Thanks! Honestly I don’t know. However, since basically all the search results I’m getting are for uranium enrichment, I’m guessing gas centrifuges are not in common industrial use for any other purpose. That probably means they aren’t well optimised.

The most relevant published literature I’ve found is this:

http://www.mate.tue.nl/mate/pdfs/5250.pdf

Which is exactly about the separation of CO2, but for natural gas production. The throughput was uneconomical in their case, however it does establish that the principle is sound, it may just need a (possibly very considerable) amount of development.

I haven’t exactly done an exhaustive search though, so there’s probably more out there.