There are six known distinct phases of solid oxygen. One of them is a dark-red cluster. When oxygen is subjected to a pressure of 96 GPa, it becomes metallic, in a similar manner to hydrogen, and becomes more similar to the heavier chalcogens, such as tellurium and polonium, both of which show significant metallic character. At very low temperatures, this phase also becomes superconducting.
Phases of solid oxygen
Allotropes of oxygen
Allotropes of oxygen | Phases of solid oxygen
Sorry. I cannot find the answer based on the context. Smelting of iron ore into steel consumes 55% of commercially produced oxygen is one the industrial use Smelting of iron ore into steel consumes 55% of commercially produced oxygen.Another 25% of commercially produced oxygen is used by the chemical industry. Smelting of iron ore into steel and in the chemical industry.
oxygen (o2) is formed in photosynthesis as a direct result of
user
Light-driven splitting of water during oxygenic photosynthesis
assistant
how does lavoisier contribute?
user
He conducted the first adequate quantitative experiments on oxidation and gave the first correct explanation of how combustion works
assistant
what are its isotopes?
user
They are variants of a particular chemical element which differ in neutron number, and consequently in nucleon number
assistant
what are its allotropes?
user
Sorry. I cannot find the answer based on the context.
assistant
how is it stored?
user
Sorry. I cannot find the answer based on the context.
assistant
is it toxic?
user
No it is not toxic
assistant
what are its industrial uses?
user
It was proven in 2006 that this phase, created by pressurizing to 20 GPa, is in fact a rhombohedral cluster. This cluster has the potential to be a much more powerful oxidizer than either or and may therefore be used in rocket fuel. A metallic phase was discovered in 1990 when solid oxygen is subjected to a pressure of above 96 GPa and it was shown in 1998 that at very low temperatures, this phase becomes superconducting.
Oxygen | Allotropes
There are six known distinct phases of solid oxygen. One of them is a dark-red cluster. When oxygen is subjected to a pressure of 96 GPa, it becomes metallic, in a similar manner to hydrogen, and becomes more similar to the heavier chalcogens, such as tellurium and polonium, both of which show significant metallic character. At very low temperatures, this phase also becomes superconducting.
Allotropes of oxygen | Phases of solid oxygen
On the other hand, the electrochemical synthesis of hydrogen peroxide from oxygen is a promising technology to replace the currently used hydroquinone-process. Last but not least, catalytic oxidation is used in afterburners to get rid of hazardous gases. Most of the remaining 20% of commercially produced oxygen is used in medical applications, metal cutting and welding, as an oxidizer in rocket fuel, and in water treatment. Oxygen is used in oxyacetylene welding, burning acetylene with to produce a very hot flame. In this process, metal up to thick is first heated with a small oxy-acetylene flame and then quickly cut by a large stream of .
Oxygen | Industrial
Singlet oxygen is the common name used for the two metastable states of molecular oxygen (O) with higher energy than the ground state triplet oxygen. Because of the differences in their electron shells, singlet oxygen has different chemical and physical properties than triplet oxygen, including absorbing and emitting light at different wavelengths. It can be generated in a photosensitized process by energy transfer from dye molecules such as rose bengal, methylene blue or porphyrins, or by chemical processes such as spontaneous decomposition of hydrogen trioxide in water or the reaction of hydrogen peroxide with hypochlorite.
Allotropes of oxygen | Singlet oxygen
Tetraoxygen had been suspected to exist since the early 1900s, when it was known as oxozone. It was identified in 2001 by a team led by Fulvio Cacace at the University of Rome. The molecule was thought to be in one of the phases of solid oxygen later identified as . Cacace's team suggested that probably consists of two dumbbell-like molecules loosely held together by induced dipole dispersion forces.
Allotropes of oxygen | Tetraoxygen
Smelting of iron ore into steel consumes 55% of commercially produced oxygen. In this process, is injected through a high-pressure lance into molten iron, which removes sulfur impurities and excess carbon as the respective oxides, and . The reactions are exothermic, so the temperature increases to 1,700 °C. Another 25% of commercially produced oxygen is used by the chemical industry. Ethylene is reacted with to create ethylene oxide, which, in turn, is converted into ethylene glycol; the primary feeder material used to manufacture a host of products, including antifreeze and polyester polymers (the precursors of many plastics and fabrics). Large quantities of oxygen or air is used in oxy-cracking process and for the production of acrylic acid, diformyl-furane, and benzylic acid.
Oxygen | Industrial
There are several known allotropes of oxygen. The most familiar is molecular oxygen (O), present at significant levels in Earth's atmosphere and also known as dioxygen or triplet oxygen. Another is the highly reactive ozone (O). Others are:
Allotropes of oxygen | Introduction
After a set cycle time the operation of the two beds is interchanged, thereby allowing for a continuous supply of gaseous oxygen to be pumped through a pipeline. This is known as pressure swing adsorption. Oxygen gas is increasingly obtained by these non-cryogenic technologies (see also the related vacuum swing adsorption). Oxygen gas can also be produced through electrolysis of water into molecular oxygen and hydrogen. DC electricity must be used: if AC is used, the gases in each limb consist of hydrogen and oxygen in the explosive ratio 2:1. A similar method is the electrocatalytic evolution from oxides and oxoacids.
Oxygen | Industrial production
As the pressure of oxygen at room temperature is increased through 10 GPa (1,450,377 psi), it undergoes a dramatic phase transition to a different allotrope. Its volume decreases significantly, and it changes color from sky-blue to deep red. This ε-phase was discovered in 1979, but the structure has been unclear. Based on its infrared absorption spectrum, researchers assumed in 1999 that this phase consists of molecules in a crystal lattice. However, in 2006, it was shown by X-ray crystallography that this stable phase known as ε oxygen or red oxygen is in fact . No one predicted the structure theoretically: a rhomboid cluster consisting of four molecules.
