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Nitrogen Generators are a common resource used in abundance by factories all over the world.
Nitrogen or N2 makes up 78 percent of Earth’s atmosphere and is the seventh most common element in the universe. N2 is responsible for helping plants grow, it is an integral part of explosives production and has an almost endless application in manufacturing.
This premium guide is the first step to saving your business hundreds of thousands of dollars in nitrogen resources. Let’s dive in.
1. How Do Nitrogen Generators Work?
PSA Nitrogen Generators (Pressure Swing Adsorption)
Common Configuration of a PSA Nitrogen Generator System:
The earth’s atmosphere is composed primarily of nitrogen and oxygen. Once atmospheric air is compressed, its pressure is increased while proportions of nitrogen and oxygen remain unchanged. The compressed air is filtered, dried and then introduced to the PSA nitrogen generator. As the air flows through a bed of CMS (Carbon Molecular Sieve) oxygen molecules are selectively adsorbed into the CMS allowing the larger Nitrogen molecules to pass. With the oxygen molecules trapped in the CMS bed, a high purity stream of nitrogen is discharged from the PSA nitrogen generator.
When one bed has reached its adsorption capacity the towers invert and a regenerated bed continues adsorbing oxygen while the other tower begins a regeneration process. This repeated action continues allowing the generator to produce a steady flow of high purity nitrogen gas.
PSA Nitrogen Generators Pros and Cons:
+ Low operating costs
+ High nitrogen purity
Membrane Nitrogen Generator
Common Configuration of a Membrane Nitrogen Generator System:
Membrane nitrogen generators separate nitrogen from the atmosphere by passing compressed air through a permeable membrane. This process relies on the principle of selective gas permeation. Each gas has a different permeation rate. As the compressed feed air stream passes across the membrane gases with faster permeation rates, like oxygen and carbon dioxide, will be released back into the atmosphere as waste gas.
The product nitrogen, now stripped of most of the oxygen and carbon dioxide, passes out the other end of the separator at a lower pressure for collection or straight into your application.
Membrane Nitrogen Generators Pros and Cons:
+ Can be combined with a trailer system for ultimate portability
+ No moving parts, which makes for excellent reliability
– Limited capacity
– Lower purity rating and less pressure
2. Industrial Nitrogen Generator Applications
Nitrogen has a wide range of uses in almost every industry you can imagine. An Industrial Nitrogen Generator is involved in the food and beverage industry, laser-cutting and metal fabrication, and with tank blanketing to prevent explosions.
It’s not just plain air that is pumped into your favorite potato chip bag, its nitrogen. Pumping N2 into food containers not only adds air that prevents your chips from becoming crumbs, but it also preserves the crunch.
In addition to protecting your favorite snacks, N2 is fundamental for food preservation.
Ever wonder how fruit stays crisp during its journey to your local supermarket? After nitrogen is added to storage containers, it displaces the oxygen inside preventing oxidation, the process that allows germs and mold to grow on food. This addition of N2 is what helps keep your bananas from spotting and browning before you get the chance to enjoy them. Nitrogen is a non-chemical method for keeping food fresh and delicious for the consumer.
Nitrogen generator systems are most widely used in the laser cutting industry. N2 doesn’t react with molten metals such as stainless steel and aluminum. This means no additional generated heat, producing a cooler cut, resulting in cleaner edges. Using Nitrogen also speeds up the cutting process when the right amount of pressure is applied.
Large quantities of nitrogen are also part of a process called annealing, a heat treatment that makes steel easier to work with. During annealing, metal is heated to a specific temperature, where any defects caused by deformation of the metal are repaired. Annealing is also used to improve metal’s machinability, strength, formability, elasticity and enhance electrical conductivity.
Tank blanketing is utilized by many industries to prevent fires, explosions and to protect product quality during their production, storage and transport. Blanketing is the use of an inert gas, like nitrogen, into a storage tank to protect materials from the effects of oxygen.
Remember the bananas? Manufacturers use this method to store more than just food. Products like adhesives, chemicals, fuels, pharmaceuticals, photographic chemicals, inks and soaps are also kept fresh by using blanketing.
Exposure to oxygen will not only ruin food faster, but it can also react with chemicals present in materials, creating potentially explosive conditions. Nitrogen is an inert gas or a gas that has an extremely low reactivity with other substances.
Using inert gasses neutralizes hazardous environments. Petrochemical companies store fuel until consumers are ready to use it. Fuel requires oxygen to ignite, adding a layer of nitrogen to fuel containers reduces oxygen content in the extra container space which lowers the risk of fire and unwanted combustion.
