78-471: LPG may refer to: Science [ edit ] Liquefied petroleum gas , a flammable mixture of hydrocarbon gases Lipophosphoglycan , a class of molecule found on the surface of some eukaryotes, in particular protozoa Music groups [ edit ] La Perdita Generacio , a Swedish alternative rock band that sings in Esperanto LPG (Dutch band) ,
156-459: A boiling liquid expanding vapor explosion (BLEVE). This is typically a concern for large refineries and petrochemical plants that maintain very large containers. In general, tanks are designed so that the product will vent faster than pressure can build to dangerous levels. One remedy that is utilized in industrial settings is to equip such containers with a measure to provide a fire-resistance rating . Large, spherical LPG containers may have up to
234-454: A gas absorption refrigerator . Blended from pure, dry propane (refrigerant designator R-290 ) and isobutane (R-600a) the blend "R-290a" has negligible ozone depletion potential , very low global warming potential and can serve as a functional replacement for R-12 , R-22 , R-134a and other chlorofluorocarbon or hydrofluorocarbon refrigerants in conventional stationary refrigeration and air conditioning systems. Such substitution
312-648: A greenhouse gas . The reaction also produces some carbon monoxide . LPG does, however, release less CO 2 per unit of energy than does coal or oil, but more than natural gas. It emits 81% of the CO 2 per kWh produced by oil, 70% of that of coal, and less than 50% of that emitted by coal-generated electricity distributed via the grid. Being a mix of propane and butane, LPG emits less carbon per joule than butane but more carbon per joule than propane. LPG burns more cleanly than higher molecular weight hydrocarbons because it releases less particulate matter . As it
390-432: A 15 cm steel wall thickness. They are equipped with an approved pressure relief valve . A large fire in the vicinity of the vessel will increase its temperature and pressure . The relief valve on the top is designed to vent off excess pressure in order to prevent the rupture of the container itself. Given a fire of sufficient duration and intensity, the pressure being generated by the boiling and expanding gas can exceed
468-481: A Dutch indie-pop band LPG (South Korean group) (Lovely Pretty Girls), South Korean girl group that debuted in 2005 LPG (American band) , an American Christian hip-hop group Other uses [ edit ] Landwirtschaftliche Produktionsgenossenschaft (Agricultural Production Cooperative), the official designation for large, collectivised farms in former East Germany Llanfairpwll railway station (National Rail station code), Wales Lycée Paul-Gauguin ,
546-424: A lower energy density per liter than either petrol or fuel-oil, so the equivalent fuel consumption is higher. Many governments impose less tax on LPG than on petrol or fuel-oil, which helps offset the greater consumption of LPG than of petrol or fuel-oil. However, in many European countries, this tax break is often compensated by a much higher annual tax on cars using LPG than on cars using petrol or fuel-oil. Propane
624-422: A molecule of O 2 and an individual atom of oxygen, a continuing process called the ozone–oxygen cycle . Chemically, this can be described as: About 90 percent of the ozone in the atmosphere is contained in the stratosphere. Ozone concentrations are greatest between about 20 and 40 kilometres (66,000 and 131,000 ft), where they range from about 2 to 8 parts per million. If all of the ozone were compressed to
702-426: A negative impact on the ozone layer, so they are also being phased out. These in turn are being replaced by hydrofluorocarbons (HFCs) and other compounds that do not destroy stratospheric ozone at all. The residual effects of CFCs accumulating within the atmosphere lead to a concentration gradient between the atmosphere and the ocean. This organohalogen compound is able to dissolve into the ocean's surface waters and
780-553: A politically sensitive matter in India as it potentially affects the middle class voting pattern. LPG was once a standard cooking fuel in Hong Kong ; however, the continued expansion of town gas to newer buildings has reduced LPG usage to less than 24% of residential units. However, other than electric, induction, or infrared stoves, LPG-fueled stoves are the only type available in most suburban villages and many public housing estates. LPG
858-619: A professor at the University of New South Wales , unintentionally tested the worst-case scenario of a sudden and complete refrigerant expulsion into the passenger compartment followed by subsequent ignition. He and several others in the car sustained minor burns to their face, ears, and hands, and several observers received lacerations from the burst glass of the front passenger window. No one was seriously injured. Global LPG production reached over 292 million metric tons per year (Mt/a) in 2015, while global LPG consumption to over 284 Mt/a. 62% of LPG
