Methane
Other names	Marsh gas, firedamp
Identifiers
CAS number	[74-82-8]
SMILES	C
InChI	1/CH4/h1H4
Properties
Molecular formula	CH4
Molar mass	16. Firedamp is a Flammable Gas found in coal mines. It is actually the name given to a number of flammable gases including Methane. CAS registry numbers are unique numerical identifiers for Chemical compounds Polymers biological sequences mixtures and Alloys They are also referred to The IUPAC International Chemical Identifier ( InChI, pronounced "INchee" is a textual Identifier for Chemical substances designed to provide a A chemical formula is a way of expressing information about the Atoms that constitute a particular Chemical compound, and how the relationship between those atoms changes Molar mass, symbol M, is the Mass of one mole of a substance ( Chemical element or Chemical compound) 0425 g/mol
Appearance	Colorless gas
Density	0. The density of a material is defined as its Mass per unit Volume: \rho = \frac{m}{V} Different materials usually have different 717 kg/m3, gas
Melting point	-182. The melting point of a solid is the temperature range at which it changes state from solid to Liquid. 5 °C, 91 K, -297 °F
Boiling point	-161. The boiling point of a liquid is the temperature at which the Vapor pressure of the liquid equals the environmental pressure surrounding the liquid 6 °C, 112 K, -259 °F
Solubility in water	3. Solubility is the characteristic Physical property referring to the ability of a given substance the Solute, to dissolve in a Solvent. Water is a common Chemical substance that is essential for the survival of all known forms of Life. 5 mg/100 mL (17 °C)
Hazards
MSDS	External MSDS
Main hazards	Highly flammable (F+)
NFPA 704	4 1 0
R-phrases	R12
S-phrases	(S2), S9, S16, S33
Flash point	-188 °C
Related compounds
Related Alkanes	Ethane, propane
Related compounds	Methanol, chloromethane, formic acid, formaldehyde, silane
Supplementary data page
Structure and properties	n, εr, etc. A material safety data sheet ( MSDS) is a form containing data regarding the properties of a particular substance and save the page --> This page provides supplementary chemical data on Methane. Occupational safety and health is a cross-disciplinary area concerned with protecting the Safety, Health and welfare of people engaged in Symbolism The four divisions are typically color-coded with blue indicating level of Health Hazard, red indicating R-phrases (short for Risk Phrases) are defined in Annex III of European Union Directive 67/548/EEC: Nature of special risks attributed to dangerous R-phrases (short for Risk Phrases) are defined in Annex III of European Union Directive 67/548/EEC: Nature of special risks attributed to dangerous S-phrases are defined in Annex IV of European Union Directive 67/548/EEC: Safety advice concerning dangerous substances and preparations. S-phrases are defined in Annex IV of European Union Directive 67/548/EEC: Safety advice concerning dangerous substances and preparations. S-phrases are defined in Annex IV of European Union Directive 67/548/EEC: Safety advice concerning dangerous substances and preparations. S-phrases are defined in Annex IV of European Union Directive 67/548/EEC: Safety advice concerning dangerous substances and preparations. S-phrases are defined in Annex IV of European Union Directive 67/548/EEC: Safety advice concerning dangerous substances and preparations. The flash point of a flammable liquid is the lowest Temperature at which it can form an ignitable mixture in air Alkanes, also known as Paraffins are Chemical compounds that consist only of the elements Carbon (C and Hydrogen (H (i ETHANE is a mnemonic indicating a protocol used by Emergency services to report situations which they may be faced with especially as it relates to major incidents where Propane is a three- Carbon Alkane, normally a gas but compressible to a liquid that is transportable Methanol, also known as methyl alcohol, carbinol, wood alcohol, wood naphtha or wood spirits, is a Chemical compound Chloromethane, also called Methyl chloride, R-40 or HCC 40 is a Chemical compound of the group of Organic compounds called Haloalkanes. Formic acid (systematically called methanoic acid) is the simplest Carboxylic acid. Formaldehyde is a Chemical compound with the formula H2CO It is the simplest Aldehyde —an organic compound containing a terminal Carbonyl Silane is a Chemical compound with Chemical formula Si[[hydrogen H]]4 and save the page --> This page provides supplementary chemical data on Methane. and save the page --> This page provides supplementary chemical data on Methane. The refractive index (or index of Refraction) of a medium is a measure for how much the speed of light (or other waves such as sound waves is reduced inside the medium Measurement The relative static permittivity εr can be measured for static Electric fields as follows first the Capacitance of a test
Thermodynamic data	Phase behaviour Solid, liquid, gas
Spectral data	UV, IR, NMR, MS
Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) Infobox disclaimer and references

