What is natural gas?
Natural gas is a naturally occurring hydrocarbon gas mixture consisting primarily of methane, but commonly including varying amounts of other higher alkanes, and sometimes a small percentage of carbon dioxide, nitrogen, hydrogen sulfide, or helium.
Natural gas: 1-4 Carbon atoms
Crude oil: 5-60 Carbon atoms
How Does Natural Gas form?
Natural gas formed below the earth surface when a layer of decomposing plants or microorganism or animal matter or other organic matter experienced an intense heat and pressure over the millions of years then it turns into gas. The final natural gas is purer and but at the initial stage is to gradually release gas from the decomposed organic matter.
Where do we get Natural gas?
After the formation of natural gas, we can not get the gas unless it is stored somewhere inside the subsurface within a trap. This trap is the most important to get gas from the gas reservoir. Natural gas can be stored as a methane clathrate.
Most of the natural gas can be formed over time by two mechanisms.
- Biogenic process
- Thermogenic process
Biogenic gas is formed by the methanogenic organisms in landfills, lake, marshes, swamps etc. in shallow sedimentary sequences. The main decomposition mechanism here is the bacterial decay, high temperature and pressure are not responsible for this type of gas formation.
Thermogenic gas is formed in the deep of the subsurface by the greater temperature and pressure. These high temperatures and pressure can fragment and break down the organic matter after the buried over time.
Natural gas is simply called as ‘gas’ but it contains many gases together, some are toxic also.