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Introduction to Pressure Swing Adsorption Nitrogen Generators

Nitrogen is an essential gas in many industries, including food preservation, pharmaceuticals, manufacturing and construction, and fire suppression. It can be used to remove contaminants, prevent combustible dust explosions, and create a nonreactive production environment in settings where oxygen may cause explosions or harmful oxidation. However, though nitrogen is the most abundant gas in the atmosphere, it is not readily available because it must undergo purification to make it usable.

Pressure swing adsorption (PSA) nitrogen generators ensure a constant and consistent supply of high-purity nitrogen to facilitate uses on-site. Below, we cover everything there is to know about PSA nitrogen generators and whether they’re worth the investment. 

What Is a PSA Nitrogen Generator?

A PSA nitrogen generator is a stationary or portable machine used to isolate nitrogen from other elements in the atmosphere. It separates nitrogen gas from oxygen molecules, moisture, and any other impurities present in compressed air. PSA nitrogen generators produce nitrogen with a purity rating of up to 99.99% using constant temperature. The purity of the nitrogen produced by PSA generators depends on the reliability and efficiency of the adsorbent used in the system. 

How Does Pressure Swing Adsorption Work?

Most PSA nitrogen generators have two towers, one for absorption and one for regeneration. Adsorption is the process of using a solid substance to attract gas and liquid molecules. The pressure swing adsorption technique involves passing compressed air through several filters to remove moisture, oil, and impurities. 

The air is first pressurized into the absorption tower, where it contacts an adsorbent that allows carbon dioxide, oxygen, impurities, and water molecules through but blocks out nitrogen. The adsorption process is made possible by a carbon molecular sieve (CMS) that absorbs the remaining oxygen into the atmosphere. Nitrogen can’t pass through the CMS pores because its molecules are larger.

In the second phase, the pressure in the regeneration tower is reduced to produce a constant supply of high-purity nitrogen. Often, the compressed air is treated using a dryer placed between the compressor and the generator. This practice prevents damage to the CMS and ensures the production of high-purity nitrogen. 

PSA Generators Versus Membrane Nitrogen Generators

Membrane nitrogen generators are a popular alternative to PSA nitrogen generators that use a semipermeable barrier to isolate nitrogen from other gases and materials. When atmospheric air passes through the hollow fiber membrane, oxygen molecules and other impurities are filtered out and nitrogen is collected and stored.

Membrane nitrogen generators are smaller and lighter than PSA systems and are suitable for mobile nitrogen applications. However, these systems produce nitrogen at a maximum purity level of up to 95% and are not capable of the same level of performance as PSA systems. They also don’t last as long and will experience a gradual performance decline with every use. 

PSA Nitrogen Generator Pros and Cons

PSA nitrogen generators have numerous benefits that make them a reliable solution for many industries, including fire protection. 

Advantages of PSA Nitrogen Generators 

If you’re looking to start producing nitrogen for industrial use, here are a few factors that may make a PSA system a worthwhile investment:

  • Produces high-quality nitrogen gas: The best PSA nitrogen generator models are capable of producing up to 99.9995% pure nitrogen from atmospheric air. This level of output purity is highly beneficial to industries like food preservation and fire suppression. 
  • Establishes a reliable nitrogen supply: Nitrogen generators supply industrial plants with a constant flow of gas at a consistent percentage to ensure workflow productivity and efficiency. The reliable supply prevents pipeline contamination that could cause supply chain interruptions. PSA generators can run 24/7, provided they have power, and you can easily divert the application of the purified nitrogen to meet evolving company needs.
  • Offers low cost of ownership and operation: Traditionally, companies used bottled or liquified nitrogen to power their plants. However, the shift to modern PSA generators eliminates up to 50% of the costs associated with constantly rendering nitrogen cylinders. While nitrogen generators require a significant initial investment, you save more in the long run because they require minimal maintenance and incur relatively low utility costs.
  • Minimizes your company’s carbon footprint: PSA nitrogen generation is a sustainable, energy-efficient approach. These systems eliminate the use of fossil fuels to transport nitrogen cylinders, which reduces your carbon footprint, and require limited power to facilitate the adsorption process. Their ability to bring your nitrogen generation in-house at a low energy cost makes them ideal for eco-conscious businesses.
  • Requires low maintenance: PSA nitrogen generators have a long life span when they receive proper maintenance, potentially offering up to 20 years of service. One of the most crucial maintenance procedures is regularly inspecting the CMS to prevent contamination and maintain its capacity. 

If you ever do need a CMS replacement, it’s best to leave this task to a manufacturer representative who will disassemble and reassemble the adsorption columns according to the original specifications.

Disadvantages of PSA Nitrogen Generators

Though a PSA nitrogen generator is an excellent way to source nitrogen for industrial applications, users should be aware of the following considerations before purchasing one:

  • Significant capital investment: A PSA nitrogen generator will be more expensive than a membrane generator, and you may pay a premium for a high-flow-rate generator capable of achieving a higher degree of purity. However, many enterprises find that the longevity and performance of these systems ultimately translate to cost savings in the longer term.
  • Sensitive to moisture: PSA nitrogen generators work best with clear, dry atmospheric air. If the air is not dried before entering the generator, it could cause permanent damage to the CMS and decrease flow capacity as well as nitrogen purity.
  • Negatively affected by oil: Any small amounts of oil that leak into a nitrogen generator may cause an irreversible decrease in the system’s performance. These units require a clean, carefully maintained environment for optimal output. 

Get Efficient Pressure Swing Adsorption Nitrogen Generators 

General Air Products is a reliable manufacturer and supplier of fully tested and assembled turnkey PSA nitrogen generators. Our units produce nitrogen with a purity minimum of 98%, ready for use in new or existing fire sprinkler systems. These PSA nitrogen generators provide a constant on-site nitrogen supply that prevents corrosion in dry pipes and improves the life span of the sprinkler system.

The team at General Air Products goes beyond selling nitrogen generators and air compressors — we back every product we sell with lifetime customer service and technical support. Check out our range of PSA nitrogen generators and accessories online or contact us via form for additional information about our products. You can also call 855-769-5652 to speak with a team member.