NITROGEN

  • Home
  • Industrial
  • Nitrogen

Nitrogen

Nitrogen (N2) is a colourless, odour less and tasteless gas that makes up 78% (by volume) of the air. It is non-flammable and it will not support combustion. Nitrogen gas is slightly lighter than air and slightly soluble in water. It is commonly used as an inert gas. The boiling temperature of nitrogen is −196 °C.

Nitrogen can be used as an inert atmosphere for reactions requiring the exclusion of oxygen and moisture. In the liquid state, nitrogen has valuable cryogenic applications. Except for the gases hydrogen, methane, carbon monoxide, fluorine, and oxygen, practically all chemical substances have negligible vapour pressures at the boiling point of nitrogen .

Nitrogen is used as a preventive of oxidation of a product, as an inert diluent of a reactive gas, as a carrier to remove heat or chemicals and as an inhibitor of fire or explosions.

In the food industry nitrogen gas is employed to prevent spoilage through oxidation, mold, or insects, and liquid nitrogen is used for freeze drying and for refrigeration systems.

In the electrical industry nitrogen is used to prevent oxidation and other chemical reactions, to pressurize cable jackets, and to shield motors.

Nitrogen finds application in the metals industry in welding, soldering, and brazing, where it helps prevent oxidation, carburization, and decarburization.

As a nonreactive gas, nitrogen is employed to make foamed or expanded rubber, plastics and elastomers. Nitrogen also serves a propellant gas for aerosol cans, and to pressurize liquid propellants for reaction jets.

In Pharma industry, rapid freezing with liquid nitrogen may be used to preserve blood, bone marrow, tissue, bacteria, and semen.

Liquid nitrogen has also proven useful in cryogenic research. Liquid Nitrogen is very much used in Environmental Test Facilities in Aerospace, Defence and Space research.

The application used for Nitrogen

Multi-Industry Uses for Nitrogen:

The inert properties of nitrogen make it a good blanketing gas in many applications. Nitrogen blanketing is used to protect flammable or explosive solids and liquids from contact with air. Certain chemicals, surfaces of solids, and stored food products have properties that must be protected from degradation by the effects of atmospheric oxygen and moisture. Protection is achieved by keeping these items in (under) a nitrogen atmosphere. "Inerting" or "padding" are other terms used to describe the displacement of air and nitrogen blanketing. "Sparging" with nitrogen is the bubbling of nitrogen gas through a liquid to remove unwanted volatile components, including volatile organic compounds (VOC) which may be necessary to meet pollution reduction regulations. Certain substances are difficult to pulverize or shred because they are tough or the materials will be degraded by the heat generated by mechanical processes such as grinding. Liquid nitrogen can be used to freeze soft or tough substances prior to their entering a size reduction process. Cold vaporized nitrogen can be used to keep materials cool (and in an inert atmosphere) during grinding. Cryogenic grinding is used in diverse applications, including the production of finely ground pharmaceuticals, plastics and pigments; and for shredding tires in recycling plants.

Metals Manufacturing Uses for Nitrogen:

Nitrogen is used to treat the melt in the manufacture of steel and other metals and as a shield gas in the heat treatment of iron, steel and other metals. It is also used as a process gas, together with other gases for reduction of carbonization and nitriding. Flash or fins on cast metal can be removed by cooling with liquid nitrogen, making them brittle, allowing them to be broken off by mechanical action.

Manufacturing and Construction Uses:

Shrink fitting is an interesting alternative to traditional expansion fitting. Instead of heating the outer metal part, the inner part is cooled by liquid nitrogen so that the metal shrinks and can be inserted. When the metal returns to its normal temperature, it expands to its original size, giving a very tight fit.

Liquid nitrogen is used to cool concrete, which leads to better-cured properties. When construction operations must be done in the soft, water-soaked ground such as tunnel construction underneath waterways, the ground can be frozen effectively with liquid nitrogen. Pipes are driven into the ground, liquid nitrogen is pumped through the pipes under the earth's surface. When the nitrogen exits into the soil, it vaporizes, removing heat from the soil and freezing it.