Methane is a chemical compound with the molecular formula CH₄. and save the page --> This page provides supplementary chemical data on Methane. and save the page --> This page provides supplementary chemical data on Methane. Ultraviolet-visible spectroscopy or ultraviolet-visible spectrophotometry ( UV/ VIS) involves the Spectroscopy of Photons in the UV-visible Infrared spectroscopy (IR spectroscopy is the subset of Spectroscopy that deals with the Infrared region of the Electromagnetic spectrum. Nuclear magnetic resonance spectroscopy, most commonly known as NMR spectroscopy, is the name given to a technique which exploits the magnetic properties of certain nuclei Mass spectrometry is an analytical technique that identifies the chemical composition of a compound or sample based on the Mass-to-charge ratio of charged particles In Chemistry, the standard state of a material is its state at 1 bar (100 Kilopascals exactly A chemical compound is a substance consisting of two or more different elements chemically bonded together in a fixed proportion by Mass. It is the simplest alkane, and the principal component of natural gas. Alkanes, also known as Paraffins are Chemical compounds that consist only of the elements Carbon (C and Hydrogen (H (i Natural gas is a Gaseous Fossil fuel consisting primarily of Methane but including significant quantities of Ethane, Propane, Methane's bond angles are 109. 5 degrees. Burning methane in the presence of oxygen produces carbon dioxide and water. Combustion or burning is a complex sequence of Exothermic chemical reactions between a Fuel and an Oxidant accompanied by the production of Oxygen (from the Greek roots ὀξύς (oxys (acid literally "sharp" from the taste of acids and -γενής (-genēs (producer literally begetteris the Carbon dioxide ( Chemical formula:) is a Chemical compound composed of two Oxygen Atoms covalently bonded to a single The relative abundance of methane and its clean burning process makes it a very attractive fuel. Fuel is any material that is burned or altered in order to obtain energy However, because it is a gas at normal temperature and pressure, methane is difficult to transport from its source. In Physical sciences standard conditions for temperature and pressure are Standard sets of conditions for experimental measurements to allow comparisons to be made In its natural gas form, it is generally transported in bulk by pipeline or LNG carriers; few countries still transport it by truck. Natural gas is a Gaseous Fossil fuel consisting primarily of Methane but including significant quantities of Ethane, Propane, Pipeline transport is the transportation of goods through a pipe. An LNG carrier is a ship designed for transporting liquefied natural gas ( LNG)

Methane is a relatively potent greenhouse gas with a high global warming potential of 72 (averaged over 20 years) or 25 (averaged over 100 years). Greenhouse gases are gaseous constituents of the atmosphere bothnatural and anthropogenic that absorb and emit radiation at specific wavelengths within the spectrum of thermal infrared Global warming potential (GWP is a measure of how much a given mass of Greenhouse gas is estimated to contribute to Global warming. ^[1] Methane in the atmosphere is eventually oxidized, producing carbon dioxide and water. As a result, methane in the atmosphere has a half life of seven years (if no methane was added, then every seven years, the amount of methane would halve). Half-Life (computer-game page here It's already listed in the disambiguation page

The abundance of methane in the Earth's atmosphere in 1998 was 1745 parts per billion, up from 700 ppb in 1750. In the same time period, CO₂ increased from 278 to 365 parts per million. The radiative forcing effect due to this increase in methane abundance is about one-third of that of the CO₂ increase. In Climate science radiative forcing is (loosely defined as the change in net Irradiance at the Tropopause. ^[2] In addition, there is a large, but unknown, amount of methane in methane clathrates in the ocean floors. Methane clathrate, also called methane hydrate or methane ice, is a solid form of water that contains a large amount of Methane within its Crystal Global warming could release this methane, which could cause a further sharp rise in global temperatures. Global warming is the increase in the average measured temperature of the Such releases of methane may have been a major factor in previous major extinction events. An extinction event (also known as mass extinction; extinction-level event, ELE is a sharp decrease in the number of Species in a relatively short period The Earth's crust also contains huge amounts of methane. In Geology, a crust is the outermost solid shell of a planet or moon Large amounts of methane are produced anaerobically by methanogenesis. Methanogenesis or biomethanation is the formation of Methane by Microbes known as Methanogens Organisms capable of producing methane have been Other sources include mud volcanoes which are connected with deep geological faults. Note See the Volcano article for information on Magmatic volcanoes such as Mount St

Properties

Methane is the major component of natural gas, about 87% by volume. Natural gas is a Gaseous Fossil fuel consisting primarily of Methane but including significant quantities of Ethane, Propane, At room temperature and standard pressure, methane is a colorless, odorless gas; the smell characteristic of natural gas is an artificial safety measure caused by the addition of an odorant, often methanethiol or ethanethiol. Room temperature (also referred to as ambient temperature) is a common term to denote a certain Temperature within enclosed space at which humans are accustomed In Physical sciences standard conditions for temperature and pressure are Standard sets of conditions for experimental measurements to allow comparisons to be made Methanethiol (also known as methyl mercaptan) is a colorless gas with a smell like rotten Cabbage. Ethanethiol is the Organic compound with the formula CH3CH2SH Methane has a boiling point of −161 °C at a pressure of one atmosphere. The Celsius Temperature scale was previously known as the centigrade scale. The Standard atmosphere is an international reference pressure defined as 101325 Pa and formerly used as unit of Pressure (symbol atm As a gas it is flammable only over a narrow range of concentrations (5–15%) in air. Flammability is the ease with which a substance will ignite causing Fire or Combustion. Liquid methane does not burn unless subjected to high pressure (normally 4–5 atmospheres. )

Potential health effects

Methane is not toxic; however, it is highly flammable and may form explosive mixtures with air. An explosive material is a material that either is chemically or otherwise Energetically unstable or produces a sudden expansion of the material usually accompanied Methane is violently reactive with oxidizers, halogens, and some halogen-containing compounds. An oxidizing agent or oxidising agent (also called an oxidant, oxidizer or oxidiser) can be defined as either a Chemical compound Abundance Owing to their high Reactivity, the halogens are found in the environment only in compounds or as Ions Halide ions and oxoanions Methane is also an asphyxiant and may displace oxygen in an enclosed space. An asphyxiant gas is a non-toxic or minimally Oxygen (from the Greek roots ὀξύς (oxys (acid literally "sharp" from the taste of acids and -γενής (-genēs (producer literally begetteris the Asphyxia may result if the oxygen concentration is reduced to below 19. 5% by displacement. The concentrations at which flammable or explosive mixtures form are much lower than the concentration at which asphyxiation risk is significant. When structures are built on or near landfills, methane off-gas can penetrate the buildings' interiors and expose occupants to significant levels of methane. For other uses see Water treatment and Land reclamation. A landfill, also known as a dump (and historically as Some buildings have specially engineered recovery systems below their basements to actively capture such fugitive off-gas and vent it away from the building. An example of this type of system is in the Dakin Building, Brisbane, California. The Dakin Building is an architectural award winning class A office building on the San Francisco Bay in Brisbane California. Brisbane is a small city located in the northern part of San Mateo County California on the lower slopes of San Bruno Mountain.

