage limited you are missing one massive reservoir - the ocean. Obviously, it's not a good idea to add concentrated CO2 directly to seawater, which would be insecure and just further acidify the ocean. Rather, use "de-mineralization" to spontaneously convert CO2 to dissoved alkaline bicarbonate and carbonate ions to add to the marine pool of these that already compose the largest C reservoir in communication with the atmosphere (35,000 Gt C). Eg, CaCO3 + 1.7 CO2 + H2O --> Ca++ + 1.48HCO3- + 0.17CO3--.... This provides 70% more C storage per mol of alkaline rock than does mineralization (pure carbonate formation), plus helps counter ocean acidification. Coastally deploy DAC at sites near limestone and power with marine energy, no wells needed. Win, win, win?! Where's the DAC hub and $Bs for marine CO2 storage? greg@planetarytech.com
Thanks Greg. I mention Equatic toward the end, which "avoids CO2 (re)production" via the produced carbonates/bicarbonates that are returned to the ocean, leveraging ocean storage.
As long as developer can make the costs pencil and find an MRV protocol developer willing to sign off, then this definitely holds significant potential.
Nice review, but if DAC is storage limited you are missing one massive reservoir - the ocean. Obviously, it's not a good idea to add concentrated CO2 directly to seawater, which would be insecure and just further acidify the ocean. Rather, use "de-mineralization" to spontaneously convert CO2 to dissoved alkaline bicarbonate and carbonate ions to add to the marine pool of these that already compose the largest C reservoir in communication with the atmosphere (35,000 Gt C). Eg, CaCO3 + 1.7 CO2 + H2O --> Ca++ + 1.48HCO3- + 0.17CO3--.... This provides 70% more C storage per mol of alkaline rock than does mineralization (pure carbonate formation), plus helps counter ocean acidification. Coastally deploy DAC at sites near limestone and power with marine energy, no wells needed. Win, win, win?! Where's the DAC hub and $Bs for marine CO2 storage? greg@planetarytech.com
Thanks Greg. I mention Equatic toward the end, which "avoids CO2 (re)production" via the produced carbonates/bicarbonates that are returned to the ocean, leveraging ocean storage.
As long as developer can make the costs pencil and find an MRV protocol developer willing to sign off, then this definitely holds significant potential.
Thank you for writing this, very helpful!