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Methane
other names
Methyl hydride, Marsh gas, firedamp
Identifiers
CAS number 74-82-8 Yes check.svgY
PubChem 297
ChemSpider 291
SMILES
InChI
Properties
Molecular formula CH4
Molar mass 16.042 g/mol
Appearance Colorless gas
Density 0.717 kg/m3, gas
415 kg/m3 liquid
Melting point
-182.5 °C, 91 K, -297 °F
Boiling point
-161.6 °C, 112 K, -259 °F
Solubility in water 35 mg/L (17 °C)
Hazards
MSDS External MSDS
R-phrases R12
S-phrases (S2), S9, S16, S33
NFPA 704
NFPA 704.svg
4
1
0
Flash point -188 °C
Explosive limits 5 – 15% [1]
Related compounds
Related alkanes Ethane, propane
Related compounds Methanol, chloromethane, formic acid, formaldehyde, silane
Supplementary data page
Structure and
properties		 n, εr, etc.
Thermodynamic
data		 Phase behaviour
Solid, liquid, gas
Spectral data UV, IR, NMR, MS
 Yes check.svgY (what is this?)  (verify)
Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references
Methane is a chemical compound with the chemical formula CH4. It is the simplest alkane, and the principal component of natural gas. Methane's bond angles are 109.5 degrees. .Burning methane in the presence of oxygen produces carbon dioxide and water.^ The combustion of methane also requires oxygen to burn producing heat, water vapor and carbon dioxide.

 ^ While carbon dioxide has been fingered as the main culprit, there seems to have been a "fiery" component to the eruption indicating possible presence of combustible methane: "Skin discoloration found on some victims were tentatively interpreted as burns, but this diagnosis is still controversial.
  • Global Warming: Methane Could Be Far Worse Than Carbon Dioxide - Health Supreme 15 January 2010 12:012 UTC www.newmediaexplorer.org [Source type: FILTERED WITH BAYES]

 ^ Response: When methane is combusted, or if it reacts with oxygen in the atmosphere (a very slow type of combustion) the hydrogen in it produces water vapor, rather than hydrogen.
  • RealClimate: Methane hydrates and global warming 15 January 2010 12:012 UTC www.realclimate.org [Source type: FILTERED WITH BAYES]

 The relative abundance of methane makes it an attractive fuel. .However, because it is a gas at normal temperature and pressure, methane is difficult to transport from its source.^ Most important, however, may have been the rise of global temperatures, initiated by carbon dioxide from Traps volcanism, and followed by the high atmospheric levels of methane and its successor greenhouse gas carbon dioxide.
  • Methane Catastrophe 15 January 2010 12:012 UTC www.dcn.davis.ca.us [Source type: FILTERED WITH BAYES]

 ^ Methane is difficult to store, since at normal temperatures the gas can be compressed but not liquefied without special, very expensive equipment.

 ^ Gas storage vessels should be designed with variable volumes, because they must adjust for differences in the rate of gas production and consumption while maintaining uniform pressure.

 .In its natural gas form, it is generally transported in bulk by pipeline or LNG carriers; few countries transport it by truck.^ In my locality the bulk of homes, not mine, are over-heated by natural gas, burned in poorly maintained and, by their nature, in-efficient gas boilers.
  • Global Warming: Methane Could Be Far Worse Than Carbon Dioxide - Health Supreme 15 January 2010 12:012 UTC www.newmediaexplorer.org [Source type: FILTERED WITH BAYES]
.Methane was discovered and isolated by Alessandro Volta between 1776 and 1778 when studying marsh gas from Lake Maggiore.^ I have been working on a project in Africa on Lake Kivu, mentioned in the original article, to produce methane from the 2tcf of dissolved methane gas (and 10tcf of carbon dioxide.
  • Global Warming: Methane Could Be Far Worse Than Carbon Dioxide - Health Supreme 15 January 2010 12:012 UTC www.newmediaexplorer.org [Source type: FILTERED WITH BAYES]
.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).^ Methane is 25 times more potent than carbon dioxide as a greenhouse gas.
  • Could Methane Trigger a Climate Doomsday Within a Human Lifespan? | Wired Science | Wired.com 15 January 2010 12:012 UTC www.wired.com [Source type: General]

 ^ Responses to “Methane hydrates and global warming” .
  • RealClimate: Methane hydrates and global warming 15 January 2010 12:012 UTC www.realclimate.org [Source type: FILTERED WITH BAYES]

 ^ Methane hydrates and global warming .
  • RealClimate: Methane hydrates and global warming 15 January 2010 12:012 UTC www.realclimate.org [Source type: FILTERED WITH BAYES]

 [2] .Methane in the atmosphere is eventually oxidized, producing carbon dioxide and water.^ Methane, as noted numerous times, is quickly oxidized to carbon dioxide.
  • Methane Catastrophe 15 January 2010 12:012 UTC www.dcn.davis.ca.us [Source type: FILTERED WITH BAYES]

 ^ Its current atmospheric concentration of 1.7 ppm by volume, up from 0.7 ppm in preindustrial times, is much lower than the 345 ppm of carbon dioxide, up from 275 ppm.

 ^ The carbon dioxide also would have combined with water to form bicarbonate ions (HCO^3­), which reacted chemically with dissolved calcium to produce calcium carbonate.
  • Methane Catastrophe 15 January 2010 12:012 UTC www.dcn.davis.ca.us [Source type: FILTERED WITH BAYES]

 .As a result, methane in the atmosphere has a half life of seven years.^ The heating effect of the atmospheric methane increase is approximately half that of the carbon dioxide increase (Dickinson and Cicerone 1986, Ramanathan et al.

 ^ The other possibility for our future is an increase in the year-in, year-out chronic rate of methane emission to the atmosphere.
  • RealClimate: Methane hydrates and global warming 15 January 2010 12:012 UTC www.realclimate.org [Source type: FILTERED WITH BAYES]

 ^ Methane concentration in the atmosphere has more than doubled during the last 200 years.
.The abundance of methane in the Earth's atmosphere in 1998 was 1745 parts per billion (ppb), up from 700 ppb in 1750. By 2008, however, global methane levels, which had stayed mostly flat since 1998, had risen to 1,800 ppb[3] and by 2010, methane levels, at least in the arctic, were measured at 1850 ppb, a level scientists described as being higher than at any time in the previous 400,000 years, while noting that historically, methane concentrations in the world's atmosphere have ranged between 300 and 400 ppb in cool periods and 600 to 700 ppb in warm periods.^ Responses to “Methane hydrates and global warming” .
  • RealClimate: Methane hydrates and global warming 15 January 2010 12:012 UTC www.realclimate.org [Source type: FILTERED WITH BAYES]

 ^ Methane hydrates and global warming .
  • RealClimate: Methane hydrates and global warming 15 January 2010 12:012 UTC www.realclimate.org [Source type: FILTERED WITH BAYES]

 ^ September 2008: The methane time bomb Scientists aboard a research ship that has sailed the entire length of Russia's northern coast have discovered intense concentrations of methane – sometimes at up to 100 times background levels – over several areas covering thousands of square miles of the Siberian continental shelf.
  • Global Warming: Methane Could Be Far Worse Than Carbon Dioxide - Health Supreme 15 January 2010 12:012 UTC www.newmediaexplorer.org [Source type: FILTERED WITH BAYES]

 [4]
.Methane can trap about 20 times the heat of CO2.^ Methane is more than 20 times as strong a greenhouse gas as carbon dioxide.
  • Global Warming: Methane Could Be Far Worse Than Carbon Dioxide - Health Supreme 15 January 2010 12:012 UTC www.newmediaexplorer.org [Source type: FILTERED WITH BAYES]

 ^ This fertilizer value is about 1 cent per gallon of digester effluent (1980 price), which works out to 1.5 times the fuel value of the methane.

 ^ Thus even as a trigger for another, greater environmental disaster -- the release of hydrate methane -- the Deccan Traps had poor timing and bad "location, location, location."
  • Methane Catastrophe 15 January 2010 12:012 UTC www.dcn.davis.ca.us [Source type: FILTERED WITH BAYES]

 .In the same time period, CO2 increased from 278 to 365 parts per million.^ Sediment waves presumably develop regularly in various parts of the world ocean seafloor over long periods of time, and their methane likely is also released gradually.
  • Methane Catastrophe 15 January 2010 12:012 UTC www.dcn.davis.ca.us [Source type: FILTERED WITH BAYES]

 ^ An ammonia concentration of 1500 parts per million (ppm) is considered the maximum allowable for good methane production (Table 2).

