Bulk Liquid Nitrogen  [ Return towards  Bulk Gases  ]

Nitrogen, N2, comprises 78% of the earth's atmosphere. Commercially available liquid nitrogen is made in large cryogenic air separation plants , where normal atmospheric air is cleaned, compressed and cooled by expansion to create liquefied air which is subsequently separated by fractional distillation at cryogenic temperatures.
Liquid nitrogen is stored and transported in special vacuum-insulated tanks and tankers at temperatures in the range - 196 to - 155 º C and corresponding pressures ranging from atmospheric to about 20 bar.
Tanks and tankers have no refrigeration systems to maintain the internal temperature, hence heat ingress may cause the liquid to boil and increase the pressure in the tank. Automatic systems vent any excess pressure. Generally, liquid nitrogen is transported cold at a low pressure. Customers' tanks may be low or high pressure, depending on the application. Cryogenic users have low pressure tanks (5 bar or less) and companies using nitrogen as a gas tend to have higher pressure tanks ( up to 20 bar).

Gaseous nitrogen is ….

• Tasteless, odourless, colourless
• Non-flammable and chemically inert except at very high temperatures
• Only slightly soluble in water

Liquid nitrogen ….

• Can exist as a liquid at atmospheric pressure and -
  196 º C, e.g. in a Thermos® flask
• Absorbs a lot of heat when it vaporises - as much as 420 kJ per kg in an efficient system
• Has a very high heat transfer rate because of its extremely low temperature

At our plant, quality is assured by continuous on-line process analysis and individual analysis of every tanker both before and after filling.