Tell us about yourself!
So how long do your 6 rechargeable AA batteries last before the pi loses power?
Not sure what a pressure swing adsor(b?)er is. If you are either blowing off the somewhat purer O2 into the air, or separating it as liq O2, be aware of its dangers. It is very reactive, and can cause fires and explosions.
Getting Started With Robots
Welcome to CNC
Raspberry Pi Class
Wow, you have limited experience. Try living in the desert southwest for a while. This is at least an idea worth trying!