 .The radiative forcing effect due to this increase in methane abundance is about one-third of that of the CO2 increase.^ Roughly one-third of current global warming is attributable to atmospheric methane (though little of the present methane comes from hydrate).
  • Methane Catastrophe 15 January 2010 12:012 UTC www.dcn.davis.ca.us [Source type: FILTERED WITH BAYES]

 ^ The heating effect of the atmospheric methane increase is approximately half that of the carbon dioxide increase (Dickinson and Cicerone 1986, Ramanathan et al.

 ^ The last one occurred 2-3 kyr years after the stability zone thinned due to increasing water temperature [Mienert et al., 2005], about 8150 years ago.
  • RealClimate: Methane hydrates and global warming 15 January 2010 12:012 UTC www.realclimate.org [Source type: FILTERED WITH BAYES]

 [5] .In addition, there is a large, but unknown, amount of methane in methane clathrates in the ocean floors.^ It started with a buildup of methane on the bottom of large, shallow, stagnant oceans.
  • RealClimate: Methane hydrates and global warming 15 January 2010 12:012 UTC www.realclimate.org [Source type: FILTERED WITH BAYES]

 ^ The massive release of seafloor methane does cause anoxia in the water column, and the accumulation of large amounts of carbon in the sediments would be an immediate effect of the extinction.
  • Methane Catastrophe 15 January 2010 12:012 UTC www.dcn.davis.ca.us [Source type: FILTERED WITH BAYES]

 ^ There is about 400 billion tons of methane inside ice called “hydrate” locked in permafrost, and about 10,000 billion tons under the ocean.
  • Could Methane Trigger a Climate Doomsday Within a Human Lifespan? | Wired Science | Wired.com 15 January 2010 12:012 UTC www.wired.com [Source type: General]

 .The Earth's crust contains huge amounts of methane.^ And slumping -- also attributable to warming or depressurization -- can release huge amounts of methane almost instantaneously.
  • Methane Catastrophe 15 January 2010 12:012 UTC www.dcn.davis.ca.us [Source type: FILTERED WITH BAYES]

 ^ Response: The amount of oxygen in the atmosphere is huge, enough to oxidize 400,000 Gton of C in methane.
  • RealClimate: Methane hydrates and global warming 15 January 2010 12:012 UTC www.realclimate.org [Source type: FILTERED WITH BAYES]

 .Large amounts of methane are produced anaerobically by methanogenesis.^ Large portions of methane formed in an anaerobic soil may remain trapped in the flooded soil.

 ^ The massive release of seafloor methane does cause anoxia in the water column, and the accumulation of large amounts of carbon in the sediments would be an immediate effect of the extinction.
  • Methane Catastrophe 15 January 2010 12:012 UTC www.dcn.davis.ca.us [Source type: FILTERED WITH BAYES]

 ^ A certain amount of methane is also carried upwards by the warmer fluids produced where ocean floor is being subducted beneath continents.
  • Methane Catastrophe 15 January 2010 12:012 UTC www.dcn.davis.ca.us [Source type: FILTERED WITH BAYES]

 Other sources include mud volcanoes, which are connected with deep geological faults, landfill and livestock (primarily ruminants) from enteric fermentation.

Contents

Properties

.Methane is the major component of natural gas, about 87% by volume.^ Methane (CH4), the major component of natural gas, is second in importance as a greenhouse gas.

 ^ Hydroxyl is the major methane-limiting component of the atmosphere; without it, methane concentrations can increase almost without limit.
  • Methane Catastrophe 15 January 2010 12:012 UTC www.dcn.davis.ca.us [Source type: FILTERED WITH BAYES]

 ^ Regarding that methane gas and climate change are non linear, chaotic elements, in nature, is their evidence to support that period doubling has occurred or is occurring?
  • Could Methane Trigger a Climate Doomsday Within a Human Lifespan? | Wired Science | Wired.com 15 January 2010 12:012 UTC www.wired.com [Source type: General]

 .At room temperature and standard pressure, methane is a colorless, odorless gas; the smell characteristic of natural gas as used in homes is an artificial safety measure caused by the addition of an odorant, often methanethiol or ethanethiol.^ Methane is difficult to store, since at normal temperatures the gas can be compressed but not liquefied without special, very expensive equipment.

 ^ The primary constituent of "natural gas," this greenhouse gas is often associated with petroleum or coal, and can cause asphyxiation or explosions in coal mines.
  • Methane Catastrophe 15 January 2010 12:012 UTC www.dcn.davis.ca.us [Source type: FILTERED WITH BAYES]

 ^ The amount of gas released would be enough to cause a shock wave propagating outwards with increasing velocity and pressure until it reached ignition temperature, and then hell would break loose more or less literary.
  • RealClimate: Methane hydrates and global warming 15 January 2010 12:012 UTC www.realclimate.org [Source type: FILTERED WITH BAYES]

 .Methane has a boiling point of −161 °C at a pressure of one atmosphere.^ Could there be a point of break in the equilibrium of atmospheric composition where a celestial body's gas cover can switch from a predominantly nitrogen/oxygen composition to predominantly methane?
  • Global Warming: Methane Could Be Far Worse Than Carbon Dioxide - Health Supreme 15 January 2010 12:012 UTC www.newmediaexplorer.org [Source type: FILTERED WITH BAYES]

 ^ Roughly one-third of current global warming is attributable to atmospheric methane (though little of the present methane comes from hydrate).
  • Methane Catastrophe 15 January 2010 12:012 UTC www.dcn.davis.ca.us [Source type: FILTERED WITH BAYES]

 .As a gas it is flammable only over a narrow range of concentrations (5–15%) in air.^ Even then its range is still narrower: it does not signify every form of wholesome concentration, but only the intensified concentration that results from a deliberate attempt to raise the mind to a higher, more purified level of awareness.
  • The Noble Eightfold Path: The Way to the End of Suffering 16 September 2009 22:022 UTC www.accesstoinsight.org [Source type: Original source]

 .Liquid methane does not burn unless subjected to high pressure (normally 4–5 atmospheres).^ The expelled fluid does mix with the seawater, however, often producing detectable plumes of water of low salinity and high methane content in the seawater above.
  • Methane Catastrophe 15 January 2010 12:012 UTC www.dcn.davis.ca.us [Source type: FILTERED WITH BAYES]

 ^ The increased and sustained production of methane would have protracted marine anoxia and sustained high methane levels in the atmosphere.
  • Methane Catastrophe 15 January 2010 12:012 UTC www.dcn.davis.ca.us [Source type: FILTERED WITH BAYES]

 ^ Kevin Whilden says: 13 December 2005 at 1:38 PM When Methane decomposes in the atmosphere, does it absorb oxygen in significant quantities?
  • RealClimate: Methane hydrates and global warming 15 January 2010 12:012 UTC www.realclimate.org [Source type: FILTERED WITH BAYES]

Potential health effects

.Methane is not toxic; however, it is highly flammable and may form explosive mixtures with air.^ Finally, methane can form an explosive mixture if exposed to air.

 ^ Large portions of methane formed in an anaerobic soil may remain trapped in the flooded soil.

 ^ Methane is extremely explosive when mixed with air at the proportions of 6-15 percent methane.

