ON-SITE Nitrogen Generation

When speaking about nitrogen, the term purity refers to the level of gas concentration.  A common misconception when discussing nitrogen purity, is that it refers to the presence of contaminants, such as particulate matter and oil vapour. While filtering these contaminants is highly critical, it should not be confused for purity when speaking about nitrogen.

Our solutions are engineered to produce nitrogen gas ranging from 95% to 99.999% purity. One of the core benefits of nitrogen gas generation is the ability to produce nitrogen at the purity the application truly requires, often creating tremendous cost reduction opportunities for the user. A higher tolerance for remaining oxygen content will result in lower capital and operating costs of the system.

Nitrogen generation is the most cost effective way of procuring nitrogen gas. When purchasing nitrogen in conventional liquid and bottled supply, the buyer has to pay for transport, storage, rental, compliance, handling and many other charges, in addition to the stated price of nitrogen gas. All of these additional charges need to be considered when calculating the cost per m3 of nitrogen.

Once a nitrogen generation system is installed, the only costs of operation are electricity to power the system and equipment maintenance. The sum of these two values is what determines the cost per m3.

Typical price ranges of varying nitrogen supply types in the North American market are as follows:

• Bottled Gas (most expensive) $3.00 – $15.00 per m3
• Liquid dewar (more expensive) $1.50 – $3.00 per m3
• Liquid bulk tank (expensive) $0.40 – $1.50 per m3
• Nitrogen gas generation (least expensive) $0.005 – $0.09 per m3
  • Price per m3 is dictated by application requirements

First it’s important to understand the difference between a nitrogen generator and a nitrogen generation system. When evaluating technology solutions, it’s often overlooked that the ‘nitrogen generator’ itself, is not a system.  A nitrogen generator is a piece of equipment that works within a system, no different than a motor in a car. The nitrogen generator requires supporting inputs, components, controls and settings which are customized by industry, application and process, and without the correct system structure, it will likely not meet your needs.

Your business is likely not nitrogen generation, so don’t go at it alone. Engage an expert in system design with a proven track record for YOUR application. Ensure your integration partner is focused on nitrogen, or better yet, “all in” on nitrogen. From our experience, it’s likely your first time buying nitrogen generation system, make sure it’s not their first time designing one!

All of our nitrogen gas generation systems are modular and infinitely expandable, so it depends on the purity and volume of nitrogen being used by the application. A small nitrogen generation system that delivers 400 scfh can cost $10,000 and a large, highly engineered system can cost millions of dollars. Our first step of discovery begins with Free Assement to help nitrogen users determine if the juice is worth the squeeze for their business, before investing too much time in the project.

One isn’t better than the other. They both separate air molecules, but they use different processes in order to do so. Pressure swing adsorption (PSA) nitrogen generators use carbon molecular sieve (CMS) and an adsorption process to remove unwanted gas molecules, and can reliably deliver nitrogen purity up to 99.999%.  Membrane nitrogen generators use hollow fibre membrane tubes and selective permeation to remove unwanted gas molecules, and can typically deliver nitrogen purity up to 99.5%. Our Application Engineering team will select the most appropriate gas separation technology for each environment, application and process.

CMS is a class of activated carbon with uniform pore diameters similar to those of oxygen. So, how does this apply to nitrogen generation?

The air we breathe is made up of 78% nitrogen, 21% oxygen and the remainder are trace gases. The CMS have pore diameters similar to those of oxygen and therefore the oxygen molecule can be adsorbed by the CMS, while the larger nitrogen molecule can not. The difference between adsorption & absorption is the oxygen and trace gas molecules adhere to the surface of the CMS instead of being drawn in or “absorbed”.  At higher pressures the CMS adsorb the oxygen and trace gases while allowing nitrogen to pass through at the desired purity level.  The purity level is a function of the contact time with the CMS; the longer the air remains in contact with the CMS, the more oxygen will get adsorbed and the higher the purity will climb.

Since the CMS can only adsorb a finite number of molecules, it has to be purged with nitrogen gas when it is fully saturated.  Now, introduce Pressure Swing Adsorption. PSA systems are therefore made up of two vessels filled with CMS, in which one vessel is producing nitrogen while the other is depressurized and flushed with nitrogen gas to remove the adsorbed oxygen.  The cycling between the two vessels allows for the continuous production of high purity nitrogen gas within a self-regenerating system.