Nitrogen generators offer on-demand access to high-purity nitrogen gas at any time and place. By doing so, they reduce costs associated with transporting costly gas cylinders as well as any safety hazards they present when handled manually.
At the centre of every nitrogen generator lies a membrane air separation module. As compressed air flows through it, oxygen, water vapour, and other fast-acting gases pass quickly through, while nitrogen molecules move much more slowly through. This piece delves into how nitrogen generators operate, their advantages, and the financial considerations businesses must evaluate when contemplating their installation. By examining the operational mechanisms and cost factors of nitrogen generators, organisations can make informed decisions that align with their operational needs and budgetary constraints.
Understanding Nitrogen Generators: Functionality and Financial Implications
On-site nitrogen generation is transforming industries by providing a reliable and cost-efficient solution compared to traditional methods. These systems, called nitrogen generators, use readily available air and employ either pressure swing adsorption (PSA) or membrane technology to extract pure nitrogen. This innovative approach not only guarantees a consistent supply, but also eliminates the need for external suppliers and the logistical headaches associated with gas cylinder deliveries.
Nitrogen Generation Methods:
There are two main ways to generate nitrogen on-site: pressure swing adsorption (PSA) and membrane separation.
PSA Technology:
On-demand PSA generators convert compressed air into high-purity nitrogen. They utilise two vessels filled with carbon molecular sieves (CMS) that selectively absorb specific gases. Compressed air flows through the vessels, and the CMS traps oxygen molecules, allowing pure nitrogen to pass through for collection.
Membrane Technology:
Membrane generators use semipermeable membranes to separate gases. Hollow polymer fibers with microscopic pores force compressed air through them. Oxygen and other molecules (water, carbon dioxide, and argon) pass through the pores, while nitrogen is retained. After purging the membrane, a purified nitrogen stream is available for use.
Benefits of On-Site Generation:
On-site generators not only reduce the cost of nitrogen gas, but also offer significant savings in delivery time and cost. They eliminate the need for expensive cylinder rentals and wasted gas, saving hundreds of hours and dollars compared to traditional methods.
Choosing the Right Generator:
Finding the perfect nitrogen generator requires a thorough evaluation of your needs, capacity requirements, and budget. Our experts can assist you in selecting the ideal equipment to match these factors. Additionally, we offer booster and regulator configuration services for high-pressure applications.
How much does a nitrogen generator cost?
Nitrogen generators typically cost anywhere from $5,000 to $30,000. While initially this initial investment may appear high, most typically pay back their cost within two years and offer significant cost savings over delivered nitrogen services.
Nitrogen generators deliver an uninterrupted supply of high-purity nitrogen gas on demand, helping minimise operational downtime and enhance efficiency. Furthermore, onsite nitrogen generation eliminates costly delays associated with shipping and storage issues surrounding compressed nitrogen gas cylinder deliveries from vendors; such delays cost industrial users thousands of dollars in product losses and labour expenses every year.
On-site nitrogen generation also reduces workplace accidents caused by handling and transporting nitrogen cylinders. Nitrogen generators are designed to be safe and easy to use; they work by extracting the already present nitrogen in the air and increasing its concentration by filtering out molecules such as water vapour, carbon dioxide, and argon to reach the desired purity levels.
There are two primary categories of nitrogen generators, each differing in terms of how they function and their prices. Small generators suited for food and beverage applications, as well as LC-MS instruments, generally cost between $10,000 and $30,000. Mid-flow nitrogen generators designed specifically to supply labs needing large volumes of pure nitrogen, such as laser cutting, require between $12,000 and $31,000 to purchase.
Large nitrogen generators are more expensive options that can produce up to 100,000 standard cubic feet per hour (SCFH) of nitrogen for oil and gas exploration, aerospace, or automotive use. Although more costly in terms of upfront costs, large nitrogen generators will ultimately save the most money over time.
