what is Natural Gas?

           Natural gas is mainly methane  which burns to produce heat. The calorific value by mass (per kg) of natural gas is better than most of the conventional fuels being used, such as petrol, diesel, LPG, kerosene, etc. However, in gaseous form natural gas has a very low energy density, which makes it difficult to store or transport. So it is either stored in compressed (CNG) form, which leads to a volume reduction of around 200 times, or in liquid form (LNG) at about -162^oC, which gives about 600 times volume reduction. Natural gas is transported to the consumer points either through gas pipeline networks, or in LNG form though specially designed ships and cryogenic road tankers. However, setting up of a LNG production plant is a very costly proposition. As a thumb rule, gas transport over land up to 4000 kms, and undersea up to 2000 kms is considered economical through pipelines, and beyond these distances shipment of LNG is a better option.