Elemental carbon is a valuable industrial material -- and even low-quality carbon, like "carbon black" soot, ain't cheap!
Nah, separating carbon from oxygen in CO2 and CO is too expensive and energetically demanding.
To simplify things a little bit, what they do here is inject CO2 into water at high pressure, which results in highly acidic H2CO3. They then pump H2CO3 into basalt rock, which chemically reacts with the acid -- in fact, it is partially dissolved. Then there's a second stage reaction between the partially-dissolved basalt and the remnant HCO3-, and it recrystallizes as carbonate minerals, e.g. FeCO3 or CaCO3.
So they're turning CO2 into a liquid acid, and then injecting it into rock where it reacts with basalt and crystallizes as carbonates.
Nah, separating carbon from oxygen in CO2 and CO is too expensive and energetically demanding.
To simplify things a little bit, what they do here is inject CO2 into water at high pressure, which results in highly acidic H2CO3. They then pump H2CO3 into basalt rock, which chemically reacts with the acid -- in fact, it is partially dissolved. Then there's a second stage reaction between the partially-dissolved basalt and the remnant HCO3-, and it recrystallizes as carbonate minerals, e.g. FeCO3 or CaCO3.
So they're turning CO2 into a liquid acid, and then injecting it into rock where it reacts with basalt and crystallizes as carbonates.