 Methane is violently reactive with oxidizers, halogens, and some halogen-containing compounds. .Methane is also an asphyxiant and may displace oxygen in an enclosed space.^ Peter Ward has a theory that the Permian extinction may have been exacerbated by methane releases coupled with plummeting oxygen levels that further reduced the ability of animals to cope.
  • RealClimate: Methane hydrates and global warming 15 January 2010 12:012 UTC www.realclimate.org [Source type: FILTERED WITH BAYES]

 ^ It may as David speculated they need oxygen or sulfates in an area to be viable, and are thus unable to exploit all the methane hydrates on the sea bed.
  • RealClimate: Methane hydrates and global warming 15 January 2010 12:012 UTC www.realclimate.org [Source type: FILTERED WITH BAYES]

 ^ Methane itself First, methane itself is, like carbon dioxide, an asphyxiating gas, depriving aerobic organisms of needed oxygen.
  • Methane Catastrophe 15 January 2010 12:012 UTC www.dcn.davis.ca.us [Source type: FILTERED WITH BAYES]

 .Asphyxia may result if the oxygen concentration is reduced to below 19.5% by displacement[citation needed].^ Sulfate-reducers, not being quite as strict anaerobes as methanogens, would have expanded into areas where there were low concentrations of oxygen (highly dysoxic areas), from which methanogens would have been excluded.
  • Methane Catastrophe 15 January 2010 12:012 UTC www.dcn.davis.ca.us [Source type: FILTERED WITH BAYES]

 ^ Peter Ward has a theory that the Permian extinction may have been exacerbated by methane releases coupled with plummeting oxygen levels that further reduced the ability of animals to cope.
  • RealClimate: Methane hydrates and global warming 15 January 2010 12:012 UTC www.realclimate.org [Source type: FILTERED WITH BAYES]

 ^ Lake Nyos fills a volcanic crater; the high concentrations of carbon dioxide in its bottom waters result from the continual seepage of that gas from the magma chamber below.
  • Methane Catastrophe 15 January 2010 12:012 UTC www.dcn.davis.ca.us [Source type: FILTERED WITH BAYES]

 .The concentrations at which flammable or explosive mixtures form are much lower than the concentration at which asphyxiation risk is significant.^ Its current atmospheric concentration of 1.7 ppm by volume, up from 0.7 ppm in preindustrial times, is much lower than the 345 ppm of carbon dioxide, up from 275 ppm.

 ^ Response: I think even water vapor is a small component of the density differences in the atmosphere, and methane is much lower concentration.
  • RealClimate: Methane hydrates and global warming 15 January 2010 12:012 UTC www.realclimate.org [Source type: FILTERED WITH BAYES]

 .When structures are built on or near landfills, methane off-gas can penetrate the buildings' interiors and expose occupants to significant levels of methane.^ On occasion, the pressure of the buoyant methane hydrate and free methane gas can break through the domal structure to erupt as a mud volcano.
  • Methane Catastrophe 15 January 2010 12:012 UTC www.dcn.davis.ca.us [Source type: FILTERED WITH BAYES]

 ^ China and India Exploit Icy Energy Reserves China and India have reported massive finds of frozen methane gas off their coasts, which they hope will satisfy their energy needs.
  • Global Warming: Methane Could Be Far Worse Than Carbon Dioxide - Health Supreme 15 January 2010 12:012 UTC www.newmediaexplorer.org [Source type: FILTERED WITH BAYES]

 .Some buildings have specially engineered recovery systems below their basements to actively capture such fugitive off-gas and vent it away from the building.^ The demise of the last members of such species may hang on for some decades, but their ultimate doom is assured.
  • Methane Catastrophe 15 January 2010 12:012 UTC www.dcn.davis.ca.us [Source type: FILTERED WITH BAYES]

 ^ Some may have "re-crystalized" but crystal growth processes are slow and CH4 gas would have gone upward and away.
  • Global Warming: Methane Could Be Far Worse Than Carbon Dioxide - Health Supreme 15 January 2010 12:012 UTC www.newmediaexplorer.org [Source type: FILTERED WITH BAYES]

 [citation needed] An example of this type of system is in the Dakin Building, Brisbane, California.

Reactions of methane

Main reactions with methane are: combustion, steam reforming to syngas, and halogenation. 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.^ The carbon dioxide also would have combined with water to form bicarbonate ions (HCO^3­), which reacted chemically with dissolved calcium to produce calcium carbonate.
  • Methane Catastrophe 15 January 2010 12:012 UTC www.dcn.davis.ca.us [Source type: FILTERED WITH BAYES]

 ^ The proposal cites as an example of such explosive effervescence the eruption of volcanic Lake Nyos in Cameroon, Africa, in 1986, where carbon dioxide that had accumulated in the bottom of the lake blasted out in a gas-water fountain for several hours.
  • Methane Catastrophe 15 January 2010 12:012 UTC www.dcn.davis.ca.us [Source type: FILTERED WITH BAYES]

 ^ They sequentially oxidize methane to carbon dioxide via methanol, formaldehyde, and formate.

Combustion

In the combustion of methane, several steps are involved:
Methane is thought to form a formaldehyde (HCHO or H2CO). .The formaldehyde gives a formyl radical (HCO), which then forms carbon monoxide (CO).^ The carbon dioxide also would have combined with water to form bicarbonate ions (HCO^3­), which reacted chemically with dissolved calcium to produce calcium carbonate.
  • Methane Catastrophe 15 January 2010 12:012 UTC www.dcn.davis.ca.us [Source type: FILTERED WITH BAYES]

 ^ In addition, the excess alkalinity (represented in the equation by the bicarbonate ion, HCO^3­) combines with dissolved calcium ions to form calcium carbonate, which also precipitates out.
  • Methane Catastrophe 15 January 2010 12:012 UTC www.dcn.davis.ca.us [Source type: FILTERED WITH BAYES]

 The process is called oxidative pyrolysis:
CH4 + O2 → CO + H2 + H2O
Following oxidative pyrolysis, the H2 oxidizes, forming H2O, releasing heat. This occurs very quickly, usually in significantly less than a millisecond.
2 H2 + O2 → 2 H2O
Finally, the CO oxidizes, forming CO2 and releasing more heat. .This process is generally slower than the other chemical steps, and typically requires a few to several milliseconds to occur.^ Right view requires more than a simple knowledge of the general meaning of kamma.
  • The Noble Eightfold Path: The Way to the End of Suffering 16 September 2009 22:022 UTC www.accesstoinsight.org [Source type: Original source]

 ^ They can be more aptly described as components rather than as steps, comparable to the intertwining strands of a single cable that requires the contributions of all the strands for maximum strength.
  • The Noble Eightfold Path: The Way to the End of Suffering 16 September 2009 22:022 UTC www.accesstoinsight.org [Source type: Original source]

 ^ Sulfate Reduction Sulfate reduction produces hydrogen sulfide (and several other ionic compounds, including the bicarbonate ion, HCO^3­) according the following generalized equation.
  • Methane Catastrophe 15 January 2010 12:012 UTC www.dcn.davis.ca.us [Source type: FILTERED WITH BAYES]
2 CO + O2 → 2 CO2
The result of the above is the following total equation:
CH4(g) + 2 O2(g) → CO2(g) + 2 H2O(l) +891 kJ/mol
where bracketed "g" stands for gaseous form and bracketed "l" stands for liquid form.

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.^ It may as David speculated they need oxygen or sulfates in an area to be viable, and are thus unable to exploit all the methane hydrates on the sea bed.
  • RealClimate: Methane hydrates and global warming 15 January 2010 12:012 UTC www.realclimate.org [Source type: FILTERED WITH BAYES]

 ^ Thus the continental margin methane release proposal meets all of the criteria suggested by Bowring and his co-workers (1998).
  • Methane Catastrophe 15 January 2010 12:012 UTC www.dcn.davis.ca.us [Source type: FILTERED WITH BAYES]

 ^ But hydrogen sulfide is also a chemically active gas, and it can combine with and neutralize those gases which would interfere with methane's rise into the stratosphere.
  • Methane Catastrophe 15 January 2010 12:012 UTC www.dcn.davis.ca.us [Source type: FILTERED WITH BAYES]

 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. 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.

