Liquefied petroleum gas (also called liquified petroleum gas, liquid petroleum gas, LPG, LP Gas) is a mixture of hydrocarbon gases used primarily as a fuel in heating appliances, and increasingly replacing chlorofluorocarbons as an aerosol propellant and a refrigerant to reduce damage to the ozone layer.

Varieties of LPG bought and sold include mixes that are primarily propane or primarily butane, and the more common, mixes including both propane (60%) and butane (40%), depending on the season - in winter more propane, in summer more butane. Propylene and butylenes are usually also present in small concentration. A powerful odorant, ethanethiol, is added so that leaks can be detected easily.

LPG is manufactured during the refining of crude oil, or extracted from oil or gas streams as they emerge from the ground. It is then stored in a spherical tank
At normal temperatures and pressures, LPG will evaporate. Because of this, LPG is supplied in pressurised steel bottles and cylinders of various size for cooking in household, hotels and restrurants and also for lighting lanterns. In order to allow for thermal expansion of the contained liquid, these bottles are not filled completely; typically, they are filled to between 80% and 85% of their capacity. LPG is heavier than air, and thus will flow along floors and tend to settle in low spots, such as basements. This can cause ignition or suffocation hazards if not dealt with.

A hydrocarbon is a chemical compound that consists only of the elements carbon (C) and hydrogen (H). Hydrocarbons contain a backbone consisting of carbon atoms, called a carbon skeleton with hydrogen atoms attached to that backbone. Hydrocarbons, which are combustible, are the main components of fossil fuels, which include petroleum, coal, and natural gas. The most abundant hydrocarbon is methane. Hydrocarbons are refined at oil refineries and processed at chemical plants

Hydrocarbon

Hydrocarbons are one of the Earth's most important energy resources. Hydrocarbons are currently the main source of the world's electric energy and heat sources because of the energy produced when burnt.

Hydrocarbons (usually coal) are burnt and the energy released in this way is used to turn water into steam, which is used to turn a turbine that generates energy.