Reactions of methane

Main reactions with methane are: combustion, steam reforming to syngas, and halogenation. Combustion or burning is a complex sequence of Exothermic chemical reactions between a Fuel and an Oxidant accompanied by the production of Steam reforming (SR hydrogen reforming or catalytic oxidation, is a method of producing Hydrogen from Hydrocarbons. Syngas (from syn thesis gas) is the name given to a gas mixture that contains varying amounts of Carbon monoxide and Hydrogen. "Fluorination" redirects here For the addition of fluoride to drinking water see Water fluoridation. In general, methane reactions are hard to control. Partial oxidation to methanol, for example, is difficult to achieve; the reaction typically progresses all the way to carbon dioxide and water. Methanol, also known as methyl alcohol, carbinol, wood alcohol, wood naphtha or wood spirits, is a Chemical compound Carbon dioxide ( Chemical formula:) is a Chemical compound composed of two Oxygen Atoms covalently bonded to a single Water is a common Chemical substance that is essential for the survival of all known forms of Life.

Combustion

In the combustion of methane, several steps are involved:

Methane is believed to form a formaldehyde (HCHO or H₂CO). Combustion or burning is a complex sequence of Exothermic chemical reactions between a Fuel and an Oxidant accompanied by the production of Formaldehyde is a Chemical compound with the formula H2CO It is the simplest Aldehyde —an organic compound containing a terminal Carbonyl The formaldehyde gives a formyl radical (HCO), which then forms carbon monoxide (CO). In Chemistry, radicals (often referred to as free radicals) are atoms molecules or ions with Unpaired electrons on an otherwise Open shell Carbon monoxide, with the chemical formula CO is a colorless odorless tasteless yet highly toxic Gas. The process is called oxidative pyrolysis:

CH₄ + O₂ → CO + H₂ + H₂O

Following oxidative pyrolysis, the H₂ oxidizes, forming H₂O, replenishing the active species, and releasing heat. Pyrolysis is the Chemical decomposition of organic materials by heating in the absence of Oxygen or any other reagents except possibly Steam In Physics, heat, symbolized by Q, is Energy transferred from one body or system to another due to a difference in Temperature This occurs very quickly, usually in significantly less than a millisecond. A millisecond (from Milli- and Second; abbreviation ms is one thousandth of a Second.

2H₂ + O₂ →2H₂O

Finally, the CO oxidizes, forming CO₂ and releasing more heat. Redox (shorthand for reduction-oxidation reaction describes all Chemical reactions in which atoms have their Oxidation number ( Oxidation state This process is generally slower than the other chemical steps, and typically requires a few to several milliseconds to occur.

2CO + O₂ →2CO₂

The result of the above is the following total equation:

CH₄ + 2O₂ → CO₂ + 2H₂O + 809 kJ^[3]

Hydrogen activation

The strength of the carbon-hydrogen covalent bond in methane is among the strongest in all hydrocarbons, and thus its use as a chemical feedstock is limited. Kilo- (symbol k is a prefix in the SI and other systems of units denoting 103 or 1000 The joule (written in lower case ˈdʒuːl or /ˈdʒaʊl/ (symbol J) is the SI unit of Energy measuring heat, Electricity Carbon (kɑɹbən is a Chemical element with the symbol C and its Atomic number is 6 Hydrogen (ˈhaɪdrədʒən is the Chemical element with Atomic number 1 Despite the high activation barrier for breaking the C–H bond, CH₄ is still the principal starting material for manufacture of hydrogen in steam reforming. Hydrogen (ˈhaɪdrədʒən is the Chemical element with Atomic number 1 Steam reforming (SR hydrogen reforming or catalytic oxidation, is a method of producing Hydrogen from Hydrocarbons. The search for catalysts which can facilitate C–H bond activation in methane and other low alkanes is an area of research with considerable industrial significance. Catalysis is the process in which the rate of a Chemical reaction is increased by means of a Chemical substance known as a catalyst Alkanes, also known as Paraffins are Chemical compounds that consist only of the elements Carbon (C and Hydrogen (H (i

Reactions with halogens

Methane reacts with all halogens given appropriate conditions, as follows:

CH₄ + X₂ → CH₃X + HX

where X is a halogen: fluorine (F), chlorine (Cl), bromine (Br), or iodine (I). Abundance Owing to their high Reactivity, the halogens are found in the environment only in compounds or as Ions Halide ions and oxoanions Fluorine, fluorum meaning "to flow" is the Chemical element with the symbol F and Atomic number 9 Chlorine (ˈklɔriːn from the Greek word 'χλωρóς' ( khlôros, meaning 'pale green' is the Chemical element with Atomic number 17 and Iodine (ˈaɪədaɪn ˈaɪədɪn or /ˈaɪədiːn/ from ιώδης iodes "violet" is a Chemical element that has the symbol I and Atomic This mechanism for this process is called free radical halogenation. In Organic chemistry, free radical halogenation is a type of Halogenation.

