The Claus process is the most significant gas desulfurizing process, recovering elemental sulfur from gaseous hydrogen sulfide . First patented in 1883 by the chemist Carl Friedrich Claus , the Claus process has become the industry standard.
109-636: The multi-step Claus process recovers sulfur from the gaseous hydrogen sulfide found in raw natural gas and from the by-product gases containing hydrogen sulfide derived from refining crude oil and other industrial processes. The by-product gases mainly originate from physical and chemical gas treatment units ( Selexol , Rectisol , Purisol and amine scrubbers ) in refineries , natural gas processing plants and gasification or synthesis gas plants . These by-product gases may also contain hydrogen cyanide , hydrocarbons , sulfur dioxide or ammonia . Gases with an H 2 S content of over 25% are suitable for
218-569: A central muffle by the following chemical reaction: This is a strongly exothermic free-flame total oxidation of hydrogen sulfide generating sulfur dioxide that reacts away in subsequent reactions. The most important one is the Claus reaction: The overall equation is: The temperature inside Claus furnace is often maintained above 1050°C. This ensures BTEX (Benzene, Toluene, Ethyl benzene and Xylene) destruction which otherwise would clog downstream Claus catalyst. Gases containing ammonia, such as
327-465: A component of bad breath odor. Not all organic sulfur compounds smell unpleasant at all concentrations: the sulfur-containing monoterpenoid grapefruit mercaptan in small concentrations is the characteristic scent of grapefruit, but has a generic thiol odor at larger concentrations. Sulfur mustard , a potent vesicant , was used in World War ;I as a disabling agent. Sulfur–sulfur bonds are
436-476: A density 0.5539 times that of air (0.678 kg per standard cubic meter). In the early 1800s, natural gas became known as "natural" to distinguish it from the dominant gas fuel at the time, coal gas . Unlike coal gas, which is manufactured by heating coal, natural gas can be extracted from the ground in its native gaseous form. When the use of natural gas overtook the use of coal gas in English speaking countries in
545-572: A major industrial product, especially in automobile tires. Because of the heat and sulfur, the process was named vulcanization , after the Roman god of the forge and volcanism . Being abundantly available in native form, sulfur was known in ancient times and is referred to in the Torah ( Genesis ). English translations of the Christian Bible commonly referred to burning sulfur as "brimstone", giving rise to
654-477: A major source of natural gas in the United States and Canada. Because of increased shale gas production the United States was in 2014 the number one natural gas producer in the world. The production of shale gas in the United States has been described as a "shale gas revolution" and as "one of the landmark events in the 21st century." Following the increased production in the United States, shale gas exploration
763-426: A maximum of three times. Where an incineration or tail-gas treatment unit (TGTU) is added downstream of the Claus plant, only two catalytic stages are usually installed. The first process step in the catalytic stage is the gas heating process. It is necessary to prevent sulfur condensation in the catalyst bed, which can lead to catalyst fouling. The required bed operating temperature in the individual catalytic stages
872-416: A structural component used to stiffen rubber, similar to the disulfide bridges that rigidify proteins (see biological below). In the most common type of industrial "curing" or hardening and strengthening of natural rubber , elemental sulfur is heated with the rubber to the point that chemical reactions form disulfide bridges between isoprene units of the polymer. This process, patented in 1843, made rubber
981-538: A synthetic crude that can be further refined into finished products, while MTG can produce synthetic gasoline from natural gas. STG+ can produce drop-in gasoline, diesel, jet fuel and aromatic chemicals directly from natural gas via a single-loop process. In 2011, Royal Dutch Shell's 140,000 barrels (22,000 m ) per day F–T plant went into operation in Qatar . Natural gas can be "associated" (found in oil fields ), or "non-associated" (isolated in natural gas fields ), and
1090-433: A tracer in hydrologic studies. Differences in the natural abundances can be used in systems where there is sufficient variation in the S of ecosystem components. Rocky Mountain lakes thought to be dominated by atmospheric sources of sulfate have been found to have measurably different S values than lakes believed to be dominated by watershed sources of sulfate. The radioactive S is formed in cosmic ray spallation of
1199-503: A valuable material, is as a binder for concrete, the resulting product having many desirable properties (see sulfur concrete ). Natural gas Natural gas (also called fossil gas, methane gas , or simply gas ) is a naturally occurring mixture of gaseous hydrocarbons consisting primarily of methane (95%) in addition to various smaller amounts of other higher alkanes . Traces of carbon dioxide , nitrogen , hydrogen sulfide , and helium are also usually present. Methane
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#17328555216361308-566: Is a chemical element ; it has symbol S and atomic number 16. It is abundant , multivalent and nonmetallic . Under normal conditions , sulfur atoms form cyclic octatomic molecules with the chemical formula S 8 . Elemental sulfur is a bright yellow, crystalline solid at room temperature . Sulfur is the tenth most abundant element by mass in the universe and the fifth most common on Earth. Though sometimes found in pure, native form, sulfur on Earth usually occurs as sulfide and sulfate minerals . Being abundant in native form, sulfur
1417-465: Is a common reagent in organic synthesis . Bromine also oxidizes sulfur to form sulfur dibromide and disulfur dibromide . Sulfur oxidizes cyanide and sulfite to give thiocyanate and thiosulfate , respectively. Sulfur reacts with many metals. Electropositive metals give polysulfide salts. Copper, zinc, and silver are attacked by sulfur; see tarnishing . Although many metal sulfides are known, most are prepared by high temperature reactions of