Nitrogen generators come in the form of either membrane or pressure swing adsorption (PSA) systems. PSA systems tend to be more efficient, as they’re known for handling heavy loads and complex applications in offshore environments more effectively than their membrane counterparts; nevertheless, both options provide long lifespans with reduced operating costs.
How is nitrogen generated?
Nitrogen generators use pressure swing adsorption or membrane technology to separate nitrogen from other molecules and create high-purity gas that is safe for laser cutting, chemical blanketing, food packaging, and other industrial uses. Their work begins by isolating it from other gases in the air (mainly oxygen with trace amounts of carbon dioxide, water, and argon). They use either of these techniques to produce an uninterrupted supply of high-purity nitrogen gas.
A membrane nitrogen generator uses semipermeable membranes to separate compressed air into its component gases. These membranes consist of bundles of hollow fibres covered by small pores on their surfaces; compressed air is forced through these fibres while oxygen molecules are drawn away by the membrane as it passes. After going through, nitrogen gas flows out through an outlet port into storage tanks until needed in a process.
On-site nitrogen generation is becoming a popular alternative to purchasing bottled nitrogen from gas companies, giving business owners more flexibility and savings without long contracts or ordering large volumes every month. Plus, generators save money due to reduced transportation and storage costs!
Nitrogen generators in draft beer systems help keep it fresher and carbonated for longer, which benefits customers, brand reputation, and bottom lines alike. Nitrogen generators also play an essential role in medical equipment sterility testing; oil and gas processes such as blanketing and purging to avoid explosions of flammable dust; food production for preventing oxidation; as well as medical diagnostic equipment sterilisation testing.
Nitrogen generators that use membrane technology are all-in-one units with minimal maintenance requirements and operational costs, making them perfect for applications requiring a lower flow rate of nitrogen with purity levels under 99.9%. They are ideal for use in the food and beverage industries, pharmaceutical, automotive, aerospace, metal fabrication, and electronics applications. Nitrogen generators that utilise pressure swing adsorption technology consist of two tower systems with carbon molecular sieves (CMS), which absorb oxygen and other trace gases through an adsorption process. Regeneration for such nitrogen generators takes place by lowering pressure in tower B; this allows oxygen molecules to detach themselves while creating room for new ones to attach themselves to CMS and generate nitrogen molecules for use as fertiliser.
What are the risks of nitrogen generators?
Nitrogen generators are machines used to separate nitrogen from air. By extracting oxygen and other molecules from air, nitrogen generators provide a more convenient and safer alternative than renting cylinders, taking up less floor space in your office and saving on expenses associated with high-pressure bottles of nitrogen delivery. Businesses also benefit from being able to control how much gas they use as well as its purity and flow rate.
An obvious risk associated with on-site nitrogen generation is leakage. Should a generator leak, oxygen levels in its surroundings can become severely depleted very rapidly, creating serious health and safety concerns for workers in its vicinity. For safety’s sake, nitrogen generators should be equipped with pressure relief valves and piped to an open area outside. Threaded outlet port variants make this easier and simpler; for added effectiveness, it would be wise to position vessels as close as possible to an exterior wall to decrease backpressure or over pressurisation risks.
Another risk associated with nitrogen generators is contamination. Nitrogen produced may contain trace amounts of impurities like water vapor or carbon dioxide in the form of nitrates or hydrocarbons; these impurities could present issues for certain applications and must be eliminated using appropriate filters and purification processes. Most systems include pre-filters to remove moisture before passing it through separation membranes, while some incorporate multiple stages for eliminating contaminants.
To prevent issues and extend the lifetime of a nitrogen generator, regular inspection and maintenance should be conducted on its equipment. Regular checks can help identify any potential issues early, before they snowball into more expensive repairs later. Regular cleaning, flushing, and replacement of filter seals also prolong its life and keep it working effectively. For more complex systems, a service contract provides peace of mind that your system will be professionally maintained as required.
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