How is Nitrogen Gas (N2) Produced for Industrial Purposes?

July 22, Welcome

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Nitrogen gas (N2) is a colorless and odorless gas that constitutes approximately 78% of the Earth's atmosphere. It serves various industrial applications due to its inerting properties, making it suitable in numerous scenarios where oxidation is not desired.

N2 can be generated through one of the following methods:

• Fractional distillation of liquid air (from suppliers like Praxair, Air Liquide, Linde, etc.)
• Mechanical methods using gaseous air:
  • Polymeric Membrane
  • Pressure Swing Adsorption (PSA)

Methods of Nitrogen Generation

Fractional Distillation (99.999% purity)

This technique involves cooling air until it liquefies, followed by selectively distilling the components at their respective boiling points. While this method can yield high-purity gases, it is notably energy-intensive.

Polymeric Membrane (90 - 99.9% purity)

Membrane technology employs permeable fibers to separate air based on the molecular speeds of its constituents. This process requires conditioning of feed air due to the small openings in the fibers, which are about the diameter of a human hair.

Pressure Swing Adsorption (99 - 99.999% purity)

PSA technology separates gas species from mixtures under pressure based on molecular characteristics and adsorption affinities. This method operates at near-ambient temperatures and is distinct from cryogenic distillation techniques. Specific adsorptive materials such as zeolites, activated carbon, and molecular sieves selectively trap target gas species under high pressure.

The primary technology utilized by IFS centers on the polymeric membrane separation of gaseous air.

Feed Air Conditioning for N2 Generation

Feed Filter Coalescers

Each nitrogen generation system must include a filtration system to protect the nitrogen membrane and enhance its effectiveness. The initial two coalescer filters eliminate moisture as small as 0.01 Micron from incoming air.

Immersion Heater

This component is crucial as it prevents liquid migration past the coalescer filters. The heater adds approximately 10°F of superheat to the air, ensuring no liquids can enter the nitrogen membranes.

Activated Carbon Vessel

After heating, air flows through an activated carbon bed to remove additional hydrocarbon vapors before entering the membranes.

Particulate Filter

A .01 Micron filter located downstream of the carbon bed provides a final conditioning step before air enters the membranes.

Nitrogen Membranes

Polymeric membrane materials at the heart of this technology allow for rapid passage of specific gases, thereby effectively separating O2 and other "fast gases" from compressed air, resulting in a high-purity N2 stream.

These membrane materials are formed into hollow (tubular) fibers, offering a substantial surface area to achieve high volumetric gas processing rates.

The filters employed by IFS operate at high temperatures (up to 180°F) and are certified by PED and DNV. N1 and P3 membrane fibers are available, with P3 offering the highest recovery rates in the market.

N2 Generation Control Systems

Efficiency relates to the volume of N2 produced against the amount of feed air supplied to the membrane. Efficiency can be managed by adjusting the following process variables:

• Feed air temperature (higher temperatures yield more N2)
• Feed air pressure (higher pressure results in more N2)
• Product oxygen content (higher O2 content enhances efficiency)

Purity levels of the generated N2 can be monitored using Oxygen Analyzers (Zirconium Oxide Type or Galvanic Fuel Cell Type). Purity valves work alongside the analyzers to maintain the desired nitrogen purity. Off-Spec/Product Valves are automated valves that manage the flow of N2 product to either process or vent.

IFS typically employs the Allen Bradley CompactLogix controller, though they can adapt to various project specifications (such as Siemens) and HMI configurations.

N2 Products and Their Applications

Nitrogen Generation

• General inerting in the Oil & Gas industry
• Food storage and transportation
• OBIGGS (onboard inert gas generation systems for airplanes)
• Tire inflation
• Beverage dispensing
• Marine inerting systems
• Oxygen Enriched Air

Process Gas Separations

• Hydrogen purification in refineries
• Ammonia plant purge recovery
• Syn Gas ratio adjustments
• Helium purification

Dehydration

If you're seeking further details, feel free to visit nitrogen compressor manufacturers.

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For additional information:

Download: "How is Nitrogen Gas Produced" Presentation PDF

Download: Process Flow Diagram (P&ID) for Nitrogen Generation Membrane Package PDF

Explore our Skid-Mounted Packages:

Membrane Nitrogen Generation Systems: Modular, Engineered-to-Order, Shipped Ready to Plug In

For more information, visit fire extinguisher refill machine to get professional answers.