1526-493: Is a flammable gaseous fuel made by the destructive distillation of coal . It contains a variety of calorific gases including hydrogen , carbon monoxide , methane , and other volatile hydrocarbons , together with small quantities of non-calorific gases such as carbon dioxide and nitrogen , and was used in a similar way to natural gas. This is a historical technology and is not usually economically competitive with other sources of fuel gas today. Most town "gashouses" located in
1635-458: Is a schematic block flow diagram of a typical natural gas processing plant. It shows the various unit processes used to convert raw natural gas into sales gas pipelined to the end user markets. The block flow diagram also shows how processing of the raw natural gas yields byproduct sulfur, byproduct ethane, and natural gas liquids (NGL) propane, butanes and natural gasoline (denoted as pentanes +). As of mid-2020, natural gas production in
1744-511: Is a soft, bright-yellow solid that is odorless. It melts at 115.21 °C (239.38 °F), and boils at 444.6 °C (832.3 °F). At 95.2 °C (203.4 °F), below its melting temperature, cyclo-octasulfur begins slowly changing from α-octasulfur to the β- polymorph . The structure of the S 8 ring is virtually unchanged by this phase transition, which affects the intermolecular interactions. Cooling molten sulfur freezes at 119.6 °C (247.3 °F), as it predominantly consists of
1853-599: Is about 2 g/cm , depending on the allotrope; all of the stable allotropes are excellent electrical insulators. Sulfur sublimes more or less between 20 °C (68 °F) and 50 °C (122 °F). Sulfur is insoluble in water but soluble in carbon disulfide and, to a lesser extent, in other nonpolar organic solvents, such as benzene and toluene . Under normal conditions, sulfur hydrolyzes very slowly to mainly form hydrogen sulfide and sulfuric acid : The reaction involves adsorption of protons onto S 8 clusters, followed by disproportionation into
1962-399: Is achieved by heating the process gas in a reheater until the desired operating bed temperature is reached. Several methods of reheating are used in industry: The typically recommended operating temperature of the first catalyst stage is 315 °C to 330 °C (bottom bed temperature). The high temperature in the first stage also helps to hydrolyze COS and CS 2 , which is formed in
2071-399: Is also found in coal beds (as coalbed methane ). It sometimes contains a significant amount of ethane , propane , butane , and pentane —heavier hydrocarbons removed for commercial use prior to the methane being sold as a consumer fuel or chemical plant feedstock. Non-hydrocarbons such as carbon dioxide , nitrogen , helium (rarely), and hydrogen sulfide must also be removed before
2180-484: Is an essential element for all life, almost always in the form of organosulfur compounds or metal sulfides. Amino acids (two proteinogenic : cysteine and methionine , and many other non-coded : cystine , taurine , etc.) and two vitamins ( biotin and thiamine ) are organosulfur compounds crucial for life. Many cofactors also contain sulfur, including glutathione , and iron–sulfur proteins . Disulfides , S–S bonds, confer mechanical strength and insolubility of
2289-616: Is beginning in countries such as Poland, China, and South Africa. Chinese geologists have identified the Sichuan Basin as a promising target for shale gas drilling, because of the similarity of shales to those that have proven productive in the United States. Production from the Wei-201 well is between 10,000 and 20,000 m per day. In late 2020, China National Petroleum Corporation claimed daily production of 20 million cubic meters of gas from its Changning-Weiyuan demonstration zone. Town gas
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#17328555216362398-556: Is colorless and odorless, and the second largest greenhouse gas contributor to global climate change after carbon dioxide. Because natural gas is odorless, odorizers such as mercaptan (which smells like rotten eggs ) are commonly added to it for safety so that leaks can be readily detected. Natural gas is a fossil fuel that is formed when layers of organic matter (primarily marine microorganisms) decompose under anaerobic conditions and are subjected to intense heat and pressure underground over millions of years. The energy that
2507-537: Is estimated to have 51,000 cubic kilometers (12,000 cu mi) of natural gas and 50 billion barrels (7.9 billion cubic meters) of natural gas condensates . Because natural gas is not a pure product, as the reservoir pressure drops when non-associated gas is extracted from a field under supercritical (pressure/temperature) conditions, the higher molecular weight components may partially condense upon isothermic depressurizing—an effect called retrograde condensation . The liquid thus formed may get trapped as
2616-417: Is explained by its production in the so-called alpha-process (one of the main classes of nuclear fusion reactions) in exploding stars. Other stable sulfur isotopes are produced in the bypass processes related with Ar, and their composition depends on a type of a stellar explosion. For example, proportionally more S comes from novae than from supernovae . On the planet Earth the sulfur isotopic composition
2725-694: Is heated and compressed deep underground. Methanogenic organisms produce methane from a variety of sources, principally carbon dioxide. During petroleum production, natural gas is sometimes flared rather than being collected and used. Before natural gas can be burned as a fuel or used in manufacturing processes, it almost always has to be processed to remove impurities such as water. The byproducts of this processing include ethane , propane , butanes , pentanes , and higher molecular weight hydrocarbons. Hydrogen sulfide (which may be converted into pure sulfur ), carbon dioxide , water vapor , and sometimes helium and nitrogen must also be removed. Natural gas
2834-464: Is higher than the melting point of sulfur. Native sulfur is synthesized by anaerobic bacteria acting on sulfate minerals such as gypsum in salt domes . Significant deposits in salt domes occur along the coast of the Gulf of Mexico , and in evaporites in eastern Europe and western Asia. Native sulfur may be produced by geological processes alone. Fossil-based sulfur deposits from salt domes were once