Uses

Fuel

For more on the use of methane as a fuel, see: natural gas

Methane is important for electrical generation by burning it as a fuel in a gas turbine or steam boiler. Natural gas is a Gaseous Fossil fuel consisting primarily of Methane but including significant quantities of Ethane, Propane, Electricity generation is the process of converting non-electrical Energy to Electricity. A gas turbine, also called a combustion turbine, is a rotary Engine that extracts energy from a flow of Combustion gas A boiler is a closed vessel in which Water or other Fluid is heated Compared to other hydrocarbon fuels, burning methane produces less carbon dioxide for each unit of heat released. Fossil fuels or mineral fuels are fossil source Fuels that is Hydrocarbons found within the top layer of the Earth’s crust. Carbon dioxide ( Chemical formula:) is a Chemical compound composed of two Oxygen Atoms covalently bonded to a single At about 891 kJ/mol, methane's combustion heat is lower than any other hydrocarbon; but a ratio with the molecular mass (16. 0 g/mol) divided by the heat of combustion (891 kJ/mol) shows that methane, being the simplest hydrocarbon, produces more heat per mass unit than other complex hydrocarbons. In many cities, methane is piped into homes for domestic heating and cooking purposes. In this context it is usually known as natural gas, and is considered to have an energy content of 39 megajoules per cubic meter, or 1,000 BTU per standard cubic foot. Natural gas is a Gaseous Fossil fuel consisting primarily of Methane but including significant quantities of Ethane, Propane, The joule (written in lower case ˈdʒuːl or /ˈdʒaʊl/ (symbol J) is the SI unit of Energy measuring heat, Electricity A standard cubic foot (abbreviated as scf is a measure of quantity of gas equal to a cubic foot of volume at 60 degrees Fahrenheit and either 14

Methane in the form of compressed natural gas is used as a fuel for vehicles, and is claimed to be more environmentally friendly than alternatives such as gasoline/petrol and diesel. Compressed Natural Gas (CNG is a Fossil fuel substitute for Gasoline (petrol Diesel, or Propane Fuel. Research is being conducted by NASA on methane's potential as a rocket fuel. The National Aeronautics and Space Administration ( NASA, ˈnæsə is an agency of the United States government, responsible for the nation's public space program Rocket propellant is mass that is stored usually in some form of Propellant tank prior to being used as the propulsive mass that is ejected from a rocket engine in the form One advantage of methane is that it is abundant in many parts of the solar system and it could potentially be harvested in situ, providing fuel for a return journey. [1]

Industrial uses

Methane is used in industrial chemical processes and may be transported as a refrigerated liquid (liquefied natural gas, or LNG). Not to be confused with Natural Gas Liquids (NGL Liquefied natural gas or LNG is Natural gas (primarily Methane, CH4 While leaks from a refrigerated liquid container are initially heavier than air due to the increased density of the cold gas, the gas at ambient temperature is lighter than air. Gas pipelines distribute large amounts of natural gas, of which methane is the principal component. Pipeline transport is the transportation of goods through a pipe. Natural gas is a Gaseous Fossil fuel consisting primarily of Methane but including significant quantities of Ethane, Propane,

In the chemical industry, methane is the feedstock of choice for the production of hydrogen, methanol, acetic acid, and acetic anhydride. Hydrogen (ˈhaɪdrədʒən is the Chemical element with Atomic number 1 Methanol, also known as methyl alcohol, carbinol, wood alcohol, wood naphtha or wood spirits, is a Chemical compound Acetic acid, also known as ethanoic acid, is an organic chemical compound, giving Vinegar its sour taste Acetic anhydride is the Chemical compound with the formula (CH3CO2O When used to produce any of these chemicals, methane is first converted to synthesis gas, a mixture of carbon monoxide and hydrogen, by steam reforming. Syngas (from syn thesis gas) is the name given to a gas mixture that contains varying amounts of Carbon monoxide and Hydrogen. Carbon monoxide, with the chemical formula CO is a colorless odorless tasteless yet highly toxic Gas. Hydrogen (ˈhaɪdrədʒən is the Chemical element with Atomic number 1 Steam reforming (SR hydrogen reforming or catalytic oxidation, is a method of producing Hydrogen from Hydrocarbons. In this process, methane and steam react on a nickel catalyst at high temperatures (700–1100 °C). Uses A Steam engine uses the expansion of steam in order to drive a Piston or Turbine to perform Mechanical work. Nickel (ˈnɪkəl is a metallic Chemical element with the symbol Ni and Atomic number 28

CH₄ + H₂O → CO + 3H₂

The ratio of carbon monoxide to hydrogen in synthesis gas can then be adjusted via the water gas shift reaction to the appropriate value for the intended purpose. The water gas shift reaction (WGS is a Chemical reaction in which Carbon monoxide reacts with Water to form Carbon dioxide and Hydrogen

CO + H₂O → CO₂ + H₂

Less significant methane-derived chemicals include acetylene, prepared by passing methane through an electric arc, and the chloromethanes (chloromethane, dichloromethane, chloroform, and carbon tetrachloride), produced by reacting methane with chlorine gas. Acetylene ( IUPAC name ethyne), C2H2 is a Hydrocarbon belonging to the group of Alkynes It is the simplest of all alkynes An electric arc is an Electrical breakdown of a gas which produces an ongoing plasma discharge, resulting from a current flowing through normally nonconductive Chloromethane, also called Methyl chloride, R-40 or HCC 40 is a Chemical compound of the group of Organic compounds called Haloalkanes. Dichloromethane ( DCM) or methylene chloride is the Chemical compound with the formula CH2Cl2 Chloroform, also known as trichloromethane and methyl trichloride, is a Chemical compound with formula C[[Hydrogen H]] Cl Carbon tetrachloride, also known by many other names (see Table is the Organic compound with the formula CCl4 Chlorine (ˈklɔriːn from the Greek word 'χλωρóς' ( khlôros, meaning 'pale green' is the Chemical element with Atomic number 17 and However, the use of these chemicals is declining, acetylene as it is replaced by less costly substitutes, and the chloromethanes due to health and environmental concerns.

