vp vs temperature plot

[aken]

hi. I am plotting vapour pressure as function temperature. I am getting results totally different from Aspen Plus. I then noticed l cannot select liquid on phase and its plotting for phase in overall, and vapour pressure is only for liquids.


kind regards
Akan

[jasper]

I am not sure what you are doing in Aspen Plus, but your COFE document contains pure compound properties (not mixture properties) and the property is the temperature dependent vapor pressure correlation for the compound. This is, as a function of temperature, the pressure at which the vapor and the liquid co-exist (so a phase specification does not make sense for this property).

Clearly this property is temperature dependent. You get a better view in COFE if you change the Y axis to logarithmic. The plot that you show below does not make sense for this property - can you double check that you are indeed plotting pure compound vapor pressure?

[aken]

hi. here is the document.
https://lms.nchu.edu.tw/mobile/media/41987

[jasper]

Vapor pressure is not defined above the boiling temperature - perhaps this is why the H2 plot seems to have a flat line. Remove H2, set the vertical axis to logarithmic and try again?