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).^ Then came the end-Permian volcanism, spewing out halogen gases (fluorine, chlorine, and bromine), helping deplete stratospheric ozone.
  • Methane Catastrophe 15 January 2010 12:012 UTC www.dcn.davis.ca.us [Source type: FILTERED WITH BAYES]

 This mechanism for this process is called free radical halogenation. When X is Cl, this mechanism has the following form:
1. Radical generation:
\mathrm{Cl_2 \xrightarrow[ riangle]{UV} 2Cl^\bullet - 239 \; kJ}
The needed energy comes from UV radiation or heating,
2. Radical exchange:
CH4 + Cl· → CH3· + HCl + 14 kJ
CH3· + Cl2 → CH3Cl + Cl· + 100 kJ
3. Radical extermination:
2 Cl· → Cl2 + 239 kJ
CH3· + Cl· → CH3Cl + 339 kJ
2 CH3· → CH3CH3 + 347 kJ
.If methane and X2 are used in equimolar quantities, CH2X2, CHX3, and even CX4 are formed.^ Produced by the dissociation of large quantities of methane hydrate, mud volcanoes form structures that resemble typical volcanic cones.
  • Methane Catastrophe 15 January 2010 12:012 UTC www.dcn.davis.ca.us [Source type: FILTERED WITH BAYES]

 .Using a large excess of CH4 reduces the production of CH2X2, CHX3, CX4, and thus more CH3X is formed.^ In preferentially using the oceanic sulfate with the lighter rather than the heavier isotope (that is, ^ 32S rather than ^ 34S), the lighter isotope would have become more prominent in the sulfide waste product of the sulfur-reducers and the heavier isotope more prominent in the remaining sulfate.
  • Methane Catastrophe 15 January 2010 12:012 UTC www.dcn.davis.ca.us [Source type: FILTERED WITH BAYES]

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.^ The methane gas is a great fuel.
  • Global Warming: Methane Could Be Far Worse Than Carbon Dioxide - Health Supreme 15 January 2010 12:012 UTC www.newmediaexplorer.org [Source type: FILTERED WITH BAYES]

 ^ "How likely is it that humans will cause methane burps by burning fossil fuels?
  • Global Warming: Methane Could Be Far Worse Than Carbon Dioxide - Health Supreme 15 January 2010 12:012 UTC www.newmediaexplorer.org [Source type: FILTERED WITH BAYES]

 ^ The methane is oxidized to CO 2 , another greenhouse gas that accumulates for hundreds of thousands of years, same as fossil fuel CO 2 does.
  • RealClimate: Methane hydrates and global warming 15 January 2010 12:012 UTC www.realclimate.org [Source type: FILTERED WITH BAYES]

 .Compared to other hydrocarbon fuels, burning methane produces less carbon dioxide for each unit of heat released.^ The carbon dioxide also would have combined with water to form bicarbonate ions (HCO^3­), which reacted chemically with dissolved calcium to produce calcium carbonate.
  • Methane Catastrophe 15 January 2010 12:012 UTC www.dcn.davis.ca.us [Source type: FILTERED WITH BAYES]

 ^ The massive release of seafloor methane does cause anoxia in the water column, and the accumulation of large amounts of carbon in the sediments would be an immediate effect of the extinction.
  • Methane Catastrophe 15 January 2010 12:012 UTC www.dcn.davis.ca.us [Source type: FILTERED WITH BAYES]

 ^ Methanotrophs use oxygen to oxidize methane into carbon dioxide (CO2).
  • RealClimate: Methane hydrates and global warming 15 January 2010 12:012 UTC www.realclimate.org [Source type: FILTERED WITH BAYES]

 .At about 891 kJ/mol, methane's heat of combustion is lower than any other hydrocarbon but the ratio of the heat of combustion (891 kJ/mol) to the molecular mass (16.0 g/mol) shows that methane, being the simplest hydrocarbon, produces more heat per mass unit (55.7 kJ/g) than other complex hydrocarbons.^ "Abstaining from taking life" has a wider application than simply refraining from killing other human beings.
  • The Noble Eightfold Path: The Way to the End of Suffering 16 September 2009 22:022 UTC www.accesstoinsight.org [Source type: Original source]

 ^ It exhibits lower permeability and higher bulk density and mechanical strength than other soil layers.

 ^ However, methanogenesis and sulfate reduction are nor mutually exclusive when methane is produced from methanol and methylated amines for which sulfate reducers show little affinity (Oremland et al.

 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.
.Methane in the form of compressed natural gas is used as a vehicle fuel, and is claimed to be more environmentally friendly than other fossil fuels such as gasoline/petrol and diesel.^ The methane gas is a great fuel.
  • Global Warming: Methane Could Be Far Worse Than Carbon Dioxide - Health Supreme 15 January 2010 12:012 UTC www.newmediaexplorer.org [Source type: FILTERED WITH BAYES]

 ^ We need to use more fossil fuels.
  • Global Warming: Methane Could Be Far Worse Than Carbon Dioxide - Health Supreme 15 January 2010 12:012 UTC www.newmediaexplorer.org [Source type: FILTERED WITH BAYES]

 ^ Yet methane gas could be used as a cleaner fuel than gasoline or diesel.
  • Global Warming: Methane Could Be Far Worse Than Carbon Dioxide - Health Supreme 15 January 2010 12:012 UTC www.newmediaexplorer.org [Source type: FILTERED WITH BAYES]

 [6]
Research is being conducted by NASA on methane's potential as a rocket fuel.[7] One advantage of methane is that it is abundant in many parts of the solar system and it could potentially be harvested in situ (i.e. on the surface of another solar-system body), providing fuel for a return journey.[8]
Current methane engines in development produce a thrust of 7,500 pounds-force (33 kN), which is far from the 7,000,000 lbf (31 MN) needed to launch the Space Shuttle. .Instead, such engines will most likely propel voyages from our moon or send robotic expeditions to other planets in the solar system.^ Whether this is a man made effect or depends on solar activity or other environmental factors outside of our control is an open question.
  • Global Warming: Methane Could Be Far Worse Than Carbon Dioxide - Health Supreme 15 January 2010 12:012 UTC www.newmediaexplorer.org [Source type: FILTERED WITH BAYES]

 [9]
Recently methane emitted from coal mines has been successfully converted to electricity.[10]

Industrial uses

.Methane is used in industrial chemical processes and may be transported as a refrigerated liquid (liquefied natural gas, or LNG).^ Some may have "re-crystalized" but crystal growth processes are slow and CH4 gas would have gone upward and away.
  • Global Warming: Methane Could Be Far Worse Than Carbon Dioxide - Health Supreme 15 January 2010 12:012 UTC www.newmediaexplorer.org [Source type: FILTERED WITH BAYES]

 ^ Could the same process be used in the tundra lakes which are beginning to release methane as a result of global warming.
  • Global Warming: Methane Could Be Far Worse Than Carbon Dioxide - Health Supreme 15 January 2010 12:012 UTC www.newmediaexplorer.org [Source type: FILTERED WITH BAYES]

 ^ If natural gas (methane) must be used then it would be better burned in specialised efficient power stations, with CO2 cleaners, and the resulting power distributed as clean electricity.
  • Global Warming: Methane Could Be Far Worse Than Carbon Dioxide - Health Supreme 15 January 2010 12:012 UTC www.newmediaexplorer.org [Source type: FILTERED WITH BAYES]

 .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.^ Worse, as the Arctic Council found, the highest temperature increases from human greenhouse gas emissions will occur in the arctic regions - an area rich in these unstable clathrates.
  • Global Warming: Methane Could Be Far Worse Than Carbon Dioxide - Health Supreme 15 January 2010 12:012 UTC www.newmediaexplorer.org [Source type: FILTERED WITH BAYES]

 ^ Carbon dioxide is heavier than air, and therefore does not dissipate as readily as methane, which is lighter than air, does.
  • Methane Catastrophe 15 January 2010 12:012 UTC www.dcn.davis.ca.us [Source type: FILTERED WITH BAYES]

 ^ I wonder whether collapsing of ice-shelves of antarctica is due to increase in temperature of outer atmosphere or something going on on or under the surface of the earth.
  • Global Warming: Methane Could Be Far Worse Than Carbon Dioxide - Health Supreme 15 January 2010 12:012 UTC www.newmediaexplorer.org [Source type: FILTERED WITH BAYES]

 .Gas pipelines distribute large amounts of natural gas, of which methane is the principal component.^ The massive release of seafloor methane does cause anoxia in the water column, and the accumulation of large amounts of carbon in the sediments would be an immediate effect of the extinction.
  • Methane Catastrophe 15 January 2010 12:012 UTC www.dcn.davis.ca.us [Source type: FILTERED WITH BAYES]

 ^ Hydrogen sulfide escape from ocean confinement depends in part on the amount of oxygen in surface waters, which largely depends on the amount of oxygen in the atmosphere as it exchanges gas with the ocean across their interface.
  • Methane Catastrophe 15 January 2010 12:012 UTC www.dcn.davis.ca.us [Source type: FILTERED WITH BAYES]