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#1732848728211936-597: A secondary school in Papeete, Tahiti Liberal Party of Gibraltar , a political party in Gibraltar Leisure Pass Group, the former name for the travel company Go City Labeled property graphs , a widely used graph data model See also [ edit ] Local Land and Property Gazetteer (LLPG) National Land and Property Gazetteer (NLPG) Topics referred to by the same term [REDACTED] This disambiguation page lists articles associated with
1014-606: A supplementary fuel. This is where LPG is used as fuel as well as diesel. Systems are now available that integrate with OEM engine management systems. Conversion kits can switch a vehicle dedicated to gasoline to using a dual system, in which both gasoline and LPG are used in the same vehicle. In 2020, BW LPG successfully retrofitted a Very Large Gas Carrier (VLGC) with LPG propulsion technology, pioneering LPG's application in large-scale maritime operations. LPG’s lowers emissions of carbon dioxide, sulfur oxides, nitrogen oxides, and particulate matter align with stricter standards set by
1092-501: A variety of manners. LPG, as with other fossil fuels , can be combined with renewable power sources to provide greater reliability while still achieving some reduction in CO 2 emissions. However, as opposed to wind and solar renewable energy sources, LPG can be used as a standalone energy source without the prohibitive expense of electrical energy storage . In many climates, renewable sources such as solar and wind power would still require
1170-433: Is a fuel gas which contains a flammable mixture of hydrocarbon gases, specifically propane , n -butane and isobutane . It can sometimes contain some propylene , butylene , and isobutene . LPG is used as a fuel gas in heating appliances , cooking equipment, and vehicles. It is increasingly used as an aerosol propellant and a refrigerant , replacing chlorofluorocarbons in an effort to reduce damage to
1248-486: Is a gas, it does not pose ground or water pollution hazards, but it can cause air pollution . LPG has a typical specific calorific value of 46.1 MJ/kg compared with 42.5 MJ/kg for fuel oil and 43.5 MJ/kg for premium grade petrol (gasoline). However, its energy density per volume unit of 26 MJ/L is lower than either that of petrol or fuel oil, as its relative density is lower (about 0.5–0.58 kg/L, compared to 0.71–0.77 kg/L for gasoline ). As
1326-445: Is a possible explosion if the mixture of LPG and air is within the explosive limits and there is an ignition source. The second is suffocation due to LPG displacing air, causing a decrease in oxygen concentration. A full LPG gas cylinder contains 86% liquid; the ullage volume will contain vapour at a pressure that varies with temperature. LPG has a wide variety of uses in many different markets as an efficient fuel container in
1404-472: Is able to act as a time-dependent tracer . This tracer helps scientists study ocean circulation by tracing biological, physical and chemical pathways. As ozone in the atmosphere prevents most energetic ultraviolet radiation reaching the surface of the Earth, astronomical data in these wavelengths have to be gathered from satellites orbiting above the atmosphere and ozone layer. Most of the light from young hot stars
1482-424: Is able to reach the Earth's surface at a higher intensity. Ozone levels have dropped by a worldwide average of about 4 percent since the late 1970s. For approximately 5 percent of the Earth's surface, around the north and south poles, much larger seasonal declines have been seen, and are described as "ozone holes". "Ozone holes" are actually patches in the ozone layer in which the ozone is thinner. The thinnest parts of
1560-399: Is approximately 220 kilopascals (32 psi) for pure butane at 20 °C (68 °F), and approximately 2,200 kilopascals (320 psi) for pure propane at 55 °C (131 °F). LPG in its gaseous phase is still heavier than air , unlike natural gas , and thus will flow along floors and tend to settle in low spots, such as basements . There are two main dangers to this. The first
1638-552: Is below room temperature , LPG will evaporate quickly at normal temperatures and pressures and is usually supplied in pressurized steel vessels . They are typically filled to 80–85% of their capacity to allow for thermal expansion of the contained liquid. The ratio of the densities of the liquid and vapor varies depending on composition, pressure, and temperature, but is typically around 250:1. The pressure at which LPG becomes liquid, called its vapour pressure , likewise varies depending on composition and temperature; for example, it
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#17328487282111716-541: Is derived, stand at 300 trillion cubic meters (10,600 trillion cubic feet). Production continues to grow at an average annual rate of 2.2%. LPG is composed mainly of propane and butane, while natural gas is composed of the lighter methane and ethane . LPG, vaporised and at atmospheric pressure, has a higher calorific value (46 MJ/m equivalent to 12.8 kWh/m ) than natural gas (methane) (38 MJ/m equivalent to 10.6 kWh/m ), which means that LPG cannot simply be substituted for natural gas. In order to allow