Sources of methane

Natural gas fields

The major source of methane is extraction from geological deposits known as natural gas fields. Oil and Natural gas are produced by the same geological process anaerobic Decay of Organic matter deep under the Earth's surface It is associated with other hydrocarbon fuels and sometimes accompanied by helium and nitrogen. In Organic chemistry, a hydrocarbon is an Organic compound consisting entirely of Hydrogen and Carbon. Helium ( He) is a colorless odorless tasteless non-toxic Inert Monatomic Chemical Nitrogen (ˈnaɪtɹəʤɪn is a Chemical element that has the symbol N and Atomic number 7 and Atomic weight 14 The gas at shallow levels (low pressure) is formed by anaerobic decay of organic matter and reworked methane from deep under the Earth's surface. An anaerobic organism is any Organism that does not require Oxygen for growth and may even die in its presence Organic matter (or organic material) is Matter that has come from a once-living Organism; is capable of In general, sediments buried deeper and at higher temperatures than those which give oil generate natural gas. Petroleum ( L petroleum, from Greek πετρέλαιον, lit Methane is also produced in considerable quantities from the decaying organic wastes of solid waste landfills. For other uses see Water treatment and Land reclamation. A landfill, also known as a dump (and historically as

Alternative sources

Apart from gas fields an alternative method of obtaining methane is via biogas generated by the fermentation of organic matter including manure, wastewater sludge, municipal solid waste (including landfills), or any other biodegradable feedstock, under anaerobic conditions. See also Natural gas, Biofuel Biogas typically refers to a Gas produced by the biological breakdown of Organic matter in the Fermentation is the process of deriving energy from the oxidation of organic compounds such as carbohydrates using an endogenous electron acceptor which is Manure is Organic matter used as Organic fertilizer in Agriculture. Methane hydrates/clathrates (icelike combinations of methane and water on the sea floor, found in vast quantities) are a potential future source of methane. Cattle belch methane accounts for 16% of the world's annual methane emissions to the atmosphere. ^[4] The livestock sector in general (primarily cattle, chickens, and pigs) produces 37% of all human-induced methane". ^[5] However animals "that put their energies into making gas are less efficient at producing milk and meat". Early research has found a number of medical treatments and dietary adjustments that help limit the production of methane in ruminants. Physiologically a ruminant is a Mammal of the order Artiodactyla that digests plant-based food by initially softening it within the animal's first stomach known ^{[6] [7] [8]}

Industrially, methane can be created from common atmospheric gases and hydrogen (produced, perhaps, by electrolysis) through chemical reactions such as the Sabatier process, Fischer-Tropsch process. In chemistry and manufacturing electrolysis is a method of separating chemically bonded elements and compounds by passing an Electric current The Sabatier reaction or Sabatier process involves the reaction of Hydrogen with Carbon dioxide at elevated temperatures and pressures in the presence of The Fischer-Tropsch process (or Fischer-Tropsch Synthesis is a catalyzed chemical reaction in which synthesis gas ( Syngas) a mixture of Carbon monoxide Coal bed methane extraction is a method for extracting methane from a coal deposit. Coal bed methane extraction (CBM extraction is a method for extracting Methane from a Coal deposit

A recent scientific experiment has also yielded results pointing to one species of plant^[9] producing trace methane. ^[10].

Methane in Earth's atmosphere

Methane concentrations graph

Computer models showing the amount of methane (parts per million by volume) at the surface (top) and in the stratosphere (bottom).

Early in the Earth's history—about 3. 5 billion years ago—there was 1,000 times as much methane in the atmosphere as there is now. The earliest methane was released into the atmosphere by volcanic activity. During this time, Earth's earliest life appeared. These first, ancient bacteria added to the methane concentration by converting hydrogen and carbon dioxide into methane and water. Oxygen did not become a major part of the atmosphere until photosynthetic organisms evolved later in Earth's history. With no oxygen, methane stayed in the atmosphere longer and at higher concentrations than it does today.

In present times, due to the increase in oxygen, the amount of methane has decreased. The average mole concentration of methane at the Earth's surface in 1998 was 1,745 ppb. "Parts-per" notation is used especially in Science and Engineering, to denote Ratios (relative proportions in measured quantities particularly ^[11] Its concentration is higher in the northern hemisphere as most sources (both natural and human) are larger. The concentrations vary seasonally with a minimum in the late summer mainly due to removal by the hydroxyl radical. Hydroxyl in Chemistry describes a molecule consisting of an Oxygen atom and a Hydrogen atom joined by a Covalent bond.

Methane is created near the surface, and it is carried into the stratosphere by rising air in the tropics. The stratosphere is the second major layer of Earth's atmosphere, just above the Troposphere, and below the Mesosphere. The Tropics are centered on the Equator and limited in Latitude by the Tropic of Cancer in the northern hemisphere at approximately 23°26' (23 Uncontrolled build-up of methane in Earth's atmosphere is naturally checked—although human influence can upset this natural regulation—by methane's reaction with hydroxyl radicals formed from singlet oxygen atoms and with water vapor. Hydroxyl in Chemistry describes a molecule consisting of an Oxygen atom and a Hydrogen atom joined by a Covalent bond. Singlet oxygen is the common name used for the two Metastable states of molecular Oxygen (O2 with higher energy than the ground state Triplet oxygen

Methane as a greenhouse gas

Methane in the Earth's atmosphere is an important greenhouse gas with a global warming potential of 25 over a 100-year period. This means that a methane emission will have 25 times the impact on temperature of a carbon dioxide emission of the same mass over the following 100 years. Methane has a large effect for a brief period (about 10 years), whereas carbon dioxide has a small effect for a long period (over 100 years). Because of this difference in effect and time period, the global warming potential of methane over a 20 year time period is 72. The Earth's methane concentration has increased by about 150% since 1750, and it accounts for 20% of the total radiative forcing from all of the long-lived and globally mixed greenhouse gases. In Climate science radiative forcing is (loosely defined as the change in net Irradiance at the Tropopause. ^[12]

Emissions of methane

Houweling et al. (1999) give the following values for methane emissions (Tg/a=teragrams per year):^[11]

Global average methane concentrations from measurement (NOAA)

Slightly over half of the total emission is due to human activity. ^[12]

Living plants (e. g. forests) have recently been identified as a potentially important source of methane. A 2006 paper calculated emissions of 62–236 Tg a^-1, and "this newly identified source may have important implications". Annum is one form of the Latin noun meaning Year, not a form normally used for derivatives in modern languages the accusative singular ^[13][14] However the authors stress "our findings are preliminary with regard to the methane emission strength". ^[15] These findings have been called into question in a 2007 paper which found "there is no evidence for substantial aerobic methane emission by terrestrial plants, maximally 0. 3% of the previously published values". ^[16]

Long term atmospheric measurements of methane by NOAA show that the build up of methane has slowed dramatically over the last decade, after nearly tripling since pre-industrial times ^[17]. The National Oceanic and Atmospheric Administration ( NOAA) is a scientific agency within the United States Department of Commerce focused on the conditions of the It is thought that this reduction is due to reduced industrial emissions and drought in wetland areas.

