Carbon Engineering - industrial-scale capture of CO2 from ambient air

I'm really, really curious to know the specific chemistry of the carbon dioxide sequestration at 2:55. I guess it could be a solution of calcium oxide (that would react with the carbon dioxide to make calcium carbonate, though I don't think calcium oxide is highly soluble), I guess.

Yes, we need to get the carbon dioxide out of the atmosphere, but there has to be a lot of energy input to get the solution made, the metals refined, the fans churning, and the polymer liner made. We're going to have to take a whole lot of carbon dioixde out of the atmosphere to balance all that out.