Mechanical Insights

Nitrogen Generator - Easy Installation, Operation and Quick ROI

Aug 31, 2020 8:30:00 AM / by Tate Engineering

Nitrogen Generator ROI

Does your facility still purchase bottled or liquid nitrogen? The air we breathe is over 78% nitrogen, so why are you still buying bulk liquid nitrogen for your facility? On-site nitrogen generation systems are an easy and affordable way to cut costs, and they are not as complicated as you might think.

Easy to Install, Easy to Operate

Many facilities that use nitrogen as part of their production process purchase their nitrogen - either as a compressed gas that comes in bottles, or as bulk liquid nitrogen that must be delivered and pumped into a tank. Industries including laser cutting, medical device manufacturing, food and beverage, electronics, chemical, and plastics all require nitrogen as part of their manufacturing process. Facilities that still purchase nitrogen have a massive opportunity to cut costs, increase safety, reduce downtime, and guarantee purity through on-site nitrogen generation.

On-site generation takes out the hassle of scheduling deliveries, stopping production so that employees can unload nitrogen bottles, and waiting for your nitrogen delivery to arrive so that production can resume. Liquid nitrogen in bulk tanks, dewars and cylinders can lose up to 10% of the contained nitrogen through “Boil Off.” Liquid nitrogen is condensed from a gas before the process needs it. The nitrogen is vented to the atmosphere during use. Cylinders stop flowing when the process pressure is reached. The higher the process pressure, the more nitrogen goes back into the bottle.

Nitrogen generators produce nitrogen using Pressure Swing Adsorption. PSA takes in clean, filtered compressed air and passes it through a bed of Carbon Molecular Sieve (CMS). The CMS is very special because of its pore size (about 3 angstrom). Nitrogen molecules (N2) are slightly bigger than oxygen molecules (O2). CMS pores are just big enough for the oxygen molecule to fit in, but too small for the nitrogen molecule. Because of this, oxygen molecules are pushed into the CMS while the nitrogen molecules are allowed to pass on through. The nitrogen generator uses two pressure vessels which switch back and forth. Once the CMS in one vessel is full of oxygen, water vapor, and trace gases like argon and carbon dioxide, the pressure is released, and the CMS releases all of the molecules it adsorbed. It is then ready to begin the cycle again.

Nitrogen generator 1

Adding a PSA nitrogen generator to your plant is as easy as piping clean, dry compressed air to the generator and piping nitrogen to the plant. Our nitrogen generator providers can size N2 generators to meet a variety of different needs and applications. All it takes is three simple parameters to determine what will work best for your facility:

  • Pressure: Inlet compressed air pressure and nitrogen pressure required for the plant.
  • Flow Rate: Rates can be extremely low or go as high as 100,000 standard cubic feet per hour.
  • Purity: 95% nitrogen up to 99.999% pure nitrogen.

One of the best parts of N2 generators is their reliability. N2 PSA generators can be thought of as “set it and forget it” machines. Most of the installation process is compressed air piping and labeling components. Once installed and in operation, all these N2 generators require is an annual filter change and an O2 analyzer replacement every 48 months.

Nitrogen generator 2

What’s the ROI?

So what do you need for your facility? In addition to the PSA nitrogen generator, you will need to have a compressor to deliver feed air to the generator. This feed must pass through a drier before it gets to the N2 generator. The dried air also must pass through a filtration system to ensure the N2 generator is able to deliver high-purity nitrogen without all of those impurities in it. After setting up the N2 generator system, the ROI can be as short as 6 months, but is typically in the range of 12 to 18 months.

To determine what the ROI of your N2 generator will be, it’s important to look at what your nitrogen is costing you now. On-site generation is typically 50%-90% less expensive than traditional bulk liquid supply. How is this possible? In addition to the high cost of the liquid nitrogen, traditional nitrogen deliveries involve restrictive long term contracts with fees that add up at every turn. Some common fees are:

  • Delivery charges ($30 to $75 per delivery).
  • Tank rental fee (up to $2,500 per month).
  • Environmental surcharges ($30 to $50 per delivery).
  • Annual tank inspection ($1,000 per year).
  • Boil Off of liquid nitrogen (Up to 10% of the purchased product).
  • Annual price increases (Typically 10% to 15%).

In addition, on-site generation means no more hidden fees. The cost to generate nitrogen is based solely on the desired purity and the cost of electricity. You also get rid of the logistics headache that often comes with purchasing bulk nitrogen. N2 generators provide a safe, cost effective source of high quality nitrogen ready for any type of facility.

Learn More About Nitrogen Generators

Tags: Equipment, Nitrogen Generator

Written by Tate Engineering