Solid oxygen | Red oxygen
In this phase it exhibits a dark-red color, very strong infrared absorption, and a magnetic collapse. It is also stable over a very large pressure domain and has been the subject of numerous X-ray diffraction, spectroscopic and theoretical studies. It has been shown to have a monoclinic C2/m symmetry and its infrared absorption behaviour was attributed to the association of oxygen molecules into larger units.
Solid oxygen | Red oxygen
The magnetic properties of oxygen have been studied extensively. At very high pressures, solid oxygen changes from an insulating to a metallic state; and at very low temperatures, it even transforms to a superconducting state. Structural investigations of solid oxygen began in the 1920s and, at present, six distinct crystallographic phases are established unambiguously. The density of solid oxygen ranges from 21 cm/mol in the α-phase, to 23.5 cm/mol in the γ-phase.
Solid oxygen | Introduction
Members of the class can all use molecular oxygen as a terminal electron acceptor (i.e. are aerobic) as well as nitrate, which can be used by some members during denitrification. The autotrophic members of the class do not use carboxysomes to concentrate carbon dioxide or improve RuBisCO efficiency as a carboxylase versus an oxygenase. The dominant respiratory quinone of the class is ubiquinone-8 and menaquinones or rhodoquinones are not observed, though they are in the neighbouring "Betaproteobacteria".
Hydrogenophilalia | Introduction
Oxygen's most common allotrope is diatomic oxygen, or O, a reactive paramagnetic molecule that is ubiquitous to aerobic organisms and has a blue color in its liquid state. Another allotrope is O, or ozone, which is three oxygen atoms bonded together in a bent formation. There is also an allotrope called tetraoxygen, or O, and six allotropes of solid oxygen including "red oxygen", which has the formula O. Sulfur has over 20 known allotropes, which is more than any other element except carbon. The most common allotropes are in the form of eight-atom rings, but other molecular allotropes that contain as few as two atoms or as many as 20 are known.
Chalcogen | Allotropes
Oxygen finds broad application in various technological processes and in almost all industry branches. The primary oxygen application is associated with its capability of sustaining burning process, and the powerful oxidant properties. Due to that, oxygen has become widely used in the metal processing, welding, cutting and brazing processes. In the chemical and petrochemical industries, as well as in the oil and gas sector oxygen is used in commercial volumes as an oxidizer in chemical reactions. The use of oxygen in gas-flame operations, such as metal welding, cutting and brazing is one of the most significant and common applications of this gas.
Oxygen plant | Application
The term "allotropy" is used for elements only, not for compounds. The more general term, used for any crystalline material, is polymorphism. Allotropy refers only to different forms of an element within the same phase (i.e.: solid, liquid or gas states); the differences between these states would not alone constitute examples of allotropy. For some elements, allotropes have different molecular formulae despite difference in phase; for example, two allotropes of oxygen (dioxygen, O, and ozone, O) can both exist in the solid, liquid and gaseous states. Other elements do not maintain distinct allotropes in different phases; for example, phosphorus has numerous solid allotropes, which all revert to the same P form when melted to the liquid state.
Allotropy | Introduction
Chemical catalysts can be used as well, such as in chemical oxygen generators or oxygen candles that are used as part of the life-support equipment on submarines, and are still part of standard equipment on commercial airliners in case of depressurization emergencies. Another air separation method is forcing air to dissolve through ceramic membranes based on zirconium dioxide by either high pressure or an electric current, to produce nearly pure gas.
Oxygen | Industrial production
In commerce, liquid oxygen is classified as an industrial gas and is widely used for industrial and medical purposes. Liquid oxygen is obtained from the oxygen found naturally in air by fractional distillation in a cryogenic air separation plant. Air forces have long recognized the strategic importance of liquid oxygen, both as an oxidizer and as a supply of gaseous oxygen for breathing in hospitals and high-altitude aircraft flights. In 1985 the USAF started a program of building its own oxygen-generation facilities at all major consumption bases.
Liquid oxygen | Uses
The neon-burning process creates additional O. Solid samples (organic and inorganic) for O studies are usually stored in silver cups and measured with pyrolysis and mass spectrometry. Researchers need to avoid improper or prolonged storage of the samples for accurate measurements.
Oxygen-16 | Introduction
Chemical oxygen generators consist of chemical compounds that release O upon some stimulation, usually heat. They are used in submarines and commercial aircraft, providing emergency oxygen. Oxygen is generated by high-temperature decomposition of sodium chlorate: Potassium permanganate also releases oxygen upon heating, but the yield is modest.
Oxygen evolution | Chemical oxygen generation
The doublet state requires an odd number of electrons, and so cannot occur in dioxygen without gaining or losing electrons, such as in the superoxide ion () or the dioxygenyl ion (). The ground state of has a bond length of 121 pm and a bond energy of 498 kJ/mol. It is a colourless gas with a boiling point of . It can be condensed from air by cooling with liquid nitrogen, which has a boiling point of . Liquid oxygen is pale blue in colour, and is quite markedly paramagnetic due to the unpaired electrons; liquid oxygen contained in a flask suspended by a string is attracted to a magnet.
Allotropes of oxygen | Dioxygen
The cryogenic air separation achieves high purity oxygen of more than 99.5%. The resulting high purity product can be stored as a liquid and/or filled into cylinders. These cylinders can even be distributed to customer in the medical sector, welding or mixed with other gases and used as breathing gas for diving. Typical production ranges from 50 normal m/hour up to 860,000 Nm/hour (Ras Laffan refinery).
Cryogenic oxygen plant | Purpose
A ζ-phase appears at 96 GPa when ε-phase oxygen is further compressed. This phase was discovered in 1990 by pressurizing oxygen to 132 GPa. The ζ-phase with metallic cluster exhibits superconductivity at pressures over 100 GPa and a temperature below 0.6 K.
