There are various cost-effective alternatives to traditional nitrogen cylinders, of which on-site nitrogen generators represent the most sustainable solution. These systems produce nitrogen directly on-site by using PSA or membrane technology. This not only saves on cylinder costs and logistics but also provides continuous access to nitrogen whenever you need it. For companies with regular nitrogen consumption, these generators offer a significantly lower cost per cubic meter of nitrogen and eliminate dependence on external suppliers.
Why look for alternatives to nitrogen cylinders?
Many industrial companies are seeking alternatives to traditional nitrogen cylinders due to the significant disadvantages they bring. The high costs are often a decisive factor – in addition to the price of the gas itself, you pay for cylinder rental, transportation costs, and administrative processing of orders and deliveries.
Furthermore, cylinders present logistical challenges. Changing cylinders requires labor time, takes up storage space, and requires careful planning to prevent shortages. For projects where continuity is crucial, dependence on timely deliveries poses a significant risk.
Safety risks also play an important role in the search for alternatives. High-pressure cylinders require careful handling and storage. Incidents during transport or use can have serious consequences. Additionally, the purity of cylinder nitrogen can vary, which is problematic for applications where consistent quality is required.
Finally, increasingly stringent environmental and safety regulations create additional administrative burdens when using gas cylinders, encouraging companies to look for more sustainable, safer alternatives.
What is an on-site nitrogen generator and how does it work?
An on-site nitrogen generator is a system that produces nitrogen at the location where it is needed by extracting nitrogen from ambient air. This eliminates the need for external deliveries of nitrogen cylinders or tank fillings. The generator separates nitrogen molecules from other gases in the air (mainly oxygen) by using specific technologies.
The process begins with drawing in ambient air which is then filtered to remove contaminants. Afterward, the air is compressed to the appropriate pressure for the separation process. The actual separation occurs via one of two main technologies: Pressure Swing Adsorption (PSA) or membrane filtration. PSA technology adsorbs oxygen through a carbon molecular sieve, while membrane technology enables the separation of gas molecules through a selective membrane.
The advantages of on-site generators are significant:
- Continuous availability of nitrogen at any desired time
- Long-term cost savings by eliminating delivery costs
- Independence from external suppliers and their delivery times
- Consistent quality and purity of the produced nitrogen
- Reduced CO2 emissions by eliminating transport
For companies with regular nitrogen consumption, an on-site generator offers the most reliable and cost-efficient solution.
What are the differences between PSA and membrane technology?
PSA technology (Pressure Swing Adsorption) and membrane technology are the two main methods for on-site nitrogen production, each with specific advantages and disadvantages. In PSA systems, air under pressure is directed through a vessel containing carbon molecular sieve. This sieve adsorbs oxygen molecules while nitrogen flows through. This process works cyclically with at least two vessels that are alternately in use.
Membrane technology, on the other hand, uses hollow fiber membranes that are selectively permeable. Oxygen and other gases diffuse more quickly through the membrane than nitrogen, leaving a nitrogen-rich stream. This technique is a continuous process without cyclic pressure changes.
| Property | PSA Technology | Membrane Technology |
|---|---|---|
| Purity | Very high (up to 99.9995%) | Good (up to 99.5%) |
| Energy consumption | Higher at higher purities | Lower, especially at lower purities |
| Maintenance requirements | Periodic replacement of molecular sieve | Periodic replacement of membranes |
| Start-up time | Longer start-up time | Quick start-up time |
| Ideal applications | High purity, stable consumption | Lower purity, variable consumption |
PSA technology is particularly suitable for applications requiring very high purity, such as in the electronics industry or for certain chemical processes. Membrane systems are more compact and flexible, making them ideal for applications with limited space or variable nitrogen consumption, such as food packaging.
The choice between both technologies depends on your specific requirements regarding purity, consumption pattern, available space, and energy costs.
How do you calculate the payback period of a nitrogen generator?
Calculating the payback period of a nitrogen generator is essential for making a sound investment decision. The payback period is the time in which the initial investment is recovered through savings on current nitrogen costs. For an accurate calculation, you must consider various factors.
Start by mapping your current nitrogen costs, including:
- Costs of nitrogen cylinders or tank fillings
- Rental costs for cylinders or tanks
- Delivery costs and additional surcharges
- Labor costs for handling and changing cylinders
- Storage costs for spare cylinders
Next, determine the costs of a nitrogen generator:
- Purchase price of the generator
- Installation costs
- Energy consumption (electricity for compressor and generator)
- Maintenance costs (filters, membranes, or molecular sieve)
- Potential financing costs
The formula for the payback period is: Payback period = Total investment ÷ Annual savings. With average usage, the payback period typically ranges between 1 and 3 years, depending on your consumption volume and the current costs of cylinder nitrogen.
Consider future developments such as rising energy prices or growth in your nitrogen needs. A well-dimensioned system can pay for itself faster than expected, especially if your consumption increases.
What industry-specific solutions are available?
For different industries, there are specialized nitrogen solutions that optimally align with specific needs and applications. These solutions vary in purity level, production volume, and integration method with existing processes.
In greenhouse horticulture, nitrogen is used to create a controlled atmosphere in storage areas, which extends the shelf life of flowers and plants. Here, compact generators with medium purity (95-99%) are usually sufficient.
Breweries use nitrogen for displacing oxygen in tanks and bottles, preventing oxidation and preserving beer quality. For this application, systems with stable, continuous production and purity around 99.5% are ideal.
Data centers require nitrogen for fire prevention systems, where highly reliable, redundant systems are necessary. These systems must be able to deliver large volumes quickly and integrate seamlessly with automatic fire detection systems.
For laboratories and medical applications, high-purity systems (99.9%+) are required, often with additional purification modules and certification for medical use. These are designed with specific attention to reliability and backup provisions.
In the food industry where nitrogen extends shelf life, nitrogen is crucial for MAP packaging (Modified Atmosphere Packaging), where nitrogen is used to replace oxygen, thus extending the shelf life of products. Here, systems that comply with food quality standards and are easy to integrate with packaging lines are needed.
What are the key considerations when choosing a nitrogen solution?
When selecting the right alternative to nitrogen cylinders, you must consider several critical factors. First, the consumption pattern is decisive: analyze not only the total volume but also consumption peaks and whether usage is constant or intermittent.
The required purity is crucial for your choice. Some applications, such as in the electronics industry, require ultra-high purity (99.999%), while others, such as MAP packaging, can function with lower purity (95-99%). The higher the required purity, the greater the impact on system costs and energy consumption.
Practical considerations such as available space and installation possibilities often determine which type of system is feasible. Membrane systems are more compact than PSA systems but require adequate ventilation. Also consider whether your existing compressed air installation has sufficient capacity or if additional compressors are needed.
Reliability and maintenance requirements are important for the total cost of ownership. Evaluate the frequency of maintenance, availability of parts, and whether you can perform maintenance yourself or are dependent on external technicians.
Finally, future-proofing is an important consideration. Choose a system that can grow with your needs or is easily expandable. Also consider whether energy efficiency and sustainability are important factors in your business strategy.
At Presscon, we are happy to help you make the right choice by thoroughly analyzing your specific situation. Our advisors can provide customized nitrogen solutions that perfectly matches your current and future needs, allowing you to maximize the benefits of on-site nitrogen production.