Removal processes

The major removal mechanism of methane from the atmosphere involves radical chemistry ; it reacts with the hydroxyl radical (·OH), initially formed from water vapor broken down by oxygen atoms that come from the cleavage of ozone by ultraviolet radiation:

CH₄ + ·OH → ·CH₃ + H₂O

This reaction in the troposphere gives a methane lifetime of 9. In Chemistry, radicals (often referred to as free radicals) are atoms molecules or ions with Unpaired electrons on an otherwise Open shell Hydroxyl in Chemistry describes a molecule consisting of an Oxygen atom and a Hydrogen atom joined by a Covalent bond. OZONE is an object oriented Operating system written in the C programming language. Ultraviolet ( UV) light is Electromagnetic radiation with a Wavelength shorter than that of Visible light, but longer than X-rays The troposphere is the lowest portion of Earth's atmosphere. It contains approximately 75% of the atmosphere's mass and almost all of its Water vapor and 6 years. Two more minor sinks are soil sinks (160 year lifetime) and stratospheric loss by reaction with ·OH, ·Cl and ·O¹D in the stratosphere (120 year lifetime), giving a net lifetime of 8. 4 years. ^[11] Oxidation of methane is the main source of water vapor in the upper stratosphere (beginning at pressure levels around 10 kPa).

Sudden release from methane clathrates

At high pressures, such as are found on the bottom of the ocean, methane forms a solid clathrate with water, known as methane hydrate. A clathrate or clathrate compound or cage compound is a Chemical substance consisting of a lattice of one type of molecule trapping Methane clathrate, also called methane hydrate or methane ice, is a solid form of water that contains a large amount of Methane within its Crystal An unknown, but possibly very large quantity of methane is trapped in this form in ocean sediments. The sudden release of large volumes of methane from such sediments into the atmosphere has been suggested as a possible cause for rapid global warming events in the Earth's distant past, such as the Paleocene–Eocene Thermal Maximum of 55 million years ago. Global warming is the increase in the average measured temperature of the The Paleocene /Eocene boundary, was marked by the most rapid and significant climatic disturbance of the Cenozoic Era.

One source estimates the size of the methane hydrate deposits of the oceans at ten trillion tons (10 exagrams). Theories suggest that should global warming cause them to heat up sufficiently, all of this methane could again be suddenly released into the atmosphere. Since methane is twenty-three times stronger (for a given weight, averaged over 100 years) than CO₂ as a greenhouse gas; this would immensely magnify the greenhouse effect, heating Earth to unprecedented levels (see Clathrate gun hypothesis). The clathrate gun hypothesis is the popular name given to the hypothesis that rises in sea temperatures (and/or falls in sea level can trigger the sudden release of Methane

Release of methane from bogs

Although less dramatic than release from clathrates, but already happening, is an increase in the release of methane from bogs as permafrost melts. This article is about frozen ground For other meanings see Permafrost (disambiguation. Although records of permafrost are limited, recent years (1999 to 2007) have seen record thawing of permafrost in Alaska and Siberia. Alaska ( Аляска Alyaska) is a state in the United States of America, in the northwest of the North American continent Siberia (Сиби́рь Sibir) is the name given to the vast region constituting almost all of Northern Asia and for the most part currently serving

Recent measurements in Siberia show that the methane released is five times greater than previously estimated ^[18].

Extraterrestrial methane

Methane has been detected or is believed to exist in several locations of the solar system. The Solar System consists of the Sun and those celestial objects bound to it by Gravity. It is believed to have been created by abiotic processes, with the possible exception of Mars. In Biology, abiotic components are non-living Chemical and Physical factors in the environment. Scientists have long speculated about the possibility of life on Mars owing to the planet's proximity and similarity to Earth.

