Nitrogen is represented chemically by symbol N having an atomic number of 7 in the periodic table.  It is a nonmetallic gas which is colorless and odorless. It is valued for its inert properties which have several industrial, medical and scientific applications discussed later in the article.  Comprising around 79% of Earth’s atmosphere, nitrogen is the most abundantly occurring gas. It is essential for all living beings being the constituent of DNA, considered to contain the blueprint of life. Since the nonmetallic element is found in living beings it is also found in fossils and coal. On the soil of the planet, it mostly occurs in nitrates and nitrites which are constituents of nitrogen cycle.

History of Nitrogen

Discovered in 1772 by the Scottish physician Daniel Rutherford, nitrogen has been known to occur in various compounds since the time of Herodotus during 5th century BC. In Middle Ages compounds containing nitrogen were known—nitric acid and nitrate salts. Mixture of nitric and hydrochloric acids was known to dissolve gold. Rutherford knew that a component of air did not support combustion but did not have the awareness that it was an element. It was called as azote, a Greek word meaning “no life” because of its inert properties by the French chemist Antoine Lavoisier.  Etymologically the word nitrogen is derived from the French word “nitrogene” which was coined by French Chemist Jean-Antoine Chaptal in 1794 who thought nitrogen basic building block of nitric acid. Mostly nitrogen compounds such as sodium nitrate or potassium nitrate were used in agricultural and military applications. Later the compounds of the nonmetallic gas were started to be used in fertilizers. Supply of nitrogen compounds was limited as it was found either in biological materials or through atmospheric reactions. Later industrial processes like Frank–Caro process (1895–1899) and Haber–Bosch process (1908–1913) made the production of nitrogen compounds possible on commercial scale. Now it is estimated that over 50% of all food production uses some kind of synthetic nitrogen fertilizers.

Industrial Applications of nitrogen

Nitrogen has numerous applications for its inert properties. Many synthetically compound such as ammonia and nitrates are used as fertilizers.  In industrial applications of nitrogen are extensive so much so that it is the most industrially consumed gas.  While talking of industrial applications it must be understood that we talking of commercially produced high purity nitrogen. Still further, it is estimated that around 75% of all industrially produced nitrogen is used in its gaseous form. Remaining 25% of the nonmetallic is used in its liquid form.  It mostly used for creating modified atmosphere by displacing oxygen that causes moisture and fires due to oxidation.

  1. Applications of gaseous nitrogen

Being the largest industrially consumed gas, nitrogen is used in various industries in its gaseous form. It is difficult to list all applications at one place. However, important applications are summarized below:

  • It is widely used for creating an inert atmosphere for preservation of food with its key characteristics like taste, texture, integrity and increasing its shelf life due to oxidation.
  • Its use is also important in the manufacturing of IT equipment.
  • Manufacturing of incandescent light bulbs
  • Used for manufacturing important chemicals such as nylon, dyes, ammonia, fertilizers, nitric acid, etc.
  • Used as fire suppressant system
  1. Applications of liquid nitrogen

Liquid nitrogen with its boiling point of -195.8 deg C is extremely cold. It is used in numerous industrial applications, some of which are described below:

  • Primarily liquid nitrogen is used for refrigeration
  • Used for cryopreservation of biological samples including sperm, blood, tissue and materials
  • Cryosurgery for removal of warts and cysts
  • As coolant for CPUs of computers
  • Used for freeze grinding foods ingredients to make consistent powder
  • Used in shrink fitting and assembling of engineering components

Biological applications and significance of nitrogen

Nitrogen is found mostly in the atmospheric air from where it moves into living beings and organic compounds returning back into the atmosphere. This is what we call the nitrogen cycle. To clear it further, nitrogen from air is taken by plants and algae for making the bases which in turn will help in the making of RNA, DNA and amino acids, which constitute the very basis of life.

Source of nitrogen for animals including humans is through consumption of other living things. After digesting proteins and DNA from other living things, it is passed into their own amino acids which are modified for their own use.  There are microbes in the soil which transform nitrogen compound into nitrates, which are then used by the plants again.

Also Read: What is Cryogenic Distillation Process for Liquid Nitrogen Generation?