How Does a Nitrogen Generator Work? 

Importance of Nitrogen in Various Industries

Nitrogen, a critical industrial gas, finds extensive applications across various sectors because of its inert and non-reactive nature. So where is it used?

• The food and beverage industry uses high-purity nitrogen for packaging to prolong product shelf life, reduce oxidation, and prevent bacterial growth.
• The electronics industry uses nitrogen for soldering and reflow processes. It prevents oxidation, ensures clean solder joints, and improves product quality.
• The pharmaceutical sector uses nitrogen gas to create inert atmospheres for chemical reactions, reducing the risk of flammable or explosive environments.
• Laser-cutting operations use nitrogen to assist the cutting process and prevent oxidation on the cut surface.
• The oil and gas industry uses nitrogen purging as a standard procedure to displace potentially hazardous gases and reduce the risk of an explosive atmosphere.
• The marine industry uses nitrogen to prevent the corrosion of ship’s storage tanks through inerting, especially those used for storing hydrocarbons.
• The mining sector uses nitrogen in the prevention of mine fires and explosions, as well as for filling the tyres of heavy machinery.

The examples above highlight the importance and widespread use of nitrogen in diverse applications and the need to generate it safely and efficiently.

The Need for Nitrogen Generators

Given the widespread applications of nitrogen gas across various sectors, the efficient, safe, and cost-effective generation of nitrogen is a priority. 

Nitrogen generators meet this need by providing on-demand, high-purity nitrogen gas without the logistical challenges of delivering and storing cylinders or liquid nitrogen.

So, using an on-site nitrogen generator is a logistical convenience and a key contributor to operational safety, efficiency, and cost-effectiveness across industries.

Nitrogen generators are devices that use a physical or chemical process to separate nitrogen gas from other gases in the air. They come in various sizes suitable for applications ranging from industrial processes to medical treatments.

• A nitrogen generator can provide high volumes of pure nitrogen on demand, eliminating the need for traditional nitrogen gas cylinders. 
• Depending on the type of nitrogen generator, they can produce nitrogen gas with purity levels over 99.999%. 
• The most common types are a membrane nitrogen generator and a pressure swing adsorption (PSA) nitrogen generator.

Regardless of the type, both have the same fundamental parts: a compressor to draw in ambient atmospheric air, a filter to remove dust particles, an air-drying system, and a storage tank to hold the nitrogen gas.

How Does a Nitrogen Generator Work?

A nitrogen generator works by producing high-purity nitrogen gas on-site, whether in an industrial or laboratory setting. It does this by using the physical property of gases: different gases diffuse through a membrane at different rates.

There are two main types of nitrogen generators: PSA and membrane.

PSA nitrogen generators separate the nitrogen molecules from other molecules in the air using a carbon molecular sieve (CMS). The CMS adsorbs oxygen molecules and other trace gases under high pressure while allowing nitrogen to pass through and be collected.

Membrane nitrogen generators use a membrane that allows some atmospheric gases to permeate it more readily than others. Oxygen, water vapour, and other gases diffuse through the membrane wall more readily than nitrogen, leaving a nitrogen-enriched gas stream on the other side. This technology is efficient, reliable, and can produce nitrogen gas with purities as high as 99.999%.

Let us dive a little deeper into each type.

PSA Nitrogen Generators

A PSA nitrogen generator operates on the pressure swing adsorption principle. The process involves generating nitrogen from atmospheric air using two pressurised vessels filled with carbon molecular sieves (CMS).

How Does a PSA Nitrogen Generator Work?

The process involves the steps outlined below:

1. Compression Phase: compressed air enters one vessel, and the CMS selectively adsorbs oxygen, carbon dioxide, water vapour, and other gases, allowing nitrogen to pass through to a storage tank.
2. Regeneration Phase: after the CMS in the first vessel gets saturated with the adsorbed gases, the system depressurises it by venting the trapped gases into the atmosphere.
3. Swing to Second Vessel: simultaneously, the system directs the pressurised air to the second vessel, and the process repeats. The swing between the two vessels ensures uninterrupted nitrogen production.
4. Purity Control: a PSA system can control the purity of the nitrogen produced. It depends on the air pressure, the sieve characteristics, and the time allowed for adsorption. With accurate control of these variables, a PSA system can deliver nitrogen with purity up to 99.9995%.