Solid oxygen | Metallic oxygen
Oxygen storage methods include high pressure oxygen tanks, cryogenics and chemical compounds. For reasons of economy, oxygen is often transported in bulk as a liquid in specially insulated tankers, since one liter of liquefied oxygen is equivalent to 840 liters of gaseous oxygen at atmospheric pressure and . Such tankers are used to refill bulk liquid oxygen storage containers, which stand outside hospitals and other institutions that need large volumes of pure oxygen gas. Liquid oxygen is passed through heat exchangers, which convert the cryogenic liquid into gas before it enters the building. Oxygen is also stored and shipped in smaller cylinders containing the compressed gas; a form that is useful in certain portable medical applications and oxy-fuel welding and cutting.
Oxygen | Storage
Oxygen plants are industrial systems designed to generate oxygen. They typically use air as a feedstock and separate it from other components of air using pressure swing adsorption or membrane separation techniques. Such plants are distinct from cryogenic separation plants which separate and capture all the components of air.
Oxygen plant | Introduction
These compounds form by oxidation of alkali metals with larger ionic radii (K, Rb, Cs). For example, potassium superoxide () is an orange-yellow solid formed when potassium reacts with oxygen. Hydrogen peroxide () can be produced by passing a volume of 96% to 98% hydrogen and 2 to 4% oxygen through an electric discharge. A more commercially-viable method is to allow autoxidation of an organic intermediate, 2-ethylanthrahydroquinone dissolved in an organic solvent, to oxidize to and 2-ethylanthraquinone. The 2-ethylanthraquinone is then reduced and recycled back into the process.
Compounds of oxygen | Other inorganic compounds
Liquid oxygen in a cryogenic storage dewar (vacuum-insulated flask) is used in aerospace, submarine and gas industries.
Oxygen storage | Cryogenic
Repurposed medical oxygen concentrators or specialized industrial oxygen concentrators can be made to operate "small" oxyacetylene or other fuel gas cutting, welding and lampworking torches.
Oxygen concentrator | Alternate applications
Six different phases of solid oxygen are known to exist: It has been known that oxygen is solidified into a state called the β-phase at room temperature by applying pressure, and with further increasing pressure, the β-phase undergoes phase transitions to the δ-phase at 9 GPa and the ε-phase at 10 GPa; and, due to the increase in molecular interactions, the color of the β-phase changes to pink, orange, then red (the stable octaoxygen phase), and the red color further darkens to black with increasing pressure. It was found that a metallic ζ-phase appears at 96 GPa when ε-phase oxygen is further compressed.
Solid oxygen | Phases
One hundred million tonnes of are extracted from air for industrial uses annually by two primary methods. The most common method is fractional distillation of liquefied air, with distilling as a vapor while is left as a liquid. The other primary method of producing is passing a stream of clean, dry air through one bed of a pair of identical zeolite molecular sieves, which absorbs the nitrogen and delivers a gas stream that is 90% to 93% . Simultaneously, nitrogen gas is released from the other nitrogen-saturated zeolite bed, by reducing the chamber operating pressure and diverting part of the oxygen gas from the producer bed through it, in the reverse direction of flow.
Oxygen | Industrial production
These materials include CrO and SiO. They can, however, be used as support materials along with active oxygen carrier materials. In addition to the relative redox potentials of metal oxide materials illustrated in Fig 1b, the development of desired oxygen carriers for chemical looping applications requires to consider such properties as oxygen carrying capacity, redox reactivity, reaction kinetics, recyclability, attrition resistance, heat carrying capacity, melting point, and production cost.
Chemical looping reforming and gasification | Oxygen carriers
The common allotrope of elemental oxygen on Earth, , is generally known as oxygen, but may be called "dioxygen", "diatomic oxygen", "molecular oxygen", or "oxygen gas" to distinguish it from the element itself and from the triatomic allotrope "ozone," . As a major component (about 21% by volume) of Earth's atmosphere, elemental oxygen is most commonly encountered in the diatomic form. Aerobic organisms release the chemical energy stored in the weak sigma bond of atmospheric dioxygen, the terminal oxidant in cellular respiration. The ground state of dioxygen is known as triplet oxygen, O, because it has two unpaired electrons. The first excited state, singlet oxygen, ""O has no unpaired electrons and is metastable.
Allotropes of oxygen | Dioxygen
The common allotrope of elemental oxygen on Earth is called dioxygen, , the major part of the Earth's atmospheric oxygen (see Occurrence). O has a bond length of 121 pm and a bond energy of 498 kJ/mol, which is smaller than the energy of other double bonds or pairs of single bonds in the biosphere and responsible for the exothermic reaction of O with any organic molecule. Due to its energy content, O is used by complex forms of life, such as animals, in cellular respiration. Other aspects of are covered in the remainder of this article. Trioxygen () is usually known as ozone and is a very reactive allotrope of oxygen that is damaging to lung tissue.
Oxygen | Allotropes
Steelmaking is the most important use of oxygen; 55% of all oxygen produced goes to this application. The chemical industry also uses large amounts of oxygen; 25% of all oxygen produced goes to this application. The remaining 20% of oxygen produced is mostly split between medical use, water treatment (as oxygen kills some types of bacteria), rocket fuel (in liquid form), and metal cutting. Most sulfur produced is transformed into sulfur dioxide, which is further transformed into sulfuric acid, a very common industrial chemical. Other common uses include being a key ingredient of gunpowder and Greek fire, and being used to change soil pH.
