Difference between revisions of "Methane"

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In 2004, the [[Mars Express]] mission detected methane in the Martian atmosphere at a level of approx. 10 parts per billion.  This was later confirmed by Earth-based spectroscopy.
 
In 2004, the [[Mars Express]] mission detected methane in the Martian atmosphere at a level of approx. 10 parts per billion.  This was later confirmed by Earth-based spectroscopy.
  
Methane is of particular interest for missions to Mars, as it may be possible to produce it in situ using locally-available raw materials.  This would make it an ideal fuel for rovers and rocket engines.  A number of LOX/methane fueled rockets are under development, including the [[XCOR|XCOR XR5M15]] and [[TR408 Rocket|Northrop Grumman TR408]].
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Methane is of particular interest for missions to Mars, as it may be possible to produce it in situ using locally-available raw materials.  This would make it an ideal fuel for rovers and rocket engines.
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==Synthesis of methane==
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Production of methane on the surface of Mars would likely be via the '''Sabatier reaction''':
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:CO<sub>2</sub> + 4H<sub>2</sub> &nbsp; ↔ &nbsp; CH<sub>4</sub> + 2H<sub>2</sub>O
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The forward reaction takes place in the presence of high temperatures and pressures, in the presence of a [[nickel]] catalystAll of the raw materials should be available on the surface of Mars:
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* The [[atmosphere]] contains a high proportion of [[carbon dioxide]].
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* [[Hydrogen]] could be obtained by [[electrolysis]] of indigenous [[water]] (although some schemes call for the hydrogen to be imported).
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This process could also be used during a trip to or from Mars to scrub CO<sub>2</sub> from a spacecraft atmosphere.
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Instead of nickel, a catalyst made out of [[ruthenium]] on [[alumina]] could be used.
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==Uses for methane==
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Methane works well as a rocket fuel, and a number of LOX/methane fueled rockets are under development, including the [[XCOR|XCOR XR5M15]] and [[TR408 Rocket|Northrop Grumman TR408]].
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Methane [[fuel cells]] have recently been demonstrated, and these would work well for powering rovers, semi-portable equipment or as backup generators.
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[[Carbon]] in the form of pyrolytic [[graphite]] could be recovered from methane by pyrolyzing it:
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:CH<sub>4</sub> + heat &nbsp → &nbsp 2H<sub>2</sub> + C
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The graphite so formed could be used for ablative surfaces, reinforcement of [[polymer]] materials, furnace linings or control elements in [[nuclear reactor]]s.
  
 
==External Links==
 
==External Links==
 
*[http://en.wikipedia.org/wiki/Methane Wikipedia article on Methane]
 
*[http://en.wikipedia.org/wiki/Methane Wikipedia article on Methane]
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*[http://en.wikipedia.org/wiki/Sabatier_reaction Wikipedia article on the Sabatier reaction]
 
*[http://www.esa.int/SPECIALS/Mars_Express/SEMZ0B57ESD_0.html ESA press release on detection of methane by Mars Express]
 
*[http://www.esa.int/SPECIALS/Mars_Express/SEMZ0B57ESD_0.html ESA press release on detection of methane by Mars Express]
  
 
[[Category:Biospherics]]
 
[[Category:Biospherics]]

Revision as of 11:52, 18 November 2007

Methane is the lightest of the hydrocarbons, consisting of a single carbon atom bonded to four hydrogen atoms in a tetrahedral configuration. It is volatile, and tends to break down quite quickly by being oxidized, so presence of atmospheric methane is often considered to be an indication of the presence of life. However, methane can also be produced be non-biological processes such as volcanic activity.

In 2004, the Mars Express mission detected methane in the Martian atmosphere at a level of approx. 10 parts per billion. This was later confirmed by Earth-based spectroscopy.

Methane is of particular interest for missions to Mars, as it may be possible to produce it in situ using locally-available raw materials. This would make it an ideal fuel for rovers and rocket engines.

Synthesis of methane

Production of methane on the surface of Mars would likely be via the Sabatier reaction:

CO2 + 4H2   ↔   CH4 + 2H2O

The forward reaction takes place in the presence of high temperatures and pressures, in the presence of a nickel catalyst. All of the raw materials should be available on the surface of Mars:

This process could also be used during a trip to or from Mars to scrub CO2 from a spacecraft atmosphere.

Instead of nickel, a catalyst made out of ruthenium on alumina could be used.

Uses for methane

Methane works well as a rocket fuel, and a number of LOX/methane fueled rockets are under development, including the XCOR XR5M15 and Northrop Grumman TR408.

Methane fuel cells have recently been demonstrated, and these would work well for powering rovers, semi-portable equipment or as backup generators.

Carbon in the form of pyrolytic graphite could be recovered from methane by pyrolyzing it:

CH4 + heat &nbsp → &nbsp 2H2 + C

The graphite so formed could be used for ablative surfaces, reinforcement of polymer materials, furnace linings or control elements in nuclear reactors.

External Links