Definition of Natural Gases
Natural gas is a primary energy resource. It is a combustible mixture of methane and other hydrocarbons used mainly as a fuel. The primary component is methane. When natural gas burns, it emits a lot of energy, which is clean and safe since the levels of harmful byproducts emitted into the air are very low.
Natural gas collects in pockets deep beneath the surface of the Earth. The gas sometimes flows upward from the deepest reservoirs and reaches the Earth’s surface because of tremendous internal pressure. On the ground, it undergoes a refining process to remove all the impurities like water, sand, hydrogen sulfide and other compounds. Later, it flows through pipelines to the point of use.
The purest form of natural gas is “dry” and it consists of only of methane. Methane contains one carbon and four hydrogen atoms. On the other hand, “wet” natural gas may contain other hydrocarbons such as ethane, propane or butane. The composition of natural gas varies according to the refining process used.
A turbine flow meter calculates the volume of natural gas at normal temperature and pressure, and the common metric system used is cubic feet (Mcf), millions of cubic feet (MMcf), billions of cubic feet (Bcf), or trillions of cubic feet (Tcf).
Over time, mud and other sediment pile up over organic matter and compress it. The pressure of the compression combined with the high temperatures beneath the earth’s surface result in breaking down the carbon bonds of the organic matter, which results in formation of natural gas. Many oil deposits, one to two miles beneath the earth’s crust, are the primary sources of natural gas.
The organic matter transforms into methane by the action of methanogenic bacteria. These microorganisms, usually present in the Earth’s surface and in the absence of oxygen, break the chemical bonds of the organic matter to form methane. Underground reservoirs cannot trap this biogenic methane, so it is difficult to recover. Landfills and dumping grounds, which contain organic waste, are extractable sources of biogenic methane.