Advantages

• Efficiency: PSA nitrogen generators are efficient and reliable, making them suitable for applications demanding high-purity nitrogen. They can produce nitrogen on-site, reducing the need for purchasing, storing, and handling bulky nitrogen cylinders.
• Versatility: thanks to their design, PSA nitrogen generators can be used in various industrial applications, from food packing to chemical blanketing, metallurgy, electronics, and more. They are invaluable where a continuous and reliable supply of nitrogen is required.
• Cost Effectiveness: PSA nitrogen generators reduce the constant costs of purchasing, storing, and transporting nitrogen cylinders.
• Reliability: they provide a consistent and reliable nitrogen supply, minimising the risk of running out during critical processes.
• Purity Control: the purity of the nitrogen can be controlled and adjusted according to specific application requirements, achieving purity levels up to 99.9995%.
• Safety: on-site nitrogen generation eliminates the safety risks of handling and storing high-pressure gas cylinders.
• Environmental Impact: PSA nitrogen generators have a lower carbon footprint than the traditional method of delivering nitrogen in cylinders.
• Space Saving: PSA systems save valuable floor space in facilities because they are more compact than storing gas cylinders.

Membrane Nitrogen Generators

Membrane nitrogen generators work on the selective permeation principle using nitrogen separation membranes.

How Does a Membrane Nitrogen Generator Work?

The process involves the steps outlined below:

1. Feeding Air Into the System: the generator draws compressed air in and passes it over a bundle of hollow fibres (the membrane).
2. Separation Process: the membrane has selective permeability, allowing certain gases to pass through more readily than others. Oxygen, water vapour, and other less desirable gases are diffused through the membrane wall more quickly than nitrogen.
3. Collection: the nitrogen-enriched gas stream is collected on the other side of the membrane, separated from the diffused gases.

Advantages

• Simplicity: membrane nitrogen generators have fewer moving parts, reducing the risk of mechanical failure and minimising maintenance requirements.
• Flexibility: the nitrogen purity can be adjusted by changing the feed air pressure or by altering the sweep gas flow rate to avoid lowering nitrogen purity, offering a high level of control to meet specific application needs.
• Efficiency: they provide a continuous nitrogen supply, eliminating time lost due to cylinder changeovers.
• Safety: the on-site generation of nitrogen significantly reduces the safety risks of storing and handling high-pressure gas cylinders.
• Cost-Effective: membrane nitrogen generators provide significant cost savings over time by eliminating the need for bottled nitrogen delivery and storage.
• Compact and Portable: due to their compact design, membrane nitrogen generators can be installed in small spaces and are ideal for any mobile application that requires nitrogen gas.
• Environmentally Friendly: using existing compressed air supplies and reducing the need for delivered nitrogen means these systems have a lower environmental impact.

Technological Innovations in Nitrogen Generation

Several cutting-edge innovations have made nitrogen gas generation more efficient, cost-effective, and versatile.

Custom Engineered Systems

Custom nitrogen gas generators have emerged that tailor nitrogen generation to the specific requirements of a project or business. The design of these systems is scalable, making them ideal for any business expecting growth or significant changes in its nitrogen needs. These bespoke on-site nitrogen generators ensure optimal efficiency and cost savings.

Nitrogen Container Systems

Self-contained nitrogen generation units are designed for convenience, portability, and quick setup, making them an ideal solution for remote operations or temporary sites, such as mining or oil field services.

Nitrogen Cylinder Filling Systems

These represent another major innovation. By filling cylinders with generated nitrogen on-site, these systems eliminate the need for cylinder delivery, reduce the potential safety hazards of high-pressure cylinder handling, and make it easier to meet spikes in nitrogen gas demand. 

Businesses can generate their nitrogen and fill cylinders according to their schedule, ensuring a constant nitrogen gas supply.

