[net01]

What are the use cases of CO2 appart for making my Coke fizz?

[adregan]

The main commercial use is enhanced oil recovery—shooting it into old wells to extract more oil (super ironic if captured from the air).

One application I think is neat is that it’s a pretty robust refrigerant in a heat pump application.

[n49o7]

As I understand it, the main driver behind current carbon-capture tech is selling carbon credits.

[PunchyHamster]

You can add hydrogen and make methane for those industries that can't easily electrify

[rgmerk]

All the vaguely plausible industrial use cases for CO2 are a rounding error compared to the amount coming out of vent stacks and engine exhausts.

The one exception is making synthetic fuels, but in the vast majority of applications it’ll be cheaper to use electricity from clean sources (renewables/fission/fusion/unicorn farts) directly rather than pay all of the efficiency losses of electricity -> thermal -> chemical -> thermal -> (end use).

Ballpark, running a car on synfuels takes 10x the energy of running it on batteries charged directly from renewable sources.

[goda90]

Supercritical CO2 turbines: https://energy.wisc.edu/industry/technology-highlights/super...

On a much smaller scale I've been hoping for a small solar powered CO2 compressor to exist so I could use it for mosquito traps. The state of the art for those right now is burning propane for the CO2 combined with a scent emitter for the human smell to attract female mosquitos.

[Gravityloss]

Synthetic food is a potentially big one.

Synthetic materials is another. For example carbon electrodes for batteries.

[marcusb]

It is used as a shielding gas in some welding processes (notably, MIG welding.)

[quickthrowman]

Off the top of my head, CO2 can be used as a solvent for dry cleaning, it can extract THC from cannabis, and can also be used as a refrigerant.

[cjbenedikt]

You can combine it with H2 to produce synthetic fuels. Not ideal but could reduce fossil fuel use and hence new CO2 released.

[HPsquared]

Third ingredient missed out: lots of energy.

[istjohn]

Dry ice blasting

[potato3732842]

You can think of industrial CO2 use as basically the same as nitrogen but a little worse and several fucktons cheaper.

CO2 is fairly inert. This makes it useful. Welding steel is a typical example of something you can use CO2 to shield. There are many other examples in the chemicals industries of things like that where you want to do something at a "higher than natural on earth" temperature to make a reaction happen or happen faster but you don't want that reaction to happen with oxygen all around.

And on the other end of the temperature spectrum....dry ice.

[black6]

Plant food.