Chalcogen | Applications
Triatomic oxygen (ozone, O), is a very reactive allotrope of oxygen that is destructive to materials like rubber and fabrics and is also damaging to lung tissue. Traces of it can be detected as a sharp, chlorine-like smell, coming from electric motors, laser printers, and photocopiers. It was named "ozon" in 1840 by Christian Friedrich Schönbein, from ancient Greek ὄζειν (ozein: "to smell") plus the suffix "-on" (in English "-one") commonly used at the time to designate a derived compound. Ozone is thermodynamically unstable toward the more common dioxygen form, and is formed by reaction of O with atomic oxygen produced by splitting of O by UV radiation in the upper atmosphere.
Allotropes of oxygen | Ozone
Methods of oxygen storage for subsequent use span many approaches, including high pressures in oxygen tanks, cryogenics, oxygen-rich compounds and reaction mixtures, and chemical compounds that reversibly release oxygen upon heating or pressure change. O is the second most important industrial gas.
Oxygen storage | Introduction
Liquid oxygen has a pale blue color and is strongly paramagnetic: it can be suspended between the poles of a powerful +U- magnet (horseshoe). Liquid oxygen has a density of 1.141 g/cm (1.141 kg/L or 1141 kg/m), slightly denser than liquid water, and is cryogenic with a freezing point of and a boiling point of at 101.325 kPa (760 mmHg). Liquid oxygen has an expansion ratio of 1:861 under and , and because of this, it is used in some commercial and military aircraft as a transportable source of breathing oxygen. Because of its cryogenic nature, liquid oxygen can cause the materials it touches to become extremely brittle.
Liquid oxygen | Physical properties
Although many other chemists have repeated this advice, IUPAC and most chemistry texts still favour the usage of allotrope and allotropy for elements only.
Allotropy | History
For industrial applications, oxygen-free copper is valued more for its chemical purity than its electrical conductivity. OF/OFE grade copper is used in plasma deposition (sputtering) processes, including the manufacture of semiconductors and superconductor components, as well as in high vacuum devices such as particle accelerators. In any of these applications, the release of oxygen or other impurities can cause undesirable chemical reactions with other materials in the local environment.
Oxygen-free copper | Industrial applications
It gradually oxidizes when exposed to water in the presence of oxygen, which is a concern when contemplating it as a material for the manufacture of transistors, for example.
Allotropes of phosphorus | Phosphorene
Chemical oxygen generators, such as those in commercial aircraft, provide emergency oxygen to passengers to protect them from drops in cabin pressure. Oxygen is generated by high-temperature decomposition of sodium chlorate: Heat required to initiate this reaction is generated by oxidation of a small amount of iron powder mixed with the sodium chlorate, and the reaction consumes less oxygen than is produced. Barium peroxide (BaO) is used to absorb the chlorine that is a minor product in the decomposition. An ignitor charge is activated by pulling on the emergency mask. Similarly, the Solidox welding system used pellets of sodium chlorate mixed with combustible fibers to generate oxygen.
Sodium chlorate | Chemical oxygen generation
Though solid magnesium and aluminum react slowly with oxygen at STP—they, like most metals, burn in air, generating very high temperatures. Finely grained powders of most metals can be dangerously explosive in air. Consequently, they are often used in solid-fuel rockets. In dry oxygen, iron readily forms iron(II) oxide, but the formation of the hydrated ferric oxides, FeO(OH), that mainly comprise rust, typically requires oxygen "and" water. Free oxygen production by photosynthetic bacteria some 3.5 billion years ago precipitated iron out of solution in the oceans as FeO in the economically important iron ore hematite.
Oxide | Formation
Extremotrophs are used as bioremediation and biodegradation agents.
Extremotroph | Industrial uses
SOECs have possible application in fuel production, carbon dioxide recycling, and chemicals synthesis. In addition to the production of hydrogen and oxygen, an SOEC could be used to create syngas by electrolyzing water vapor and carbon dioxide. This conversion could be useful for energy generation and energy storage applications. MIT will test the method on the "Perseverance" rover as a means to produce oxygen for both human sustenance and liquid oxygen rocket propellant.
Solid oxide electrolyzer cell | Applications
He was surprised that it did not answer questions like the height at which to use oxygen, flow rates other than 4 L/m, and whether to use sleeping oxygen.
Griffith Pugh | Cho Oyo 1952
Gas separation by adsorption systems is based on differential rates of adsorption of the components of a gas mixture into a solid adsorbent.
Oxygen plant | Adsorption principle
Because of the brittleness of the oxypnictides, superconducting wires are formed using the powder-in-tube process (using iron tubes).
Oxypnictide | Practical use
Industrial processes may use much higher pressures and flows than medical units. To meet that need, another process, called vacuum swing adsorption (VSA), has been developed by Air Products. This process uses a single low pressure blower and a valve that reverses the flow through the blower so that the regeneration phase occurs under a vacuum. Generators using this process are being marketed to the aquaculture industry. Industrial oxygen concentrators are often available in a much wider range of capacities than medical concentrators. Industrial oxygen concentrators are sometimes referred to as oxygen "generators" within the oxygen and ozone industries to distinguish them from medical oxygen "concentrators".
Oxygen concentrator | Industrial oxygen concentrators
At higher temperatures it burns most other metals and many non-metals (including hydrogen, carbon, and sulfur). Many oxides are extremely stable substances difficult to decompose—like water, carbon dioxide, alumina, silica, and iron oxides (the latter often appearing as rust). Oxygen is part of substances best described as some salts of metals and oxygen-containing acids (thus nitrates, sulfates, phosphates, silicates, and carbonates. Oxygen is essential to all life. Plants and phytoplankton photosynthesize water and carbon dioxide and water, both oxides, in the presence of sunlight to form sugars with the release of oxygen. The sugars are then turned into such substances as cellulose and (with nitrogen and often sulfur) proteins and other essential substances of life.
