I like the idea of getting to net neutral with carbon capture. I even did some napkin math about a month ago. I tried calculating the energy requirements to break the CO2 bond as to determine the number of solar panels you would need. To get net neutral with CO2 emissions you would need to spend something around $8.5 trillion and obtain around 84,584,490,753.28 of 300 watt, $100 panels! Note I did not calculate the cost of the actual carbon capture machines, just energy requirements. I think my number is perhaps still a bit low but I also think this is reasonably doable with global support.
If you have enough green energy to unburn CO2, why not just... use that energy directly? Digging up carbon, burning it, and polluting it, only to spend the effort to capture it, unburn it, and rebury it would be absurd and inefficient.
That being said, I believe carbon capture proposals don't typically involve unburning the carbon - just capturing it and storing it. So the energy situation isn't as bad as your calculations.
