When natural gas is pulled from the ground, the resulting hydrocarbon is a mix of several gases and liquids. About 10% of what is recovered is made up of propane, butane and ethane — or LPG. The other 90% is methane, or natural gas. In order to transport the produced gas, the LPG must be separated from the methane.

LPG is also created when crude oil is refined. One of the first products to be removed from crude oil before refining the hydrocarbon into jet fuel, diesel or gasoline, LPG constitutes about 3% of a barrel of crude oil. When crude undergoes the stabilization process in order to be transported via pipeline or tanker, associated gases, or LPG, must be removed from the hydrocarbon.

Labeled “liquefied gas” because LPG is so easily converted to a liquid state, LPG requires only slight pressure or refrigeration to transform it from its natural gaseous state into a liquid. As a gas, LPG occupies 274 times its volume as a liquid, making the liquid state much preferred for transportation and storage.