Estimating New Plant Nitrogen Demands

[Amphoteric]

I'm working on basic engineering (P&ID-level initial design) of a proposed new refinery. We will need a nitrogen plant to generate N2 for start-up/shutdown/continuously purging some lines/etc.

I've had no problems finding information and vendors to get a nitrogen plant to SUPPLY the N2.

But I am having trouble estimating the DEMAND for nitrogen and writing the vendors a design basis. I can't find any standards on how to estimate the demands for startup, shutdown, etc.

Any advice on estimating the requirements? I will need to determine the continuous (normal operating) and the maximum demand.

Thank you in advance.

 

[Amphoteric]

BUMP.

If no one knows, does anyone know someone that would know?

I mean some major companies must have design procedures for this sort of thing, right? Are any willing to sell these kinds of procedures, or perhaps be hired for a one-day consultation?

 

[roker]

hello,

the new refinery is based on some know-how from various kind of companies, usually they will give you all utilities required.

what about cooling water, instrument air, plant air,flare, etc. etc.

you asked a very general request, what is the refinery size (BPSD), what are the units to be installed.

it is very not clear that the only subject raised by you is
the nitrogen issue.

perhaps you can be more specific.

roker

 

[Amphoteric]

You're right, I'm not being specific because I was hoping (ideally) for general guidance. Some utilities fall out of your design naturally (e.g. cooling water), and some I have rules of thumb for, but nitrogen and waste water loads are proving intractable.

It's a 75kBPSD heavy middle eastern crude refinery in question, with a crude unit, gas plant, delayed coker, 5 other major processing units.

 

[MJCronin]

Ampho....

It is my understanding that a peak usage of nitrogen occurs when a large tank is initially purged. Four or five fills of the vapor space must occur.

I would incorporate the simultaneous initial purge of two or three of the largest tanks in the project in my calculation.

My opinions only

-MJC