2943-573: Is mildly acidic: Hydrogen sulfide gas and the hydrosulfide anion are extremely toxic to mammals, due to their inhibition of the oxygen-carrying capacity of hemoglobin and certain cytochromes in a manner analogous to cyanide and azide (see below, under precautions ). The two principal sulfur oxides are obtained by burning sulfur: Many other sulfur oxides are observed including the sulfur-rich oxides include sulfur monoxide , disulfur monoxide , disulfur dioxides, and higher oxides containing peroxo groups. Sulfur reacts with fluorine to give
3052-403: Is natural gas produced from shale . Because shale's matrix permeability is too low to allow gas to flow in economical quantities, shale gas wells depend on fractures to allow the gas to flow. Early shale gas wells depended on natural fractures through which gas flowed; almost all shale gas wells today require fractures artificially created by hydraulic fracturing . Since 2000, shale gas has become
3161-406: Is often stored underground [references about geological storage needed]inside depleted gas reservoirs from previous gas wells, salt domes , or in tanks as liquefied natural gas. The gas is injected in a time of low demand and extracted when demand picks up. Storage nearby end users helps to meet volatile demands, but such storage may not always be practicable. With 15 countries accounting for 84% of
3270-452: Is preparing to export natural gas. Floating liquefied natural gas (FLNG) is an innovative technology designed to enable the development of offshore gas resources that would otherwise remain untapped due to environmental or economic factors which currently make them impractical to develop via a land-based LNG operation. FLNG technology also provides a number of environmental and economic advantages: Many gas and oil companies are considering
3379-545: Is primarily dependent on proximity to markets (pipelines), and regulatory restrictions. Natural gas can be indirectly exported through the absorption in other physical output. The expansion of shale gas production in the US has caused prices to drop relative to other countries. This has caused a boom in energy intensive manufacturing sector exports, whereby the average dollar unit of US manufacturing exports has almost tripled its energy content between 1996 and 2012. A "master gas system"
Claus process - Misplaced Pages Continue
3488-429: Is primarily used in the northern hemisphere. North America and Europe are major consumers. Often well head gases require removal of various hydrocarbon molecules contained within the gas. Some of these gases include heptane , pentane , propane and other hydrocarbons with molecular weights above methane ( CH 4 ). The natural gas transmission lines extend to the natural gas processing plant or unit which removes
3597-399: Is produced by rapid cooling of molten sulfur—for example, by pouring it into cold water. X-ray crystallography studies show that the amorphous form may have a helical structure with eight atoms per turn. The long coiled polymeric molecules make the brownish substance elastic , and in bulk it has the feel of crude rubber. This form is metastable at room temperature and gradually reverts to
3706-709: Is sometimes informally referred to simply as "gas", especially when it is being compared to other energy sources, such as oil, coal or renewables. However, it is not to be confused with gasoline , which is also shortened in colloquial usage to "gas", especially in North America. Natural gas is measured in standard cubic meters or standard cubic feet . The density compared to air ranges from 0.58 (16.8 g/mole, 0.71 kg per standard cubic meter) to as high as 0.79 (22.9 g/mole, 0.97 kg per scm), but generally less than 0.64 (18.5 g/mole, 0.78 kg per scm). For comparison, pure methane (16.0425 g/mole) has
3815-557: Is the 10th most common element in the universe . Sulfur, usually as sulfide, is present in many types of meteorites . Ordinary chondrites contain on average 2.1% sulfur, and carbonaceous chondrites may contain as much as 6.6%. It is normally present as troilite (FeS), but there are exceptions, with carbonaceous chondrites containing free sulfur, sulfates and other sulfur compounds. The distinctive colors of Jupiter 's volcanic moon Io are attributed to various forms of molten, solid, and gaseous sulfur. In July 2024, elemental sulfur
3924-610: Is the endothermic reaction of sulfur with H 2 S to polysulfanes H 2 S x . Huge amounts of elemental sulfur (billions of tons) are produced worldwide by the Claus process. The process has also to be applied to heavy petroleum extracted from oil sands deposits because sulfur accumulates in the heaviest fractions of hydrocarbons. Owing to the high sulfur content of the Athabasca Oil Sands , stockpiles of elemental sulfur from this process now exist throughout Alberta , Canada. Another way of storing sulfur, while reusing it as
4033-448: Is the production of sulfuric acid for sulfate and phosphate fertilizers , and other chemical processes. Sulfur is used in matches , insecticides , and fungicides . Many sulfur compounds are odoriferous, and the smells of odorized natural gas, skunk scent, bad breath , grapefruit , and garlic are due to organosulfur compounds. Hydrogen sulfide gives the characteristic odor to rotting eggs and other biological processes. Sulfur
4142-604: Is traded on a "dry gas" basis and is required to be commercially free from objectionable odours, materials, and dust or other solid or liquid matter, waxes, gums and gum forming constituents, which might damage or adversely affect operation of equipment downstream of the custody transfer point. LNG carrier ships transport liquefied natural gas (LNG) across oceans, while tank trucks can carry LNG or compressed natural gas (CNG) over shorter distances. Sea transport using CNG carrier ships that are now under development may be competitive with LNG transport in specific conditions. Gas
4251-409: Is transported at high pressure, typically above 200 bars (20,000 kPa; 2,900 psi). Compressors and decompression equipment are less capital intensive and may be economical in smaller unit sizes than liquefaction/regasification plants. Natural gas trucks and carriers may transport natural gas directly to end-users, or to distribution points such as pipelines. In the past, the natural gas which