Chemicals, Pharmaceuticals and Petroleum Use:

Refineries, petrochemical plants and marine tankers use nitrogen to purge equipment, tanks and pipelines of dangerous vapors and gases (for example, after completing a pipeline transfer operation or ending a production run) and to maintain an inert and protective atmosphere in tanks storing flammable liquids. Cooling reactors (and the materials inside) to low temperature allows better control of side-reactions in complex reactions in the pharmaceutical industry. Liquid nitrogen is often used to provide the necessary refrigeration as it can produce rapid temperature reduction and easily maintain the required cold reaction temperatures. Reactor cooling and temperature control systems usually employ a circulating low-temperature heat transfer fluid to transfer refrigeration produced by vaporizing liquid nitrogen to the shell of the reactor vessel. The liquid nitrogen is vaporized in specially-designed heat exchangers that transfer refrigeration to the circulating heat transfer fluid. Liquid nitrogen is used during good completion to "frac" natural gas-bearing rock formations, in particular, tight gas formations, including shale gas and natural gas from coal (coal bed methane) where water-based methods should be avoided. Nitrogen is also used to maintain pressure in oil and natural gas producing formations. Unlike carbon dioxide, which is also used for pressurization, nitrogen has little affinity for liquid hydrocarbons, thus it builds up in and remains in the gas cap. Nitrogen is used as an inert gas to push liquids through lines, to clear lines and to propel "pigs" through pipelines to sweep out one material before using the line to transport another material.

Food and Beverages:

The intense cold in liquid nitrogen allows very rapid freezing of food items, resulting in minimal cell damage from ice crystals and improved appearance, taste and texture. Well-designed cryogenic tunnel and spiral freezers efficiently capture refrigeration from liquid vaporization and from the cold nitrogen gas as it flows through the freezer. When substances such as vegetable oil and wines are stored, the inert properties of nitrogen can be used to protect against loss of quality by oxidation by expelling any air entrained in the liquid (Sparging) and protecting liquids in storage tanks by filling the vapor space (Blanketing). Nitrogen (and nitrogen mixed with CO2 and oxygen) is used in transport trucks and in Modified Atmosphere Packaging (MAP) to extend the shelf life of packaged foods by preventing oxidation, mold, insect infestation and moisture migration.

Rubber and Plastics Industry Uses:

Materials become hard and brittle when cooled to very low temperatures. This property permits the removal of flash or fins on cast plastics and rubber. The castings are cooled by liquid nitrogen and the flash broken off by mechanical action.

Health Care Uses:

Nitrogen is used as a shield gas in the packing of some medicines to prevent degradation by oxidation or moisture adsorption. Nitrogen is used to freeze blood, as well as viruses for vaccination. It is also used to freeze livestock semen, which can then be stored for years. The quick freezing resulting from the intense cold minimizes cell wall damage. Liquid nitrogen is also used in some MRI (Magnetic Resonance Imaging) devices to pre-cool the low-temperature magnets prior to using much more expensive liquid helium for final cooling. Liquid nitrogen is used in cryo-surgery to destroy diseased tissue.

Miscellaneous Uses for Nitrogen:

Nitrogen is used directly as a coolant for severe environmental testing of many items, or as a refrigeration source for chilling circulating dry air.

Major Nitrogen Applications

  • Multiutility
  • Waste to Energy
  • Plant for treating industrial
    (chemical, pharmaceutical, fabrics and leather, food, paper, petrochemicals and mining) waste
  • Solid waste treatment plant
  • Waste to energy plants
  • Civil wastewater treatment plant
  • Agricolture
  • Milk and derivatives
  • Bread and confectionery
  • Meat and poultry
  • Fish processing
  • Coffee, wine and oil
  • Fruit and vegetables
  • Ready meals
  • Catering
  • Beverages
  • Ice cream
  • Precision casting (e.g. lost wax, micro-fusion casting)
  • Cast-iron production
  • Glass container and fibre production
  • Steelmaking (from scrap – arc furnace)
  • Secondary aluminium production (recycling)
  • Plate glass production
  • Aluminium extrusion
  • Non-ferrous metal production (copper, lead, gold and bronze)
  • Steelmaking (from pig iron – blast furnace)
  • Artistic glass production
  • Steel forging
  • Refractory products production, marble
  • Lime production
  • Precious metal working
  • Cement production
  • Aeronautical production
  • Printed circuit board production
  • Automotive
  • Thermal treatment for third parties
  • Carbon steel working
  • Aluminium working
  • Stainless steel working
  • Carpentry
  • Nonferrous metal working
  • Tool working
  • Pharmaceutical specialities
  • Rubber and plastic
  • Bulk pharmaceuticals
  • Fine chemistry
  • Polymers
  • Cosmetics and herbalism
  • Basic and organic chemistry, synthesised intermediates
  • Offshore
  • Extraction
  • Oil refining
  • Raw material and finished product stockage
  • Transport and pipelines
  • Plant components and equipment
  • Energy production