propanes

Propane, chemical formula C3H8, is a simple alkane and a widely used hydrocarbon. The term propanes is rarely used; propane refers to a single compound, which has no structural isomers.

At room temperature, propane is a colorless, odorless gas. For safety, an odorant is typically added to detect leaks. It is pre-eminently stored and transported as a liquid under modest pressure in cylinders or tanks, a form known as liquefied petroleum gas (LPG). Propane is nonpolar and is moderately soluble in organic solvents but only sparingly soluble in water. Its boiling point is −42.1 °C, so it vaporizes readily at ambient conditions and can be delivered as a gas for combustion.

Propane burns cleanly in air, with a balanced combustion reaction: C3H8 + 5 O2 → 3 CO2 + 4 H2O, releasing heat. Its energy density makes it a common fuel for heating, cooking, and outdoor equipment, especially in places without piped natural gas. It is also used as a fuel for certain engines and as a petrochemical feedstock to produce propylene, a building block for various plastics and chemicals.

In industry, propane forms part of LPG, a mixture of propane and butane used for heating and portable fuel. It is produced mainly during natural gas processing and petroleum refining. Safety considerations are important: propane is highly flammable and expands with pressure, so proper storage, ventilation, and leak detection are essential.

Environmentally, burning propane releases carbon dioxide and water vapor; it emits far fewer particulates and sulfur compounds than many liquid fuels, contributing to lower air pollution in properly vented applications.