Liquefied gas (sometimes referred to as liquid gas) is a gas that has been turned into a liquid by cooling or compressing it. Examples of liquefied gases include

liquid air Liquid air is air that has been cooled to very low temperatures ( cryogenic temperatures), so that it has condensed into a pale blue mobile liquid. To thermally insulate it from room temperature, it is stored in specialized containers ( vacuum in ...

liquefied natural gas Liquefied natural gas (LNG) is natural gas (predominantly methane, CH4, with some mixture of ethane, C2H6) that has been cooled down to liquid form for ease and safety of non-pressurized storage or transport. It takes up about 1/600th the volu ...

, and

liquefied petroleum gas Liquefied petroleum gas (LPG or LP gas) is a fuel gas which contains a flammable mixture of hydrocarbon gases, specifically propane, propylene, butylene, isobutane and n-butane. LPG is used as a fuel gas in heating appliances, cooking e ...

Liquid air

At the

Lister Institute of Preventive Medicine The Lister Institute of Preventive Medicine, informally known as the Lister Institute, was established as a research institute (the British Institute of Preventive Medicine) in 1891, with bacteriologist Marc Armand Ruffer as its first director, us ...

, liquid air has been brought into use as an agent in biological research. An inquiry into the intracellular constituents of the

typhoid Typhoid fever, also known as typhoid, is a disease caused by '' Salmonella'' serotype Typhi bacteria. Symptoms vary from mild to severe, and usually begin six to 30 days after exposure. Often there is a gradual onset of a high fever over several ...

bacillus ''Bacillus'' (Latin "stick") is a genus of Gram-positive, rod-shaped bacteria, a member of the phylum ''Bacillota'', with 266 named species. The term is also used to describe the shape (rod) of other so-shaped bacteria; and the plural ''Bacilli ...

, initiated under the direction of Doctor

Allan Macfadyen Allan Macfadyen (26 May 1860 in Glasgow – 1 March 1907 in Hampstead, London) was a Scottish bacteriologist, a pioneer in immunization against bacterial infection. Early life and education The youngest of four sons of a brass founder in G ...

, necessitated the separation of the cell-plasma of the organism. The method at first adopted for the disintegration of the bacteria was to mix them with silver-sand and churn the whole up in a closed vessel in which a series of horizontal vanes revolved at a high speed. But certain disadvantages attached to this procedure, and accordingly some means was sought to do away with the sand and triturate the bacilli per se. This was found in liquid air, which, as had long before been shown at the Royal Institution, has the power of reducing materials like grass or the leaves of plants to such a state of brittleness that they can easily be powdered in a mortar. By its aid a complete

trituration Trituration (Latin, ''grinding'') is the name of several different methods used to process materials. In one sense, it is a form of comminution (reducing the particle size of a substance). In another sense, it is the production of a homogeneous pow ...

of the typhoid bacilli has been accomplished at the

Jenner Institute The Jenner Institute is a research institute on the Old Road Campus in Headington, east Oxford, England. It was formed in November 2005 through a partnership between the University of Oxford and the UK Institute for Animal Health. It is ass ...

, and the same process, already applied with success also to

yeast Yeasts are eukaryotic, single-celled microorganisms classified as members of the fungus kingdom. The first yeast originated hundreds of millions of years ago, and at least 1,500 species are currently recognized. They are estimated to constitut ...

cells and animal cells, is being extended in other directions. When air is liquefied the oxygen and nitrogen are condensed simultaneously. However, owing to its greater volatility the latter boils off the more quickly of the two, so that the remaining liquid becomes gradually richer and richer in oxygen.

Liquefied natural gas

Liquefied natural gas is natural gas that has been liquefied for the purpose of storage or transport. Since transportation of natural gas requires a large network of pipeline that crosses through various terrains and oceans, a huge investment and long term planning are required. Before transport, natural gas is liquefied by pressurization. The liquefied gas is then transported through tankers with special airtight compartments. When the tanks are opened and the liquid exposed to atmospheric pressure, the liquid boils off from the latent heat of the air or its container.

Liquid air

Liquefied natural gas

References

See also