The Use of Nitrogen in Different Industries

  1. Metallurgy

Used for annealing shielding gas, nitriding, slugging and purging gas. Some industries need nitrogen owning over 99.5% fineness, some require high-quality nitrogen having over 99.995% fineness or below -65℃ dew point.

  1. Chemistry and New Material

Mainly used for chemical material, pipe purging,atmosphere replacement, atmosphere protection, production delivery and etc.  Some chemical industries do not require too much fineness, 98% is enough for some of them.

3. Food and Medical Industry

Mainly used for food packaging, food preservation, medical package, medical gas replacement and medical gas delivery. In usual cases, the nitrogen has to undergo de-germing, de-dusting and de-watering to satisfy special requirements of this industry. Most companies of food industries just require nitrogen having over 98% fineness. Medical industries always require nitrogen having over 99.9% nitrogen. When the needed amount of nitrogen is little, membrane separation is applied. While needing large amount of nitrogen, PSA is used.

4. Electricity Industries

Used for the sealings, sintering, annealing, reduction and storage of electricity equipment. The industries include wave-soldering, reflow soldering, crystal, piezoe-electric, electronic ceramics, electronic copper strip, battery, electron. Electricity industries always require high-quality nitrogen (fineness should be over 99.9% or 99.99%).

  1. Other Fields

Apart from the above industries,  the nitrogen generator is widely used in coal, petroleum and other industries. Along with the advanced technique and development of the society, the nitrogen is more and more widely used. The nitrogen generator has already replaced liquid nitrogen evaporator and bottling nitrogen for its low investment, low cost and convenience. Nitrogen could prolong the lives of bulbs and protect valuable books and drawings because it suffocates moths. Nitrogen could also be used for making fertilizer and explosives.


Pure nitrogen cannot be refined directly from nature, the method is air separation. The method is divided into deep freezing, PSA and barrier separation.

 The Process of PSA and a Brief Introduction of Equipments

  1. The Process of the Procedure

The air penetrates into the compressor after swiping dust and impurities through the air filtering machine and is compressed into the needed amount of pressure, the clean compressed air is output after strictly getting rid of oil,water and dust, the goal is to keep the longevity of the molecular sieve.There are two adsorber equipped with carbon molecular sieve.

Brief Introduction of the Deep Freezing Nitrogen Making

The typical deep freezing nitrogen-making process is made up of air compression, air separation and vaporization of liquid nitrogen

2. Air compression and Purification

After the filtering of dust and machinery, the air goes into the air compressor and it will be compressed into needed pressure, and then goes into the air freezing machine to calm the heat of air to get rid of other impurities.

Air Separation

The purified air enters the main heat exchanger and will be freezed to saturation degree and sent to the bottom of rectifying tower, then the nitrogen will be produced on the top. Through the throttling, the liquid air will evaporate. Part of the nitrogn will be reflux, the rest will be production. The exhaust gas produced by freezing evaporator will reheat to 130K in the expander to produce cold air for the air distillation. Part of the expanding air will be used for reusing and refrigeration, then will be discharged into atmosphere.

3. Nitrogen-From Liquid to Gas

The liquid nitrogen coming from the distillation tower will be stored in the storage tank, and when the separation equipment is under examination, the liquid nitrogen in the tank will go to vaporizer and be heated and sent to the nitrogen pipeline. The freezing technique can produce nitrogen has over 99.999%fineness.