1794-408: Is divided into three categories, based on its wavelength; these are referred to as UV-A (400–315 nm), UV-B (315–280 nm), and UV-C (280–100 nm). UV-C, which is very harmful to all living things, is entirely screened out by a combination of dioxygen (< 200 nm) and ozone (> about 200 nm) by around 35 kilometres (115,000 ft) altitude. UV-B radiation can be harmful to
1872-505: Is extracted from natural gas while the rest is produced by petroleum refineries from crude oil . 44% of global consumption is in the domestic sector. The U.S. is the leading producer and exporter of LPG. Because of the natural gas and the oil-refining industry, Europe is almost self-sufficient in LPG. Europe's security of supply is further safeguarded by: According to 2010–12 estimates, proven world reserves of natural gas , from which most LPG
1950-400: Is in place before gas supplies can be connected. Developing markets in India and China (among others) use LPG-SNG systems to build up customer bases prior to expanding existing natural gas systems. LPG-based SNG or natural gas with localized storage and piping distribution network to the households for catering to each cluster of 5000 domestic consumers can be planned under the initial phase of
2028-529: Is most often used in areas that do not have direct access to piped natural gas . In the UK about 200,000 households use LPG for heating. LPG can be used as a power source for combined heat and power technologies (CHP). CHP is the process of generating both electrical power and useful heat from a single fuel source. This technology has allowed LPG to be used not just as fuel for heating and cooking, but also for decentralized generation of electricity. LPG can be stored in
2106-405: Is much less polluting than most traditional solid-fuel stoves, replacing cookstoves used in developing countries with LPG is one of the key strategies adopted to reduce household air pollution in the developing world. In a refinery or gas plant, LPG must be stored in pressure vessels . These containers are either cylindrical and horizontal (sometimes referred to as bullet tanks) or spherical (of
2184-515: Is prepared by refining petroleum or "wet" natural gas , and is almost entirely derived from fossil fuel sources, being manufactured during the refining of petroleum (crude oil), or extracted from petroleum or natural gas streams as they emerge from the ground. It was first produced in 1910 by Walter O. Snelling , and the first commercial products appeared in 1912. It currently provides about 3% of all energy consumed, and burns relatively cleanly with no soot and very little sulfur emission. As it
2262-455: Is produced over the tropics and is transported towards the poles by stratospheric wind patterns. In the northern hemisphere these patterns, known as the Brewer–Dobson circulation , make the ozone layer thickest in the spring and thinnest in the fall. When ozone is produced by solar UV radiation in the tropics, it is done so by circulation lifting ozone-poor air out of the troposphere and into
2340-516: Is significantly less harmful to DNA , although it may still potentially cause physical damage, premature aging of the skin, indirect genetic damage, and skin cancer. The thickness of the ozone layer varies worldwide and is generally thinner near the equator and thicker near the poles. Thickness refers to how much ozone is in a column over a given area and varies from season to season. The reasons for these variations are due to atmospheric circulation patterns and solar intensity. The majority of ozone
2418-495: Is the most common cooking fuel in Brazilian urban areas, being used in virtually all households, with the exception of the cities of Rio de Janeiro and São Paulo, which have a natural gas pipeline infrastructure. Since 2001, poor families receive a government grant ("Vale Gás") used exclusively for the acquisition of LPG. Since 2003, this grant is part of the government's main social welfare program (" Bolsa Família "). Also, since 2005,
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2496-520: Is the third most widely used motor fuel in the world. 2013 estimates are that over 24.9 million vehicles are fueled by propane gas worldwide. Over 25 million tonnes (over 9 billion US gallons) are used annually as a vehicle fuel. Not all automobile engines are suitable for use with LPG as a fuel. LPG provides less upper cylinder lubrication than petrol or diesel, so LPG-fueled engines are more prone to valve wear if they are not suitably modified. Many modern common rail diesel engines respond well to LPG use as
2574-602: Is used to fuel internal combustion engines , it is often referred to as autogas or auto propane. In some countries, it has been used since the 1940s as a petrol alternative for spark ignition engines. In some countries, there are additives in the liquid that extend engine life and the ratio of butane to propane is kept quite precise in fuel LPG. Two recent studies have examined LPG-fuel-oil fuel mixes and found that smoke emissions and fuel consumption are reduced but hydrocarbon emissions are increased. The studies were split on CO emissions, with one finding significant increases, and
