Cryogenic Air Separation Process for the Production of Nitrogen

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How Cryogenic Air Separation Process Produces Nitrogen?

Nitrogen is produced for commercial applications through liquefaction of atmospheric air. The process of nitrogen production trough cryogenic air separation process starts with taking atmospheric air into the air separation unit (ASU). After being let into the ASU, the air is filtered for removal of dust particles. Then, it is compressed in the air compressor. The compressed air now becomes feedstock which is passed through cleanup system called purification unit where contaminants and impurities like hydrocarbons, carbon dioxide and water moisture are removed.

At this stage, the air is passed through a series of heat exchangers for cooling it to cryogenic temperatures in order to achieve liquefaction of atmospheric air. The liquefied air is moved into a high pressure distillation column where nitrogen is physically separated from other gases like oxygen and argon.  At the this point, the chosen gas is collected and is moved into a low pressure distillation column where nitrogen is distilled to achieve commercial grade purity.

Some Useful Information about Nitrogen

Nitrogen is one of the most abundant nonmetallic gases in the atmosphere constituting as it does 78% of Earth’s atmosphere.  It constituent of all living beings as it is present in DNA and RNA.  It is said to make up around 16% of the complex compounds like proteins which are present in most living beings.  And, it is vital plant life as without nitrogen they will wither and with too much of it they also go to waste. The plants must have the nonmetallic gas in proper balance for their optimum growth.  Although it is the most plentiful element in the planet’s atmosphere but its occurrence in Earth’s crust is estimated to comprise 0.3 parts per 1000.

Most importantly, it is one element which is so heavily used in the chemical industry. It is used for making ammonia by reacting it with hydrogen. Ammonia is essential for making fertilizers, nylon, etc.  It is said to be the largest industrial gas.  It is also used for providing inert atmosphere which is widely beneficial for preservation of foods. It is used in annealing stainless steel and steel products.   We get nitrogen through eating other living things digesting them into proteins and DNA. Nitrogen compounds are turned back into nitrates for reuse by the plants.