Is there anything nitrogen can’t do?
3. Benefits of Nitrogen Generators (Instant Savings)
1. Reduce Costs
It is 40 to 80 percent less expensive to create your own nitrogen than it is to rent tanks. This means that purchasing a nitrogen generator will “generate” a return on investment in as little as six months.
The average price of delivered nitrogen can range from $0.35 to $1.50 per hundred cubic feet, depending on user’s location and market costs. On-site generation can initially drop costs to around $0.21 per hundred cubic feet, regardless of location. In each following year, regular operational expenses can continue to plummet to about $0.11 per hundred cubic feet.
Your savings from buying a N2 generator will continue to build over time, cutting nitrogen costs by 50 percent or more.
In addition to saving on material costs, nitrogen generators erase the need for rental fees on cylinders, long contracts and re-supply ordering.
2. No More Nitrogen Cylinders
Having an industrial nitrogen generator eliminates the never-ending overhead expense of N2 cylinders; including the cost of nitrogen itself, delivery charges, fuel surcharges, hazmat charges, tank rental fees… the list goes on.
Extra tanks will be gone, no longer sitting around, idly crowding workspaces while leaking product.
3. Supply on Demand
On-site production means never having to wait on shipments and deliveries. No downtime increases efficiencies and maximizes productivity. Access to a consistent and reliable supply means fewer product defects or rejections.
You are in complete control.
Time will never be wasted waiting on shipments. You’ll never have to guess how much N2 you will need ever again. Running low? Simply create more.
4. No Product Loss During Transportation
Ten percent of nitrogen volume is lost as waste during the transportation process. Even with a good vacuum seal, tanks that are not put to use right away will build up internal pressure resulting in a minimum 0.4 percent volume decrease daily.
Continuing to rent tanks is the same as watching money disappear into thin air.
5. Purity Level Control
N2 generators are custom configured to meet almost any volume and purity requirement. Purchased nitrogen is always delivered at 99.999% purity even if is not required for your application.
Annual operating expenses for generated nitrogen do increase with the purity requirement but these numbers are tiny compared to the costs associated with bulk nitrogen. Bulk nitrogen is the highest cost for a facility in almost all cases.
6. Increased Safety for Employees
People are a manufacturer’s greatest resource, and providing a safe work environment is any employer’s top priority. Removing nitrogen tanks means getting rid of risks to your employees while simultaneously reducing extra insurance costs.
Nitrogen is colorless, odorless and tasteless, making it impossible to detect if things go awry. When liquid nitrogen spills into a small, sealed off environment it begins to boil at room temperature, expelling gas. This nitrogen gas literally sucks all the oxygen out of the room, making air in the enclosure unbreathable. The lack of oxygen can lead to death of an employee by inert gas asphyxiation.
At negative 320 degrees Fahrenheit, nitrogen is dangerously frigid. Any contact with human skin is devastating, causing damage instantly.
Removing employee’s potential exposure to nitrogen while the tanks are being moved during transportation will significantly reduce the chance of a catastrophic incident. Taking extra safety precautions will also put your employee’s minds at ease while working.
7. Minimize Environmental Impact
Reduce your carbon footprint by eliminating the back and forth of cylinders to your site. By removing the need for transport, resources are not wasted in the form of gasoline and greenhouse gas emissions. For example, a tractor-trailer that travels 100,000 miles expels about 360,000 pounds of carbon dioxide.
Concern is growing for how manufacturers run factories and how those operations impact the world around it. Now more than ever consumers want to know what steps companies are taking to reduce their carbon footprint. The difference between a sale and a pass could come down to whether or not your company has gone the extra mile to reduce its impression on the environment.
Environmentally conscious customers have become more vigilant in doing research on companies, accessing records and reports instantly through online searches. It is not enough that manufacturers assume responsibility making sure that their practices are just compliant. Consumers are examining their products to ensure manufacturers are making advancements to go above-and-beyond to protect the environment. Don’t get left behind.
4. Common Nitrogen Generator Questions Answered
What expenses should I expect?
Expenses will vary, determined by system type and which application the generator is being used for. After purchasing generator equipment, the electricity costs to power it are the only expenses after installation. By purchasing a nitrogen generator, your business will save an exponential amount in comparison to renting bulk storage tanks.
What should I consider when buying a nitrogen generator?
Depending on the application it will be put to use in, you will need to account for purity, pressure, air flow and where it will be located.