2652-471: Is why many countries have set in place regulations to improve "good" ozone and prevent the increase of "bad" ozone in urban or residential areas. In terms of ozone protection (the preservation of "good" ozone) the European Union has strict guidelines on what products are allowed to be bought, distributed or used in specific areas. With effective regulation, the ozone is expected to heal over time. In 1978,
2730-504: Is widely prohibited or discouraged in motor vehicle air conditioning systems, on the grounds that using flammable hydrocarbons in systems originally designed to carry non-flammable refrigerant presents a significant risk of fire or explosion. Vendors and advocates of hydrocarbon refrigerants argue against such bans on the grounds that there have been very few such incidents relative to the number of vehicle air conditioning systems filled with hydrocarbons. One particular test, conducted by
2808-615: The Horton sphere type). Typically, these vessels are designed and manufactured according to some code. In the United States, this code is governed by the American Society of Mechanical Engineers (ASME). LPG containers have pressure relief valves, such that when subjected to exterior heating sources, they will vent LPGs to the atmosphere or a flare stack . If a tank is subjected to a fire of sufficient duration and intensity, it can undergo
2886-456: The Sun 's ultraviolet radiation. It contains a high concentration of ozone (O 3 ) in relation to other parts of the atmosphere, although still small in relation to other gases in the stratosphere. The ozone layer contains less than 10 parts per million of ozone, while the average ozone concentration in Earth's atmosphere as a whole is about 0.3 parts per million. The ozone layer is mainly found in
2964-637: The United States , mainly two grades of LPG are sold: commercial propane and HD-5. These specifications are published by the Gas Processors Association (GPA) and the American Society of Testing and Materials. Propane/butane blends are also listed in these specifications. Propylene , butylenes and various other hydrocarbons are usually also present in small concentrations such as C 2 H 6 , CH 4 , and C 3 H 8 . HD-5 limits
3042-440: The ozone layer . When specifically used as a vehicle fuel, it is often referred to as autogas or just as gas . Varieties of LPG that are bought and sold include mixes that are mostly propane ( C 3 H 8 ), mostly butane ( C 4 H 10 ), and, most commonly, mixes including both propane and butane. In the northern hemisphere winter, the mixes contain more propane, while in summer, they contain more butane. In
3120-460: The spectrum of a black body with a temperature in the range of 5,500–6,000 K (5,230–5,730 °C), except that there was no radiation below a wavelength of about 310 nm at the ultraviolet end of the spectrum. It was deduced that the missing radiation was being absorbed by something in the atmosphere. Eventually the spectrum of the missing radiation was matched to only one known chemical, ozone. Its properties were explored in detail by
3198-493: The 2023-24 financial year in the domestic sector, mainly for cooking. In 2016, the number of domestic connections was 215 million (i.e., one connection for every six people) with a circulation of more than 350 million LPG cylinders. Most of the LPG requirement is imported. Piped city gas supply in India is not yet developed on a major scale. LPG is subsidised by the Indian government for domestic users. An increase in LPG prices has been
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3276-561: The British meteorologist G. M. B. Dobson , who developed a simple spectrophotometer (the Dobsonmeter ) that could be used to measure stratospheric ozone from the ground. Between 1928 and 1958, Dobson established a worldwide network of ozone monitoring stations, which continue to operate to this day. The " Dobson Unit " (DU), a convenient measure of the amount of ozone overhead, is named in his honor. The ozone layer absorbs 97 to 99 percent of
3354-461: The British physicist Sydney Chapman in 1930. Ozone in the Earth's stratosphere is created by ultraviolet light striking ordinary oxygen molecules containing two oxygen atoms (O 2 ), splitting them into individual oxygen atoms ( atomic oxygen ); the atomic oxygen then combines with unbroken O 2 to create ozone, O 3 . The ozone molecule is unstable (although, in the stratosphere, long-lived) and when ultraviolet light hits ozone it splits into
3432-479: The International Maritime Organization (IMO), making LPG a viable transition option as the maritime industry transitions towards net zero carbon emissions. LPG can be converted into alkylate which is a premium gasoline blending stock because it has exceptional anti-knock properties and gives clean burning. LPG is instrumental in providing off-the-grid refrigeration, usually by means of
