4 replies to this topic

Hi all,

I am currently preparing a technical specification for a Nitrogen Generation Package to be installed on an offshore FPSO.

While listing the scope of supply and services, using some previous projects as go-by, i was confronted with the question of the possibility of the package having on skid air compressor for the feed air or depending on the instrument air from the Instrument and Plant air compressor package.

The available PID is not really detailed and does not show the contents within the battery limits.
I would like see if anyone out there has had a similar experience

Regards

[djack77494]

I would like see if anyone out there has had a similar experience

Speedy,
You must do what makes sense to you. If you have or can design an adequate dried air system capable of meeting the needs of your nitrogen generation package (I assume membrance), then why not? In offshore platforms I have seen, exactly this approach was taken. You must decide that the IA system's pressure, temperature, and capacity are acceptable.

[Zack Adam]

Sometime utility air can also be used as the air source for N2 Generator.

If the air feed is taken from instrument air, then control valve shall be installed on the line so that during shortage of air to instrument air main users, the priority will be given to instrument air users




regards
Zack

[ankur2061]

Hi all,

I am currently preparing a technical specification for a Nitrogen Generation Package to be installed on an offshore FPSO.

While listing the scope of supply and services, using some previous projects as go-by, i was confronted with the question of the possibility of the package having on skid air compressor for the feed air or depending on the instrument air from the Instrument and Plant air compressor package.

The available PID is not really detailed and does not show the contents within the battery limits.
I would like see if anyone out there has had a similar experience

Regards

Speedy,

For offshore nitrogen generation package check out section 27 of Norsok Std P-100. Here is the link:

http://www.standard..../1132/P-100.pdf

Hope this helps.

Regards,
Ankur.

[imtiaz]

Speedy,
First of all i assume that the Nitrogen production capacity is known. From a material balance standpoint 1.3 to 1.5 kmoles of Air may be required to produce 1 kmole of N2, depending on the specification of the membrane unit and the process conditions. If you intend to use the existing IA package, you need to determine the reserve capacity in the system so that the instruments are not comprised. Membrane packages are designed for particluar inlet pressure below which the capacity is affected. Furthermore, the moisture dew point of the supply air is also important - usually recommended at -40degC or lower so that the membranes do not lose efficiency over time. Since you are in a moisture rich environment, you need to ensure that your dryers are working properly.
Regards,
Imtiaz