 ^ Second, this boundary layer can be made even more unstable by the increase of gas pressure produced as the amount of free methane accumulates below.
  • Methane Catastrophe 15 January 2010 12:012 UTC www.dcn.davis.ca.us [Source type: FILTERED WITH BAYES]
.In the chemical industry, methane is the feedstock of choice for the production of hydrogen, methanol, acetic acid, and acetic anhydride.^ More importantly, a large methane release would have inhibited the production of oxygen both from marine phytoplankton, via altered oceanic chemical and biological conditions, and from terrestrial plants, by the increase of acid rain.
  • Methane Catastrophe 15 January 2010 12:012 UTC www.dcn.davis.ca.us [Source type: FILTERED WITH BAYES]

 ^ But hydrogen sulfide is also a chemically active gas, and it can combine with and neutralize those gases which would interfere with methane's rise into the stratosphere.
  • Methane Catastrophe 15 January 2010 12:012 UTC www.dcn.davis.ca.us [Source type: FILTERED WITH BAYES]

 .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.^ Response: When methane is combusted, or if it reacts with oxygen in the atmosphere (a very slow type of combustion) the hydrogen in it produces water vapor, rather than hydrogen.
  • RealClimate: Methane hydrates and global warming 15 January 2010 12:012 UTC www.realclimate.org [Source type: FILTERED WITH BAYES]

 ^ The carbon dioxide also would have combined with water to form bicarbonate ions (HCO^3­), which reacted chemically with dissolved calcium to produce calcium carbonate.
  • Methane Catastrophe 15 January 2010 12:012 UTC www.dcn.davis.ca.us [Source type: FILTERED WITH BAYES]

 ^ Methane is more than 20 times as strong a greenhouse gas as carbon dioxide.
  • Global Warming: Methane Could Be Far Worse Than Carbon Dioxide - Health Supreme 15 January 2010 12:012 UTC www.newmediaexplorer.org [Source type: FILTERED WITH BAYES]

 In this process, methane and steam react on a nickel catalyst at high temperatures (700–1100 °C).
\mathrm{CH}_4 + \mathrm{H_2O} \xrightarrow[700-1100 \ \mathrm{^oC}]{\mathrm{Ni}} \mathrm{CO + 3H_2}
.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.^ Hydrogen sulfide escape from ocean confinement depends in part on the amount of oxygen in surface waters, which largely depends on the amount of oxygen in the atmosphere as it exchanges gas with the ocean across their interface.
  • Methane Catastrophe 15 January 2010 12:012 UTC www.dcn.davis.ca.us [Source type: FILTERED WITH BAYES]

 ^ In the atmosphere, carbon dioxide, methane, ozone, and water vapor absorb IR by this method (Vibration of Gas Molecules).
  • Global Warming: Methane Could Be Far Worse Than Carbon Dioxide - Health Supreme 15 January 2010 12:012 UTC www.newmediaexplorer.org [Source type: FILTERED WITH BAYES]

 ^ This warming would have been caused by the greenhouse gas methane, its successor gas carbon dioxide, and the increased presence in the atmosphere of water vapor, the result of the warming.
  • Methane Catastrophe 15 January 2010 12:012 UTC www.dcn.davis.ca.us [Source type: FILTERED WITH BAYES]
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.^ Response: When methane is combusted, or if it reacts with oxygen in the atmosphere (a very slow type of combustion) the hydrogen in it produces water vapor, rather than hydrogen.
  • RealClimate: Methane hydrates and global warming 15 January 2010 12:012 UTC www.realclimate.org [Source type: FILTERED WITH BAYES]

 ^ The carbon dioxide also would have combined with water to form bicarbonate ions (HCO^3­), which reacted chemically with dissolved calcium to produce calcium carbonate.
  • Methane Catastrophe 15 January 2010 12:012 UTC www.dcn.davis.ca.us [Source type: FILTERED WITH BAYES]

 ^ Small amounts of methane are always being released through dissociation; massive dissociation refers to significant breakup of the clathrates, and a major release of methane.
  • Methane Catastrophe 15 January 2010 12:012 UTC www.dcn.davis.ca.us [Source type: FILTERED WITH BAYES]

 .However, the use of these chemicals is declining.^ We leave these comments on the social context, however, to concentrate on the moral issues surrounding the positive/negative distinction and its uses.
  • http://www.nyu.edu/gsas/dept/philo/courses/bioethics/Papers/GeneBook/CH4.html 16 September 2009 22:022 UTC www.nyu.edu [Source type: Original source]

 Acetylene is replaced by less costly substitutes, and the use of chloromethanes is diminishing due to health and environmental concerns.

Sources of methane for human use

Natural gas fields

.The major source of methane is extraction from geological deposits known as natural gas fields.^ If natural gas (methane) must be used then it would be better burned in specialised efficient power stations, with CO2 cleaners, and the resulting power distributed as clean electricity.
  • Global Warming: Methane Could Be Far Worse Than Carbon Dioxide - Health Supreme 15 January 2010 12:012 UTC www.newmediaexplorer.org [Source type: FILTERED WITH BAYES]

 ^ Regarding that methane gas and climate change are non linear, chaotic elements, in nature, is their evidence to support that period doubling has occurred or is occurring?
  • Could Methane Trigger a Climate Doomsday Within a Human Lifespan? | Wired Science | Wired.com 15 January 2010 12:012 UTC www.wired.com [Source type: General]

 ^ In his study’s scenario, methane frozen with water in what’s known as a "clathrate" (or gas hydrate) became destabilized at lower latitudes and began to release methane gas.
  • Could Methane Trigger a Climate Doomsday Within a Human Lifespan? | Wired Science | Wired.com 15 January 2010 12:012 UTC www.wired.com [Source type: General]

 It is associated with other hydrocarbon fuels and sometimes accompanied by helium and nitrogen. .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.^ Corganic + 2H2O = CO2 + CH4 This is a strictly anaerobic process, methanogenic bacteria are poisoned by the presence of oxygen at levels as low as 0.18 mg/L of soluble oxygen (as O2).
  • RealClimate: Methane hydrates and global warming 15 January 2010 12:012 UTC www.realclimate.org [Source type: FILTERED WITH BAYES]

 ^ Coal and tar and oil and methane may all come from a different source - not the decaying matter of ancient tree growth as it is often said.
  • Global Warming: Methane Could Be Far Worse Than Carbon Dioxide - Health Supreme 15 January 2010 12:012 UTC www.newmediaexplorer.org [Source type: FILTERED WITH BAYES]

 ^ Both methane and hydrogen sulfide destroy ozone, but because hydrogen sulfide is a much heavier gas, it tends to destroy the ozone closest to Earth's surface.
  • Methane Catastrophe 15 January 2010 12:012 UTC www.dcn.davis.ca.us [Source type: FILTERED WITH BAYES]

 .In general, sediments buried deeper and at higher temperatures than those which give oil generate natural gas.^ Response: I'm skeptical about methane for the PETM myself, in that the temperature change and pH change seems to require more CO2 than the isotope spike will give you, if it's methane.
  • RealClimate: Methane hydrates and global warming 15 January 2010 12:012 UTC www.realclimate.org [Source type: FILTERED WITH BAYES]

 ^ Here the doming provides places where oil and natural gas can accumulate.
  • Methane Catastrophe 15 January 2010 12:012 UTC www.dcn.davis.ca.us [Source type: FILTERED WITH BAYES]

 ^ At some depth it becomes too warm for hydrate, so hydrate melts if it becomes buried deeper than this depth.
  • RealClimate: Methane hydrates and global warming 15 January 2010 12:012 UTC www.realclimate.org [Source type: FILTERED WITH BAYES]

 .Methane is also produced in considerable quantities from the decaying organic wastes of solid waste landfills.^ Produced by the dissociation of large quantities of methane hydrate, mud volcanoes form structures that resemble typical volcanic cones.
  • Methane Catastrophe 15 January 2010 12:012 UTC www.dcn.davis.ca.us [Source type: FILTERED WITH BAYES]

 ^ Obviously, the amount of oxygen drawn down, and the amount of carbon dioxide produced, depended on the quantity of methane released.
  • Methane Catastrophe 15 January 2010 12:012 UTC www.dcn.davis.ca.us [Source type: FILTERED WITH BAYES]

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.^ Sulfate Reduction Sulfate reduction produces hydrogen sulfide (and several other ionic compounds, including the bicarbonate ion, HCO^3­) according the following generalized equation.
  • Methane Catastrophe 15 January 2010 12:012 UTC www.dcn.davis.ca.us [Source type: FILTERED WITH BAYES]