4360-416: Is turned into liquid at a liquefaction plant, and is returned to gas form at regasification plant at the terminal . Shipborne regasification equipment is also used. LNG is the preferred form for long distance, high volume transportation of natural gas, whereas pipeline is preferred for transport for distances up to 4,000 km (2,500 mi) over land and approximately half that distance offshore. CNG
4469-408: Is used as a reagent to make the polymer rayon and many organosulfur compounds. Unlike carbon monoxide , carbon monosulfide is stable only as an extremely dilute gas, found between solar systems. Organosulfur compounds are responsible for some of the unpleasant odors of decaying organic matter. They are widely known as the odorant in domestic natural gas, garlic odor, and skunk spray, as well as
Claus process - Misplaced Pages Continue
4578-490: The Hershey-Chase experiment . Because of the weak beta activity of S, its compounds are relatively safe as long as they are not ingested or absorbed by the body. S is created inside massive stars, at a depth where the temperature exceeds 2.5×10 K, by the fusion of one nucleus of silicon plus one nucleus of helium. As this nuclear reaction is part of the alpha process that produces elements in abundance, sulfur
4687-649: The catalytic step with activated aluminum(III) or titanium(IV) oxide, and serves to boost the sulfur yield. More hydrogen sulfide ( H 2 S ) reacts with the SO 2 formed during combustion in the reaction furnace in the Claus reaction, and results in gaseous, elemental sulfur. One suggested mechanism is that S 6 and S 8 desorb from the catalyst's active sites with simultaneous formation of stable cyclic elemental sulfur. The catalytic recovery of sulfur consists of three substeps: heating, catalytic reaction and cooling plus condensation. These three steps are normally repeated
4796-408: The noble gases . Sulfur polycations, S 2+ 8 , S 2+ 4 and S 2+ 16 are produced when sulfur is reacted with oxidizing agents in a strongly acidic solution. The colored solutions produced by dissolving sulfur in oleum were first reported as early as 1804 by C. F. Bucholz, but the cause of the color and the structure of the polycations involved was only determined in
4905-473: The sulfate minerals , such as gypsum (calcium sulfate), alunite (potassium aluminium sulfate), and barite (barium sulfate). On Earth, just as upon Jupiter's moon Io, elemental sulfur occurs naturally in volcanic emissions, including emissions from hydrothermal vents . The main industrial source of sulfur has become petroleum and natural gas . Common oxidation states of sulfur range from −2 to +6. Sulfur forms stable compounds with all elements except
5014-427: The supply chain can result in natural gas having a similar carbon footprint to other fossil fuels overall. Natural gas can be found in underground geological formations , often alongside other fossil fuels like coal and oil (petroleum). Most natural gas has been created through either biogenic or thermogenic processes. Thermogenic gas takes a much longer period of time to form and is created when organic matter
5123-409: The (among others) protein keratin , found in outer skin, hair, and feathers. Sulfur is one of the core chemical elements needed for biochemical functioning and is an elemental macronutrient for all living organisms. Sulfur forms several polyatomic molecules. The best-known allotrope is octasulfur , cyclo-S 8 . The point group of cyclo-S 8 is D 4d and its dipole moment is 0 D. Octasulfur
5232-548: The 19th century, natural gas was primarily obtained as a by-product of producing oil . The small, light gas carbon chains came out of solution as the extracted fluids underwent pressure reduction from the reservoir to the surface, similar to uncapping a soft drink bottle where the carbon dioxide effervesces . The gas was often viewed as a by-product, a hazard, and a disposal problem in active oil fields. The large volumes produced could not be used until relatively expensive pipeline and storage facilities were constructed to deliver
5341-414: The 2010s, it was thought that sulfate reduction could fractionate sulfur isotopes up to 46 permil and fractionation larger than 46 permil recorded in sediments must be due to disproportionation of sulfur compounds in the sediment. This view has changed since the 2010s as experiments showed that sulfate-reducing bacteria can fractionate to 66 permil. As substrates for disproportionation are limited by
5450-406: The 20th century, it was increasingly referred to as simply "gas." In order to highlight its role in exacerbating the climate crisis , however, many organizations have criticized the continued use of the word "natural" in referring to the gas. These advocates prefer the term "fossil gas" or "methane gas" as better conveying to the public its climate threat. A 2020 study of Americans' perceptions of
5559-530: The 3rd century, the Chinese had discovered that sulfur could be extracted from pyrite . Chinese Daoists were interested in sulfur's flammability and its reactivity with certain metals, yet its earliest practical uses were found in traditional Chinese medicine . The Wujing Zongyao of 1044 AD described various formulas for Chinese black powder , which is a mixture of potassium nitrate ( KNO 3 ), charcoal , and sulfur. Indian alchemists, practitioners of
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#17328555216365668-452: The 64,000,000 tonnes of sulfur produced worldwide in 2005 was byproduct sulfur from refineries and other hydrocarbon processing plants. Sulfur is used for manufacturing sulfuric acid , medicine, cosmetics, fertilizers and rubber products. Elemental sulfur is used as fertilizer and pesticide. The process was invented by Carl Friedrich Claus , a German chemist working in England. A British patent
5777-480: The Claus reactor must be operated above the sulfur dew point (120–150 °C) to avoid liquid sulfur physically deactivating the catalyst. To overcome this problem, the sub dew point Clauss reactors are oriented in parallel, with one operating and one spare. When one reactor has become saturated with adsorbed sulfur, the process flow is diverted to the standby reactor. The reactor is then regenerated by sending process gas that has been heated to 300–350 °C to vaporize
