# Liquid Nitrogen Supply

1. Jun 1, 2012

### Avis

Im working on an exisiting Ntirogen supply system thats used to blanket boilers and pipelines etc. at a thermal power plant. Im trying to determine the capacity of the system. I have determined the size of the liquid ntrogen tank to be 8m^3 but I'm lost on how to determine the amount of gas that can be produced from the expansion of the liquid.

I'd like to assume Normal conditions. 0 celcius 1atm.

Any Ideas?

2. Jun 1, 2012

### phyzguy

The density of LN2 at its boiling point (from Wikipedia) is 0.808 g/cm^3. If you have 8 m^3, this is 8*10^6 cm^3, so this is about 6.5 * 10^6 g. This is 6.5 tons - must be a big tank! Since N2 is 28 g/mole, this is 2.3 * 10^5 moles. At STP of 0 Celsius and atmospheric pressure, each mole occupies 22.4 liters, so this would be 5.2 * 10^6 liters.

3. Jun 1, 2012

### Avis

Where did you come up with the mole density?

4. Jun 1, 2012

### phyzguy

The atomic weight of nitrogen is 14 g/mole - this is something you look up in the periodic table. Since Nitrogen gas is N2, a mole of nitrogen gas weighs 28 g.

5. Jun 1, 2012

### Avis

Sorry, I ment molar volume. I know relise that its from the idea gas law.

Thanks for the help, this all makes sence now!