 ^ With anoxic conditions in the deeper ocean, anaerobic organisms, including methanogens and sulfate-reducers, would have thrived.
  • Methane Catastrophe 15 January 2010 12:012 UTC www.dcn.davis.ca.us [Source type: FILTERED WITH BAYES]

 ^ To resolve some of these issues, we will have to discuss alternative accounts of our obligations to assist others with medical services, including those based on genetic technologies.
  • http://www.nyu.edu/gsas/dept/philo/courses/bioethics/Papers/GeneBook/CH4.html 16 September 2009 22:022 UTC www.nyu.edu [Source type: Original source]

 .Methane hydrates/clathrates (ice-like combinations of methane and water on the sea floor, found in vast quantities) are a potential future source of methane.^ Hydrates, remember, are composed of water ice.
  • Methane Catastrophe 15 January 2010 12:012 UTC www.dcn.davis.ca.us [Source type: FILTERED WITH BAYES]

 ^ Why do we have vast quantities of methane hydrates in the ocean at all?
  • RealClimate: Methane hydrates and global warming 15 January 2010 12:012 UTC www.realclimate.org [Source type: FILTERED WITH BAYES]

 ^ Hydrate floats in water just like regular ice floats in water, carrying methane to the atmosphere much more efficiently than bubbles [Brewer et al., 2002].
  • RealClimate: Methane hydrates and global warming 15 January 2010 12:012 UTC www.realclimate.org [Source type: FILTERED WITH BAYES]

 .Cattle belch methane accounts for 16% of the world's annual methane emissions to the atmosphere.^ The other possibility for our future is an increase in the year-in, year-out chronic rate of methane emission to the atmosphere.
  • RealClimate: Methane hydrates and global warming 15 January 2010 12:012 UTC www.realclimate.org [Source type: FILTERED WITH BAYES]

 [11] The livestock sector in general (primarily cattle, chickens, and pigs) produces 37% of all human-induced methane.[12] Early research has found a number of medical treatments and dietary adjustments that help slightly limit the production of methane in ruminants.[13][14]
.Industrially, methane can be created from common atmospheric gases and hydrogen (produced, for example, by electrolysis) through chemical reactions such as the Sabatier process, Fischer-Tropsch process.^ Over such extended lengths of time, neither methane nor additional carbon dioxide would have had much effect -- if any -- on atmospheric concentrations of carbon dioxide or ocean chemistry.
  • Methane Catastrophe 15 January 2010 12:012 UTC www.dcn.davis.ca.us [Source type: FILTERED WITH BAYES]

 ^ The quantities of hydrogen sulfide that would have been produced in an anoxic ocean are not negligible: for each sulfate ion that is employed in the sulfate-reduction process, a molecule of hydrogen sulfide is produced (see Box).
  • Methane Catastrophe 15 January 2010 12:012 UTC www.dcn.davis.ca.us [Source type: FILTERED WITH BAYES]

 ^ But hydrogen sulfide is also a chemically active gas, and it can combine with and neutralize those gases which would interfere with methane's rise into the stratosphere.
  • Methane Catastrophe 15 January 2010 12:012 UTC www.dcn.davis.ca.us [Source type: FILTERED WITH BAYES]

 Coal bed methane extraction is a method for extracting methane from a coal deposit, while enhanced coal bed methane recovery is a method of recovering methane from an non-minable coal seam.
.Scientific experiments have given variable results in determining whether plants are a source of methane emissions.^ Consider the accompanying figure, which reports on the results of an experiment testing how different genotypes from natural populations survive in a variety of environments that vary in temperature.
  • http://www.nyu.edu/gsas/dept/philo/courses/bioethics/Papers/GeneBook/CH4.html 16 September 2009 22:022 UTC www.nyu.edu [Source type: Original source]

 [15][16][17]

Atmospheric methane

Main article: Atmospheric methane
2006-2009 Methane concentration in the upper troposphere.
.Methane is created near the Earth's surface, primarily in soils, rivers/seas and in animal innards.^ Both methane and hydrogen sulfide destroy ozone, but because hydrogen sulfide is a much heavier gas, it tends to destroy the ozone closest to Earth's surface.
  • Methane Catastrophe 15 January 2010 12:012 UTC www.dcn.davis.ca.us [Source type: FILTERED WITH BAYES]

 ^ As with other methane that is released through the sediments by trickling, most is consumed by methanogens near the sediment surface.
  • Methane Catastrophe 15 January 2010 12:012 UTC www.dcn.davis.ca.us [Source type: FILTERED WITH BAYES]

 .It is carried into the stratosphere by rising air in the tropics.^ But hydrogen sulfide is also a chemically active gas, and it can combine with and neutralize those gases which would interfere with methane's rise into the stratosphere.
  • Methane Catastrophe 15 January 2010 12:012 UTC www.dcn.davis.ca.us [Source type: FILTERED WITH BAYES]

 ^ Being much lighter, however, methane can rise into the stratosphere.
  • Methane Catastrophe 15 January 2010 12:012 UTC www.dcn.davis.ca.us [Source type: FILTERED WITH BAYES]

 .Uncontrolled build-up of methane in the 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.^ With the rise of atmospheric oxygen beginning about 2 1/2 billion years ago, this gas -- composed of molecules with three oxygen atoms -- was also produced.
  • Methane Catastrophe 15 January 2010 12:012 UTC www.dcn.davis.ca.us [Source type: FILTERED WITH BAYES]

 ^ The quantity of water vapor in the atmosphere is determined by temperature, and varies greatly from place to place.
  • Methane Catastrophe 15 January 2010 12:012 UTC www.dcn.davis.ca.us [Source type: FILTERED WITH BAYES]

 ^ Hydrogen sulfide escape from ocean confinement depends in part on the amount of oxygen in surface waters, which largely depends on the amount of oxygen in the atmosphere as it exchanges gas with the ocean across their interface.
  • Methane Catastrophe 15 January 2010 12:012 UTC www.dcn.davis.ca.us [Source type: FILTERED WITH BAYES]
.Methane in the Earth's atmosphere is an important greenhouse gas with a global warming potential of 25 compared to CO2 over a 100-year period.^ Most important, however, may have been the rise of global temperatures, initiated by carbon dioxide from Traps volcanism, and followed by the high atmospheric levels of methane and its successor greenhouse gas carbon dioxide.
  • Methane Catastrophe 15 January 2010 12:012 UTC www.dcn.davis.ca.us [Source type: FILTERED WITH BAYES]

 ^ Traps volcanism would have had important additional consequences unrelated to continental margin methane release, but providing in themselves mechanisms for altering the course of life on Earth.
  • Methane Catastrophe 15 January 2010 12:012 UTC www.dcn.davis.ca.us [Source type: FILTERED WITH BAYES]

 ^ With the rise of atmospheric oxygen beginning about 2 1/2 billion years ago, this gas -- composed of molecules with three oxygen atoms -- was also produced.
  • Methane Catastrophe 15 January 2010 12:012 UTC www.dcn.davis.ca.us [Source type: FILTERED WITH BAYES]

 .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, as noted numerous times, is quickly oxidized to carbon dioxide.
  • Methane Catastrophe 15 January 2010 12:012 UTC www.dcn.davis.ca.us [Source type: FILTERED WITH BAYES]

 ^ Most important, however, may have been the rise of global temperatures, initiated by carbon dioxide from Traps volcanism, and followed by the high atmospheric levels of methane and its successor greenhouse gas carbon dioxide.
  • Methane Catastrophe 15 January 2010 12:012 UTC www.dcn.davis.ca.us [Source type: FILTERED WITH BAYES]

 ^ Once the dumping of carbon dioxide into the atmosphere ceases, the amount of carbon dioxide will decline over the centuries, but an appreciable quantity (perhaps 7%) will still be around in 100,000 years.
  • Methane Catastrophe 15 January 2010 12:012 UTC www.dcn.davis.ca.us [Source type: FILTERED WITH BAYES]