Overall, such innovations have made nitrogen generation more flexible, convenient, and reliable than ever before, helping businesses across sectors optimise their operations, reduce costs, and enhance safety.

Whether you are in the food and beverage industry, marine, electronics, laser cutting, mining, oil and gas, or pharmaceuticals, Anglian Compressors has a nitrogen generation solution for your needs. 

Applications of Nitrogen Generators in Various Industries

Nitrogen is crucial in various industries, each with unique requirements.

• Food and Beverages: consistent delivery of food-grade nitrogen to ensure product quality, freshness, oxidation prevention, and extended shelf life.
• Marine Industry: reliable performance for safety, corrosion prevention, and resilience in harsh marine conditions.
• Electronics and Laser Cutting: efficient delivery of high-purity nitrogen to create an inert atmosphere and enhance product quality.
• Mining and Mineral Processing: ideal in remote and harsh terrain mining operations for fire suppression and tyre inflation.
• Oil and Gas: used in enhanced oil recovery, well stimulation, and pipeline testing with high flow rates and purities.
• Pharmaceutical Industry: used for inerting, blanketing, and purging to meet rigorous quality standards.
• Steel and Metal Production: used in making stainless steel to enhance its strength and corrosion resistance and in metal casting for improved product quality.
• Chemical Industry: ideal for inerting, purging and blanketing to ensure safety and maintain the integrity of the chemical compounds.
• Automotive: used in air conditioning systems, tyre inflation and for producing synthetic materials for car interiors.
• Wine Production: nitrogen is used in various steps of the winemaking process, including sparging and barrel ageing, to prevent oxidation and maintain strict quality.
• Agriculture: it is used in controlled atmosphere storage systems to slow down the ageing process of fruits and vegetables, extending their shelf life.

Irrespective of your industry, Atlas Copco nitrogen generators, supplied by Anglian Compressors, are game-changers, offering a reliable, cost-effective, and safe nitrogen solution.

Choosing the Right Nitrogen Generator

Below are some of the key factors you should consider before selecting a nitrogen generator:

• Purity Requirements: PSA nitrogen generators can achieve higher levels of purity (up to 99.9995%) compared to membrane systems, making them suitable for applications demanding extreme purity, such as semiconductor manufacturing or specific chemical processes.
• Flow Rate: the required nitrogen flow rate can influence the choice of generator. Generally, PSA systems are better suited to applications requiring high flow rates. However, a membrane system can be more cost-effective and efficient for low to moderate nitrogen demand.
• Operating Environment: if the generator is destined for use in harsh or risky conditions (e.g. offshore oil platforms), a membrane system with fewer moving parts and less susceptibility to mechanical failure might be a better choice.
• Availability of Compressed Air: both systems require a source of compressed air. Does your facility have an existing compressed air system? If not, the added cost of installing one might impact your choice.
• Cost: consider upfront costs and ongoing operational costs. While the initial cost of a PSA system can be higher, its lower operating cost may make it more cost-effective in the long run, especially for applications requiring high-purity nitrogen.
• Safety Considerations: both on-site nitrogen generation systems eliminate the safety risks of handling and storing high-pressure gas cylinders. The specific safety requirements of your project or application may influence which system is the best choice.
• Environmental Impact: both systems have a lower carbon footprint than delivered bottled nitrogen.

Still not sure which nitrogen generator to go for? Contact us, and we can help you decide!

The Environmental Benefits of Using Nitrogen Generators

Nitrogen generators are revolutionising industries, offering reliable, cost-effective, and safe supply. They optimise operations, cut costs, reduce emissions, and enhance sustainability. Choose the right one for your needs, considering purity levels, flow rates, safety measures, and maintenance routines.

Final Thoughts

Reliable, cost-effective, and safe nitrogen generation solutions help businesses optimise their operations, reduce costs, and meet their environmental goals by reducing emissions and improving sustainability.

As an Atlas Copco premier distributor, Anglian Compressors offers complete solutions for your air compressor needs. From supply and installation to expert servicing, we have got you covered. Trust our expertise to help you choose the perfect air compressor for your specific requirements.

Take the first step towards optimal performance and efficiency.