Propane
Propane, with three-C Hydrocarbons, is sometimes derived from other petroleum products during oil or natural gas processing.
Propane is not produced for its own sake, but as a byproduct of two other processes: natural gas processing and petroleum refining. Unlike natural gas, Propane is heavier than air (1.5 times denser). Liquid Propane will flash to a vapor at atmospheric pressure and appears white due to moisture condensing from the air.