Methane

The simplest hydrocarbon, methane isgas withchemical formulaCH₄.

---

Lewis Structure:

  H
  |
H-C-H  
  |
  H

---

A principal componentnatural gas, methane is significant fuel. Burning one moleculemethane inpresenceoxygen releases one moleculeCO₂ (carbon dioxide)two moleculesH₂O (water):

CH₄ + 2O₂ → CO₂ + 2H₂O

The strength ofcarbon-hydrogen covalent bondmethaneamongstrongestall hydrocarbons,thus its use aschemical feedstocklimited. The searchcatalysts which can facilitate C-H bond activationmethaneother low alkanesan arearesearchconsiderable industrial significance.

Methane isgreenhouse gas withglobal warming potential22 (meaning thathas 22 timeswarming abilitycarbon dioxide).

Methane results fromdecompositioncertain organic matters inabsenceoxygen. Ittherefore also classified asbiogas.

Principal sources are

• decompositionorganic wastes
• natural sources (marshes) : 23 %
• fossil fuel extraction : 20 % See Coal bed methane extraction
• processesdigestionanimals (cattle) : 17 %
• bacteria foundrice plantations : 12 %
• biomass anaerobic heating or combustion

80% ofworld emissionsof human source. They come primarily from agriculturalother human activities. Duringpast 200 years,concentrationthis gas inatmosphere doubled, passing from 0.81.7 ppm.

See also methyl group, which isfunctional group similarmethane.