Period 2 element | Oxygen
In April 2003, fullerenes were under study for potential medicinal use — binding specific antibiotics to the structure to target resistant bacteria and even target certain cancer cells such as melanoma.
Allotropes of carbon | Buckminsterfullerenes
The partial pressure of oxygen was controlled by temperature, which was controlled by controlling the pressure at which liquid nitrogen was allowed to boil, which was controlled by an adjustable pressure relief valve. No control valves other than the nitrogen pressure relief valve were required. Low temperature was also used to freeze out up to 230 grams of carbon dioxide per hour from the loop, corresponding to an oxygen consumption of 2 litres per minute as carbon dioxide will freeze out of the gaseous state at -43.3 °C or below. If oxygen was consumed faster due to a high workload, a regular scrubber was needed.
Rebreather | Cryogenic rebreather
Oxygen condenses at 90.20 K (−182.95 °C, −297.31 °F), and freezes at 54.36 K (−218.79 °C, −361.82 °F). Both liquid and solid are clear substances with a light sky-blue color caused by absorption in the red (in contrast with the blue color of the sky, which is due to Rayleigh scattering of blue light). High-purity liquid is usually obtained by the fractional distillation of liquefied air. Liquid oxygen may also be condensed from air using liquid nitrogen as a coolant. Oxygen is a highly reactive substance and must be segregated from combustible materials.
Oxygen | Physical properties
Many nonmetals have less stable allotropes, with either nonmetallic or metallic properties. Graphite, the standard state of carbon, has a lustrous appearance and is a fairly good electrical conductor. The diamond allotrope of carbon is clearly nonmetallic, however, being translucent and having a relatively poor electrical conductivity. Carbon is also known in several other allotropic forms, including semiconducting buckminsterfullerene (C). Nitrogen can form gaseous tetranitrogen (N), an unstable polyatomic molecule with a lifetime of about one microsecond. Oxygen is a diatomic molecule in its standard state; it also exists as ozone (O), an unstable nonmetallic allotrope with a half-life of around half an hour.
Nonmetal | Allotropes
Cells in factories are operated 24 hours a day so that the molten material in them will not solidify. Temperature within the cell is maintained via electrical resistance. Oxidation of the carbon anode increases the electrical efficiency at a cost of consuming the carbon electrodes and producing carbon dioxide. While solid cryolite is denser than solid aluminium at room temperature, liquid aluminium is denser than molten cryolite at temperatures around . The aluminium sinks to the bottom of the electrolytic cell, where it is periodically collected. The liquid aluminium is removed from the cell via a siphon every 1 to 3 days in order to avoid having to use extremely high temperature valves and pumps.
Hall–Héroult process | Cell operation
Ozone is produced in the upper atmosphere when combines with atomic oxygen made by the splitting of by ultraviolet (UV) radiation. Since ozone absorbs strongly in the UV region of the spectrum, the ozone layer of the upper atmosphere functions as a protective radiation shield for the planet. Near the Earth's surface, it is a pollutant formed as a by-product of automobile exhaust. At low earth orbit altitudes, sufficient atomic oxygen is present to cause corrosion of spacecraft. The metastable molecule tetraoxygen () was discovered in 2001, and was assumed to exist in one of the six phases of solid oxygen.
Oxygen | Allotropes
Oxygen tanks containing pressures up to 200 bar (3000 psi) are used for industrial processes including the manufacture of steel and monel, welding and cutting, medical breathing gas, diving and as emergency backup in aircraft. A small steel tank of 16 liters water capacity with a working pressure of 139 bar (2015 psi) holds about 2150 liters of gas and weighs empty. 2150 liters of oxygen weighs about
Oxygen storage | High pressure
Chemical oxygen generators are used in aircraft, breathing apparatus for firefighters and mine rescue crews, submarines, and everywhere a compact emergency oxygen generator with long shelf life is needed. They usually contain a device for absorption of carbon dioxide, sometimes a filter filled with lithium hydroxide; a kilogram of LiOH absorbs about half a kilogram of CO.
Chemical oxygen generator | Uses
Heparin-coated oxygenators are thought to:
Oxygenator | Rationale
Adding Gamma loop additives keeps the iron in a body-centered cubic structure and prevents the steel from suffering phase transition to other solid states.
Allotropes of iron | Structural phase transitions
In Robert L. Forward's science fiction novel "Camelot 30K", oxygen difluoride was used as a biochemical solvent by fictional life forms living in the solar system's Kuiper belt. While would be a solid at 30 K, the fictional alien lifeforms were described as endothermic, maintaining elevated body temperatures and liquid blood by radiothermal heating.
Oxygen difluoride | Popular culture
To supply the electrons in the circuit, hydrogen is stripped from water, leaving oxygen as a waste product. Some organisms, including purple bacteria and green sulfur bacteria, use an anoxygenic form of photosynthesis that uses alternatives to hydrogen stripped from water as electron donors; examples are hydrogen sulfide, sulfur and iron. Such extremophile organisms are restricted to otherwise inhospitable environments such as hot springs and hydrothermal vents. The simpler anoxygenic form arose about 3.8 Ga, not long after the appearance of life. The timing of oxygenic photosynthesis is more controversial; it had certainly appeared by about 2.4 Ga, but some researchers put it back as far as 3.2 Ga.
History of Earth | Oxygen revolution
Ozone is a pale blue gas condensable to a dark blue liquid. It is formed whenever air is subjected to an electrical discharge, and has the characteristic pungent odour of new-mown hay or subways – the so-called 'electrical odour'.
Allotropes of oxygen | Ozone
OF precipitates as a brown solid upon the UV irradiation of a mixture of liquid O and F at -196 °C. It also only appears to be stable below -160 °C. The general method of preparation of many oxygen fluorides is a gas-phase electric discharge in cold containers including OF. It is typically an orange-yellow solid which rapidly decomposes to O and F close to its normal boiling point of about 216 K. OF reacts violently with red phosphorus, even at -196 °C. Explosions can also occur if Freon-13 is used to moderate the reaction.
