Propane - LPG - Liquified Petroleum Gas
Propane is a three-carbon alkane, normally a gas, but compressible to a liquid that is transportable. It is derived from other petroleum products during oil or natural gas processing. It is commonly used as a fuel for engines, barbecues, and home heating systems.
When sold as fuel, it is commonly known as liquified petroleum gas (LPG or LP-gas) which can be a mixture of propane along with small amounts of propylene, butane, and butylene. The odorant ethanethiol is also added so that people can easily smell the gas in case of a leak.
Propane is used as fuel in cooking on many barbecues, portable stoves and in motor vehicles. The ubiquitous 4.73-gallon (20 Lb.) steel container is often dubbed a "barbecue bottle". Propane powers some locomotives, buses, forklifts, and taxis and is used for heat and cooking in recreational vehicles and campers. In many rural areas of North America, propane is used in furnaces, cooking stoves, water heaters, laundry dryers, and other heat-producing appliances. As of 2000, 6.9 million American households use propane as their primary heating fuel.
Commercially-available "propane" fuel, or LPG, is not pure. Typically in the USA and Canada, it is primarily propane (at least 90%), with the rest mostly butane and propylene, plus odorants. This is the HD5 standard, written for vehicle fuels; note that not all products labeled "propane" conform to this standard. In Mexico, for example, the butane content is much higher.
