Oxygen fractional distillation

Industrially, elemental nitrogen is extracted from the air by the fractional distillation of liquid air from which carbon dioxide and water have been removed. The major fractions are nitrogen, b.p. 77 K and oxygen, b.p. 90 K, together with smaller quantities of the noble gases. 

On the industrial scale oxygen is obtained by the fractional distillation of air. A common laboratory method for the preparation of oxygen is by the decomposition of hydrogen peroxide. H Oj, a reaction catalysed by manganese(IV) oxide ... 

A gaseous element, oxygen forms 21 % of the atmosphere by volume and is obtained by liquefaction and fractional distillation. The atmosphere of Mars contains about 0.15% oxygen. The element and its compounds make up 49.2%, by weight, of the earth s crust. About two thirds of the human body and nine tenths of water is oxygen. 

In nature, oxygen occurs in three stable isotopic species oxygen-16 [14797-70-7] O, 99.76% oxygen-17 [13968-48-4], 0.038% and oxygen-18 [14797-71-8], 0.20% (7). Commercial fractional distillation of water produces concentrations of as high as 99.98% concentrations up to 55% are also produced. The isotope has been used to trace mechanisms of organic reactions. 

Fractional distillation of NO provides another effective route and, as the heavier isotope of oxygen is simultaneously enriched, the product has a high concentration of Many... 

Despite the general availability of unlimited quantities of oxygen in the air, tremendous quantities of the pure gas are prepared annually for industrial and medical use. Billions of cubic feet of oxygen gas are manufactured every year, by liquefaction of air followed by fractional distillation to separate it from nitrogen. 

Pure ozone is made by fractional distillation of the blue liquid resulting from the cooling of ozonized oxygen in liquid air. Commercially it is often supplied dissolved in chlorofluorocarbons in stainless steel cylinders at ca 475 psig cylinder pressure at 20°C often transported chilled with dry ice. These solutions can be handled safely at vapour concentrations of ca 20% by volume of ozone. 

Nitrogen, oxygen and argon are produced by fractional distillation of air. Liquid nitrogen (LN) is a quite cheap and safe source of cold and finds applications such as ... 

Linde Also called Hampson-Linde. A process for separating oxygen and nitrogen from air by liquifation followed by fractional distillation. Developed by K. P. G. von Linde in Germany and W. Hampson in England at the start of the 20th century. 

Using a potential of approximately 20000 V the ozonised oxygen produced can contain up to 10% ozone and pure ozone can be obtained by liquifaction of the mixture followed by fractional distillation (02, b.p. 90 K 03, b.p. 161 K). 

Preparation. Oxygen is obtained on large-scale process by the fractional distillation of liquid air. 

Krypton is a rather dense, tasteless, colorless, odorless gas. Its critical temperature is between that of oxygen and carbon dioxide. It is extracted during fractional distillation of liquid oxygen at a temperature of about -63.8°C. At one time it was thought that krypton, as well as the other noble gases, were completely inert. However, in 1967 scientists were able to combine fluorine with krypton at low temperatures to form the compound krypton difluoride (KrFj). In this case krypton has a valence of 2. 

Xenon has a relatively high atomic weight and is about 4.5 times heavier than air. It is colorless, tasteless, and odorless. Its critical temperature is comparatively high at 16.6°C, which is far above oxygen (-188°C). This means that xenon will boil away from commercial fractional distillation of liquid oxygen. 

Nonen-2-one. J. Gen. Chem. (USSR), Vol. 33, p. 134 of the English translation. Oxidation of the ketone is accomplished in this manner 0.5 mole of n-hexylideneacetone (this should be freshly distilled at 93-95° with 16 mm of vacuo) is shaken in an oxygen atmosphere at 30° for 8 hours. Decompose the hydroperoxides with a little sodium sulphite. Fractionally distill in three steps about 40° at 16 mm vacuo, 93-95° at 16 mm vacuo, and the product is obtained by reducing the vacuum to 1 mm and raising the temp to 107-108°. Yield of pale, yellow, viscous liquid, 6 g. The unreacted starting material (93-95° 16 mm) is used over and over until reacted. 

All commercial processes involve either separation of nitrogen from air by cryogenic distillation or combustion of air with natural gas to remove oxygen. In the former process, air is liquefied and the liquid air is subjected to fractional distillation to separate its components. 

Xenon is recovered from air by liquefaction and fractional distillation. Usually it is obtained as a by-product of making other noble gases. It is collected in the liquid oxygen fraction along with krypton, acetylene, and other hydrocarbons that may be present in air. The xenon fraction is flash vaporized. Hydrocarbons present are separated by burning over a catalyst. Xenon is absorbed on silica gel at low temperatures. Finally, it is separated from krypton by selective absorption and desorption from charcoal. 

Asphalt Hydrocarbon material ranging in consistency from heavy liquid to a solid. Most common source is residue left after fractional distillation of crude oils used primarily for surfacing roads. Asphyxia Suffocation from lack of oxygen. Chemical asphyxia is produced by a substance, such as carbon monoxide, that combines with hemoglobin to reduce die blood s capacity to transport oxygen. Simple asphyxia is the result of exposure to a substance, such as carbon dioxide, that displaces oxygen. 

Oxygen occurs as the free element (O2) in the atmosphere (21%), from which it is obtained by fractional distillation of liquid air or by membrane technologies, but far greater amounts are found in the Earth s crust in... 

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