Oxygen fluoride | Dioxygen difluoride (OF)
Chemical oxygen generators store oxygen in their chemical composition, and can be used only one time. "Oxygen Candles" contain a mix of sodium chlorate and iron powder, which when ignited smolders at about 600 °C (1,112 °F) and results in sodium chloride, iron oxide, and oxygen, about 270 liters per kg of mixture. Some commercial airliners use emergency oxygen generators containing a mixture of sodium chlorate (NaClO), 5 percent barium peroxide (BaO) and 1 percent potassium perchlorate (KClO), which after ignition, reacts releasing oxygen for 12 to 22 minutes while the unit reaches .
Oxygen storage | Chemical oxygen generators
The development of an analytical instrument that utilizes the reduction-oxidation (redox) chemistry of oxygen in the presence of dissimilar metal electrodes was introduced during the 1950s. This redox electrode utilized an oxygen-permeable membrane to allow the diffusion of the gas into an electrochemical cell and its concentration determined by polarographic or galvanic electrodes. This analytical method is sensitive and accurate down to levels of ± 0.1 mg/l dissolved oxygen. Calibration of the redox electrode of this membrane electrode still requires the use of the Henry's law table or the Winkler test for dissolved oxygen.
Biochemical oxygen demand | Polargraphic method
Pressurized commercial airplanes have an emergency supply of automatically supplied to the passengers in case of cabin depressurization. Sudden cabin pressure loss activates chemical oxygen generators above each seat, causing oxygen masks to drop. Pulling on the masks "to start the flow of oxygen" as cabin safety instructions dictate, forces iron filings into the sodium chlorate inside the canister. A steady stream of oxygen gas is then produced by the exothermic reaction.
Oxygen | Life support and recreational use
As a result, none of these elements is found in nature as a free metal. Caesium is so reactive with oxygen that it is used as a getter in vacuum tubes. Although solid magnesium reacts slowly with oxygen at STP, it is capable of burning in air, generating very high temperatures, and its metal powder may form explosive mixtures with air. Oxygen is present as compounds in the atmosphere in trace quantities in the form of carbon dioxide () and oxides of nitrogen (NO). The earth's crustal rock is composed in large part of oxides of silicon (silica , found in granite and sand), aluminium (aluminium oxide , in bauxite and corundum), iron (iron (III) oxide , in hematite and rust) and other oxides of metals.
Compounds of oxygen | Oxides
A cryogenic oxygen plant is an industrial facility that creates molecular oxygen at relatively high purity. Oxygen is the most common element in the earth's crust and the second largest industrial gas. This process was pioneered by Dr. Carl von Linde in 1902.
Cryogenic oxygen plant | Introduction
Similarly, yellow arsenic is a molecular solid composed of As units. Some forms of sulfur and selenium are composed of S (or Se) units and are molecular solids at ambient conditions, but converted into covalent allotropes having atomic chains extending throughout the crystal.
Molecular solid | Allotropes
A one-dimensional carbon polymer with the structure —(C≡C)—.
Allotropes of carbon | Linear acetylenic carbon
Unlike carbon aerogels, carbon nanofoam is a poor electrical conductor.
Allotropes of carbon | Carbon nanofoam
Solid oxygen forms at normal atmospheric pressure at a temperature below 54.36 K (−218.79 °C, −361.82 °F). Solid oxygen O, like liquid oxygen, is a clear substance with a light sky-blue color caused by absorption in the red part of the visible light spectrum. Oxygen molecules have attracted attention because of the relationship between the molecular magnetization and crystal structures, electronic structures, and superconductivity. Oxygen is the only simple diatomic molecule (and one of the few molecules in general) to carry a magnetic moment. This makes solid oxygen particularly interesting, as it is considered a "spin-controlled" crystal that displays antiferromagnetic magnetic order in the low temperature phases.
Solid oxygen | Introduction
Aerobic life make extensive use of metals such as iron, copper, and manganese. Heme is utilized by red blood cells in the form of hemoglobin for oxygen transport and is perhaps the most recognized metal system in biology. Other oxygen transport systems include myoglobin, hemocyanin, and hemerythrin. Oxidases and oxygenases are metal systems found throughout nature that take advantage of oxygen to carry out important reactions such as energy generation in cytochrome c oxidase or small molecule oxidation in cytochrome P450 oxidases or methane monooxygenase. Some metalloproteins are designed to protect a biological system from the potentially harmful effects of oxygen and other reactive oxygen-containing molecules such as hydrogen peroxide.
Bioinorganic chemistry | Oxygen transport and activation proteins
Its use as a cryoprotectant in commercial systems has been patented widely.
Cryoprotectant | Conventional
It was formerly used to produce iodoform, bromoform, and even chloroform industrially.
Haloform reaction | Industrially
Liquid oxygen is the most common cryogenic liquid oxidizer propellant for spacecraft rocket applications, usually in combination with liquid hydrogen, kerosene or methane. Liquid oxygen was used in the first liquid fueled rocket. The World War II V-2 missile also used liquid oxygen under the name "A-Stoff" and "Sauerstoff". In the 1950s, during the Cold War both the United States' Redstone and Atlas rockets, and the Soviet R-7 Semyorka used liquid oxygen. Later, in the 1960s and 1970s, the ascent stages of the Apollo Saturn rockets, and the Space Shuttle main engines used liquid oxygen. In 2020, many rockets use liquid oxygen:
Liquid oxygen | In rocket propellant
In low-pressure environments oxygen toxicity may be avoided since the toxicity is caused by high partial pressure of oxygen, not merely by high oxygen fraction. This is illustrated by modern pure oxygen use in spacesuits, which must operate at low pressure (also historically, very high percentage oxygen and lower than normal atmospheric pressure was used in early spacecraft, for example, the Gemini and Apollo spacecraft). In such applications as extra-vehicular activity, high-fraction oxygen is non-toxic, even at breathing mixture fractions approaching 100%, because the oxygen partial pressure is not allowed to chronically exceed .
