What Is a Nitrogen Generator? PSA & Membrane Systems

A nitrogen generator is a system that produces high-purity nitrogen gas on-site using atmospheric air as feedstock. Nitrogen, which makes up approximately 78% of atmospheric air, is separated from oxygen and other gases using specialized technologies and delivered to the process line. This method eliminates dependence on cylinder or liquid nitrogen supply, removes cylinder exchange logistics and storage costs, and provides a continuous, safe nitrogen source at the facility.

PSA Technology: Continuous Production with Carbon Molecular Sieve

In PSA (Pressure Swing Adsorption) technology, two columns containing Carbon Molecular Sieve (CMS) operate alternately. While the first column is under pressure adsorbing oxygen molecules from atmospheric air, nitrogen-enriched gas is obtained at the outlet. During this time, the second column is in the regeneration phase: pressure is reduced to expel the retained oxygen and the column is readied for use again. Since the columns automatically cycle in sequence, continuous nitrogen production is achieved.

PSA systems can deliver purity between 95% and 99.999%. For food packaging and MAP (modified atmosphere packaging) applications, 99–99.5% is generally sufficient. In laser cutting, stainless steel fiber laser cutting requires 99.999% (Grade 5.0) to prevent edge burr and oxidation, while mild steel cutting typically operates at 99.5% to 99.9%.

Membrane Technology

In membrane nitrogen generators, pressurized air is passed through hollow polymer fiber membranes. Small molecules such as oxygen and water vapor escape through the membrane walls while nitrogen is retained inside and directed to the outlet. These systems are more compact and lower in maintenance cost; however, maximum purity is typically limited to 99.5%. They are sufficient for tire inflation, fire prevention, and basic packaging applications — for critical processes, PSA should be preferred.

On-Site Nitrogen Generation System

• Tailored gas purity from 95% up to 99.999% based on process needs
• Completely eliminates cylinder rental and liquid nitrogen refill logistics
• Integrated analyzers for real-time monitoring of gas purity and dew point

Our Nitrogen Generator Service & Purity Inspection Solutions

The Critical Importance of Quality Feed Air

In both technologies, generator performance depends directly on the quality of the feed air. PSA feed air must strictly meet ISO 8573-1:2010 Class 1:4:1 standard (0.1–0.5 µm particulates, -40°C pressure dew point, and residual oil ≤ 0.01 mg/m³). Moisture and oil particles rapidly foul the microscopic pores of Carbon Molecular Sieve (CMS) or polymer membranes, degrading purity and shortening equipment lifespan. For this reason, an appropriate dryer and filtration system must always be placed upstream of the nitrogen generator.

Periodic Maintenance

Periodic maintenance on nitrogen generators covers inlet filter element replacement, solenoid valve inspection, cycle timing calibration, and regular purity analysis measurements. The performance of CMS columns degrades over time; regular measurement of outlet purity and dew point therefore enables timely intervention planning.

For details on desiccant dryers and inline filters that should be installed upstream of nitrogen generators, see our technical blog posts.

At HAVKOM Engineering, we provide independent technical maintenance and periodic servicing, gas purity and dew point calibration, and CMS and spare parts supply for PSA and membrane nitrogen generators. You can review our supported equipment on our brands page or contact our engineering team for professional support.