Process Selection for removal of CO2, H2S & H2O from Natural Gas Well 4

[TomOC]

Suggestions on process selection preferences for purification(Removal of CO2, H2S and H2O)from natural gas well. Have heard of difficulties with membranes and that MDEA is the latest hottest way to go if scrubbing.

Temperature Rating : 130 - 140 degree Farenheit
Pressure Rating : 1200 - 1300 PSIG

Well Head Gas Data:
CO2 - 10 mol%
H2S - 15 - 18 ppmv
H2O - 5000 barrels/day (calc gas sat'd w/ 20 b/day)

Expect some kind of basic feed gas separator first.

Product requirements:
CO2 - </= 3 mol%
H2S - o.24 grains/100 scf
H20 - 7 lb / mmscf at 14.7 psia max

Thank you in advance for any advice

Sincerely,
Tom

 

[MortenA]

Well i would call amine the &quot;safe choise&quot;. Its the process thats been around for longest and you have may licenses to choose from.

Best regards

Morten

 

[Petr98]

It is engineering recommedation whether that process or this would be economic and effic. to be use for you and your site conditions.

There are many of process such as; Amines processes, Benfield Process and membrane Procoesses.
you can get alot of information through many Gas books.

 

[Nightwing]

A good reference on this topic is Gas Process Suppliers Association (GPSA) Engineering data book, section 21, Hydrocarbon treating. It lists numerous technologies for the treatment of sour gas. Water removal is specifically dealt with in section 20 of the same GPSA book.

I agree with MortenA that the amine route seems to be the industry standard and has a proven track record.

Good luck
Nightwing

 

[25362]

With natural gas for domestic use -among others- water must be removed to prevent condensation of solid hydrates at low temperatures. Gas purification and drying operations are combined in a glycol-amine process which uses a mix of DEG or TEG, MEA or DEA, and water as the solvent. Both, amines and glycols, are considered good drying agents, but the amines are considerably more viscous than the glycols, hence the mixture. Selectivity for removing H₂S in the presence of CO₂ is achieved, as TomOC says, by using MDEA.

It has been claimed that even when the removal of water is not required, this process show advantages over others regarding the production of very pure gas, low initial investment, low steam consumption, and less foaming tendency. Main disadvantages are the large amount of HCs dissolved by the solution and the corrosivity developed on regeneration.

 

[TomOC]

Thanks. You are all awesome!

 

[JaccoH]

Dear TomOC

A recent development that does not use amine (results in chemical waste) is based on an absorber with a buffer solution. The H2S that is washed in is converted to elemental sulfur by partical oxidation in a seperate reactor. It will produce reusable elemetal sulfur instead of waste. Have a look at

http://www.uop.com/refining/processes_and_products/thiopaq_intro.htm

for an explanation.
This process will remove the water upto the dew point at the scrubber temperature (30oC) and part of the CO2. However, I don't think that the performance of an amine scrubber will be much better.

Greetings,

Jacco