3510-555: The Sun's medium-frequency ultraviolet light (from about 200 nm to 315 nm wavelength ), which otherwise would potentially damage exposed life forms near the surface. In 1985, atmospheric research revealed that the ozone layer was being depleted by chemicals released by industry, mainly chlorofluorocarbons (CFCs). Concerns that increased UV radiation due to ozone depletion threatened life on Earth, including increased skin cancer in humans and other ecological problems, led to bans on
3588-554: The US. The production phaseout was possible because of efforts to ensure that there would be substitute chemicals and technologies for all ODS uses. On August 2, 2003, scientists announced that the global depletion of the ozone layer might be slowing because of the international regulation of ozone-depleting substances. In a study organized by the American Geophysical Union , three satellites and three ground stations confirmed that
3666-618: The United States, Canada and Norway enacted bans on CFC -containing aerosol sprays that damage the ozone layer but the European Community rejected a similar proposal. In the U.S., chlorofluorocarbons continued to be used in other applications, such as refrigeration and industrial cleaning, until after the discovery of the Antarctic ozone hole in 1985. After negotiation of an international treaty (the Montreal Protocol ), CFC production
3744-493: The ability of the valve to vent the excess. Alternatively, if, due to continued venting, the liquid level drops below the area being heated, the tank structure can be overheated and subsequently weakened in that area. If either occurs, the container may rupture violently, launching pieces of the vessel at high velocity, while the released products can ignite as well, potentially causing catastrophic damage to anything nearby, including other containers. People can be exposed to LPG in
3822-440: The agricultural, recreation, hospitality, industrial, construction, sailing and fishing sectors. It can serve as fuel for cooking, central heating and water heating and is a particularly cost-effective and efficient way to heat off-grid homes. LPG is used for cooking in many countries for economic reasons, for convenience or because it is the preferred fuel source. In India, nearly 28.5 million metric tons of LPG were consumed in
3900-401: The amount of propylene that can be placed in LPG to 5% and is utilized as an autogas specification. A powerful odorant , ethanethiol , is added so that leaks can be detected easily. The internationally recognized European Standard is EN 589. In the United States, tetrahydrothiophene (thiophane) or amyl mercaptan are also approved odorants, although neither is currently being utilized. LPG
3978-441: The atmosphere for decades. Estimates for 2022 alone were ~17 metric tons (~30 kg of nanoparticles per ~250 kg satellite). Increasing populations of satellite constellations can eventually lead to significant ozone depletion. "Bad" ozone can cause adverse health risks respiratory effects (difficulty breathing) and is proven to be an aggravator of respiratory illnesses such as asthma , COPD and emphysema . That
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#17328487282114056-571: The chemicals, and the latest evidence is that ozone depletion has slowed or stopped. The United Nations General Assembly has designated September 16 as the International Day for the Preservation of the Ozone Layer . Venus also has a thin ozone layer at an altitude of 100 kilometers above the planet's surface. The photochemical mechanisms that give rise to the ozone layer were discovered by
4134-474: The city gas network system. This would eliminate the last mile LPG cylinders road transport which is a cause of traffic and safety hurdles in Indian cities. These localized natural gas networks are successfully operating in Japan with feasibility to get connected to wider networks in both villages and cities. Commercially available LPG is currently derived mainly from fossil fuels. Burning LPG releases carbon dioxide ,
4212-405: The concentrations are greater in high northern latitudes than in high southern latitudes, with spring ozone columns in high northern latitudes occasionally exceeding 600 DU and averaging 450 DU whereas 400 DU constituted a usual maximum in the Antarctic before anthropogenic ozone depletion. This difference occurred naturally because of the weaker polar vortex and stronger Brewer–Dobson circulation in
4290-424: The construction, installation and maintenance of reliable baseload power sources such as LPG fueled generation to provide electrical power during the entire year. 100% wind/solar is possible, the caveat being that the expense of the additional generation capacity necessary to charge batteries plus the cost of battery electrical storage makes this option economically feasible in only a minority of situations. When LPG
