I am currently designing a tank for the bubbling of CO2 gas(7-10 psig)on a potassium permanganate liquid. CO2 gas come the beer fermentation. Can anybody tell me the necessary parameters in order for my CO2 scrubber tank to work? The tank is 1.20m in diameter and 2m in height. A bubbler is installed at the bottom 232 holes at 10mm diameter per hole (Is 10mm diameter enough for scrubbing?). Also I need to know how much would be the volume(or height from the bottom of tank) of KMnO4 to be able to really scrub the odors from CO2 gas. Please tell also the headspace that I should provide.

What you are proposing is the old-time method of oxidizing and removing the pernicious odor of fermentation CO2.  I have done this many times in purifying and liquefying CO2 industrially.  Allow me to detail out the answers to what you asking and give some pointers at the same time:

1)    You haven