Three specific things are important to take note of:
Temperature can impact compressor and dryer performance. The ambient condition of inlet air to the air compressor affects the net weight of the final delivered compressed air to the system.
Increases in ambient air temperature reduce the efficiency of air compressors and air dryers. Proper ventilation and ducting of the “compressor room” is required to maintain inlet air temperatures within design specifications.
The altitude at which a compressor is installed must always be considered. As altitude rises, the weight of the earth’s atmosphere is less and your compressor will need more power to pump the same amount of gas because positive suction pressure dropped because of altitude. If you are in a high altitude, you should oversize the compressor.
Humidity will not affect generator performance like altitude and temperature will. However, extremes should be considered.
What does the nitrogen storage vessel do? Do I need one?
The storage vessel contains the condensed nitrogen. The vessel is included in the purchase of a PSA system and is not required for use with a membrane system.
Will I need to replace the carbon molecule sieve in PSA systems?
Eventually, yes. The carbon molecular sieves in PSA systems are designed to last 10 or more years.
Do you offer testing certificates?
ISC Sales does not do any testing in-house, however, testing certificates may be requested from the manufacturer.
What is included when I purchase a nitrogen generator?
A typical PSA system will have PSA generator with a control unit and oxygen monitor. The complete operating system may also require an air package consisting of a feed air compressor, an air dryer, filters, air-receiving tank and product tank.
How is purity calculated?
Because N2 is utilized in many industries. Some names of grades are common but the actual grades of nitrogen aren’t standardized across industries and even within industries grades can change. The manufacturer of the nitrogen chooses the name of the grade, because of this it is possible for two nitrogen products that have the same grade to have different purity levels. It is important to choose N2 based on its purity specifications because grade can vary.
There are many terms that can indicate the purity of a given gas but these terms are not absolute and variance in the same term can be found across different industries.
In the specialty gas industry, a system has been adopted that simplifies purity ratings so that they are easily compared. Since specialty gases generally have a much higher purity than in other industries, purity ratings are based on the number of nines in the purity percentage.
This rating is sometimes prefixed with an upper-case N. Examples include;
- 2.0 or N2.0 = 99%
- 3.0 or N3.0 = 99.9%
- 6.0 or N6.0 = 99.9999%
To calculate the purity rating The Nitrogen outflow is measured for Oxygen content. Subtracting the oxygen percentage from 100 will give you your Nitrogen percentage.
What size air compressor will be required for producing N2?
The size of the air compressor needed will depend on the air flow and pressure requirements for the type of application you are using the nitrogen generator for.
For a factory that consumes large quantities of high purity nitrogen, a PSA system would be the recommended solution.
Membrane generators are perfect for applications that do not require the high levels of purity nor the quantity of N2.
What Nitrogen pressure can I expect?
Low-Pressure Nitrogen is 90-110 psi (pounds per square inch)
High-Pressure Nitrogen is 300-450 psi
How do I know what purity to specify?
Determining the minimum purity level required for the applications at your facility is essential to ensure that you benefit the most from your on-site nitrogen production. Below is an average of major industry purity demands:
- Food and Beverage: on average 98-99.5%
- Metal Industry: between 95-99.5%, laser cutting: 99-99.999%
- Oil, Gas, Petrochemical: 95-99 %
- Pharmaceutical Industry: most applications require 97-99.99%
- Plastics: 95-99.5%
- Power Generation: 95-99%
These numbers are only estimates; always confirm that your purity level is correct for your specific application.
Can a Nitrogen Generator be portable?
Membrane generators are easily portable by adding a trailer. PSA systems can be made mobile, but additional equipment is required.
Can I put a Nitrogen Generator outside?
Yes, but they must be properly protected from the environment. Nitrogen generators must be enclosed and kept between 40 and 100 degrees Fahrenheit. The generator cannot be exposed to water, dust or extreme temperature changes.
What are my maintenance costs?
Maintenance costs are variable, dependent on system type and what application they are being used for. However, maintaining a nitrogen generator is significantly less expensive than bulk nitrogen tank rental and delivery, even when factoring in upkeep costs. Most systems only require maintenance replacements every two to five years. Most filter elements will last up to 4,000 hours of use before needing a replacement.
Is this liquid or gaseous Nitrogen?
ISC Sales only deals with gaseous nitrogen.
Can a Nitrogen Generator be used in a hazardous location?
Nitrogen generators are not rated to be placed in hazardous locations.
Are nitrogen generators safe?
Manufacturers test the generators, ensuring safety and quality standards are met before they are installed at your facility.