Does pure-ish CO2 have advantages over regular air or the freon-like substance used in air conditioning?
How much energy us used to purify and maintain the CO2?
Does pure-ish CO2 have advantages over regular air or the freon-like substance used in air conditioning?
How much energy us used to purify and maintain the CO2?
These days CO2 is actually quite commonly used in air-conditioners as a refrigerant, R-744. Fluorinated gases like Freon are being phased out due to being even worse for global warming.
I thought it was ozone depletion, not greenhouse effects, that led to the fluorinated gas phaseout?
The original ones yes. They are already banned - but the next generation of fluorinated refrigerants are apparently ok for the ozone layer but have a greenhouse effect. That's my understanding anyway, I'm far from an expert.
Edited to add: https://en.wikipedia.org/wiki/Kigali_Amendment has some information on this.
It's easy to liquefy, so it has a density advantage over air, and would be bad if released but not super bad.
Suffocation seems like the most relevant concern in the event of a catastrophic leak.
It is a necessary risk. Oxygen is dangerous when heat is involved, and its low critical point is harder to work with than co2.
It's pretty cheap to acquire a boatload of and, assuming you don't get it directly from burning fossil fuels, there's really no environmental harms of it leaking into the atmosphere. [1]
[1] https://en.wikipedia.org/wiki/Carbon_capture_and_storage
> CCS could have a critical but limited role in reducing greenhouse gas emissions.[6] However, other emission-reduction options such as solar and wind energy, electrification, and public transit are less expensive than CCS and are much more effective at reducing air pollution. Given its cost and limitations, CCS is envisioned to be most useful in specific niches. These niches include heavy industry and plant retrofits.[8]: 21–24
> The cost of CCS varies greatly by CO2 source. If the facility produces a gas mixture with a high concentration of CO2, as is the case for natural gas processing, it can be captured and compressed for USD 15–25/tonne.[66] Power plants, cement plants, and iron and steel plants produce more dilute gas streams, for which the cost of capture and compression is USD 40–120/tonne CO2.[66]
... And then for this usage, presumably you'd have to separate the CO2 from the rest of the gas.