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Methane, CH<sub>4</sub>, is the lightest (least dense) and simplest [[hydrocarbon]]. It is the major constituent of [[natural gas]], and a potent [[greenhouse gas]]. | '''Methane''', CH<sub>4</sub>, is the lightest (least dense) and simplest [[hydrocarbon]]. It is the major constituent of [[natural gas]], and a potent [[greenhouse gas]]. It may be captured as [[biogas]]. | ||
Many biological processes produce it | Many biological processes produce it as it is a a byproduct of [[fermentation]] and [[composting]]. This method of production is called [[methanogenesis]]. The method hence does not use electricity at all, but in some cases this may also be a disadvantage is it then doesn't allow to store the electricity ie generated using PV-panels. | ||
It can also be produced artificially using electricity ([[Sabatier process]]) This process basically combines CO² and hydrogen (H). See http://en.wikipedia.org/wiki/Sabatier_process This may be useful as although hydrogen can be made at home using electricity and is even in its current state a useful fuel, it has many problems regarding the storage. Methane has fewer storage problems ? | |||
==Disadvantages== | |||
{{copyvio|non-commercial license}} | {{copyvio|non-commercial license}} | ||
If allowed to escape it has a negative impact on the climate. This, as it's a very potent GHG-gas. It breaks down when burned, so not a problem if burned; yet it can be a problem ie in case of leaks. Although it is a potent greenhouse gas, it does not last as long in the atmosphere as many other such gases, eventually breaking down into [[carbon dioxide]] and [[water vapor]]. | |||
However, it has many drawbacks as a mass energy source ([[fuel]]). Because it is so ephemeral, it contains relatively little energy per unit volume at easily obtainable pressures. Also due to its lightness, it has a very low boiling point, and it takes tremendous pressure and/or refrigeration to liquefy it. [http://journeytoforever.org/biofuel_library/MethaneDigesters/MD4.html One analysis] indicates that, when compressed adequately to have energy density required by moving vehicles, it actually consumes more energy to compress it than is released in work when combusted. | However, it has many drawbacks as a mass energy source ([[fuel]]). Because it is so ephemeral, it contains relatively little energy per unit volume at easily obtainable pressures. Also due to its lightness, it has a very low boiling point, and it takes tremendous pressure and/or refrigeration to liquefy it. [http://journeytoforever.org/biofuel_library/MethaneDigesters/MD4.html One analysis] indicates that, when compressed adequately to have energy density required by moving vehicles, it actually consumes more energy to compress it than is released in work when combusted. | ||
This does not mean it is without use! It can be handy for low pressure, relatively low heat uses, such as [[mantle lighting]] or [[cooking]]. | This does not mean it is without use! It can be handy for low pressure, relatively low heat uses, such as [[mantle lighting]] or [[cooking]]. | ||
==See also== | ==See also== | ||
* [[Biogas]] | * [[Biogas]] | ||
* [[Alternative energy]] | * [[Alternative energy]] | ||
== External links == | |||
* [[Wikipedia:methane]] | * [[Wikipedia:methane]] | ||
* [http://www.ecoreality.org/wiki/Methane_digestor Methane digestor] at EcoReality. | * [http://www.ecoreality.org/wiki/Methane_digestor Methane digestor] at EcoReality. | ||
[[Category: Biogas]] | [[Category: Biogas]] | ||
Revision as of 08:51, 19 July 2012
Methane, CH4, is the lightest (least dense) and simplest hydrocarbon. It is the major constituent of natural gas, and a potent greenhouse gas. It may be captured as biogas.
Many biological processes produce it as it is a a byproduct of fermentation and composting. This method of production is called methanogenesis. The method hence does not use electricity at all, but in some cases this may also be a disadvantage is it then doesn't allow to store the electricity ie generated using PV-panels.
It can also be produced artificially using electricity (Sabatier process) This process basically combines CO² and hydrogen (H). See http://en.wikipedia.org/wiki/Sabatier_process This may be useful as although hydrogen can be made at home using electricity and is even in its current state a useful fuel, it has many problems regarding the storage. Methane has fewer storage problems ?
Disadvantages
If allowed to escape it has a negative impact on the climate. This, as it's a very potent GHG-gas. It breaks down when burned, so not a problem if burned; yet it can be a problem ie in case of leaks. Although it is a potent greenhouse gas, it does not last as long in the atmosphere as many other such gases, eventually breaking down into carbon dioxide and water vapor.
However, it has many drawbacks as a mass energy source (fuel). Because it is so ephemeral, it contains relatively little energy per unit volume at easily obtainable pressures. Also due to its lightness, it has a very low boiling point, and it takes tremendous pressure and/or refrigeration to liquefy it. One analysis indicates that, when compressed adequately to have energy density required by moving vehicles, it actually consumes more energy to compress it than is released in work when combusted.
This does not mean it is without use! It can be handy for low pressure, relatively low heat uses, such as mantle lighting or cooking.
See also
External links
- Wikipedia:methane
- Methane digestor at EcoReality.