Supercompressibility
Supercompressibility
(OP)
I know that the molar volume of a gas is 22.4 mol/m3 at reference conditions. I then calculated a shifted molar volume at my regulatory conditions of 15 Deg C and 101.325 kPa to be 23.645 mol/m3. So far, so good. Now my regulator is insisting that I account for supercompressibility in my calc. Molar volume is equal to:
RTz/P - this means that as z decreases, the molar density appears to decrease but this seems backwards to me. I would have thought that a compressibility less than 1 would result in a higher density.
So, my question is, once I get the supercompressibility out of my DCS, how do I apply it to my molar density calc?
RTz/P - this means that as z decreases, the molar density appears to decrease but this seems backwards to me. I would have thought that a compressibility less than 1 would result in a higher density.
So, my question is, once I get the supercompressibility out of my DCS, how do I apply it to my molar density calc?





RE: Supercompressibility
supercompressibility = 1/Z^2
hope this helps.
-pmover
RE: Supercompressibility
So, suppose (as an example) I calculate a z of 0.991 at 15 Deg C and 101.325 kPa, the resulting supercompressibility should be 1.01825. This means that I would then use this as a flow multiplier. This seems sort of correct to me, but I'm curious as to why the z is squared and inverted. If the z is a direct compressibility function, why is it adjusted in this manner?
I still revert back to my PV=znRT basics, and the molar density is a direct relation to z.
RE: Supercompressibility
I have added some papers hoping they could help
RE: Supercompressibility
RE: Supercompressibility
RE: Supercompressibility
you are looking for a similar adjustment to correct the density from 1 standard condition to another, the way I read it.
here is the AGA program that will correct all the volumes, densities, energy from 1 pressure base to another. It uses the AGA8 zfactor method of summation factors.