

I’m sure it’s more complex than I’m making it out to be, but each gas in the air has its own freezing/melting boiling/condensation/sublimation points, so I’d imagine you could just kind of take advantage of that
Basically just cool it down to x temperature at y pressure, and all of the carbon dioxide should be solid, the oxygen a liquid and the nitrogen still a gas, and they’ve all sort of separated themselves out. Fish out the dry ice, siphon off the oxygen, and you’re left with nitrogen.
Might need to do a couple more rounds of that on each of those to account for other gases in the mix depending on how pure you need it to be, but in theory I imagine it could be that simple (again in practice I’m sure there’s probably a lot of details I’m missing)






I don’t know the knife laws in Italy, especially not for the specific part of Italy this occurred in
But often laws about switchblades and such have to do with carrying them, or occasionally selling them, but often just owning a switchblade and keeping it at home isn’t really an issue
As far as manufacturing, I again don’t know about the specific regulations, if there’s maybe any kind of licensing or something needed, but I know for a fact that it is either not totally illegal to manufacture a switchblade in Italy, or they are *very * selectively enforcing those laws because there are some very well-known manufacturers of them based there (if I had more disposable income I’ve had my eye on a Frank Beltrame stiletto for a while)