you can inject it into peridotites and let it mineralize. there is enough exposed peridotite outcrops in the world that we could inject all the co2 produced and store it there indefinitely. this process also produces elemental hydrogen.
This is more about the mechanics of how the rock breaks to allow fluids to move around.
And here is another paper currently in review that we coauthored about how we know there’s gas moving in the system and therefore hydrogen is being produced:
Someone proposed to make giant beaches of malachite and let the sea break the rocks. Malachite has two -OH that can be replaced by a CO3= and so capture the CO2.
I can't find a good link now, but at least it's the only method I know where it's not obvious that requires a huge amount of energy that makes the whole process net negative.
