Nitrogen Onsite

[cougarfan]

I am looking for an onsite system for about 99.5 % purity of nitorgen at 15000 scfh at 90 spig - I am hearing PSA,Membrane and onsite generation - does anyone have any experience in any of these to help me out?

 

[MarkkraM]

Should this be in the process control thread. Perhaps try chemical plant design and operation.

The site I work on obtains nitrogen by liquefaction of air. Our provider has 4 compressors two at 60 tonnes/day and two at 80 tonnes/day.

You may want to consider bulk liquid nitrogen delivery as a source? As a back-up,the plant I work on hires a cryogenic storage system that provides nitrogen at 1300kPag (purity 99.9% N2). It has a capacity of 1300Nm3/hr, obviously this can easily be adjusted to suit. Supply of nitrogen in this case is delivered in liquid form via road tankers.

Final I don't have experience with membrane technology

 

[dcasto]

PSA is the way to go. we have a surplus one that we may be able to part with. email me at dcasto@oneok.com

 

[chemicalcc]

In our company we use liquid nitrogn from a local vender, it is quit expensive, so we decided to buy a small nitrogen generator ( membrane type , produce nitrogen in a gas phase) to supply our normal use. The capacity is 20000 scfh, during abnormal demand use liquid nitrogen because it is not economical justified to have a huge nitrogen generator and make our and connect it to the nitrogn header comes from the evaporated liquid nitrogn from the nitrogen storage tanks. The cost of this generator is not expensive but it is strongly depends on the purity and capacity. your system might cost you 200,000 to 300,000 US$ depends on the vendor and depends on your requirments. to get qoutation on that search on the internet " ONSITE NITROGEN" you will get many many manufacturers

 

[TD2K]

You are looking at 250 scfm of N2 which is well within membrane packages, especially at 90 psig delivery pressure. Air consumption would be 3 to 4 times this flow (membranes that I have looked at have quite a high rate of rejection). The option might be a PSA unit but you might on the small side, on-site generation isn't practical for this flow rate IMO.

Do a search for N2 membranes, there are many companies which make these packages. Essentially, the more product you take from them, the lower the N2 quality as more and more O2 is left in it. 99.5% is well within the purity limits of membrane technology. I would strongly recommend oil-less compressors to avoid fouling the membranes.