• Moon - traces are present in the thin atmosphere^[19]
• Mars - the atmosphere contains 10 ppb methane
• Jupiter - the atmosphere contains about 0. 3% methane
• Saturn - the atmosphere contains about 0. 4% methane
  • Iapetus
  • Titan — the atmosphere contains 1. TemplateInfobox Planet.--> Iapetus (aɪˈæpɨtəs, or as in Greek TemplateInfobox Planet.--> Titan (ˈtaɪtən, or as 6% methane^[20]
  • Enceladus - the atmosphere contains 1. TemplateInfobox Planet.--> This article is about the moon of 7% methane^[21]
• Uranus - the atmosphere contains 2. 3% methane
  • Ariel - methane is believed to be a constituent of Ariel's surface ice
  • Miranda
  • Oberon - about 20% of Oberon's surface ice is composed of methane-related carbon/nitrogen compounds
  • Titania - about 20% of Titania's surface ice is composed of methane-related organic compounds
  • Umbriel - methane is a constituent of Umbriel's surface ice
• Neptune - the atmosphere contains 1. TemplateInfobox Planet.--> Ariel (ˈɛəriəl) is a moon TemplateInfobox Planet.--> Miranda (mɨˈrændə) is the smallest TemplateInfobox Planet.--> Oberon (ˈoʊbərɒn) is the outermost Titania (, also) is the largest moon of Uranus and the eighth largest moon in the Solar System. Umbriel (ˈʌmbriəl) is a moon of Uranus discovered on October 24, 1851 by William Lassell. Neptune ( English|AmE] ] is the eighth and farthest Planet from the Sun in the Solar System. 6% methane
  • Triton - Triton has a tenuous nitrogen atmosphere with small amounts of methane near the surface. TemplateInfobox Planet.--> Triton (ˈtraɪtən, or as in Greek ^[22][23]
• Pluto - spectroscopic analysis of Pluto's surface reveals it to contain traces of methane^[24][25]
  • Charon - methane is believed to be present on Charon, but it is not completely confirmed^[26]
• Eris - infrared light from the object revealed the presence of methane ice
• Comet Halley
• Comet Hyakutake - terrestrial observations found ethane and methane in the comet^[27]
• Extrasolar planet HD 189733b - This is the first detection of an organic compound on planets outside the solar system. Spectroscopy was originally the study of the interaction between Radiation and Matter as a function of Wavelength (λ Charon (ˈʃærən; also, as in Χάρων) discovered in 1978 is either the largest Moon of Pluto or the smaller member of a double Halley's Comet, officially designated 1P/Halley and also referred to as Comet Halley after Edmond Halley, is a Comet that can be seen every Comet Hyakutake (çʲakɯ̥take formally designated C/1996 B2) is a Comet discovered on January 30 1996 which passed very close to Earth ETHANE is a mnemonic indicating a protocol used by Emergency services to report situations which they may be faced with especially as it relates to major incidents where An extrasolar planet, or exoplanet, is a Planet beyond the Solar System, orbiting around other Stars As of September 2008 312 HD 189733 b is an Extrasolar planet approximately 63 Light-years away in the Constellation of Vulpecula (the Fox) It is unknown how it originated, when the high temperature (700°C) favors the formation of carbon monoxide instead. Carbon monoxide, with the chemical formula CO is a colorless odorless tasteless yet highly toxic Gas. ^[28]
• Interstellar clouds^[29]

