What is the difference between petroleum gas and natural gas?
The composition and source. One is found naturally the other is produced by catalytic cracking.
Petroleum gas is mainly C3 and C4 based (propane and butane), whilst natural gas is predominantly C1 and C2 (methane and ethane).
Petroleum gas is generally produced via the cracking of naphtha, which is one of the components separated during crude oil refining.
Natural gas is found, for example, in natural gas fields, and also in the form of shale gas.