5886-432: The US had peaked three times, with current levels exceeding both previous peaks. It reached 24.1 trillion cubic feet per year in 1973, followed by a decline, and reached 24.5 trillion cubic feet in 2001. After a brief drop, withdrawals increased nearly every year since 2006 (owing to the shale gas boom ), with 2017 production at 33.4 trillion cubic feet and 2019 production at 40.7 trillion cubic feet. After
5995-427: The US, over one-third of households (>40 million homes) cook with gas. Natural gas dispensed in a residential setting can generate temperatures in excess of 1,100 °C (2,000 °F) making it a powerful domestic cooking and heating fuel. Stanford scientists estimated that gas stoves emit 0.8–1.3% of the gas they use as unburned methane and that total U.S. stove emissions are 28.1 gigagrams of methane. In much of
6104-515: The United States begins with localized use. In the seventeenth century, French missionaries witnessed the American Indians setting fire to natural gas seeps around lake Erie, and scattered observations of these seeps were made by European-descended settlers throughout the eastern seaboard through the 1700s. In 1821, William Hart dug the first commercial natural gas well in the United States at Fredonia, New York , United States, which led in 1858 to
6213-494: The activity of sulfate-reducing bacteria in the time of formation of the sample, or suggest the main sources of sulfur in ecosystems. However, there are ongoing discussions over the real reason for the δ S shifts, biological activity or postdeposit alteration. For example, when sulfide minerals are precipitated, isotopic equilibration among solids and liquid may cause small differences in the δ S values of co-genetic minerals. The differences between minerals can be used to estimate
6322-436: The atmospheric Ar . This fact may be used to verify the presence of recent (up to 1 year) atmospheric sediments in various materials. This isotope may be obtained artificially by different ways. In practice, the reaction Cl + n → S + p is used by irradiating potassium chloride with neutrons. The isotope S is used in various sulfur-containing compounds as a radioactive tracer for many biological studies, for example,
6431-592: The basis for commercial production in the United States, Russia, Turkmenistan, and Ukraine. Such sources have become of secondary commercial importance, and most are no longer worked but commercial production is still carried out in the Osiek mine in Poland. Common naturally occurring sulfur compounds include the sulfide minerals , such as pyrite (iron sulfide), cinnabar (mercury sulfide), galena (lead sulfide), sphalerite (zinc sulfide), and stibnite (antimony sulfide); and
6540-697: The bottoms of the gashouse ovens was often used for roofing and other waterproofing purposes, and when mixed with sand and gravel was used for paving streets. Huge quantities of natural gas (primarily methane) exist in the form of clathrates under sediment on offshore continental shelves and on land in arctic regions that experience permafrost , such as those in Siberia . Hydrates require a combination of high pressure and low temperature to form. In 2013, Japan Oil, Gas and Metals National Corporation (JOGMEC) announced that they had recovered commercially relevant quantities of natural gas from methane hydrate. The image below
6649-501: The composition of reaction products. While reaction between sulfur and oxygen under normal conditions gives sulfur dioxide (oxidation state +4), formation of sulfur trioxide (oxidation state +6) requires a temperature of 400–600 °C (750–1,100 °F) and presence of a catalyst. In reactions with elements of lesser electronegativity , it reacts as an oxidant and forms sulfides, where it has oxidation state −2. Sulfur reacts with nearly all other elements except noble gases, even with
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#17328555216366758-451: The crystalline molecular allotrope, which is no longer elastic. This process happens over a matter of hours to days, but can be rapidly catalyzed. Sulfur has 23 known isotopes , four of which are stable: S ( 94.99% ± 0.26% ), S ( 0.75% ± 0.02% ), S ( 4.25% ± 0.24% ), and S ( 0.01% ± 0.01% ). Other than S, with a half-life of 87 days, the radioactive isotopes of sulfur have half-lives less than 3 hours. The preponderance of S
6867-654: The decayed organisms originally obtained from the sun via photosynthesis is stored as chemical energy within the molecules of methane and other hydrocarbons. Natural gas can be burned for heating, cooking, and electricity generation . Consisting mainly of methane, natural gas is rarely used as a chemical feedstock . The extraction and consumption of natural gas is a major industry. When burned for heat or electricity , natural gas emits fewer toxic air pollutants, less carbon dioxide, and almost no particulate matter compared to other fossil and biomass fuels. However, gas venting and unintended fugitive emissions throughout
6976-535: The developed world it is supplied through pipes to homes, where it is used for many purposes including ranges and ovens, heating / cooling , outdoor and portable grills , and central heating . Heaters in homes and other buildings may include boilers, furnaces , and water heaters . Both North America and Europe are major consumers of natural gas. Sulfur This is an accepted version of this page Sulfur (also spelled sulphur in British English )
7085-446: The eastern US in the late 19th and early 20th centuries were simple by-product coke ovens that heated bituminous coal in air-tight chambers. The gas driven off from the coal was collected and distributed through networks of pipes to residences and other buildings where it was used for cooking and lighting. (Gas heating did not come into widespread use until the last half of the 20th century.) The coal tar (or asphalt ) that collected in
7194-446: The economic and environmental benefits of floating liquefied natural gas (FLNG). There are currently projects underway to construct five FLNG facilities. Petronas is close to completion on their FLNG-1 at Daewoo Shipbuilding and Marine Engineering and are underway on their FLNG-2 project at Samsung Heavy Industries . Shell Prelude is due to start production 2017. The Browse LNG project will commence FEED in 2019. Natural gas
7303-464: The elements. Geoscientists also study the isotopes of metal sulfides in rocks and sediment to study environmental conditions in the Earth's past. Some of the main classes of sulfur-containing organic compounds include the following: Compounds with carbon–sulfur multiple bonds are uncommon, an exception being carbon disulfide , a volatile colorless liquid that is structurally similar to carbon dioxide. It
