Natural gas is a mixture of gases formed under the surface of the Earth by the anaerobic decomposition of organic matters. Natural gas is extracted from the oil and gas fields and transported through the gas transportation system to consumers. As NGV fuel, natural gas is used in two forms: compressed and liquefied.
Compressed natural gas (CNG) and liquefied natural gas (LNG) differ in their physical properties, transportation and application methods.
Compressed natural gas — CNG
CNG is realized through the CNG filling stations, where it is dried, compressed in a compressor and supplied to the vehicle tank at a pressure of 200 atmospheres. The key consumers of CNG are public, light cargo, passenger vehicles and utility vehicles.
Liquefied natural gas — LNG
LNG is a natural gas that is cooled down to a temperature of 162 degrees Celsius. Due to this change in physical state from gas to liquid, the volume shrinks about 1/600th the volume in gaseous states making transportation at atmospheric pressure possible in the LNG form. LNG is transported and stored in cryogenic tanks, which is later regasified and distributed to consumers through LNG filling stations, on which transport can be filled with natural gas in liquid form.
The key consumers of LNG are the road, rail, water transport, quarry and agricultural machinery. In addition, there are gas stations where both CNG and LNG are refueled. These can be LNG filling stations with regasification or CNG filling stations with cryogenic equipment.
To promote compressed natural gas as a vehicle fuel, Gazprom Gas-Engine Fuel LLC has developed and patented the EcoGas brand. Stylistics of the brand indicates the ecological component of this product and allows to distinguish it among other types of fuel.