10 replies to this topic

[m mosavi]

HI DEAR FRIENDS
I'm a chemical engineer who works in a gas refinery. In this refinery they use amine process for gas sweetening.
After absorber column there is a rich amine flash tank. In this flash tank rich amine's pressure has reduced and flash gases release.
My question is: are there any best using ways for these flash gases? (80% of these gases are methane)
In some process there is a packing column on top of the flash tank. They sweet this flash gas again for refinery fuel gas. I can't find useful information about this kind of flash tank.
In other kind of process they use multi flash drum and recycle some part of this flash gases to absorber column like Morphysorb process. I can't find useful information about this process again.
You make me happy if you give me good suggestion or give me some information about these two processes.
Tanks a lot.

[JoeWong]

It can be the make up for fuel gas system...

[Root]

Mosavi

is this correct CH4 absorbed by Amine and more over is this easy separate in flash drum?

what type of amine you are using, is this MEA, DEA, TEA?

[m mosavi]

hi QUOTE
yes that's correct.
we use DEA for gas sweetening.

[Zauberberg]

Morphysorb is a competitive process for syngas treating (acid compounds removal), based on N-formyl-morpholine solvent and developed by UHDE GmbH. It has shown many advantages over conventional chemical and physical solvents, mostly because of low hydrocarbon losses in regenerated solvent off-gas.

A lot of information is available on the internet, here are few:

http://www.gasificat...pers/31LEPP.pdf
http://media.godashb...-Morphysorb.pdf
http://www.uhde.biz/...df_en_14.00.pdf
http://media.godashb...ttlenecking.pdf

Depending on the amount of flash gas, it is usually recovered as fuel gas or vented to flare. Packed section on a separate section/column on the top of flash vessel is common - especially if this stream is to be burned in refinery flare.

[Zauberberg]

Also look at http://www.epa.gov/g...706/acidgas.pdf

[m mosavi]

Hi Zauberberg
Tanks a lot for your guidance. It was so useful.

[m mosavi]

Hi dear friends
I'm locking for best references about designing spatial vessel. This vessel is a flash tank that there is a packed column in top of it. I want to design a packed column absorber in top of a rich amine flash drum in amine gas sweetening process.
Is any body here that has good suggestion? Or introduce me a best handbook for this purpose?
Tank for your attention.

[Zauberberg]

Design of packed section in rich amine flash vessel should be based on estimated/calculated flash gas rate and acid component loadings - using the same principle as for the absorber tower. Gas flow and packing type will determine minimum section diameter.
Depending on treated gas spec and amine type/purity, number of transfer units and corresponding packing height are calculated.

You can float this inquiry to amine vendors, and give them also existing vessel dimensions. Some of the information you can find in gas treating textbooks, and by using internet resources. BRE website is an excellent starting point.

Best of luck,

[Root]

Hi Zauberberg
Tanks a lot for your guidance. It was so useful.

Hi Mosavi,

Can you tell me, where are you facing problem for your adsorber desing?, I suggest for you culson and richardson V6 is very good for Gas absorption designing.
you can send me mail and discuss more in detail for your problem.
sadartoorr@gmail.com

Good luck

[m mosavi]

In this case because of having amine process for gas sweetening in our gas refinery, the best choice for flash gas stream sweetening above rich amine flash drum is using DEA.
But there is a question here:
For this stream witch kind of tower is suitable? (Tray tower or packing tower)
Can you introduce main references (handbook or software) for designing this tower?
Flash gas stream conditions are:
P = 8 bar
T 50 c
Total kgmol/day = 478
H2S kgmol/day = 0.5
CO2 kgmol/day = 24.7
Methane kgmol/day = 393

Tanks for your attention.