4368-462: The density and vapor pressure of LPG (or its components) change significantly with temperature, this fact must be considered every time when the application is connected with safety or custody transfer operations, e.g. typical cuttoff level option for LPG reservoir is 85%. Besides its use as an energy carrier, LPG is also a promising feedstock in the chemical industry for the synthesis of olefins such as ethylene and propylene. As its boiling point
4446-399: The discussion (ozone shield, ozone hole) proved quite useful and, compared to global climate change, the ozone case was much more seen as a "hot issue" and imminent risk. Lay people were cautious about a depletion of the ozone layer and the risks of skin cancer. Satellites burning up upon re-entry into Earth's atmosphere produce aluminum oxide (Al 2 O 3 ) nanoparticles that endure in
4524-490: The general population of the existence and regulation of ozone depletion and contaminants. A scientific paper was written by Sheldon Ungar in which the author explores and studies how information about the depletion of the ozone, climate change and various related topics. The ozone case was communicated to lay persons "with easy-to-understand bridging metaphors derived from the popular culture" and related to "immediate risks with everyday relevance". The specific metaphors used in
4602-419: The lower explosive limit, LPG is considered immediately dangerous to life and health (due solely to safety considerations pertaining to risk of explosion). "Calorific value of Different Fuels" . Centre for Ecological Sciences . IISc. Archived from the original on 19 February 2020. Ozone layer The ozone layer or ozone shield is a region of Earth 's stratosphere that absorbs most of
4680-405: The lower portion of the stratosphere, from approximately 15 to 35 kilometers (9 to 22 mi) above Earth, although its thickness varies seasonally and geographically. The ozone layer was discovered in 1913 by French physicists Charles Fabry and Henri Buisson . Measurements of the sun showed that the radiation sent out from its surface and reaching the ground on Earth is usually consistent with
4758-452: The middle of the 21st century. A gradual trend toward "healing" was reported in 2016. Compounds containing C–H bonds (such as hydrochlorofluorocarbons , or HCFCs) have been designed to replace CFCs in certain applications. These replacement compounds are more reactive and less likely to survive long enough in the atmosphere to reach the stratosphere where they could affect the ozone layer. While being less damaging than CFCs, HCFCs can have
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#17328487282114836-676: The national oil company Petrobras differentiates between LPG destined for cooking and LPG destined for other uses, establishing a lower price for the former. This is a result of a directive from the Brazilian federal government, but its discontinuation is currently being debated. LPG is commonly used in North America for domestic cooking and outdoor grilling . Predominantly in Europe and rural parts of many countries, LPG can provide an alternative to electric heating , heating oil , or kerosene . LPG
4914-465: The northern hemisphere owing to that hemisphere's large mountain ranges and greater contrasts between land and ocean temperatures. The difference between high northern and southern latitudes has increased since the 1970s due to the ozone hole phenomenon. The highest amounts of ozone are found over the Arctic during the spring months of March and April, but the Antarctic has the lowest amounts of ozone during
4992-409: The other finding slight increases at low engine load but a considerable decrease at high engine load. Its advantage is that it is non-toxic, non-corrosive and free of tetraethyllead or any additives, and has a high octane rating (102–108 RON depending on local specifications). It burns more cleanly than petrol or fuel-oil and is especially free of the particulates present in the latter. LPG has
5070-627: The ozone are at the polar points of Earth's axis . The discovery of the annual depletion of ozone above the Antarctic was first announced by Joe Farman , Brian Gardiner and Jonathan Shanklin , in a paper which appeared in Nature on May 16, 1985. Regulation attempts have included but not have been limited to the Clean Air Act implemented by the United States Environmental Protection Agency . The Clean Air Act introduced
5148-415: The pressure of the air at sea level, it would be only 3 millimetres ( 1 ⁄ 8 inch) thick. Although the concentration of the ozone in the ozone layer is very small, it is vitally important to life because it absorbs biologically harmful ultraviolet (UV) radiation coming from the Sun. Extremely short or vacuum UV (10–100 nm) is screened out by nitrogen. UV radiation capable of penetrating nitrogen
5226-458: The requirement of National Ambient Air Quality Standards (NAAQS) with ozone pollutions being one of six criteria pollutants. This regulation has proven to be effective since counties, cities and tribal regions must abide by these standards and the EPA also provides assistance for each region to regulate contaminants. Effective presentation of information has also proven to be important in order to educate