Oxygen toxicity | Hypobaric setting
Oxygen concentrators using pressure swing adsorption (PSA) technology are used widely for oxygen provision in healthcare applications, especially where liquid or pressurized oxygen is too dangerous or inconvenient, such as in homes or in portable clinics. For other purposes there are also concentrators based on nitrogen separation membrane technology. An oxygen concentrator takes in air and removes nitrogen from it, leaving an oxygen enriched gas for use by people requiring medical oxygen due to low oxygen levels in their blood. Oxygen concentrators provide an economical source of oxygen in industrial processes where they are also known as oxygen gas generators or oxygen generation plants.
Oxygen concentrator | How oxygen concentrators work
CP Chem produces this material at their facilities in Borger, Texas, USA and Tessenderlo, Belgium.
Dimethyl sulfide | Industrial uses
Atomic oxygen, denoted O(P) or O(3P), is very reactive, as the single atoms of oxygen tend to quickly bond with nearby molecules. On Earth's surface, it does not exist naturally for very long, but in outer space, the presence of plenty of ultraviolet radiation results in a low Earth orbit atmosphere in which 96% of the oxygen occurs in atomic form. Atomic oxygen has been detected on Mars by Mariner, Viking, and the SOFIA observatory.
Allotropes of oxygen | Atomic oxygen
Oxygen is a colourless, odourless, and unpredictably reactive diatomic gas with a gaseous density of 1.429 × 10 g/cm (marginally heavier than air). It is generally unreactive at room temperature. Thus, sodium metal will "retain its metallic lustre for days in the presence of absolutely dry air and can even be melted (m.p. 97.82 °C) in the presence of dry oxygen without igniting". On the other hand, oxygen can react with many inorganic and organic compounds either spontaneously or under the right conditions, (such as a flame or a spark) [or ultra-violet light?]. It condenses to pale blue liquid −182.962 °C and freezes into a light blue solid at −218.79 °C.
Nonmetal | Group 16
Ethylene oxide itself is a very hazardous substance. At room temperature it is a flammable, carcinogenic, mutagenic, irritating, and anaesthetic gas. It is used for making many consumer products as well as non-consumer chemicals and intermediates. These products include detergents, thickeners, solvents, plastics, and various organic chemicals. As such, it is a vital raw material with diverse applications.
Chemical Industries of Ethylene Oxide explosion | Toxic chemicals involved
An alternate stable form, if it exists, may appear at pressures of at least 50 GPa and temperatures of at least 1,500 K; it has been thought to have an orthorhombic or a double hcp structure. as of December 2011, recent and ongoing experiments are being conducted on high-pressure and Superdense carbon allotropes.
Allotropes of iron | Experimental high temperature and pressure
Singlet oxygen, systematically named dioxygen(singlet) and dioxidene, is a gaseous inorganic chemical with the formula O=O (also written as or ), which is in a quantum state where all electrons are spin paired. It is kinetically unstable at ambient temperature, however the rate of decay is slow. The lowest excited state of the diatomic oxygen molecule is a singlet state. It is a gas with physical properties differing only subtly from those of the more prevalent triplet ground state of O. In terms of its chemical reactivity, however, singlet oxygen is far more reactive toward organic compounds. It is responsible for the photodegradation of many materials but can be put to constructive use in preparative organic chemistry and photodynamic therapy.
Singlet oxygen | Introduction
The current methods of gaseous oxygen production from air by the use of adsorption technology produce a high fraction of oxygen as their output. The mechanism of operation of a modern oxygen adsorption plant is based on the variation of uptake of a particular gas component by the adsorbent as the temperature and partial pressure of the gas is changed. The gas adsorption and adsorbent regeneration processes may therefore be regulated by varying of the pressure and temperature parameters.
Oxygen plant | Temperature and pressure influence
Aside from its use to supply medical oxygen, or as a substitute for bulk cryogenic or compressed-cylinder storage, which is the primary oxygen source for any hospital, PSA has numerous other uses. One of the primary applications of PSA is in the removal of carbon dioxide (CO) as the final step in the large-scale commercial synthesis of hydrogen (H) for use in oil refineries and in the production of ammonia (NH). Refineries often use PSA technology in the removal of hydrogen sulfide (HS) from hydrogen feed and recycle streams of hydrotreating and hydrocracking units. Another application of PSA is the separation of carbon dioxide from biogas to increase the methane (CH) ratio.
Pressure swing adsorption | Applications
A chemical oxygen generator is a device that releases oxygen via a chemical reaction. The oxygen source is usually an inorganic superoxide, chlorate, or perchlorate; ozonides are a promising group of oxygen sources. The generators are usually ignited by a firing pin, and the chemical reaction is usually exothermic, making the generator a potential fire hazard. Potassium superoxide was used as an oxygen source on early manned missions of the Soviet space program, for firefighters, and for mine rescue.
Chemical oxygen generator | Introduction
Allotropes are different structural forms of the same element and can exhibit quite different physical properties and chemical behaviours. The change between allotropic forms is triggered by the same forces that affect other structures, i.e., pressure, light, and temperature. Therefore, the stability of the particular allotropes depends on particular conditions. For instance, iron changes from a body-centered cubic structure (ferrite) to a face-centered cubic structure (austenite) above 906 °C, and tin undergoes a modification known as tin pest from a metallic form to a semiconductor form below 13.2 °C (55.8 °F). As an example of allotropes having different chemical behaviour, ozone (O) is a much stronger oxidizing agent than dioxygen (O).