7412-415: The formation of polymeric sulfur chains. Another anomaly is found in the solubility of residual H 2 S in liquid sulfur as a function of temperature. Ordinarily, the solubility of a gas increases with increasing temperature but with H 2 S it is the opposite. This means that toxic and explosive H 2 S gas can build up in the headspace of any cooling liquid sulfur reservoir. The explanation for this anomaly
7521-486: The formation of the Fredonia Gas Light Company . Further such ventures followed near wells in other states, until technological innovations allowed the growth of major long distance pipelines from the 1920s onward. By 2009, 66,000 km (16,000 cu mi) (or 8%) had been used out of the total 850,000 km (200,000 cu mi) of estimated remaining recoverable reserves of natural gas. In
7630-461: The fuel found that, across political identifications, the term "methane gas" led to better estimates of its harms and risks. Natural gas can come out of the ground and cause a long-burning fire. In ancient Greece , the gas flames at Mount Chimaera contributed to the legend of the fire-breathing creature Chimera . In ancient China , gas resulting from the drilling for brines was first used by about 400 BC. The Chinese transported gas seeping from
7739-411: The furnace and would not otherwise be converted in the modified Claus process. The catalytic conversion is maximized at lower temperatures, but care must be taken to ensure that each bed is operated above the dew point of sulfur. The operating temperatures of the subsequent catalytic stages are typically 240 °C for the second stage and 200 °C for the third stage (bottom bed temperatures). In
7848-402: The gas from the refinery's sour water stripper (SWS), or hydrocarbons are converted in the burner muffle. Sufficient air is injected into the muffle for the complete combustion of all hydrocarbons and ammonia. The air to the acid gas ratio is controlled such that in total 1/3 of all hydrogen sulfide (H 2 S) is converted to SO 2 . This ensures a stoichiometric reaction for the Claus reaction in
7957-435: The gas needs to be cooled down and compressed, as the friction in the pipeline causes the gas to heat up. Many existing pipelines in the US are close to reaching their capacity, prompting some politicians representing northern states to speak of potential shortages. The large trade cost implies that natural gas markets are globally much less integrated, causing significant price differences across countries. In Western Europe ,
8066-512: The gas pipeline network is already dense. New pipelines are planned or under construction between Western Europe and the Near East or Northern Africa . Whenever gas is bought or sold at custody transfer points, rules and agreements are made regarding the gas quality. These may include the maximum allowable concentration of CO 2 , H 2 S and H 2 O . Usually sales quality gas that has been treated to remove contamination
8175-896: The gas to consumer markets. Until the early part of the 20th century, most natural gas associated with oil was either simply released or burned off at oil fields. Gas venting and production flaring are still practised in modern times, but efforts are ongoing around the world to retire them, and to replace them with other commercially viable and useful alternatives. In addition to transporting gas via pipelines for use in power generation, other end uses for natural gas include export as liquefied natural gas (LNG) or conversion of natural gas into other liquid products via gas to liquids (GTL) technologies. GTL technologies can convert natural gas into liquids products such as gasoline, diesel or jet fuel. A variety of GTL technologies have been developed, including Fischer–Tropsch (F–T), methanol to gasoline (MTG) and syngas to gasoline plus (STG+). F–T produces
8284-518: The ground in crude pipelines of bamboo to where it was used to boil salt water to extract the salt in the Ziliujing District of Sichuan . Natural gas was not widely used before the development of long distance pipelines in the early twentieth century. Before that, most use was near to the source of the well, and the predominant gas for fuel and lighting during the industrial revolution was manufactured coal gas. The history of natural gas in
8393-442: The higher-molecular weight hydrocarbons to produce natural gas with energy content between 35–39 megajoules per cubic metre (950–1,050 British thermal units per cubic foot). The processed natural gas may then be used for residential, commercial and industrial uses. Natural gas flowing in the distribution lines is called mid-stream natural gas and is often used to power engines which rotate compressors. These compressors are required in
8502-406: The highly reactive sulfur tetrafluoride and the highly inert sulfur hexafluoride . Whereas fluorine gives S(IV) and S(VI) compounds, chlorine gives S(II) and S(I) derivatives. Thus, sulfur dichloride , disulfur dichloride , and higher chlorosulfanes arise from the chlorination of sulfur. Sulfuryl chloride and chlorosulfuric acid are derivatives of sulfuric acid; thionyl chloride (SOCl 2 )
8611-484: The largest documented single crystal measuring 22 cm × 16 cm × 11 cm (8.7 in × 6.3 in × 4.3 in). Historically, Sicily was a major source of sulfur in the Industrial Revolution . Lakes of molten sulfur up to about 200 m (660 ft) in diameter have been found on the sea floor, associated with submarine volcanoes , at depths where the boiling point of water
8720-594: The largest proven gas reserves. Sources that consider that Russia has by far the largest proven reserves include the US Central Intelligence Agency (47,600 km ) and Energy Information Administration (47,800 km ), as well as the Organization of Petroleum Exporting Countries (48,700 km ). Contrarily, BP credits Russia with only 32,900 km , which would place it in second, slightly behind Iran (33,100 to 33,800 km , depending on
8829-415: The late 1960s. S 2+ 8 is deep blue, S 2+ 4 is yellow and S 2+ 16 is red. Reduction of sulfur gives various polysulfides with the formula S x , many of which have been obtained in crystalline form. Illustrative is the production of sodium tetrasulfide : Some of these dianions dissociate to give radical anions , such as S − 3 gives the blue color of
