On-Site Nitrogen Generator: Buy & Pay In Installments

Nitrogen is an inert gas with low reactivity. That’s why nitrogen gas generators are useful for applications in chemical manufacturing, food production, laser cutting and so on. But nitrogen gas generators don’t actually create nitrogen. What they do is they seperate the nitrogen already present in the air and concentrate it by removing extra molecules. Air is about 78 percent nitrogen and 21 percent oxygen, with other molecules including carbon dioxide, argon and water.

When you look for a nitrogen generator supplier you will come across two names - PSA Nitrogen Generators (Pressure Swing Adsorption ) and Membrane Nitrogen Generators. PSA systems work on the principle of adsorption while membrane systems work on the principle of selective permeation.

Adsorption is different, but often compared to, absorption.

In adsorption atoms, ions or molecules from a gas, liquid or dissolved solid stick to a surface. It creates a film of the adsorbate on the surface of the adsorbent. Adsorption looks a lot like Tetris blocks sticking together.

This is different to absorption where a fluid, the absorbate, is dissolved in or permeates a liquid or a solid, the absorbent.

You could say adsorption occurs at the surface of an adsorbent material while absorption involves the entire volume of an absorbent material.

The PSA nitrogen generator system is sometimes called Adsorption Nitrogen Generators.

In Pressure Swing Adsorption the nitrogen is separated from a compressed air stream by trapping oxygen using adsorption.

Air is first compressed and passed through filters that remove any oil and water and other contaminants.

The purified air is then passed into two adsorption towers which both have an adsorbent material in them called a carbon molecular sieve (CMS).

As compressed air is passed through the CMS in the first tank oxygen molecules are adsorbed while nitrogen molecules pass through freely into the Buffer. Over time the CMS material in the first tank will become saturated with the oxygen that’s been adsorbed and needs to be removed. Next to it is a second tank which we can assume for now is already fully saturated with adsorbed oxygen.

The second tank is depressurized and oxygen is released into the atmosphere through vents. Some nitrogen from the first tank is passed into the second tank to help the process along. By the time the first tank is fully saturated the second tank has been emptied out and is ready to receive compressed air that will be adsorbed by its CMS material.

While one tank is producing nitrogen the other tank is depressurizing to remove the adsorbed oxygen - they switch roles. This high pressure to low pressure swing between the two tanks as they exchange gas is where the term PSA comes from.

The automatic cycling of adsorption and desorption between the two is how nitrogen flow is maintained continuously.

Here’s a great animation that demonstrates how pressure swing adsorption looks in the Atlas Copco NGP+ Nitrogen Generator with PSA technology.

In Membrane Nitrogen Generators compressed air is passed across the surface of small hollow polymer fibers with tiny pores that filter the air.

When compressed air passes through the membrane fibers oxygen, water vapor, and carbon dioxide are selectively removed creating a nitrogen rich stream of gas. The high density of the fibres makes for a large membrane surface area through which the various molecules permeate with different velocities. Some gases are filtered through the membrane faster than others. The molecules of gases with a higher diffusion rate and lower molecular size penetrate the membrane faster than large gas molecules with lesser diffusion rates. This is what is described as selective permeation.

Nitrogen has a lower permeation rate than oxygen, water vapor and carbon dioxide so these gases pass through the membrane and are released to the atmosphere through vents.

With this method the industrial nitrogen generator can produce up to 99.5 percent pure nitrogen.

An awareness of what purity of nitrogen is needed at the end will help you select between the two nitrogen generators; different applications have different requirements.

For example, if the nitrogen gas is being used for fire prevention then a 95-98% purity is enough and a membrane nitrogen generator can easily supply that.

On the other hand food preparation for oxygen sensitive foods requires a blanket of nitrogen before packing, so a higher purity of 99% and up is required and a PSA nitrogen generator can supply that.

Membrane generators are simpler to maintain with a lower initial cost so they are a good choice when capacity and purity demands aren’t so high.

But as capacity and purity demands increase a PSA nitrogen generator starts becoming a more attractive option.

Here’s a simple table for comparison between the two:

Let’s compare having an onsite nitrogen generator with the common practice of renting cylinders from a nitrogen gas supplier. Here’s what you need to consider:

• You’re paying rent for a minimum of three nitrogen gas cylinders all times. One is being used, the second is a replacement and the third is the empty cylinder waiting to be collected.
• Nitrogen gas cylinders take up a large amount of valuable floor space as they sit in their racks. And they need to be kept in an area that won’t create a health hazard. 
• They are also very heavy to maneuver and require special equipment and time to handle correctly.
• Contamination inside the nitrogen cylinder can occur over time when the pressure drops below 34 bar g. This creates an estimated 14% wastage of gas when you rent from a nitrogen gas supplier.

Most of our customers started off by renting from nitrogen gas suppliers. When they started looking into purchasing nitrogen generators it was usually because they had increased capacity needs and the amount of cylinders they needed to rent became difficult to manage.

For some of them their high nitrogen gas requirements meant that their cylinders could be consumed in a matter of days. Switching cylinders also reduced their overall up-time, which can add up over the course of a year. Then there’s the issue of contaminants and inconsistent purity levels that they discovered when dealing with rented cylinders. They chose to invest in on-site Nitrogen Generators because they wanted greater control over purity, cost-efficiency, and a continuous uninterrupted supply of nitrogen for their work.

Here’s a video where a micro-brewery in the US describes why they switched to an on-site nitrogen generator from Atlas Copco, one of the trusted nitrogen generator manufacturers worldwide.

Atlas Copco has put together a special “Lease to Own” program for customers in the UAE.

The program is designed to support you need to make smart financial decisions for your business.

When you lease one of our nitrogen generators you benefit because:

• The terms are flexible
• The monthly payments are low
• We offer an optional full service solution combined with 5 years warranty

Take a look at how on-site gas generation stacks up against renting from a nitrogen gas supplier

• Two normal bottle racks usage per day • Electricity cost = 0.45 AED/kWh • Currency used AED • 25 Nm3/h @ 7.5 bar (99.99% purity) • Operating hours 4000 per year • Above includes supply of complete system with Compressor package and nitrogen generator – PLUG and PLAY !!

You can browse our on-site nitrogen generator and oxygen generator products here.

And get in touch with one of our experts and ask about how you can finance your purchase right away!

Fill in this inquiry form or contact us directly at +971 4373 8216.