4 replies to this topic

[Leonardo TD]

Hi,

 

Could you help to advise the method to design adsorption column with molecular sieve to adsorb water, CO2, and H2S in a Natural Gas?  I already try to design a simple dehydration process with molecular sieve, but I believe that when the CO2/H2S content was quite high, the equilibrium adsorption rate on the molecular sieve will be different.  

 

Case example : Molar flow 1.852 MMSCFD.  Inlet temperature 101.4 F.  Pressure 298 psig.  Water content of natural gas from the gas dryer outlet was expected to be around 6 lb / MMSCF.  Because high CO2 content, it was expected to use AW type molecular sieve.  CO2 outlet content was expected to be less than 10% mole.  

 

 Gas dryer inlet composition (fraction mole):

 

Nitrogen 0.025784

Oxygen 0

Methane 0.599592

CO2 0.192401

H2S 0.000006

Ethane 0.062437

Propane 0.050008

i-Butane 0.020111

n-Butane 0.019064

i-Pentane 0.010483

n-Pentane 0.008602

n-Hexane 0.006834

n-Heptane 0.001424

n-Octane 0.000119

n-Nonane 0.000002

n-Decane 0

H2O 0.003134

 

Thank you.

Edited by Leonardo TD, 25 September 2013 - 01:54 AM.

[gegio1960]

with that composition you shall remove CO2 by either amine washing or membranes.

looking at in/out CO2 compositions and at available pressure, maybe membranes could be the most economical solution.

good luck!

[Leonardo TD]

Because of high CO2 content in the feed gas, the molecular sieve supplier suggest to use AW type adsorbent because it is more acid resistant.  AW type molecular sieve supposed to be able to treat the feed gas.

[gegio1960]

suppliers have to supply!

[lokesh_09]

Hi,

 

Please refer GPSA section 20 (Dehydration) for sizing of adsorption column.

 

Regards,

Lokesh.