Is LPG a natural gas

Answer 1

The majority of Natural Gas (CNG, LNG) is actually either recovered from oil wells, or recovered as a distillation or cracking product of petroleum. It is a mix of very light alkanes, primarily methane and ethane, but also containing some propane and butane. Methane is also a common byproduct from anaerobic metabolism primarily by microorganisms.

LPG (liquified petroleum gas) contains mainly propane, but also some butane and other alkanes. It is a naturally occurring petroleum product and is recovered from oil wells, or distillation and cracking of petroleum products. Propane is not frequently considered to be a byproduct of organic processes, although some notes indicate that it may naturally occur in deep marine microorganisms.

No terrestrial organisms would produce propane in the concentrated liquified form as in LPG.

While there may be some overlap in the constituent compounds between LNG and LPG, the concentrations of the different alkanes are vastly different between them, as well as different boiling points and vapor pressures.