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70-552: Partial oxidation is a technically mature process in which natural gas or a heavy hydrocarbon fuel ( heating oil ) is mixed with a limited amount of oxygen in an exothermic process. The formulas given for coal and heating oil show only a typical representative of these complex fuels. Water may be added to lower the combustion temperature and reduce soot formation. Yields are below stoichiometric due to some fuel being fully combusted to carbon dioxide and water. TPOX ( thermal partial oxidation ) reaction temperatures are dependent on

140-416: A depropanizer, a debutanizer and a butane splitter . The fractionation train typically uses a cryogenic low temperature distillation process involving expansion of the recovered NGL through a turbo-expander followed by distillation in a demethanizing fractionating column . Some gas processing plants use lean oil absorption process rather than the cryogenic turbo-expander process. The gaseous feed to

210-410: A refinery . Fractionation aims to produce useful products including natural gas suitable for piping to industrial and domestic consumers; liquefied petroleum gases (Propane and Butane) for sale; and gasoline feedstock for liquid fuel blending. The recovered NGL stream is processed through a fractionation train consisting of up to five distillation towers in series: a demethanizer , a deethanizer ,

280-481: 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

350-424: A function of a pipeline system's design and the markets that it serves. In general, the standards specify that the natural gas: January February March November October September August The natural gas should: There are a variety of ways in which to configure the various unit processes used in the treatment of raw natural gas. The block flow diagram below is a generalized, typical configuration for

420-484: 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

490-406: A range of performance and environmental constraints of the amine process, a newer technology based on the use of polymeric membranes to separate the carbon dioxide and hydrogen sulfide from the natural gas stream has gained increasing acceptance. Membranes are attractive since no reagents are consumed. The acid gases, if present, are removed by membrane or amine treating and can then be routed into

560-588: A sulfur recovery unit which converts the hydrogen sulfide in the acid gas into either elemental sulfur or sulfuric acid. Of the processes available for these conversions, the Claus process is by far the most well known for recovering elemental sulfur, whereas the conventional Contact process and the WSA ( Wet sulfuric acid process ) are the most used technologies for recovering sulfuric acid . Smaller quantities of acid gas may be disposed of by flaring. The residual gas from

630-542: 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

700-420: Is NGL at 20 barg which is fed to the deethanizer.   The overhead product from the deethanizer is ethane and the bottoms are fed to the depropanizer. The overhead product from the depropanizer is propane and the bottoms are fed to the debutanizer. The overhead product from the debutanizer is a mixture of normal and iso-butane, and the bottoms product is a C 5 + gasoline mixture. The operating conditions of

770-493: 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

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840-828: Is a range of industrial processes designed to purify raw natural gas by removing contaminants such as solids, water , carbon dioxide ( CO 2 ), hydrogen sulfide (H 2 S), mercury and higher molecular mass hydrocarbons ( condensate ) to produce pipeline quality dry natural gas for pipeline distribution and final use. Some of the substances which contaminate natural gas have economic value and are further processed or sold. Hydrocarbons that are liquid at ambient conditions: temperature and pressure (i.e., pentane and heavier) are called natural-gas condensate (sometimes also called natural gasoline or simply condensate ). Raw natural gas comes primarily from three types of wells: crude oil wells , gas wells, and condensate wells . Crude oil and natural gas are often found together in

910-458: 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

980-399: 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

1050-628: 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

1120-427: Is called acid gas . Raw natural gas typically consists primarily of methane (CH 4 ) and ethane (C 2 H 6 ), the shortest and lightest hydrocarbon molecules. It often also contains varying amounts of: Raw natural gas must be purified to meet the quality standards specified by the major pipeline transmission and distribution companies. Those quality standards vary from pipeline to pipeline and are usually

1190-556: 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

1260-537: 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

1330-694: 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

1400-403: 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

1470-406: 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

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1540-452: 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

1610-548: 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"

1680-429: 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

1750-716: 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

1820-417: Is then removed by using adsorption processes (as shown in the flow diagram) such as activated carbon or regenerable molecular sieves . Although not common, nitrogen is sometimes removed and rejected using one of the three processes indicated on the flow diagram: The NGL fractionation process treats offgas from the separators at an oil terminal or the overhead fraction from a crude distillation column in

1890-604: 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

1960-409: 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

2030-416: 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

2100-428: Is usually then transported to an oil refinery and the water is treated and disposed of as wastewater. The raw gas is then piped to a gas processing plant where the initial purification is usually the removal of acid gases (hydrogen sulfide and carbon dioxide). There are several processes available for that purpose as shown in the flow diagram, but amine treating is the process that was historically used. However, due to

2170-416: The air-fuel ratio or oxygen-fuel ratio. Typical reaction temperatures are 1200 °C and above. In CPOX ( catalytic partial oxidation ) the use of a catalyst reduces the required temperature to around 800°C – 900°C. The choice of reforming technique depends on the sulfur content of the fuel being used. CPOX can be employed if the sulfur content is below 50 ppm . A higher sulfur content can poison