 .Methane has a large effect for a brief period (a net lifetime of 8.4 years in the atmosphere), whereas carbon dioxide has a small effect for a long period (over 100 years).^ Most important, however, may have been the rise of global temperatures, initiated by carbon dioxide from Traps volcanism, and followed by the high atmospheric levels of methane and its successor greenhouse gas carbon dioxide.
  • Methane Catastrophe 15 January 2010 12:012 UTC www.dcn.davis.ca.us [Source type: FILTERED WITH BAYES]

 ^ The massive release of seafloor methane does cause anoxia in the water column, and the accumulation of large amounts of carbon in the sediments would be an immediate effect of the extinction.
  • Methane Catastrophe 15 January 2010 12:012 UTC www.dcn.davis.ca.us [Source type: FILTERED WITH BAYES]

 ^ Compounding the effects of low oxygen would have been the increase in carbon dioxide, producing further impairment or death by hypercapnia to sensitive organisms in the surface ocean (which exchanges gas with the atmosphere), and physiological damage or death to organisms along affected coastlines.
  • Methane Catastrophe 15 January 2010 12:012 UTC www.dcn.davis.ca.us [Source type: FILTERED WITH BAYES]

 .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.^ At its peak metta rises to the heights of a brahmavihara, a "divine dwelling," a total way of being centered on the radiant wish for the welfare of all living beings.
  • The Noble Eightfold Path: The Way to the End of Suffering 16 September 2009 22:022 UTC www.accesstoinsight.org [Source type: Original source]

 ^ Although, upon reaching the atmosphere, methane could have had similar effects on non-marine organisms, its concentrations would have been unlikely to do much harm, because methane is lighter than air and would have been easily dispersed by winds.
  • Methane Catastrophe 15 January 2010 12:012 UTC www.dcn.davis.ca.us [Source type: FILTERED WITH BAYES]

 ^ Roughly one-third of current global warming is attributable to atmospheric methane (though little of the present methane comes from hydrate).
  • Methane Catastrophe 15 January 2010 12:012 UTC www.dcn.davis.ca.us [Source type: FILTERED WITH BAYES]

 [18] .Usually, excess methane from landfills and other natural producers of methane is burned so CO2 is released into the atmosphere instead of methane, because methane is such a more effective greenhouse gas.^ More importantly, the depletion of hydroxyl increases the longevity of methane in the atmosphere, so that instead of having a residence time (lifetime) in the atmosphere of less than ten years, methane can stick around much longer, significantly extending its powerful greenhouse gas warming.
  • Methane Catastrophe 15 January 2010 12:012 UTC www.dcn.davis.ca.us [Source type: FILTERED WITH BAYES]

 ^ Most important, however, may have been the rise of global temperatures, initiated by carbon dioxide from Traps volcanism, and followed by the high atmospheric levels of methane and its successor greenhouse gas carbon dioxide.
  • Methane Catastrophe 15 January 2010 12:012 UTC www.dcn.davis.ca.us [Source type: FILTERED WITH BAYES]

 ^ Mud volcanism is an occasional, local phenomenon that periodically injects small quantities of methane into the ocean and atmosphere.
  • Methane Catastrophe 15 January 2010 12:012 UTC www.dcn.davis.ca.us [Source type: FILTERED WITH BAYES]

 Recently, methane emitted from coal mines has been successfully utilized to generate electricity.
.Arctic methane release from permafrost and clathrates is an expected consequence of global warming.^ By contrast, large-scale methane release can indeed produce serious global consequences.
  • Methane Catastrophe 15 January 2010 12:012 UTC www.dcn.davis.ca.us [Source type: FILTERED WITH BAYES]

 ^ Traps volcanism initiated the process, helping shut down thermohaline circulation and warming the globe, including releasing continental margin methane.
  • Methane Catastrophe 15 January 2010 12:012 UTC www.dcn.davis.ca.us [Source type: FILTERED WITH BAYES]

 ^ Traps volcanism would have had important additional consequences unrelated to continental margin methane release, but providing in themselves mechanisms for altering the course of life on Earth.
  • Methane Catastrophe 15 January 2010 12:012 UTC www.dcn.davis.ca.us [Source type: FILTERED WITH BAYES]

 [19]
.In prehistoric times, large methane excursions have been linked with dramatic shifts in the Earth's climate, notably during the Paleocene-Eocene thermal maximum and during the Permian-Triassic extinction event, which was the worst ever mass extinction.^ C isotopic excursion at or near the Permian-Triassic boundary in both marine and terrestrial ecosystems, although the precise relation between peak extinction and the isotopic shift remains unclear."
  • Methane Catastrophe 15 January 2010 12:012 UTC www.dcn.davis.ca.us [Source type: FILTERED WITH BAYES]

 ^ Such a partnership may have also existed at other times of ocean anoxia, as indicated by significant negative sulfur isotope excursions: in the Early Cretaceous (120 to 100 million years ago: Paytan, 2004), and during the Paleocene-Eocene Thermal Maximum (55 million years ago: Paytan, 1998; Faul, 2005).
  • Methane Catastrophe 15 January 2010 12:012 UTC www.dcn.davis.ca.us [Source type: FILTERED WITH BAYES]

 ^ The massive release of seafloor methane does cause anoxia in the water column, and the accumulation of large amounts of carbon in the sediments would be an immediate effect of the extinction.
  • Methane Catastrophe 15 January 2010 12:012 UTC www.dcn.davis.ca.us [Source type: FILTERED WITH BAYES]

Extraterrestrial methane

.Methane has been detected or is believed to exist in several locations of the solar system.^ This water can be detected by oceanic probes, and can be used to locate the cold seeps from which methane also exits.
  • Methane Catastrophe 15 January 2010 12:012 UTC www.dcn.davis.ca.us [Source type: FILTERED WITH BAYES]

 It is believed to have been created by abiotic processes, with the possible exception of Mars.
  • Moon - traces are outgassed from the surface[20]
  • Mars - the atmosphere contains 10 ppb methane. .In January 2009, NASA scientists announced that they had discovered that the planet often vents methane into the atmosphere in specific areas, leading some to speculate this may be a sign of biological activity going on below the surface.^ We may be more tempted to think of them very much on the model of genetic defects or diseases, especially if they work through mechanisms that have some analogy to pathological defects.
    • http://www.nyu.edu/gsas/dept/philo/courses/bioethics/Papers/GeneBook/CH4.html 16 September 2009 22:022 UTC www.nyu.edu [Source type: Original source]

     ^ Though the fires may have spared some areas (Belcher, 2003), it does seem that they were global in reach, and they did leave evidence of their destruction: soot found in numerous localities around the planet, exactly at the K-T boundary (Paine, 1999; Kring and Durda, 2003).
    • Methane Catastrophe 15 January 2010 12:012 UTC www.dcn.davis.ca.us [Source type: FILTERED WITH BAYES]

     ^ If those organisms which were engaged in similar activities in the Permian were like those of today, they also would have required periodic infusions of oxygen or nitrate, and thus Late Permian surface waters may well have been oxic, at least in this part of the world.
    • Methane Catastrophe 15 January 2010 12:012 UTC www.dcn.davis.ca.us [Source type: FILTERED WITH BAYES]

     [21]
    • .
  • Jupiter - the atmosphere contains about 0.3% methane
  • Saturn - the atmosphere contains about 0.4% methane
    • Iapetus
    • Titan — the atmosphere contains 1.6% methane and thousands of methane lakes have been detected on the surface[22]
    • Enceladus - the atmosphere contains 1.7% methane[23]
  • 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 1.6% methane
    • Triton - Triton has a tenuous nitrogen atmosphere with small amounts of methane near the surface.^ This compound employs the "Redfield ratio" of carbon to nitrogen to phosphorus -- 106 C: 16 N: 1 P -- that is typical of many organic compounds.
      • Methane Catastrophe 15 January 2010 12:012 UTC www.dcn.davis.ca.us [Source type: FILTERED WITH BAYES]

       ^ The massive release of seafloor methane does cause anoxia in the water column, and the accumulation of large amounts of carbon in the sediments would be an immediate effect of the extinction.
      • Methane Catastrophe 15 January 2010 12:012 UTC www.dcn.davis.ca.us [Source type: FILTERED WITH BAYES]

       ^ Compounding the effects of low oxygen would have been the increase in carbon dioxide, producing further impairment or death by hypercapnia to sensitive organisms in the surface ocean (which exchanges gas with the atmosphere), and physiological damage or death to organisms along affected coastlines.
      • Methane Catastrophe 15 January 2010 12:012 UTC www.dcn.davis.ca.us [Source type: FILTERED WITH BAYES]

