Propane Phases

[lewisb13]

How would I find out if Propane is a liquid or gas at 335PSIG and 240F? All the phase charts online dont go up that high. Its been a while since chemistry class in college. THANKS IN ADVANCE

 

[zdas04]

On my P-h diagram in GPSA Engineering Field Data Book, the 240F line never crosses the phase boundary and is a gas to 10,000 psia.


David Simpson, PE
MuleShoe Engineering

Law is the common force organized to act as an obstacle of injustice Frédéric Bastiat

 

[lewisb13]

So just trying to remember correctly, this means that it stays a gas all the way up to 10000PSIA if you hold steady at 240F correct?

 

[monkeydog]

Not according to the NIST website

http://webbook.nist.gov/chemistry/fluid/

 

[zdas04]

I just ran it in RefProp and it looks like there is a dense phase of propane with a critical point around 209F and 618 psia (kind of hard to narrow it down in that program). I've never heard of a dense phase in propane, but that just goes into the vast column of "stuff you don't know".

David Simpson, PE
MuleShoe Engineering

Law is the common force organized to act as an obstacle of injustice Frédéric Bastiat

 

[mbt22]

The critical temperature for pure propane is 206 deg F, critical pressure 616 psia. Above critical temperature, below critical pressure, so gaseous.

Matt

 

[dcasto]

Once you are above the critical point, the fluid has the molecular energy of a gas, but will have physical properties closer to a liquid.

 

[MortenA]

dcasto: That a pretty slck definition (i always have problems trying to explain "dense phase to non-chemists" (read maybe i dont know really myself...) Anyway - does your explantion hold true no matter from which "direction" you approch the "normal" phase diagram?

 

[dcasto]

Yikes Morten, I just look at the slope of the lines on the molliere diagrams and see how they converge so rapidly at the critical point from all directions. What is deceptive is most molliere diagrams have a scale change on energy that makes the phase diagram look linear.

Working with ethylene lead me to that description, especially in measurement.