7 replies to this topic

[mvancleave]

For a power project in Abu Dhabi, our initial indication from the gas supplier is that the H2S concentration could be as high as 250 ppm (no indication of mass or volume, but probably volume).

I have been asked to look into "what it would take" to reduce this to something on the order of single-digit concnetrations (in ppmv). At this time, we are not looking to design the system, but rather tell the owner roughly how much of a problem (cost, operations problems, environmental issues, etc.) this will be to support negotiations with the gas supplier.

For this discussion, we can assume we need to treat roughly 1,000,000 pounds per hour of natural gas flow. What proceses might we be looking at (amine?, others?)? Any ideas as to rough costs, footprints, etc.? Major environmental concerns? Special operations experience/training?

Thanks for any advice,

Mike

[joerd]

250 ppm sounds awfully high for a pipeline gas. I am surprised that the supplier can get away with this. Please make sure that their number is really what they say it is.
Typical process would indeed be amine-based. There is tons of material out on the web, so happy googling!

[gvdlans]

I did a recent project in Abu Dhabi where the H2S content in the gas was more than 10%. We indeed had an amine based unit to sweeten the fuel gas to a level where it could be used by the Gas Turbine Generators.

[Eng.Hanifa]

Dear there ,
I have my project about designing a process for methanol synthesis from natural gas . Mainly UAE NG have about 250 ppm H2S . which can pose methanol reactor (it will poise) . How can we remove or reduce this amount to 0.1 ppm (to be enviromental freindally)...

[mbeychok]

mvancleave:

It would be useful for you to read: http://en.wikipedia....ne_gas_treating

[No Heat Resources]

For a power project in Abu Dhabi, our initial indication from the gas supplier is that the H2S concentration could be as high as 250 ppm (no indication of mass or volume, but probably volume).

I have been asked to look into "what it would take" to reduce this to something on the order of single-digit concnetrations (in ppmv). At this time, we are not looking to design the system, but rather tell the owner roughly how much of a problem (cost, operations problems, environmental issues, etc.) this will be to support negotiations with the gas supplier.

For this discussion, we can assume we need to treat roughly 1,000,000 pounds per hour of natural gas flow. What proceses might we be looking at (amine?, others?)? Any ideas as to rough costs, footprints, etc.? Major environmental concerns? Special operations experience/training?

Thanks for any advice,





Dear Mike

We have a water based H2S Remover called HydraScav that would be perfect for reducing your 250ppm of H2S to zero.
I am based in Oman but this week I am in Dubai.

Regards

David Snodgrass
www.no-heat.com


Mike

[Padmakar Katre]

Dear,
Fisrt of all confirm the SweetGas spec for H2S content limit. Coming to your second question of how to select the sweetening scheme is based on the following points,
A.CO2 Removal
B.H2S Removal
C.H2S and CO2 Removal
D.Selective H2S Removal
The choice among the available sweetening processes is made based on the above points as well with some considerations bellow,
1.Partial pressure of AG in SourGas (Selection of solvents among physical and chemical).
2.SweetGas Specifications.
3.Quality of SourGas and quantity of Sulphur to be produced (Selective Solvent like MDEA)
4.Requirement of CO2 rich and H2S rich streams differently (Selexol)
There is abandunt material available regrading the AG removal processes.
I will recomment readings from
1."Gas Purification" by Arthur Kohl and Rechard Nielsen.
2.Publications from wwww.bre.com
3.Publications from Gas Treatment Inc.
Apart from above just google the topic and you will end up with some few hundred worth reading links.

Edited by Padmakar S Katre, 08 December 2009 - 08:48 AM.

[Satyajit]

Hi Mike,
I think this is a very interesting topic. For removing Sulphur more than 250 ppm we should adopt two step
sulphur removal process as following.

AA. Removal of bulk H2S using AMDEA solution and reduce S to less than 10-20 ppm.

BB. Final Desulphurisation

Natural Gas is mixed with H2 ; all the sulphur componenet is converted into H2S in a COMox or Nimox catalyst bed at about 360-370 C.
RSH + H2 = RH + H2S

Then H2S is chemically absorbed in ZnO catalyst: ZnO + H2S = ZnS + H2O.

Normally the ZnO bed volume is designed in such a way to sustain plant operation atleast for 2 years.ZnO bed should be replaced
when it is exhausted.

On investment,

Step AA: approx 40-50 million Euro
step BB: APPROX 10-12 million Euro.

Hanifa,
For methanol plant also we should adopt same strategy as explained above.

Hope this is useful.
Kind regards,
Satyajit

Edited by Satyajit, 08 December 2009 - 05:21 PM.