Recommendation for light components under high pressure using equation of state
Thread Content
As the title indicates, the pressure is around 3 MPa (absolute), the temperature is around room temperature, and the gas composition mainly consists of ethane (over 95%), along with ethylene and propane. My friends, under such pressure, which equation of state is a good choice for simulation? Thank you!
I just checked the experimental data from NIST: at 3 MPA, the boiling point of ethane is 10.7°C. Could it be that these substances form a minimum boiling azeotrope? Or does your material contain non-condensable gases?
It seems there are no azeotropes. Well, the tower problem has been resolved somewhat for now (provided that the temperature data of the jacket is incorrect), but there are issues with condensation later on. At the same temperature, the gas phase fraction of the package is higher ； In other words, my models have all cooled down, while the bags have not cooled as much. This also shows that the top temperature is incorrect, resulting in an error in the heat calculation.
It would be best to upload your model, if it’s not confidential
Use PR, SRK transformations; Method Assistant has recommendations
It’s not a matter of whether it’s confidential or not; I’ve clearly listed all the components – just those few items. Also: a very small amount of hydrogen.
Do you know the detailed composition? If the detailed composition is available, it can be calculated; moreover, at high temperatures, non-condensable gases are released.
SRK variants are SRK KD, SRKML, RKS-BM, RKSMHV, and so on; the same applies to PR.
Sure enough, there are still non-condensable gases. . . . . This small amount of hydrogen is very likely the reason for the low temperature; if you remove the hydrogen, the temperature at the top of the tower should be around 10 degrees
My temperature is high, not low. . .