How to Choose the Right
Nitrogen Generation System
Most plants shift to on-site nitrogen to escape rising cylinder costs, supply uncertainty, and safety risks. Choosing the wrong technology can lock you into years of unnecessary expense. This guide helps you make the right decision from the start.
Decision Step 1: Delivered vs On-Site Nitrogen
The first decision is foundational: should you purchase nitrogen from external suppliers or generate it on-site?
| Factor | Cylinders | On-Site |
|---|---|---|
| Operating cost | Volatile & delivery dependent | Predictable & controlled |
| Supply reliability | External dependency | Fully internal |
| Safety | Handling & storage risks | Enclosed process |
| Best suited for | Small or infrequent demand | Continuous industrial use |
Decision Step 2: PSA vs Membrane Technology
Once you've decided on on-site generation, the next choice is between PSA (Pressure Swing Adsorption) and Membrane technologies.
| Requirement | PSA | Membrane |
|---|---|---|
| Purity range | 97.5–99.999% | 95–99.5% |
| Flow rates | Medium to very high | Low to medium |
| Energy efficiency | Excellent at high purity | Best at lower purity |
| Maintenance profile | Mechanical system | Static system |
| Typical industries | Pharma, petrochemical, electronics | Packaging, remote plants |
Energy Efficiency & Feed-Air Factor
The Real Cost of Nitrogen
The real cost of nitrogen is the electricity used by the air compressor. Understanding the feed-air factor — the volume of compressed air needed to produce one unit of nitrogen — is critical to calculating true operating costs.
PSA Systems (97.5–99.999% Purity)
At medium purity levels, PSA systems are highly energy-efficient with reasonable feed-air factors.
Key Point: As purity increases beyond 98%, feed-air factor rises dramatically, making PSA progressively more cost-effective as high-purity becomes critical.
Membrane Systems (95–99.5% Purity)
Membrane systems excel at lower purity levels with excellent energy efficiency. However, above 95% purity, they become increasingly inefficient.
Key Point: Pushing membrane systems to 99%+ purity requires excessive compressed air and power, making them economically unviable for high-purity applications.
Durability & Maintenance: Lifecycle Comparison
| Component | PSA System | Membrane System |
|---|---|---|
| Core technology | Carbon Molecular Sieve (CMS) | Hollow fibre membranes |
| System nature | Mechanical – frequent valve switching | Static – no moving parts in nitrogen section |
| Primary wear point | Switching valves | Filtration protecting fibres |
| Typical lifespan | CMS lasts many years | Fibres last 10+ years if oil-free air is ensured |
Key Insight: Membrane failures are usually filtration-related. PSA failures are usually valve-related. Understanding which is more critical to your operation helps determine the right choice.
Common Mistakes Buyers Make
Choosing membrane for ultra-high purity applications (99.9%+)
Oversizing systems 'to be safe' without understanding actual demand
Ignoring compressor energy cost in TCO calculations
Designing nitrogen requirements before fully understanding the process
Not accounting for future growth and scalability needs
What We Need to Recommend the Correct System
Required nitrogen flow (Nm³/hr)
Required purity (%)
Operating pressure
Hours of operation per day
Power reliability at site
Application type
Which Nitrogen Technology Fits Your Plant?
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