Design problem

[engint8]

Hi,

I have a problem statement as part of a project. The problem statement is as follows:

I am treating effluent gas from another facility. The feed gas conditions are as follows:
Flow rate - 200 MMSCFD
Operating pressure - 100 psia
Operating temperature - 95 deg F
Feed gas composition is as follows
Mol frac
C1 - 0.02
C2 - 0.167
C3 - 0.345
C4 (iso) - 0.453
C4 (nor) - 0.0003
N2 - 0.0001
CO2 - 0.0145
H2O - 0.0001

My final product specification is as follows:
Mol frac
C1 - 0.01
C2 - 0.02
C3+ - 0.99 (min)
N2 - 0.001
CO2 - 100 ppm

Can anyone provide any advise on what processing I should use to get to my objective? I want to use low cost processes and I probably wont separate the ethane and methane. I am planning to sell the combined light ends back to the plant as fuel gas as part of the project.

Thank you.

Kay

 

[StoneCold]

Looks like you could get pretty close by just chilling the gas stream and letting the C4's condense.
Have you tried simulating that?

Regards
StoneCold.

 

[Trond]

If you want to achieve 99% C3+ in your product stream, you will most likely require some serious distillation to get rid of your C1&2s. I very much doubt chilling alone will get you that far.

 

[engint8]

What sort of acid gas removal is recommended?

 

[MortenA]

amines/physical adsorbent (e.g. Sulfinol) (in the gas stream) for that feed rate?