Question

why natural gas is called CNG ? why compressed is use in it?

Answer 1

Compressed natural gas (CNG) (methane stored at high pressure) is a fuel which can be used in place of gasoline, diesel fuel and propane/LPG. CNG combustion produces fewer undesirable gases than the aforementioned fuels.

Answer 2

CNG is the compressed natural gas and cause less pollution as compared to other source of fuels like coal . The carbon dioxide  and nitrogen oxide as well as the sulphur oxide are produced less than the petroleum or coal etc . For example carbon dioxide produced by the coal burning release about 50% more as compared to the CNG  and CO2 is the  major pollutant in the air.

natural gas is called as cng because it can be compressed

the principle for compression is low temperature and high pressure