1 reply to this topic

[Dmitry]

Hello,



I am currently working with gas dehydration unit. I’ve made a model of gas-TEG contactor. I use PR package.
At 10 C and 450 psig water content for gas feed will be next:

Hysys – 20,86 lb/MMSCF
GPSA – 22 lb/MMSCF

To meet water dew point (-8 C at 3.92 MPa) I need to remove total 4,5 kg of water per hour. According to GPSA reference recommended TEG flow is 1,5 gal TEG/lb HO2 removed. So minimum required TEG mass flow is 1,5 x 8,34 l/kg = 12,51 l TEG / kg H2O removed. Total = 12,51 x 4,5 =56,29 liters of TEG per hour. It is about 63 kg of TEG.
Hysys calculated TEG mass flow rate – 15,8 kg/hour required to meet it specification. With Glycol package
Hysys calculated TEG mass flow - 10 kg/hour.

GPSA - 63 kgTEG/hour
Hysys (PR) - 15,81 kgTEG/hour
Hysysy (Glycol package) - 10 kgTEG/hour

Question - It is very low TEG flow rate in both cases (PR and Glycol package) if compare with thumb rule or GPSA reference. Does Hysys calculates wrong TEG flow?


Many thanks

Attached Files

•  Feed gas composition.pdf   20.61KB   35 downloads
•  TEG dehydratio model.pdf   10.46KB   54 downloads

[Propacket]

Check no. of stages in contactor. If you have used the same purity and no. of stages in Hysys as per GPSA, results should not differ much. By the way 10 degC seems very low for a TEG dehydration unit as TEG viscosity below 25 degC is too much and affects tray efficiency.