       [24][25]
  • Pluto - spectroscopic analysis of Pluto's surface reveals it to contain traces of methane[26][27]
    • Charon - methane is believed to be present on Charon, but it is not completely confirmed[28]
  • 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[29]
  • Extrasolar planet HD 189733b - This is the first detection of an organic compound on a planet outside the solar system. Its origin is unknown, since the planet's high temperature (700 °C) would normally favor the formation of carbon monoxide instead.[30]
  • Interstellar clouds[31]

See also

References

  1. ^ MSDS Methane
  2. ^ IPCC Fourth Assessment Report
  3. ^ Carbon Dioxide, Methane Rise Sharply in 2007
  4. ^ Methane seen as growing climate risk
  5. ^ "Radiative Forces of Climate Change". Climate Change 2001: The Scientific Basis. IPCC. http://www.grida.no/climate/ipcc_tar/wg1/221.htm. Retrieved 2008-05-26. 
  6. ^ Clayton B. Cornell (April 29, 2008). "Natural Gas Cars: CNG Fuel Almost Free in Some Parts of the Country". http://www.gas2.org/2008/04/29/natural-gas-cars-cng-fuel-almost-free-in-some-parts-of-the-country/. "Compressed natural gas is touted as the 'cleanest burning' alternative fuel available, since the simplicity of the methane molecule reduces tailpipe emissions of different pollutants by 35 to 97%. Not quite as dramatic is the reduction in net greenhouse-gas emissions, which is about the same as corn-grain ethanol at about a 20% reduction over gasoline" 
  7. ^ Lunar Engines, Aviation Week & Space Technology, 171, 2 (13 July 2009), p. 16: "Aerojet has completed assembly of a 5,500-pound-thrust liquid oxygen/liquid methane rocket engine—a propulsion technology under consideration as the way off the Moon for human explorers"
  8. ^ Methane Blast, NASA, May 4, 2007
  9. ^ Green, V. (September). Hit the Gas: NASA's methane rocket could make long distance space travel possible, on the cheap. 271. Popular Science magazine. pp. 16-17. ISSN 0161-7370. http://books.google.co.jp/books?id=3AClY8pMg-EC&pg=PA16&lpg=PA16. 
  10. ^ A Global First: Coal Mine Turns Greenhouse Gas into Green Energy
  11. ^ Miller, G. Tyler. Sustaining the Earth: An Integrated Approach. U.S.A.: Thomson Advantage Books, 2007. 160.
  12. ^ "Livestock’s Long Shadow–Environmental Issues and Options". http://www.fao.org/docrep/010/a0701e/a0701e00.HTM. Retrieved 2009-10-27. 
  13. ^ New Zealand Tries to Cap Gaseous Sheep Burps
  14. ^ Research on use of bacteria from the stomach lining of kangaroos (who don't emit methane) to reduce methane in cattle
  15. ^ Hamilton JT, McRoberts WC, Keppler F, Kalin RM, Harper DB (July 2003). "Chloride methylation by plant pectin: an efficient environmentally significant process". Science (journal) 301 (5630): 206–9. doi:10.1126/science.1085036. PMID 12855805. http://www.sciencemag.org/cgi/pmidlookup?view=long&pmid=12855805. 
  16. ^ "Methane Emissions? Don't Blame Plants", ScienceNOW, 14 January 2009
  17. ^ Plants do emit methane after all, New Scientist, 2 December 2007
  18. ^ "Technical summary". Climate Change 2001. United Nations Environment Programme. http://www.grida.no/climate/ipcc_tar/wg1/017.htm. 
  19. ^ "Methane Releases From Arctic Shelf May Be Much Larger and Faster Than Anticipated". Press Release. National Science Foundation. http://www.nsf.gov/news/news_summ.jsp?cntn_id=116532&org=NSF&from=news. 
  20. ^ Stern, S.A. (1999). "The Lunar atmosphere: History, status, current problems, and context". Rev. Geophys. 37: 453–491. doi:10.1029/1999RG900005. 
  21. ^ Mars Vents Methane in What Could Be Sign of Life, Washington Post, January 16, 2009
  22. ^ Niemann, HB; Atreya, SK; Bauer, SJ; Carignan, GR; Demick, JE; Frost, RL; Gautier, D; Haberman, JA et al. (2005). "The abundances of constituents of Titan’s atmosphere from the GCMS instrument on the Huygens probe". Nature 438 (7069): 779–784. doi:10.1038/nature04122. PMID 16319830. 
  23. ^ 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
  24. ^ A L Broadfoot, S K Bertaux, J E Dessler et al. (December 15, 1989). "Ultraviolet Spectrometer Observations of Neptune and Triton". Science 246 (4936): 1459–1466. doi:10.1126/science.246.4936.1459. PMID 17756000. http://adsabs.harvard.edu/abs/1989Sci...246.1459B. Retrieved 2008-01-15. 
  25. ^ Ron Miller; William K. Hartmann (May 2005). The Grand Tour: A Traveler's Guide to the Solar System (3rd ed.). Thailand: Workman Publishing. pp. 172–73. ISBN 0-7611-3547-2. 
  26. ^ 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. PMID 17757212. http://www.sciencemag.org/cgi/content/abstract/261/5122/745. Retrieved 2007-03-29. 
  27. ^ "Pluto". SolStation. 2006. http://www.solstation.com/stars/pluto.htm. Retrieved 2007-03-28. 
  28. ^ Sicardy, B; Bellucci, A; Gendron, E; Lacombe, F; Lacour, S; Lecacheux, J; Lellouch, E; Renner, S et al. (2006). "Charon’s size and an upper limit on its atmosphere from a stellar occultation". Nature 439 (7072): 52. doi:10.1038/nature04351+ (inactive 2009-10-03). PMID 16397493. http://www.nature.com/nature/journal/v439/n7072/abs/nature04351.html. 
  29. ^ 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+ (inactive 2009-10-03). Bibcode: 1996Sci...272.1310M. 
  30. ^ Stephen Battersby (2008-02-11). "Organic molecules found on alien world for first time". http://space.newscientist.com/article/dn13303-organic-molecules-found-on-alien-world-for-first-time.html. Retrieved 2008-02-12. 
  31. ^ Rai, VN; Yueh, FY; Singh, JP (1991). "Discovery of interstellar methane — Observations of gaseous and solid CH4 absorption toward young stars in molecular clouds". Astrophysical Journal 376 (31): 556–560. doi:10.1086/170304+ (inactive 2009-10-03). PMID 19122700. http://adsabs.harvard.edu/abs/1991ApJ...376..556L. 

External links

.
Sustainable development portal
Alkanes
Methane (CH4) · Ethane (C2H6) · Propane (C3H8) · Butane (C4H10) · Pentane (C5H12) · Hexane (C6H14) · Heptane (C7H16) · Octane (C8H18) · Nonane (C9H20) · Decane (C10H22) · Undecane (C11H24) · Dodecane (C12H26)
Higher alkanes · List of alkanes

Simple English

Hydrocarbon - Methane
Molecular Formula CH4
Series (Family) - Alkanes
Previous
Next Ethane
Physical Properties
Melting Point -182.5 °C, 91 K, -297 °F
Boiling Point -161.6 °C, 112 K, -259 °F


[[File:|thumb|Structural formula of methane. C is carbon and H is hydrogen. The lines show that the atoms are joined by chemical bonds.]] [[File:|thumb|A picture to show simply how the atoms may fill space. The grey is carbon and the white is hydrogen.]] Methane is a hydrocarbon that is a gas at room temperature (20oC). Its molecular formula is CH4, so it has one carbon atom and four hydrogen atoms in a molecule. It is often found as the main part of natural gas. Methane is a greenhouse gas 22 times more effective than carbon dioxide. It is also less stable and slowly oxidates by oxygen to carbon dioxide and water.

Uses

Methane is used in gas taps in places such as chemistry classrooms, laboratories, etc. as it burns very easily because of its simple molecular structure.

Molecular structure

Methane's molecular structure is very simple. It is a single carbon atom surrounded by four hydrogen atoms.

Production

Methane can be produced by many chemical methods, but usually is found in natural gas and is obtained by fractional distillation, after it is become liquid.

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