8938-433: The natural gas can be transported. Natural gas extracted from oil wells is called casinghead gas (whether or not truly produced up the annulus and through a casinghead outlet) or associated gas. The natural gas industry is extracting an increasing quantity of gas from challenging, unconventional resource types : sour gas , tight gas , shale gas , and coalbed methane . There is some disagreement on which country has
9047-573: The notoriously unreactive metal iridium (yielding iridium disulfide ). Some of those reactions require elevated temperatures. Sulfur forms over 30 solid allotropes , more than any other element. Besides S 8 , several other rings are known. Removing one atom from the crown gives S 7 , which is of a deeper yellow than S 8 . HPLC analysis of "elemental sulfur" reveals an equilibrium mixture of mainly S 8 , but with S 7 and small amounts of S 6 . Larger rings have been prepared, including S 12 and S 18 . Amorphous or "plastic" sulfur
9156-441: The pores of the gas reservoir get depleted. One method to deal with this problem is to re-inject dried gas free of condensate to maintain the underground pressure and to allow re-evaporation and extraction of condensates. More frequently, the liquid condenses at the surface, and one of the tasks of the gas plant is to collect this condensate. The resulting liquid is called natural gas liquid (NGL) and has commercial value. Shale gas
9265-446: The process gas and the condensation heat evolved are utilized to produce medium or low-pressure steam . The condensed sulfur is removed at the liquid outlet section of the process gas cooler. The sulfur forms in the thermal phase as highly reactive S 2 diradicals which combine exclusively to the S 8 allotrope : Other chemical processes taking place in the thermal step of the Claus reaction are: The Claus reaction continues in
9374-407: The product of sulfate reduction , the isotopic effect of disproportionation should be less than 16 permil in most sedimentary settings. In forest ecosystems, sulfate is derived mostly from the atmosphere; weathering of ore minerals and evaporites contribute some sulfur. Sulfur with a distinctive isotopic composition has been used to identify pollution sources, and enriched sulfur has been added as
9483-420: The reaction products. The second, fourth and sixth ionization energies of sulfur are 2252 kJ/mol, 4556 kJ/mol and 8495.8 kJ/mol, respectively. The composition of reaction products of sulfur with oxidants (and its oxidation state) depends on whether releasing of reaction energy overcomes these thresholds. Applying catalysts and/or supply of external energy may vary sulfur's oxidation state and
9592-401: The recovery of sulfur in straight-through Claus plants while alternate configurations such as a split-flow set up or feed and air preheating can be used to process leaner feeds. Hydrogen sulfide produced, for example, in the hydro-desulfurization of refinery naphthas and other petroleum oils, is converted to sulfur in Claus plants. The reaction proceeds in two steps: The vast majority of
9701-509: The rock lapis lazuli . This reaction highlights a distinctive property of sulfur: its ability to catenate (bind to itself by formation of chains). Protonation of these polysulfide anions produces the polysulfanes , H 2 S x , where x = 2, 3, and 4. Ultimately, reduction of sulfur produces sulfide salts: The interconversion of these species is exploited in the sodium–sulfur battery . Treatment of sulfur with hydrogen gives hydrogen sulfide . When dissolved in water, hydrogen sulfide
9810-457: The second catalytic step (see next section below). The separation of the combustion processes ensures an accurate dosage of the required air volume needed as a function of the feed gas composition. To reduce the process gas volume or obtain higher combustion temperatures, the air requirement can also be covered by injecting pure oxygen. Several technologies utilizing high-level and low-level oxygen enrichment are available in industry, which requires
9919-543: The source). It is estimated that there are about 900,000 km of "unconventional" gas such as shale gas, of which 180,000 km may be recoverable. In turn, many studies from MIT , Black & Veatch and the US Department of Energy predict that natural gas will account for a larger portion of electricity generation and heat in the future. The world's largest gas field is the offshore South Pars / North Dome Gas-Condensate field , shared between Iran and Qatar. It
10028-488: The sulfur are removed. The tail gas from the Claus process still containing combustible components and sulfur compounds (H 2 S, H 2 and CO) is either burned in an incineration unit or further desulfurized in a downstream tail gas treatment unit. The conventional Claus process described above is limited in its conversion due to the reaction equilibrium being reached. Like all exothermic reactions, greater conversion can be achieved at lower temperatures, however as mentioned
10137-407: The sulfur condenser, the process gas coming from the catalytic reactor is cooled to between 150 and 130 °C. The condensation heat is used to generate steam at the shell side of the condenser. Before storage, liquid sulfur streams from the process gas cooler, the sulfur condensers and from the final sulfur separator are routed to the degassing unit, where the gases (primarily H 2 S) dissolved in
10246-442: The sulfur. This stream is sent to a condenser to recover the sulfur. Over 2.6 tons of steam will be generated for each ton of sulfur yield. The physical properties of elemental sulfur obtained in the Claus process can differ from that obtained by other processes. Sulfur is usually transported as a liquid ( melting point 115 °C). In elemental sulfur, viscosity increases rapidly at temperatures in excess of 160 °C due to
10355-465: The temperature of equilibration. The δ C and δ S of coexisting carbonate minerals and sulfides can be used to determine the pH and oxygen fugacity of the ore-bearing fluid during ore formation. Scientists measure the sulfur isotopes of minerals in rocks and sediments to study the redox conditions in past oceans. Sulfate-reducing bacteria in marine sediment fractionate sulfur isotopes as they take in sulfate and produce sulfide . Prior to
