Natural gas, a gaseous fuel, has considerable use:

Natural gas, a gaseous fuel, has considerable use:

Natural gas is an important fuel available in gaseous state. It is a fossil fuel consisting primarily of methane, found in oil fields either in dissolved form (associated with liquid petroleum or crude oil) or isolated in natural gas fields (non-associated with liquid petroleum or crude oil). Coal-bed methane available in coal seams can also be treated as natural gas.

Methane (CH4), a lightest and short chain hydrocarbon molecule, is the primary component in natural gas. In addition to CH4, some heavier gaseous hydrocarbons e.g., ethane (C2H6), propane (C3H8), butane (C4H10) etc., are also available. In some oil field other sulfur containing gases, in varying amounts are also found.

As far as heat value concerned, it varies greatly with the gas, however, on an average the gross heat of combustion of one normal cubic meter of commercial quality of natural gas is around 39 mega joules.

Natural gas processing is done to purify the raw natural gas extracted from underground gas fields. The processed natural gas, which is almost pure methane (dry gas), is piped for residential as well as for commercial and industrial use for manufacture of plastics, drugs and dyes. The heavy hydrocarbons such as butane, propane, and petrol are extracted as liquids.

The transportation and storage are the major difficulty faced for use of natural gas because of its low density. Transportation natural gas through gas pipelines are economical, but many a times become are impractical as it may have to cross oceans or because of political hassles between two countries. Liquefied natural gas (LNG) or compressed natural gas (CNG) can be transported across ocean or by tank trucks directly to the end users. Storing natural gas in underground caverns near ultimate end-users, now-a-days, is the best proposition; as it helps to meet gas’s volatile demands. The under ground storage system various advantages, such as it is much safer, prevents from accidental fire, protect environment and protect from terrorist attacks as well. For this purpose, depleted gas reservoirs from previous gas wells, salt domes, or specially built cavern may be used for keeping liquefied natural gas. Uses of natural gas:

• Because of availability, transportability and better storage-ability, natural gas has become a major source of electricity generation through the use of gas turbines and steam turbines. Particularly high efficiencies in power generation can be achieved through combining gas turbines with a steam turbine in combined cycle mode.

• Environmentally, natural gas is much cleaner than other fossil fuels such as oil, coal; as it produces less carbon dioxide (CO2) per unit energy released. For an equivalent amount of heat, burning natural gas produces about 30% less carbon dioxide than burning petroleum and about 45% less than burning coal. Combined cycle power generation using natural gas is thus the cleanest source of power available using fossil fuels. Because of its techno-economic advantages this technology is widely used wherever gas can be obtained at a reasonable cost.

• Natural gas is a major feedstock for the production of ammonia, for use in fertilizer production.

• Because of its environmentally cleaner in nature, compressed natural gas (CNG) is used as cleaner alternative to petrol (gasoline) or diesel driven road transport in many countries.

• Natural gas is supplied to homes for its use as cooking fuel.

• Because of relatively environment-friendly in nature, people are finding ways to use it for varied industrial and commercial purpose.

Countries such as, Russia, Iran, Qatar, Saudi Arabia, UAE, USA, Nigeria, Algeria, Venezuela, Iraq have greatest natural reserve in the world.