2 replies to this topic

[SebaM3]

I'm working on a naphtha stabilizer system handbook (in a HDT unit) and I wanted to know which reason defines the operation pressure of the system. The column works at 11 barg, I understand that it works at that pressure with the aim to obtain LPG, preassuming that the minimum temperature that you can achieve in the condenser using cooling water is about 40°C, and you need 11 barg to obtain LPG in the threephase separator at that temperature. Am I right? Could there be another reason to work at that pressure instead of a lower pressure?

 

(Excuse me for my English level)

[Bobby Strain]

Your reasoning is logical.

 

Bobby

[colt16]

I'm working on a naphtha stabilizer system handbook (in a HDT unit) and I wanted to know which reason defines the operation pressure of the system. The column works at 11 barg, I understand that it works at that pressure with the aim to obtain LPG, preassuming that the minimum temperature that you can achieve in the condenser using cooling water is about 40°C, and you need 11 barg to obtain LPG in the threephase separator at that temperature. Am I right? Could there be another reason to work at that pressure instead of a lower pressure?
 
(Excuse me for my English level)

Yes. This is just true not just for stabilizer but any column. The condensing temperature of the overhead product and the choice of condenser (fin fan - 50degC condensing temperature, cooling water - 40degC) governs the overhead pressure to operate at.

In general, lower operating pressure enables easier separation. Therefore one would want to use as low a pressure as possible but this comes with a lower condensing temperature and your cooling medium might not be able to deliver.