3 replies to this topic

[lqminh]

Dear All,

I have critical temperture, critical pressure and vapor pressure data of pure compound. How can I regress the acentric factor?

[MrShorty]

Pitzer's definition for the acentric factor is omega=-log10(Prsat)-1 where Prsat is evaluated at Tr=0.7.

[lqminh]

Is there any methods to find acentric factor from vapor pressure data of pure component? Note that the component do not have normal boiling point, it evaporates at 22 bars and 420oC.

[MrShorty]

I'm guessing there must be something about the definition of acentric factor that you are unfamiliar with, or there is more to the problem than I'm able to see.

Is there something about Pitzer's definition that you don't understand?

Note that the component do not have normal boiling point, it evaporates at 22 bars and 420oC.

On a theoretical level, I find this hard to believe. Yes there are cases like CO2 where the compound freezes at a temperature above it's normal boiling point, but we can still estimate the vapor pressure at Tr=0.7. Reading between the lines, is it possible the root of your question has more to do with estimating vapor pressures when you are given limited data?