AggieCHEN04
Chemical
I am currently designing a demethanizer for a cryogenic natural gas plant, and one of the most common problems I run into is CO2 freeze-out. One of the more interesting things I've noticed about HYSYS's CO2 freeze-out utility is that the predicted CO2 freeze-out temperature for liquid hydrocarbons is extremely pressure dependent. For example, a liquid with the following composition:
CO2: 4.1%
C1: 87.4%
C2: 8.3%
at 365 psia
CO2 Freeze is -154.82F
at 321 psia
CO2Freeze is -138.01F
Shouldn't the liquid-solid equilibrium be fairly independent of pressure?
There is also a big drop-off in the CO2 freeze temperature around 321 psi, but I've already complained about the discontinuity to their technical support staff several months ago. I haven't received much feedback, so I've given up on them for now.
CO2: 4.1%
C1: 87.4%
C2: 8.3%
at 365 psia
CO2 Freeze is -154.82F
at 321 psia
CO2Freeze is -138.01F
Shouldn't the liquid-solid equilibrium be fairly independent of pressure?
There is also a big drop-off in the CO2 freeze temperature around 321 psi, but I've already complained about the discontinuity to their technical support staff several months ago. I haven't received much feedback, so I've given up on them for now.