Partial oxidation - Misplaced Pages Continue

2240-427: 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

2310-548: 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

2380-406: 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

2450-490: The Claus process is commonly called tail gas and that gas is then processed in a tail gas treating unit (TGTU) to recover and recycle residual sulfur-containing compounds back into the Claus unit. Again, as shown in the flow diagram, there are a number of processes available for treating the Claus unit tail gas and for that purpose a WSA process is also very suitable since it can work autothermally on tail gases. The next step in

2520-449: The NGL fractionation plant is typically compressed to about 60 barg and 37 °C. The feed is cooled to -22 °C, by exchange with the demethanizer overhead product and by a refrigeration system and is split into three streams: The overhead product is mainly methane at 20 bar and -98 °C. This is heated and compressed to yield a sales gas at 20 bar and 40 °C. The bottom product

2590-429: The NGL stream is instead transported as a mixed product to standalone fractionation complexes located near refineries or chemical plants that use the components for feedstock . In case laying pipeline is not possible for geographical reason, or the distance between source and consumer exceed 3000 km, natural gas is then transported by ship as LNG ( liquefied natural gas ) and again converted into its gaseous state in

2660-432: 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

2730-427: 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

2800-523: 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

2870-702: 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

Partial oxidation - Misplaced Pages Continue

2940-540: The buyers equipment. When an upset occurs on the treatment plant buyers can usually refuse to accept the gas, lower the flow rate or re-negotiate the price. If the gas has significant helium content, the helium may be recovered by fractional distillation . Natural gas may contain as much as 7% helium, and is the commercial source of the noble gas. For instance, the Hugoton Gas Field in Kansas and Oklahoma in

3010-716: The catalyst, so the TPOX procedure is used for such fuels. However, recent research shows that CPOX is possible with sulfur contents up to 400ppm. 1926 – Vandeveer and Parr at the University of Illinois used oxygen to replace air. 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

3080-429: The composition of natural gas according to the type, depth, and location of the underground deposit and the geology of the area. Natural gas when relatively free of hydrogen sulfide is called sweet gas ; natural gas that contains elevated hydrogen sulfide levels is called sour gas ; natural gas, or any other gas mixture, containing significant quantities of hydrogen sulfide or carbon dioxide or similar acidic gases,

3150-654: 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

3220-412: 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. Natural gas processing Natural-gas processing

3290-401: The dry gas directly to a pipeline or gas plant without undergoing any separation processIng allowing immediate use . Natural-gas processing begins underground or at the well-head. In a crude oil well, natural gas processing begins as the fluid loses pressure and flows through the reservoir rocks until it reaches the well tubing. In other wells, processing begins at the wellhead which extracts

3360-446: 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

3430-446: 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

3500-497: 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

3570-461: 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

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3640-435: 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 ,

3710-517: 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

3780-404: The gas processing plant is to remove water vapor from the gas using either the regenerable absorption in liquid triethylene glycol (TEG), commonly referred to as glycol dehydration , deliquescent chloride desiccants, and or a Pressure Swing Adsorption (PSA) unit which is regenerable adsorption using a solid adsorbent. Other newer processes like membranes may also be considered. Mercury

3850-896: 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

3920-526: 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

3990-442: 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

4060-612: 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

4130-433: 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

4200-441: 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

4270-400: The processing of raw natural gas from non-associated gas wells showing how raw natural gas is processed into sales gas piped to the end user markets. and various byproducts: Raw natural gas is commonly collected from a group of adjacent wells and is first processed in a separator vessels at that collection point for removal of free liquid water and natural gas condensate . The condensate

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4340-444: The same reservoir. Natural gas produced in wells with crude oil is generally classified as associated-dissolved gas as the gas had been associated with or dissolved in crude oil . Natural gas production not associated with crude oil is classified as “non-associated.” In 2009, 89 percent of U.S. wellhead production of natural gas was non-associated. Non-associated gas wells producing a dry gas in terms of condensate and water can send

4410-550: 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

4480-654: 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

4550-412: 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

4620-475: The vessels in the NGL fractionation train are typically as follows. A typical composition of the feed and product is as follows. The recovered streams of propane, butanes and C 5 + may be "sweetened" in a Merox process unit to convert undesirable mercaptans into disulfides and, along with the recovered ethane, are the final NGL by-products from the gas processing plant. Currently, most cryogenic plants do not include fractionation for economic reasons, and

4690-563: The vicinity of the consumer. The residue gas from the NGL recovery section is the final, purified sales gas which is pipelined to the end-user markets. Rules and agreements are made between buyer and seller regarding the quality of the gas. These usually specify the maximum allowable concentration of CO 2 , H 2 S and H 2 O as well as requiring the gas to be commercially free from objectionable odours and materials, and dust or other solid or liquid matter, waxes, gums and gum forming constituents, which might damage or adversely affect operation of

4760-502: 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

4830-494: 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

4900-567: 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

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