4 replies to this topic

[mosayef]

Hi all,

 

I have tried to understand GPSA section 20 to calculate diameter and height of TEG contactor. from the manual calculation , i got this data :

 

Theoretical Stage : 2

Actual Stage : 9

TEG Flow rate : 2,5 gal TEG/lb H2O

Water removal efficiency : 87%

 

I need to reduce the water content from 70 MMSCFD natural gas, from 70 to 10 lb/MMSCF. Inlet Pressure and Temperature are 100 F and 1120 psig respectively.

 

The data i got from manual calculation will be put to  TEG Template edited from HYSYS, but i find a big problem (and a difference). after i put the calculated stage and TEG circulation rate from GPSA section 20, the water content is far below 10 lb/mmscf (around 2-3 lb/mmscf)

 

as far i understand, the water removal efficiency depends on the number of stage and TEG circulation rate. but....if i extremely reduce the number of stage and TEG circulation rate , the water content content in in the dry gas is just around 2-3 lb/MMSCF ( i tried to get water content around 9-10 lb/MMSCF by changing number of stage and TEG circulation rate ).

 

i need the mass and heat balance from HYSYS to make data sheet for each component such as reboiler, pump, etc

 

1. could you please help me to solve my simulation problem ?

2. or could you please share your TEG simulation in HYSYS ?

 

I attach my simulation below. thank you very much. i need your help

 

somehow i cant upload the file from here, this is my simulation :

https://drive.google...kTm8&authuser=0

[RockDock]

The number of stages does not affect the removal of H2O much at all. The main variables to observe are: TEG circulation, TEG purity, Temperature, Pressure. I would trust GPSA more than HYSYS for TEG dehydration. HYSYS isn't ordinarily used for dehydration applications. I wouldn't expect very accurate results. I don't think you will need more than about 4-6 trays for this. 2.5 gal TEG/lb of H2O is reasonable.

 

I can't help you with your HYSYS model because I don't use that simulator any more.

[gegio1960]

Mosayef,

could you kindly give the gas composition?

Maybe someone without Hy$y$ could give you some advice.

Good luck

[kiansafaie]

Dear Mosayef
In addition to above items, You could also changed the regeneration tempreature of TEG reboiler in less temperature as spec of your column. (Generally due to degradation is set on 204c) for example decrease it to 190c. It could be changed your water content to higher value in dehydrated acid gas, also change on concentration of TEG in less concentraion is another method for higher water content .
Obviously, This changes should be ecconomically investigated and best scheme should selected.
Thanks

[ColinR33]

The TEG purity is the most important factor for water removal as your top tray equilibrium dictates what water content you can get down to. Circulation rate and contact stages are secondary. Best bet it to reduce the TEG purity. From the information you have provided I would guess you are using 99.3-99,75 wt% TEG. Try dropping that down to 98.5-99 wt%, that should get you where you want to be. Are you using stripping gas in your regen? for 10 lb/MMSCF you won't need stripping gas.