See also

References

1. ^ IPCC Fourth Assessment Report
2. ^ Radiative Forces of Climate Change. This page is about the physical properties of gas as a state of matter Thomas Gold ( May 22, 1920 &ndash June 22, 2004) was an Austrian born Astrophysicist, a professor of Astronomy Climate Change 2001: The Scientific Basis. IPCC. Retrieved on 2008-05-26. 2008 ( MMVIII) is the current year in accordance with the Gregorian calendar, a Leap year that started on Tuesday of the Common Events 451 - The Battle of Avarayr between Armenian rebels and the Sassanid Empire takes place
3. ^ SCHAUM'S OUTLINE SERIES, ORGANIC CHEMISTRY
4. ^ Miller, G. Tyler. Sustaining the Earth: An Integrated Approach. U. S. A. : Thomson Advantage Books, 2007. 160.
5. ^ Livestock’s Long Shadow–Environmental Issues and Options. Retrieved on 2007-01-04. Year 2007 ( MMVII) was a Common year starting on Monday of the Gregorian calendar in the 21st century. Events 46 BC - Titus Labienus defeats Julius Caesar in the Battle of Ruspina.
6. ^ California Cows Fail Latest Emissions Test
7. ^ New Zealand Tries to Cap Gaseous Sheep Burps
8. ^ Research on use of bacteria from the stomach lining of kangaroos (who don't emit methane) to reduce methane in cattle
9. ^ Plants do emit methane after all - earth - 02 December 2007 - New Scientist Environment
10. ^ Methane emissions from terrestrial plants under aerobic conditions Nature, January 12, 2006
11. ^ ^{a b c} Trace Gases: Current Observations, Trends, and Budgets. Climate Change 2001. United Nations Environment Programme.
12. ^ ^{a b} Technical summary. Climate Change 2001. United Nations Environment Programme.
13. ^ Methane emissions from terrestrial plants under aerobic conditions. Nature (2006-01-12). Year 2006 ( MMVI) was a Common year starting on Sunday of the Gregorian calendar. Events 475 - Basiliscus becomes Byzantine Emperor, with a coronation ceremony in the Hebdomon palace in Constantinople Retrieved on 2006-09-07. Year 2006 ( MMVI) was a Common year starting on Sunday of the Gregorian calendar. Events 1251 BC - A Solar eclipse on this date might mark the birth of legendary Heracles at Thebes Greece.
14. ^ Plants revealed as methane source. BBC (2006-01-11). Year 2006 ( MMVI) was a Common year starting on Sunday of the Gregorian calendar. Events 1055 - Theodora is crowned Empress of the Byzantine Empire. Retrieved on 2006-09-07. Year 2006 ( MMVI) was a Common year starting on Sunday of the Gregorian calendar. Events 1251 BC - A Solar eclipse on this date might mark the birth of legendary Heracles at Thebes Greece.
15. ^ Global warming - the blame is not with the plants. eurekalert. org (2006-01-18). Year 2006 ( MMVI) was a Common year starting on Sunday of the Gregorian calendar. Events 350 - Generallus Magnentius deposes Roman Emperor Constans and proclaims himself Emperor Retrieved on 2006-09-06. Year 2006 ( MMVI) was a Common year starting on Sunday of the Gregorian calendar. Events 3114 BC - According to the Proleptic Julian calendar the current era in the Maya Long Count Calendar started
16. ^ Duek, Tom A. ; Ries de Visser, Hendrik Poorter, Stefan Persijn, Antonie Gorissen, Willem de Visser, Ad Schapendonk, Jan Verhagen, Jan Snel, Frans J. M. Harren, Anthony K. Y. Ngai, Francel Verstappen, Harro Bouwmeester, Laurentius A. C. J. Voesenek, Adrie van der Werf (2007-03-30). "No evidence for substantial aerobic methane emission by terrestrial plants: a ¹³C-labelling approach.". New Phytologist 175: 29. Blackwell. doi:10.1111/j.1469-8137.2007.02103.x. A digital object identifier ( DOI) is a permanent identifier given to an Electronic document.  
17. ^ SCIENTISTS PINPOINT CAUSE OF SLOWING METHANE EMISSIONS. NOAA news Online. Retrieved on 2007-05-23. Year 2007 ( MMVII) was a Common year starting on Monday of the Gregorian calendar in the 21st century. Events 1430 - Siege of Compiègne: Joan of Arc is captured by the Burgundians while leading an army to relieve Compiègne
18. ^ Methane bubbles climate trouble. BBC (2006-09-07). Year 2006 ( MMVI) was a Common year starting on Sunday of the Gregorian calendar. Events 1251 BC - A Solar eclipse on this date might mark the birth of legendary Heracles at Thebes Greece. Retrieved on 2006-09-07. Year 2006 ( MMVI) was a Common year starting on Sunday of the Gregorian calendar. Events 1251 BC - A Solar eclipse on this date might mark the birth of legendary Heracles at Thebes Greece.
19. ^ Stern, S. A. (1999). "The Lunar atmosphere: History, status, current problems, and context". Rev. Geophys. 37: 453–491.  
20. ^ H. B. Niemann, et al. (2005). "The abundances of constituents of Titan’s atmosphere from the GCMS instrument on the Huygens probe". Nature 438: 779–784. Nature, in the broadest sense is equivalent to the natural world, physical universe, material world or material universe. doi:10.1038/nature04122. A digital object identifier ( DOI) is a permanent identifier given to an Electronic document.  
21. ^ Waite, J. H. ; et al. ; (2006); Cassini Ion and Neutral Mass Spectrometer: Enceladus Plume Composition and Structure, Science, Vol. 311, No. 5766, pp. 1419–1422
22. ^ A L Broadfoot, S K Bertaux, J E Dessler et al. (December 15, 1989). Events 533 - Byzantine general Belisarius defeats the Vandals, commanded by King Gelimer, at the Battle of Year 1989 ( MCMLXXXIX) was a Common year starting on Sunday (link displays 1989 Gregorian calendar) "Ultraviolet Spectrometer Observations of Neptune and Triton". Science 246: 1459–1466. ISSN 0036-8075. An International Standard Serial Number ( ISSN) is a unique eight-digit number used to identify a print or electronic Periodical publication.  
23. ^ Ron Miller; William K. Ron Miller (b May 8, 1947 - Minneapolis Minnesota) is an artist and author who lives and works in South Boston Virginia in the United Hartmann (May 2005). The Grand Tour: A Traveler's Guide to the Solar System, 3rd, Thailand: Workman Publishing, 172–73. ISBN 0-7611-3547-2.  
24. ^ Tobias C. Owen, Ted L. Roush et al. (6 August 1993). "Surface Ices and the Atmospheric Composition of Pluto". Science 261 (5122): 745–748. doi:10.1126/science.261.5122.745. A digital object identifier ( DOI) is a permanent identifier given to an Electronic document.  
25. ^ Pluto. SolStation (2006). Retrieved on 2007-03-28. Year 2007 ( MMVII) was a Common year starting on Monday of the Gregorian calendar in the 21st century. Events 37 - Roman Emperor Caligula accepts the titles of the Principate, entitled to him by the Senate.
26. ^ B. Sicardy et al (2006). "Charon’s size and an upper limit on its atmosphere from a stellar occultation". Nature 439: 52. doi:10.1038/nature04351. A digital object identifier ( DOI) is a permanent identifier given to an Electronic document.  
27. ^ Mumma, M. J. ; Disanti, M. A. , dello Russo, N. , Fomenkova, M. , Magee-Sauer, K. , Kaminski, C. D. , and D. X. Xie (1996). "Detection of Abundant Ethane and Methane, Along with Carbon Monoxide and Water, in Comet C/1996 B2 Hyakutake: Evidence for Interstellar Origin". Science 272: 1310. doi:10.1126/science.272.5266.1310. A digital object identifier ( DOI) is a permanent identifier given to an Electronic document.  
28. ^ Stephen Battersby (2008-02-11). 2008 ( MMVIII) is the current year in accordance with the Gregorian calendar, a Leap year that started on Tuesday of the Common Events 660 BC - Traditional founding date of Japan by Emperor Jimmu. Organic molecules found on alien world for first time. Retrieved on 2008-02-12. 2008 ( MMVIII) is the current year in accordance with the Gregorian calendar, a Leap year that started on Tuesday of the Common Events 1429 - English Forces under Sir John Fastolf defend a supply convoy carrying rations to the army besieging Orleans from attack by the
29. ^ J. H. Lacy, J. S. Carr, N. J. Evans, II, F. Baas, J. M. Achtermann, J. F. Arens (1991). "Discovery of interstellar methane - Observations of gaseous and solid CH4 absorption toward young stars in molecular clouds". Astrophysical Journal 376: 556-560. doi:10.1086/170304. A digital object identifier ( DOI) is a permanent identifier given to an Electronic document.  

External links

• Methane thermodynamics
• Methane in tundra and oceans to be released in atmosphere
• Inorganic Methane
• International Chemical Safety Card 0291
• Methane Hydrates
• Computational Chemistry Wiki
• Molview from bluerhinos.co.uk See Methane in 3D
• Safety data for methane
• Dynamic Viscosity of Methane
• Thermal Conductivity of Methane
• METHANE-EATING BUG HOLDS PROMISE FOR CUTTING GREENHOUSE GAS. Media Release, GNS Science, New Zealand]
• Catalytic conversion of methane to more useful chemicals and fuels