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.
I like Zettlr, mainly because of its note linking & citing capabilities. I used it while working on my thesis (for notes & summaries, not for the whole text).