What are uses of inert gases



As Inert gases are gases that are very inert (inert), i.e. only take part in a few chemical reactions. If they are molecular compounds, they are usually characterized by a strongly negative standard enthalpy of formation. Whether you want to use a specific gas for a specific application as a Inert gas referred to, but still depends on the specific case. The inert gases include, for example, nitrogen, carbon dioxide and all noble gases (helium, neon, argon, krypton, xenon, radon).

Inert gases are used to keep other gases, such as air, away from certain chemical reactions. As a rule, inert gases are used to reduce or completely replace the oxygen content and to absorb the heat of reaction so that an explosion cannot propagate any further.

Natural use for inert gases

In the atmosphere in particular, the inert gas nitrogen ensures that the proportion of oxygen in the air is so low that no dangerously fast combustion processes take place. If the proportion of oxygen were significantly higher, combustion processes would take place much faster.

Technical applications for inert gases

  • Shipping (explosion protection): In tankers, when the flammable liquid cargo is pumped out (extinguished), inert gas is filled in to fill up the remaining volume in the tank, in order to prevent an explosive air / gas mixture from developing, which could be ignited by sparks. For this purpose, the inert exhaust gases from the main propulsion system (diesel engine exhaust from the motor ship or boiler exhaust from the turbine ship) are used in the oil tanker voyage. Special inert gas systems are installed on liquid gas tankers, as the qualitative requirements for the inert gas are higher than in the oil tanker voyage. Low-sulfur diesel oil is burned in a combustion chamber in such a way that the residual oxygen content in the exhaust gas does not exceed 0.2% by volume. Soot particles and water-soluble substances are then washed out using seawater. The gas is then cooled to 8 to 10 ° C with the aid of a refrigeration system (refrigeration dryer), during which the water contained in the gas condenses and is removed via a separator. The residual moisture is then removed from the pre-dried gas in an adsorption dryer in order to ensure the required dew point depending on the load. A dew point must be included in the LNG journey <= −40 °c sichergestellt="" werden.="" zum="" inertisieren="" der="" barrieren="" wird="" in="" der="" flüssiggasschifffahrt="" stickstoff="" verwendet.="" dieser="" wird="" entweder="" in="" flüssiger="" form="" mittels="" tankwagen="" an="" bord="" geliefert="" und="" dort="" je="" nach="" bedarf="" verdampft="" oder="" mittels="" membrananlagen="" an="" bord="" aus="" der="" luft="" gewonnen.="">
  • Combat aircraft (fire and explosion protection): Similar to the shipping industry, the fuel tanks are also charged with an inert gas to prevent fire and explosion. Dry nitrogen is used. Since a Boeing 747 crash, which was caused by the explosion of a fuel tank by sparking of the tank electrics, the discussion about the internal protection of the tank system has also flared up in civil aviation. In addition to the possibility of using inert gas, as in combat aircraft, the search is also being carried out to find ways of influencing the kerosene in such a way that it is incombustible or at least hardly inflammable under the conditions prevailing in the tank.
  • Fire protection: Use of inert gases for fire fighting in inert gas extinguishing systems or for preventive fire protection by inerting in active fire prevention systems
  • Welding, where argon is used as a protective gas
  • Diving, where helium is used in breathing gas mixtures as a remedy for nitrogen anesthesia
  • Gas chromatography, where it is used as a mobile phase (carrier gas)
  • Inert gas systems, a typical example of this is the so-called glove box (glove box)
  • Chemical synthesis if reaction components would react unintentionally with oxygen, moisture, carbon dioxide or nitrogen (e.g. metallic lithium) (inert gas or Schlenk technology).
  • Anesthesia, where laughing gas was considered an inert gas for a long time and for this reason was not included in the toxicological assessment of anesthetic gas exposure by anesthetists
  • Packaging technology to extend the shelf life and preserve the aroma of food

Categories: Chemical group | gas