Question

how is CNG obtained 'this is long answer'

Answer 1

Compressed Natural Gas (CNG) is obtained by drilling holes into the rocks and then inserting pipeline into that areas and the pipes suck the natural gas.
CNG is a fule which can be used in place of gasoline (petrol) , disel fuel and LPG its use is also increasing in south America,Europe and north America because of rising gasoline prices.