Allotropy | Differences in properties of an element's allotropes
Advances in technology have provided industrial oxygen generator systems for use where air is available and a higher concentration of oxygen is desired. Pressure swing adsorption (PSA) incorporates a material called molecular sieve for gas separation. In the case of oxygen generation a zeolite-based sieve forces preferential adsorption for nitrogen. Clean, dry air is passed through the sieve beds on the oxygen generator, producing an oxygen-enriched gas. Nitrogen separation membrane equipment is also used.
Chemical oxygen generator | Pressure swing adsorption (PSA) oxygen generators
They have been extensively studied in the gas phase, and sometimes dispersed in solid materials, but so far have not been produced in bulk or in solution. Nevertheless, they have attracted interest because of their stability and symmetry, a relatively low ionization potential, delayed ionization, and possibly interesting magnetic properties. Some authors suggest that they may eventually find applications in electronics and catalysis. The name is also used for the corresponding cations and anions .
Metallocarbohedryne | Introduction
Valves used in industrial hydrogen and oxygen applications, such as petrochemical processes, are often made of inconel.
Hydrogen valve | Material
Hexafluoropropylene oxide (HFPO) is an intermediate used in industrial organofluorine chemistry; specifically it is a monomer for fluoropolymers. This colourless gas is the epoxide of hexafluoropropylene, that is fluorinated analog of propylene oxide, HFPO is produced by DuPont and 3M and as a precursor to the lubricant Krytox and related materials. It is generated by oxidation of perfluoropropylene, e.g. with oxygen as well as other oxidants.
Hexafluoropropylene oxide | Introduction
Yttria-stabilized zirconia is used as a solid electrolyte in oxygen sensors in cars, generating voltage that depends on the ratio of oxygen and exhaust gas and providing electronic feedback to the fuel injector. Such sensors are also installed at many metallurgical and glass-making factories. Similar sensors of CO, chlorine and other gases based on solid silver halide electrolytes have been proposed in the 1980s–1990s. Since mid-1980s, a Li-based solid electrolyte is used to separate the electrochromic film (typically WO) and ion-storing film (typically LiCoO) in the smart glass, a window whose transparency is controlled by external voltage.
Solid state ionics | Applications
The NFPA 704 standard rates compressed oxygen gas as nonhazardous to health, nonflammable and nonreactive, but an oxidizer. Refrigerated liquid oxygen (LOX) is given a health hazard rating of 3 (for increased risk of hyperoxia from condensed vapors, and for hazards common to cryogenic liquids such as frostbite), and all other ratings are the same as the compressed gas form.
Oxygen | Safety and precautions
MOXIE collects from the Martian atmosphere, then electrochemically splits the molecules into and CO. A solid oxide electrolysis cell works on the principle that, at elevated temperatures, certain ceramic oxides, such as yttria-stabilized zirconia (YSZ) and doped ceria, become oxide ion (O) conductors. A thin nonporous disk of YSZ (solid electrolyte) is sandwiched between two porous electrodes. For oxygen generation from carbon dioxide, CO diffuses through the porous electrode (cathode) and reaches the vicinity of the electrode-electrolyte boundary. Through a combination of thermal dissociation and electrocatalysis, an oxygen atom is liberated from the molecule and picks up two electrons from the cathode to become an oxide ion (O).
Mars Oxygen ISRU Experiment | Principle
There are some theoretical indications that other nitrogen oligomers and polymers may be possible. If they could be synthesised, they may have potential applications as materials with a very high energy density, that could be used as powerful propellants or explosives. This is because they should all decompose to dinitrogen, whose N≡N triple bond (bond energy 946 kJ⋅mol) is much stronger than those of the N=N double bond (418 kJ⋅mol) or the N–N single bond (160 kJ⋅mol): indeed, the triple bond has more than thrice the energy of the single bond. (The opposite is true for the heavier pnictogens, which prefer polyatomic allotropes.) A great disadvantage is that most neutral polynitrogens are not expected to have a large barrier towards decomposition, and that the few exceptions would be even more challenging to synthesise than the long-sought but still unknown tetrahedrane.
Nitrogen | Allotropes
Animals especially but also fungi and bacteria ultimately depend upon photosynthesizing plants and phytoplankton for food and oxygen.
Period 2 element | Oxygen
It ignites spontaneously in air at about , and at much lower temperatures if finely divided. This combustion gives phosphorus (V) oxide: Because of this property, white phosphorus is used as a weapon.
Allotropes of phosphorus | Production and applications
A modern gas separation membrane used by GRASYS is no longer a flat plate, but is formed by hollow fibers. Membrane consists of a porous polymer fiber with the gas separation layer applied to its external surface. Structurally, a hollow fiber membrane is configured as a cylindrical cartridge representing a spool with specifically reeled polymer fiber.
Oxygen plant | Membrane cartridge
Very pure boron, for use in semiconductor industry, is produced by the decomposition of diborane at high temperatures, followed by purification via zone melting or the Czochralski process. Even more difficult to prepare are single crystals of pure boron phases, due to polymorphism and the tendency of boron to react with impurities; typical crystal size is ~0.1 mm.
Allotropes of boron | Introduction
The gas in a glovebox is pumped through a series of treatment devices which remove solvents, water and oxygen from the gas. Heated copper metal (or some other finely divided metal) is commonly used to remove oxygen, this oxygen removing column is normally regenerated by passing a hydrogen/nitrogen mixture through it while it is heated: the water formed is passed out of the box with the excess hydrogen and nitrogen. It is common to use molecular sieves to remove water by absorbing it in the molecular sieves' pores. Such a box is often used by organometallic chemists to transfer dry solids from one container to another container.
Glovebox | Inert atmosphere work