This is a homemade unit of a device that is normally an industrial process. You can use this to make pure nitrogen gas. I use this to supply N2 for my homemade liquid nitrogen generator. I also store the N2 so I can fill my tires. :smiley-mr-green:
Anyway, this is the link for the nitrogen generator http://homemadeliquidnitrogen.com/PSA (http://homemadeliquidnitrogen.com/PSA). It uses two pressure-swing adsorption beds. An arduino-based controller activates the solid state relays that control the pneumatic valves.
Here is a link to the LN2 generator.http://homemadeliquidnitrogen.com (http://homemadeliquidnitrogen.com)
8th Page of the first link, is where the Arduino is hiding :smiley-sleep: