Filtration in PSA Nitrogen Generation

Why filtration is a crucial component in On-Site PSA Nitrogen Gas Generation Systems

Posted on April 21st, 2022

Rather than receive nitrogen in bulk, many companies choose to install on-site nitrogen generation systems inside their facilities. While there are a few initial challenges, including space requirements and upfront costs, the ability to produce highly pure nitrogen on-demand and on-site typically far outweigh the drawbacks.

The filtration products within an on-site nitrogen generation system are crucial to having a consistently pure nitrogen supply. Without the proper compressed air filters, the entire supply could become contaminated.

The Basics of an On-Site PSA Nitrogen Gas Generation System

A nitrogen generator does not create pure nitrogen all by itself. Instead, a compressor starts by producing compressed air, which is roughly 78% nitrogen. Then, by having compressed air filters installed in the system, liquid, oil, water and other molecules are removed from the compressed air stream. Finally, inside the nitrogen generator, oxygen is extracted, leaving only nitrogen.

Filtration in a Gas Generation System

The compressed air stream must pass through a pre-filtration stage to remove moisture, oil and particles before entering a nitrogen generator. Then, when compressed air enters the generator, only oxygen and nitrogen are present. A Pressure Swing Adsorption (PSA) Nitrogen Generator uses a material called a Carbon Molecular Sieve (CMS) to remove the oxygen from the compressed air stream.

Located inside the columns within the generator, the CMS is a porous material that absorbs the oxygen molecules. PSA nitrogen generators always have two CMS columns. So, while one column is pressurised and removes oxygen from the stream, the other is depressurised and regenerated.

On-site PSA Nitrogen Generators are generally paired with a standard air compressor, which should always have compressed air filters installed before and after the compressor. By providing quality pre- and post-filters, facilities can rely on a constant supply of pure nitrogen, low maintenance costs and equipment longevity.


Walker Filtration always recommends supplying pre-filtration with nitrogen generators to remove contaminants from the compressed air stream. Installing filtration to remove contaminants from the airstream before it reaches the compressor and generator increases the equipment’s lifespan and reduces maintenance The Walker Filtration high-efficiency filters remove particles down to 0.01 micron and accommodate flows up to 1500 SCFM / 2550Nm³/h



All PSA nitrogen generators should also be supplied with a post-filter to remove any remaining particles in the nitrogen stream. The Walker Filtration dust filter removes particles down to 0.01 micron and accommodates flows up to 1500 SCFM / 2550Nm³/h.

Benefits to an On-Site PSA Nitrogen Generator

By having a PSA Nitrogen Generator on-site, facilities can streamline processes and ensure a consistently pure nitrogen supply. When purchasing bulk nitrogen, there is an opportunity for inconsistent quality and delayed shipments, which disrupt the workflow.

Overall, on-site PSA nitrogen generators have a low total cost of ownership. Generators generally require minimal service and can last 20 or more years before needing to be replaced. Comparatively, delayed shipments, subpar quality and delivery fees often add up to the purchase cost of an on-site nitrogen generator within 12 years.

However, choosing to have an on-site PSA nitrogen generator does have a few challenges for some facilities. For example, there is a rather significant initial investment. Depending on a facility’s requirement, the initial investment might take several years to pay off. For example, a more pure and higher flow rate needs a larger and more costly system. Additionally, space for the system could be an issue.

The Purer the Nitrogen, the Better

There are varying levels of purity when speaking about nitrogen generation.  Without using the proper filtration products, contaminants can enter the system and the nitrogen supply. Compressed air filters are also cost-effective to keep the compressor and nitrogen generator running efficiently and protected from damage.

At Walker Filtration, we understand the importance of a constantly pure nitrogen supply. Therefore, our compressed air filters are manufactured with efficiency as a top priority. Our filters have connection sizes up to 3” and accommodate flows up to 1500 SCFM  / 2550Nm³/h. However, our engineers can create a custom-built solution for your unique system. Contact us today to see how we can help.

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