10464-505: The term " fire-and-brimstone " sermons , in which listeners are reminded of the fate of eternal damnation that await the unbelieving and unrepentant. It is from this part of the Bible that Hell is implied to "smell of sulfur" (likely due to its association with volcanic activity). According to the Ebers Papyrus , a sulfur ointment was used in ancient Egypt to treat granular eyelids. Sulfur
10573-471: The thermal step, hydrogen sulfide-laden gas reacts in a substoichiometric combustion at temperatures above 850 °C such that elemental sulfur precipitates in the downstream process gas cooler. The H 2 S content and the concentration of other combustible components ( hydrocarbons or ammonia ) determine the location where the feed gas is burned. Claus gases (acid gas) with no further combustible contents apart from H 2 S are burned in lances surrounding
10682-640: The third peak in December 2019, extraction continued to fall from March onward due to decreased demand caused by the COVID-19 pandemic in the US . The 2021 global energy crisis was driven by a global surge in demand as the world quit the economic recession caused by COVID-19, particularly due to strong energy demand in Asia. Because of its low density, it is not easy to store natural gas or to transport it by vehicle. Natural gas pipelines are impractical across oceans, since
10791-412: The transmission line to pressurize and repressurize the mid-stream natural gas as the gas travels. Typically, natural gas powered engines require 35–39 MJ/m (950–1,050 BTU/cu ft) natural gas to operate at the rotational name plate specifications. Several methods are used to remove these higher molecular weighted gases for use by the natural gas engine. A few technologies are as follows: In
10900-418: The use of a special burner in the reaction furnace for this process option. Usually, 60 to 70% of the total amount of elemental sulfur produced in the process is obtained in the thermal process step. The main portion of the hot gas from the combustion chamber flows through the tube of the process gas cooler and is cooled down such that the sulfur formed in the reaction step condenses . The heat given off by
11009-498: The worldwide extraction, access to natural gas has become an important issue in international politics, and countries vie for control of pipelines. In the first decade of the 21st century, Gazprom , the state-owned energy company in Russia, engaged in disputes with Ukraine and Belarus over the price of natural gas, which have created concerns that gas deliveries to parts of Europe could be cut off for political reasons. The United States
11118-419: The β-S 8 molecules. Between its melting and boiling temperatures, octasulfur changes its allotrope again, turning from β-octasulfur to γ-sulfur, again accompanied by a lower density but increased viscosity due to the formation of polymers . At higher temperatures, the viscosity decreases as depolymerization occurs. Molten sulfur assumes a dark red color above 200 °C (392 °F). The density of sulfur
11227-615: Was accidentally discovered to exist on Mars after the Curiosity rover drove over and crushed a rock, revealing sulfur crystals inside it. Sulfur is the fifth most common element by mass in the Earth. Elemental sulfur can be found near hot springs and volcanic regions in many parts of the world, especially along the Pacific Ring of Fire ; such volcanic deposits are mined in Indonesia, Chile, and Japan. These deposits are polycrystalline, with
11336-549: Was determined by the Sun. Though it was assumed that the distribution of different sulfur isotopes would be more or less equal, it has been found that proportions of the two most abundant sulfur isotopes S and S varies in different samples. Assaying of the isotope ratio ( δ S ) in the samples suggests their chemical history, and with support of other methods, it allows to age-date the samples, estimate temperature of equilibrium between ore and water, determine pH and oxygen fugacity , identify
11445-488: Was invented in Saudi Arabia in the late 1970s, ending any necessity for flaring. Satellite and nearby infra-red camera observations, however, shows that flaring and venting are still happening in some countries. Natural gas is used to generate electricity and heat for desalination . Similarly, some landfills that also discharge methane gases have been set up to capture the methane and generate electricity. Natural gas
11554-767: Was issued to him in 1883. The process was later significantly modified by IG Farben . Claus was born in Kassel in the German State of Hesse in 1827, and studied chemistry in Marburg before he emigrated to England in 1852. He died in London in 1900. His grave is in Margravine Cemetery, Hammersmith. A schematic process flow diagram of a basic 2+1-reactor (converter) SuperClaus unit is shown below: The Claus technology can be divided into two process steps, thermal and catalytic . In
11663-400: Was known in ancient times, being mentioned for its uses in ancient India , ancient Greece , China , and ancient Egypt . Historically and in literature sulfur is also called brimstone , which means "burning stone". Almost all elemental sulfur is produced as a byproduct of removing sulfur-containing contaminants from natural gas and petroleum . The greatest commercial use of the element
11772-567: Was recovered in the course of recovering petroleum could not be profitably sold, and was simply burned at the oil field in a process known as flaring . Flaring is now illegal in many countries. Additionally, higher demand in the last 20–30 years has made production of gas associated with oil economically viable. As a further option, the gas is now sometimes re- injected into the formation for enhanced oil recovery by pressure maintenance as well as miscible or immiscible flooding. Conservation, re-injection, or flaring of natural gas associated with oil
11881-622: Was used for fumigation in preclassical Greece ; this is mentioned in the Odyssey . Pliny the Elder discusses sulfur in book 35 of his Natural History , saying that its best-known source is the island of Melos . He mentions its use for fumigation, medicine, and bleaching cloth. A natural form of sulfur known as shiliuhuang ( 石硫黄 ) was known in China since the 6th century BC and found in Hanzhong . By
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