Nitrogen: A Highly Dangerous or Useful Substance?

The atmosphere in which we live and the air we breathe daily are composed of 79 percent nitrogen and 21 percent oxygen, along with small amounts of other gases. But only oxygen is necessary and vital for human breathing and survival. If the oxygen in the air falls below 16 percent, it will be fatal. But nitrogen gas in the atmosphere acts to some extent like a diluent or a buffer gas. If the Earth were without nitrogen and filled only with oxygen, fires would be uncontrollable and steel skeletons would rust quickly. Therefore nitrogen is an effective diluent that we cannot live without, but large amounts of it also deprive us of vital oxygen and can cause suffocation and death. Applications and hazards of nitrogen in industry Nitrogen has numerous applications and uses in industrial units, and it comes in gas and liquid forms. The applications and hazards of nitrogen in the two states, liquid and gas, are as follows: Applications of gaseous nitrogen 1- Inerting equipment to prevent the creation of a breathable atmosphere 2- Purging the hydrocarbons present in equipment in order to prepare it for repair work 3- Purging the air or oxygen present in equipment before startup 4- Creating a blanket in tanks to prevent the ingress of air 5- For special welding operations 6- Preventing the rusting process 7- Use in firefighting operations as an air-displacing agent Applications of liquid nitrogen 1- Cooling purposes in the laboratory, freezing pipelines, etc. 2- Storage and transport in large volumes (large amounts of nitrogen) Hazards of gaseous nitrogen 1- In an enclosed space it replaces oxygen and causes suffocation or even death. 2- When using flammable-gas detectors, the presence of nitrogen gas gives us false results. 3- Like other compressed gases, when stored in pressurized cylinders it carries the hazards arising from pressure. Hazards of nitrogen gas in the liquid state 1- After it vaporizes, it becomes apparent that the hazards are like those of the gaseous state. 2- It creates extreme cold, the freezing from which can cause the breakage of metal equipment and explosion. 3- Liquid nitrogen boils at a temperature colder than that of oxygen; as a result, it condenses oxygen in the air, which can form a pre-explosive mixture with other vapors or, upon contact with organic materials, cause a violent reaction. The use and handling of chemicals, whether as raw materials or as by-products and main products, is considered an inseparable part of the process industries, and unfortunately at present many accidents occur as a result of leaks or contact with these substances, which in the worst and most severe cases lead to explosion, fire, or the death of people. Therefore, knowing the characteristics and properties of chemicals, their hazard thresholds, and how to deal with emergency situations resulting from these substances will play a significant role in reducing possible damages and the occurrence of accidents and their consequences. To gain this information, you can obtain and study the BP Process Safety series book "Hazards of Nitrogen and the Transport of Catalyst" from Hak Publications.