7 replies to this topic

[Propacket]

Dear All,

I have two questions.

It is recommended that maximum amine loading should be 80% of equilibrium loading. How equilibrium loading is calculated using Hysys?

What is purpose of component efficiencies especially in Amine Pkg.& how does Hysys calculate these?

Edited by P.Engr, 07 October 2010 - 07:28 AM.

[Propacket]

Dear All,

I have two questions.

It is recommended that maximum amine loading should be 80% of equilibrium loading. How equilibrium loading is calculated using Hysys?

What is purpose of component efficiencies especially in Amine Pkg.& how does Hysys calculate these?

23 views so far and no reply.

Is it a difficult topic or i have posted a wrong question?

[Propacket]

Dear All,

I have two questions.

It is recommended that maximum amine loading should be 80% of equilibrium loading. How equilibrium loading is calculated using Hysys?

What is purpose of component efficiencies especially in Amine Pkg.& how does Hysys calculate these?

23 views so far and no reply.

Is it a difficult topic or i have posted a wrong question?

Ok
I got it.

[Padmakar Katre]

Dear All,

I have two questions.

It is recommended that maximum amine loading should be 80% of equilibrium loading. How equilibrium loading is calculated using Hysys?

Dear,
Could you please tell us the basis for 80% of the equilibrium loading to consider.Hysys has no any other method for calculations but it's the same as we calculate i.e. based on the acid gas partial pressures. Here is the link for a tutorial on support website of the Aspen tech,

http://support.aspen....cgi?key=110029
http://support.aspen....cgi?key=130245
http://support.aspen....cgi?key=130117

What is purpose of component efficiencies especially in Amine Pkg.& how does Hysys calculate these?

Just go through the documents provided with license of Hysys,
1. Hysys Sim-Basis which will guide you the features of Amine Package and
2.Hysys Tut which will guide you to understand how the system is modeled,

Hope this helps you.

[Propacket]

Could you please tell us the basis for 80% of the equilibrium loading to consider.

Thanks Padmakar.

Attached is the reference link.

http://www.reclaim.c...undamentals.pdf

[Padmakar Katre]

Could you please tell us the basis for 80% of the equilibrium loading to consider.

Thanks Padmakar.

Attached is the reference link.

http://www.reclaim.c...undamentals.pdf

Dear,
This is not the guideline to keep. If you go through this document or other documents or even the simulation files which I have you links to download will say the same thing. It's the always one's judgement who is working on conceptualization/configuration of the unit.

[Propacket]

Padmakar,

The above guideline (80% of the equilibrium loading) should be taken as maximum loading you can achieve in an amine treating system. You can model for lower loadings depending upon your system requirements.

You are right in saying “It's the always one's judgment who is working on conceptualization /configuration of the unit.” It’s a common practice in modeling amine treating systems to follow some available guidelines (e.g. GPSA, Hysys) for max/min loadings and then select a most suitable loading based on, as you said, conceptualization /configuration of the unit. But, in software like Hysys, how can one know how much system is away from equilibrium? Let’s assume I have selected 0.4 loading based on my judgment. This loading might be the most suitable & most optimum for my system. But it does not tell me how much my system has approached to equilibrium.

The attached paper says followings in this regard:

Page 3, “A rich loading of 0.4 mole to-mole means one thing in a system operating at 10 bar (145psi) versus a system operating at 70 bar (1015psi).”

Page 4, When plants are designed, typically the maximum loading guidelines are set or represented as an approach to the equilibrium set by the VLE data. For example, some engineering companies and operating companies will specify that the plant will be designed with a maximum loading of 80 per cent of equilibrium. This means that they will set the design around the process conditions to load the solvent to 80 per cent of the value of the equilibrium set by the VLE data.

Page 4, “Therefore, instead of setting an arbitrary rich loading on a mole-to-mole basis, the maximum rich loading needs to be set as a percent of equilibrium and then translated back to a mole-to-mole basis for monitoring purposes.”

P.S. "Gas Purification" by Kohl and Nielsen also recommends to use 75-80% approach to equilibrium.

Thanks

Edited by P.Engr, 12 October 2010 - 12:23 AM.

[Propacket]

One more question.
In property packages other Amine Pkg. (e.g. Peng Robinson), stage efficiency is put as 1. This means that system is in equilibrium. In Amine Pkg., can we get equilibrium by putting component efficiency as 1?

Thanks