5304-499: The rise to the stratosphere , where Cl and Br radicals are liberated by the action of ultraviolet light. Each radical is then free to initiate and catalyze a chain reaction capable of breaking down over 100,000 ozone molecules. By 2009, nitrous oxide was the largest ozone-depleting substance (ODS) emitted through human activities. The breakdown of ozone in the stratosphere results in reduced absorption of ultraviolet radiation. Consequently, unabsorbed and dangerous ultraviolet radiation
5382-423: The same Wobbe index are held to be interchangeable. LPG-based SNG is used in emergency backup systems for many public, industrial and military installations, and many utilities use LPG peak shaving plants in times of high demand to make up shortages in natural gas supplied to their distributions systems. LPG-SNG installations are also used during initial gas system introductions when the distribution infrastructure
5460-405: The skin and is the main cause of sunburn ; excessive exposure can also cause cataracts, immune system suppression, and genetic damage, resulting in problems such as skin cancer . The ozone layer (which absorbs from about 200 nm to 310 nm with a maximal absorption at about 250 nm) is very effective at screening out UV-B; for radiation with a wavelength of 290 nm, the intensity at
5538-465: The stratosphere where the sun photolyzes oxygen molecules and turns them into ozone. Then, the ozone-rich air is carried to higher latitudes and drops into lower layers of the atmosphere. Research has found that the ozone levels in the United States are highest in the spring months of April and May and lowest in October. While the total amount of ozone increases moving from the tropics to higher latitudes,
5616-578: The summer months of September and October, The ozone layer can be depleted by free radical catalysts , including nitric oxide (NO), nitrous oxide (N 2 O), hydroxyl (OH), atomic chlorine (Cl), and atomic bromine (Br). While there are natural sources for all of these species , the concentrations of chlorine and bromine increased markedly in recent decades because of the release of large quantities of man-made organohalogen compounds, especially chlorofluorocarbons (CFCs) and bromofluorocarbons . These highly stable compounds are capable of surviving
5694-539: The title LPG . If an internal link led you here, you may wish to change the link to point directly to the intended article. Retrieved from " https://en.wikipedia.org/w/index.php?title=LPG&oldid=1237826076 " Category : Disambiguation pages Hidden categories: Short description is different from Wikidata All article disambiguation pages All disambiguation pages Liquefied petroleum gas Liquefied petroleum gas , also referred to as liquid petroleum gas ( LPG or LP gas ),
5772-473: The top of the atmosphere is 350 million times stronger than at the Earth's surface. Nevertheless, some UV-B, particularly at its longest wavelengths, reaches the surface, and is important for the skin's production of vitamin D in mammals . Ozone is transparent to most UV-A, so most of this longer-wavelength UV radiation reaches the surface, and it constitutes most of the UV reaching the Earth. This type of UV radiation
5850-413: The upper-atmosphere ozone-depletion rate slowed significantly over the previous decade. Some breakdown was expected to continue because of ODSs used by nations which have not banned them, and because of gases already in the stratosphere. Some ODSs, including CFCs, have very long atmospheric lifetimes ranging from 50 to over 100 years. It has been estimated that the ozone layer will recover to 1980 levels near
5928-448: The use of the same burner controls and to provide for similar combustion characteristics, LPG can be mixed with air to produce a synthetic natural gas (SNG) that can be easily substituted. LPG/air mixing ratios average 60/40, though this is widely variable based on the gases making up the LPG. The method for determining the mixing ratios is by calculating the Wobbe index of the mix. Gases having
6006-463: The workplace by breathing it in, skin contact, and eye contact. The Occupational Safety and Health Administration (OSHA) has set the legal limit ( Permissible exposure limit ) for LPG exposure in the workplace as 1000 ppm (1800 mg/m ) over an 8-hour workday. The National Institute for Occupational Safety and Health (NIOSH) has set a recommended exposure limit (REL) of 1000 ppm (1800 mg/m ) over an 8-hour workday. At levels of 2000 ppm, 10% of
6084-520: Was capped at 1986 levels with commitments to long-term reductions. This allowed for a ten-year phase-in for developing countries (identified in Article 5 of the protocol). Since then, the treaty was amended to ban CFC production after 1995 in developed countries, and later in developing countries. All of the world's 197 countries have signed the treaty. Beginning January 1, 1996, only recycled or stockpiled CFCs were available for use in developed countries like
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