Methane

Gas that is colourless and odourless and that occurs abundantly in nature as well as as a byproduct of certain human activities, like agriculture. Methane is the most basic member of the paraffin series of hydrocarbons, and it is also one of the most potent greenhouse gases known to science. The chemical formula for this substance is CH4.

Chemical properties of methane

Methane has a specific gravity of 0.554, making it significantly lighter than air. Only a small amount of it is soluble in water. This substance burns rapidly in air, releasing carbon dioxide and water vapour; the flame is pale, faintly brilliant, and quite hot to the touch. Methane has a boiling temperature of 162 degrees Celsius (259.6 degrees Fahrenheit) and a melting point of 182.5 degrees Celsius (296.5 degrees Fahrenheit). However, combinations of methane and air, with the methane content ranging from 5 to 14 percent by volume, are explosive due to their high methane content. Explosions of such mixes have been common in coal mines and collieries, and they have been the cause of numerous mining tragedies in recent history.

structure of methane

Methane (CH4) has a tetrahedral structure, which is explained by the VSEPR (valence-shell-electron-pair repulsion) hypothesis of molecule shape, which assumes that the four pairs of bonding electrons (shown by the grey clouds) adopt positions that minimise their mutual repulsion with one another.

Sources of methane

Methane is created naturally in the environment by the anaerobic bacterial breakdown of plant matter in the presence of water (where it is sometimes called marsh gas or swamp gas). It is believed that wetland areas are the most significant natural source of methane produced in this manner. The digestive activities of termites, volcanoes, ocean floor vents, and methane hydrate deposits that occur along continental edges, beneath Antarctic ice, and beneath Arctic permafrost are all important sources of methane in the natural environment. Also known as firedamp (flammable gas), methane is the primary constituent of natural gas, which comprises anywhere from 50 to 90 percent methane (depending on the source) and occurs naturally as a component of firedamp (flammable gas) along coal seams.

The production and combustion of natural gas and coal are the two most significant anthropogenic (human-associated) sources of methane emissions. Activity s such as the extraction and processing of natural gas, the destructive distillation of bituminous coal in the manufacture of coal gas and coke-oven gas, and the destruction of bituminous coal in the manufacture of coal gas and coke-oven gas result in significant amounts of methane being released into the atmosphere. In addition to biofuel combustion, animal rearing, and waste management are all activities that contribute to methane production (where bacteria produce methane as they decompose sludge in waste-treatment facilities and decaying matter in landfills).

Uses of methane

Methane is a significant source of hydrogen as well as a number of organic compounds. Methane interacts with steam at high temperatures to produce carbon monoxide and hydrogen, the latter of which is utilised in the production of ammonia, which is used in the production of explosives and fertilisers. Methanol, chloroform, carbon tetrachloride, and nitromethane are just a few of the useful compounds that can be produced from methane. Carbohydrate black is produced by incomplete combustion of methane and is commonly utilised as a reinforcing ingredient in rubber, such as the rubber used in automotive tyres.

Role as a greenhouse gas

In the atmosphere, methane that is created and released into the atmosphere is taken up by methane sinks, which are composed of soil and the process of methane oxidation in the troposphere (the lowest atmospheric region). The majority of methane produced naturally is compensated by the amount of methane absorbed into natural sinks. Anthropogenic methane production, on the other hand, has the potential to cause methane concentrations to rise faster than they can be countered by sinks. Since 2007, methane concentrations in the Earth’s atmosphere have increased by 6.8–10 parts per billion (ppb) every year, according to the International Energy Agency. By 2020, atmospheric methane concentrations had risen to 1873.5 parts per billion (ppb), over two to three times higher than preindustrial levels, which stayed around 600–700 ppb.

As methane levels rise in the atmosphere, it plays a role in creating the greenhouse effect, which occurs when certain greenhouse gases (primarily carbon dioxide but also methane and water vapour) absorb infrared radiation (net heat energy) and reradiate it back to the Earth’s surface, potentially trapping heat and causing significant changes in the climate. Directly or indirectly, increased atmospheric methane contributes to the greenhouse effect. Example: In methane oxidation, hydroxyl radicals (OH) remove methane from the atmosphere by reacting with it to form carbon dioxide and water vapour. As methane concentrations in the atmosphere rise, the amount of hydroxyl radicals in the atmosphere decreases, resulting in a significant extension of the lifetime of methane in the atmosphere. hydroxyl radicals in the atmosphere decreases, resulting in a significant extension of the lifetime of methane in the atmosphere.

Conclusion

Methane has significant environmental benefits, as it produces significantly more heat and light energy per unit of mass than any other hydrocarbon, or fossil fuel, including coal and gasoline refined from oil, while emitting significantly less carbon dioxide and other pollutants that contribute to smog and unhealthy air pollution.