Liquefied petroleum gas (LPG)[2]​ is the mixture of liquefied gases "Liquefaction (gases)") present in natural gas or dissolved in oil. It involves physical and chemical processes, for example the use of methane. The components of LPG, although at ambient temperature and pressure they are gases, are easy to liquefy "Liquefaction (gases)"); hence its name. In practice, it can be said that LPG is a mixture of propane and butane.

Propane and butane are present in crude oil and natural gas, although some is obtained during petroleum refining, especially as a byproduct of fractional catalytic distillation (FCC).

Liquefied petroleum gas (LPG) can appear in the form of a gas at various stages in its chain of use, which is why it requires appropriate safety measures in the event of a gas leak.

Escapes of a flammable gas outside the structure that contains it are dangerous, as this gas could produce a serious deflagration when it comes into contact with a flame.[3]​ Do not smoke or make flames appear when filling tanks with them.[3]​.

It begins when crude oil from oil wells reaches primary refining, where different distillates are obtained, including wet gas, naphtha or gasoline, kerosene, atmospheric gas oil or diesel, and vacuum gas oil.

The latter (vacuum diesels) are the raw material for the production of gasoline in catalytic cracking processes. The process begins when these are taken to an FCC plant and, through a primary reactor based on a high-temperature catalyst, LPG, gasoline and other heavier products are obtained. That mixture is then separated in distillation trains.

Propane and butane natural gas can be extracted through processes that consist of reducing the temperature of the gas until these and heavier components condense. The processes use refrigeration or turboexpanders to achieve temperatures below -40°C, necessary to recover propane. Subsequently, these liquids undergo a purification process using distillation trains to produce liquid propane and butane or directly LPG.