Nitrogen from cylinders and generated nitrogen are two fundamentally different methods of supplying nitrogen to industrial processes. With nitrogen cylinders, the gas is stored under high pressure and delivered by an external supplier, while generated nitrogen is produced on-site by a nitrogen generator that filters nitrogen from ambient air. The main difference lies in the delivery method, initial costs, operational expenses, and suitability for different applications. The choice between these methods depends on your specific needs in terms of purity, consumption volume, and continuity.
What is the difference between cylinder nitrogen and generated nitrogen?
The two main methods of nitrogen supply in industrial environments are cylinder nitrogen and generated nitrogen. Although the end product (nitrogen gas) is the same, these methods differ significantly in how they work and are applied.
Nitrogen from cylinders is delivered in high-pressure steel bottles that must be periodically replaced or refilled by an external supplier. These cylinders contain nitrogen that was previously produced in a specialized facility and then stored under pressure. This system requires storage space for the cylinders and regular deliveries to ensure continuity.
Generated nitrogen, on the other hand, is produced on-site by a nitrogen generator that takes in ordinary ambient air (which is 78% nitrogen) and separates the nitrogen from oxygen and other gases through specially designed filtration systems. This method provides a constant, uninterrupted flow of nitrogen without dependence on external deliveries.
The choice between these methods depends on factors such as consumption volume, desired purity, available space, and budget for initial investments versus long-term operational costs.
How exactly does a nitrogen generator work?
A nitrogen generator produces nitrogen by extracting it from ambient air via specialized filtration technologies. The two most commonly used technologies are Pressure Swing Adsorption (PSA) and membrane technology.
With PSA technology, compressed air is directed through carbon molecular sieve columns. These columns contain material that adsorbs oxygen, water vapor, and other gases, but allows nitrogen to pass through. The process works cyclically: while one column produces nitrogen, the other regenerates. This ensures a continuous flow of nitrogen gas with a purity that can reach up to 99.9995%, depending on the configuration.
Membrane generators use hollow fiber membranes that are selectively permeable. When compressed air flows through these fibers, smaller molecules such as oxygen, water vapor, and CO₂ diffuse through the membrane, while the larger nitrogen molecules remain inside. This technology is compact and has few moving parts, resulting in a low maintenance profile.
Both systems are powered by compressed air and therefore require a reliable compressor. The choice between PSA and membrane technology depends on your specific requirements in terms of purity, flow rate, and energy consumption.
What are the cost advantages of generated nitrogen?
The cost structure of generated nitrogen differs fundamentally from that of cylinder nitrogen. Generated nitrogen requires a higher initial investment for the purchase of the generator, but delivers significant savings in the long term.
With nitrogen cylinders, the initial costs are low – you only pay for cylinder rental and a regulator. However, the operational costs are high due to the continuous delivery, rental, and exchange of cylinders. Moreover, these costs rise proportionally with your consumption, and delivery problems can cause unexpected interruptions.
A nitrogen generator, on the other hand, has the following financial benefits:
- Lower operational costs (only electricity and periodic maintenance)
- No delivery costs or logistical challenges
- No dependence on price fluctuations from gas suppliers
- Predictable total cost of ownership (TCO)
Depending on your consumption volume, a nitrogen generator can pay for itself within 1-2 years. For businesses with medium to high nitrogen consumption, generated nitrogen almost always provides the lowest cost per cubic meter of nitrogen.
Which method delivers the highest purity?
Both nitrogen from cylinders and generated nitrogen can achieve high purity levels, but there are important differences in what is standard and what is technically possible.
Nitrogen from cylinders is delivered with a guaranteed purity, usually between 99.5% and 99.999%, depending on the specification you order. This very high purity is one of the main advantages of cylinder nitrogen, especially for applications requiring extremely low oxygen content.
With generated nitrogen, the purity depends on the type of generator and its configuration:
- PSA generators can achieve purities up to 99.9995%
- Membrane generators typically deliver purities between 95% and 99.5%
A key advantage of nitrogen generators is that the purity is adjustable according to your needs. This offers flexibility: you can fine-tune the purity precisely to your application, without paying for unnecessarily high purity when it’s not required.
For applications such as food packaging in the food industry, fire protection, or tire inflation systems, the purity of generated nitrogen is usually more than sufficient. For very specific applications such as semiconductor production or certain laboratory applications, cylinder nitrogen may be preferred due to the extremely high purity guarantees.
When is nitrogen from cylinders the better choice?
Although generated nitrogen is advantageous for many applications, there are specific situations in which nitrogen cylinders remain the most practical or cost-effective solution.
Cylinder nitrogen is ideal for:
- Occasional or very low consumption, where investment in a generator cannot be justified
- Applications requiring extremely high purity (>99.999%)
- Temporary projects or locations without reliable electricity supply
- Situations where insufficient space is available for a generator
- Businesses with limited investment budget who prefer to pay operational costs
Nitrogen cylinders also offer more flexibility with changing needs and require no technical knowledge for installation or maintenance. They are immediately deployable and offer a plug-and-play solution without initial investment costs.
For laboratories, small workshops, or businesses with very specific but limited nitrogen needs, cylinders remain a practical solution, despite the higher cost per cubic meter of nitrogen.
What are the key considerations when choosing between nitrogen cylinders and generators?
When making a choice between nitrogen cylinders and a nitrogen generator, it’s important to thoroughly analyze your specific business situation. The decision factors include your consumption volume, required purity, available space, and your financial planning (capital expenditure versus operational costs).
For continuous processes with medium to high nitrogen consumption, a nitrogen generator offers significant advantages: lower operational costs, independence from suppliers, and a constant, reliable nitrogen supply. The initial investment usually pays for itself within 1-2 years.
For occasional use, very specific purity requirements, or temporary applications, nitrogen cylinders remain a suitable solution, despite the higher cost per cubic meter.
At Presscon, we understand that every industrial application has unique requirements. We are happy to advise you on the most suitable nitrogen solution for your specific situation. With our years of experience in various sectors such as greenhouse horticulture, breweries, data centers, and laboratories, we can provide you with a system that precisely meets your needs – whether this is a customized nitrogen generator or an efficient cylinder system.
The right choice not only ensures optimal process efficiency but also contributes to sustainability and cost savings in the long term.
