Editor's Note: This post was originally published in 2017 and has been completely updated for accuracy, comprehensiveness, and new information.
It’s common for gas companies and nitrogen generator providers to tout the idea that 99.99% pure nitrogen is the level of purity needed for all applications. On one hand, this is understandable; almost every application (with few exceptions) will work with 99.99%, as it guarantees that there are very few impurities in the N2 produced. However, what this doesn’t acknowledge is that the nitrogen purity needed is based on unique application requirements – and that the purer the nitrogen needed, the higher the cost.
This begs the question: if your application doesn’t require 99.99% pure nitrogen, then why are you paying for it?
Let’s put this into perspective. The cost differential between producing 99.9%, 99.99%, and 99.999% pure nitrogen can be tens (even hundreds) of thousands of dollars. The purer the nitrogen, the larger the equipment needed to produce it – which elevates the expenses. Why? Simple. Compressor flow is always much larger than the amount of nitrogen being generated, and you need more flow to generate purer nitrogen; ergo, a larger compressor is needed to generate purer nitrogen. And given that all system equipment (including dryers, drains, and air receivers) must be sized appropriately for a given application, your related system costs skyrocket.
For example, let’s say you have an application that requires 99% nitrogen. To produce 280 cfm of nitrogen at that purity level, you’ll require a compressor that can produce 741cfm at 100psi. However, an application requiring 99.9% nitrogen will need a compressor able to produce 1360 cfm at 100 psi!
Laser cutting is a great example of an application that can require varying N2 purity levels – not just the “standard” 99.99%. Depending on what metal you’re cutting and what’s being done with the product (Is it the final product? Will it be painted or powder-coated after the cut?), nitrogen purity levels needed can vary from 95% to 99.9%.
Do you know the exact nitrogen purity that you need? Our nitrogen generation experts are ready to assist you in determining what purity level your application requires. Reach out to us at www.atlascopco.com/n2!