Gas liquefaction is the physical conversion of gas into liquid form (condensation).
Video Liquefaction of gases
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This process is used for scientific, industrial and commercial purposes. Many gases can be introduced into the liquid state at normal atmospheric pressure with simple cooling; some, like carbon dioxide, require pressure as well. Liquidation is used to analyze the basic properties of gas molecules (intermolecular forces), for gas storage, for example: LPG, and in cooling and air conditioning. There is a liquefied gas in condenser where evaporative heat is released, and evaporates in an evaporator where evaporating heat is absorbed. Ammonia is the first such refrigerant, and is still widely used in industrial refrigeration, but has largely been replaced by compounds derived from petroleum and halogens in residential and commercial applications.
Liquid oxygen is given to the hospital to be converted to gas for patients with respiratory problems, and liquid nitrogen is used in the medical field for cryosurgery, and by inseminators to freeze semen. Liquid chlorine is transported for an ultimate solution in water, after which it is used for water purification, industrial waste sanitation, waste and swimming pools, pulp and textile bleaching and carbon tetrachloride, glycol and many other organic compounds and gas phosgene.
The melting of helium ( 4 He) with the Precooled Hampson-Linde cycle led to the Nobel Prize for Heike Kamerlingh Onnes in 1913. At ambient pressure the boiling point of liquid helium was 4.22 K (-268.93 Ã, Â ° C). Below 2.17 K liquid 4 He became superfluid (1978 Nobel Prize, Pyotr Kapitsa) and exhibited characteristic properties such as heat conduction through second sound, zero viscosity and fountain effects among others.
Gas liquefaction is a complex process that uses a variety of compression and expansion to achieve high pressure and very low temperatures, using, for example, turboexpander.
Air liquefaction is used to obtain nitrogen, oxygen, and argon and other noble gases of the atmosphere by separating air components by fractional distillation in cryogenic air separation units.
Maps Liquefaction of gases
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Liquid air
Linde Process
Air is melted by the Linde process, where air is alternately compressed, cooled, and expanded, each expansion result in considerable temperature reduction. With lower temperatures, molecules move more slowly and occupy less space, so the air turns phase into liquid.
Claude Process
Air can also be liquefied by the Claude process in which the gas is allowed to expand isentrophic twice in two spaces. As it expands, the gas has to work because through an expansion turbine. The gas is not yet liquid, because it will destroy the turbine. The commercial liquefaction plant passes this problem by expanding air at supercritical pressure. The final melt occurs by isenthalpic expansion in Joule-Thomson-Valve.
See also
References
External links
- Liquefaction of Gases
- The History of Liquefying Hydrogen - NASA
Source of the article : Wikipedia
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