I have learnt here some times ago (from Katmar by the way) that standard volume is a unit of mass and not volume.
This is something that I completely agree with as, indeed, for a given gas composition: standard volume = mass * constant (this constant does not vary with T and P).
Now suppose I have a gas containing, let's say 70% vol of hydrogen (as measured in lab after being sampled in a process line at actual T and P), and flowing at 1000 Sm3/h (whatever the standard T and P).
If I want to calculate the standard flowrate of pure hydrogen, shall I multiply the total gas standard volume by the volume fraction of hydrogen (lab result)?
My problem is that I don't know much about lab methods of measurement and I believe that 75% vol is the hydrogen composition at actual plant condition and not standard condition, and as such, multiplicating 1000 Sm3/h per 75% would give me the wrong number.
I believe I should use mass fraction of hydrogen because standard volume is a unit of mass, but the chief process engineer of my company uses volume fraction instead. In the case of hydrogen both methods lead to very different results
Could you please help me understand why it should be volume fraction if I am wrong?
Thanks
Edited by sheiko, 16 September 2017 - 06:50 PM.