$\ce {CO2}$ is considered a Lewis acid. How it is an acid? According to Lewis: “species that accept an electron pair are acids”. But $\ce {CO2}$ can't accept electron pairs because oxygen and carbon ...
Anyway, is it safe? Could I put a CO2 to nitrogen adapter between the CO2 regulator and the beer gas ( 75% nitrogen and 25% co2) bottle and operate it safely? If you tell me that the CO2 regulator won't take the pressure of the beer gas bottle, I'll just spend another 30 bucks and get a nitrogen gauge. It's not really to save money anyway.
Is it safe to use a CO2 Regulator with an adapter on a Nitrogen tank ...
Here is a phase diagram: Phase I $\ce {CO2}$, shown in the bottom-left corner, is the most common dry ice crystal structure, and it is molecular, exhibiting a face-centered cubic arrangement with respect to the carbon. The high-pressure Phase V $\ce {CO2}$ (top-right), on the other hand, has a "partially collapsed cristobalite" structure.
Beer gas is usually in CGA 580 tanks but can be bought in CGA 320 tanks as well. CO2 regulators can be used on beer gas tanks, but beer gas is under higher pressure. CO2 is liquid in the tank, and beer gas being a mix of Nitrogen and CO2 is just compressed gas and usually a full tank of beer gas is in the neighborhood of 3000 psi.
CO2 is CO2, there is no food grade CO2. My welding shop traded my 5 pound tank for a 20 pound and refills are $12. Refill costs are pretty much all labor, here are the prices for my tanks: 2 pound-$6 10 pound-$11 20 and 35 pounder (an odd size they traded me for one of my 20 pounders)$12 50 pound-$20