Well a machine like the one on the right could actually be made. It’s super oversimplified, but the principle can be done. However it would require a massive amount of energy. And the tricky bit becomes how to get that energy without releasing a lot of CO2. With nuclear it is possible.
runs away before nuclear bad crowd shows up
Also note it would be way better and simpler to instead reduce energy usage, so the CO2 doesn’t get released in the first place. And use low CO2 sources when energy is required. However in the long run carbon capture would be a good idea. But as long as we can make gains on the usage and release side it makes no sense. And except for proper research projects, most of those capture things have been investor scams.
The way I understood the post: You can‘t generate electricity by burning fossil fuel, then capture the CO2 via direct air capture and still have a net gain of energy. (I guess CCS would still allow for a minor net energy gain because it doesn‘t need to fight entropy as much, but then again why bother, if one could use cheap renewables instead)
But yes, direct air capture has already been built, it‘s a necessary technology but must be powered by renewables to make sense.
Yeah, that’s essentially my point. DAC just introduces an unnecessary step to the process, which will result in some efficiency loss. Not releasing CO2 in the first place (by using renewables) should always be preferable.