TEG dehydration

[Homayun]

Guys,

Is there anyone familiar with the TEG dehydration process? I know myself how it works, but what I don't know is how such a system is generally simulated? In other words, how is the main TEG contactor where the gas is treated with Lean TEG being sized? And how about the Rich TEG regeneration?

Any response is appreciated.

 

[zerok]

Hi Homayun,

We had a TEG dehydration unit in our offshore plateform with a 500 000 sm3/d capacity. If you're using HYSYS there is a tutorial about gas dehydration with TEG. I'd recommend you have a look at the GPSA handbook (chapters 19 and through 20) to have an oveview of gas dehydration processes.

Hope this helps.

zerok.

 

[Homayun]

Thanks Zerok.

I don't have access to Hysys Tutorails on simulating TEG dehydration. Is it possible for you to somehow send it to me, if you do have access to it? Or is it possible for you just to inform me how it is done in a simualtion?
I appreciate it. and the GPSA book doesn'l also say anything about the simulations.

 

[hiebs]

Hi Homayun,

What simulator do you have access to? GPSA should be able to give you basics on sizing absorbers and regeneration (this provides a good base for figuring out how the simulation works). Details on how the contactor is simulated in your simulator may be a better question for the support team for that particular program. They may have examples available for you to follow.

From what I've seen, each simulator sizes the contactor in generally the same way, but there are quirks in getting the columns to converge.

Are you having a particular problem with sizing the contactor? Your question is very general so perhaps a few more details on the information you are looking for will help others in this thread.

Hiebs

 

[Homayun]

Hiebs,

Thanks for response. Well you are right, it is a very general question. We do have Provision however, so I'll have a look at their manual.

Thanks a lot

 

[MortenA]

Homayun

I think your level of detailing depends on what you want to acomplish.

If your wish to include "dehydration" in a simulation of e.g. well stream processing/gas recovery, recompression etc. plant. Then all you may require is a "component splitter". This is labelled differently in th various process simulation tool- but basically works this way:

1 inlet stream

2 (or more) outlet streams

3 you specify the concentration (or recovery %, flow rate or similar) for each component in n-1 streams where n is the number of avaiable outlet streams. The compinent then fits the mass balance for the remaining stream.

eg:

For a "dehydrator" you specify that 100% of all components expect water goes to your "dry gas stream" and that the water concentration is e.g. 40 ppm in this stream.

If you whish to design a TEG dehydration unit then you must include the various components (and TEG in you component list) such as contacting tower, pumps, heat exchangers, TEG still etc.

Best regards

Morten

 

[Homayun]

Thanks Morten,
You have been very helpful

 

[Hookem]

Consider inlet gas temperature (keep it as low as possible).

Consider inlet gas pressure (keep it as high as possible).

Consider inlet gas separation and filtering (keep out lube oils and amines).

Calculate water removal (lbs/mmcf times mm/d); start with 3 gallons of glycol circulation for each lb of water removal.

Calculate regen. heat duty (start with 2000 BTU/hr per lb of water removal).

 

[Buchi]

In case you are getting into full blown detailed simulation of the TEG system, I am aware that HYSYS cannot be relied on for such. There are better simulators like ProMax.

But like Mortena said, a simple component splitter will suffice if you are just simulating TEG in the overall condensate/gas separation and drying scheme.

I hope that helps

Buchi

 

[Zoobie]

The newest version of HYSYS has a property package built-in specifically for TEG dehydration. Hopefully this will correct problems from previous versions.