Liquefied petroleum gas, also referred to as liquid petroleum gas (LPG or LP gas), is a fuel gas which contains a flammable mixture of hydrocarbon gases, specifically propane, n-butane and isobutane. It can sometimes contain some propylene, butylene, and isobutene.

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LPG is prepared by refining petroleum or "wet" natural gas, and is almost entirely derived from fossil fuel sources, being manufactured during the refining of petroleum (crude oil), or extracted from petroleum or natural gas streams as they emerge from the ground.

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Besides its use as an energy carrier, LPG is also a promising feedstock in the chemical industry for the synthesis of olefins such as ethylene, propylene.Global LPG production reached over 292 million metric tons per year (Mt/a) in 2015, while global LPG consumption to over 284 Mt/a. 62% of LPG is extracted from natural gas while the rest is produced by petroleum refineries from crude oil.

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LPG is composed mainly of propane and butane, while natural gas is composed of the lighter methane and ethane. LPG, vaporised and at atmospheric pressure, has a higher calorific value (46 MJ/m3 equivalent to 12.8 kWh/m3) than natural gas (methane) (38 MJ/m3 equivalent to 10.6 kWh/m3).