Written by Eric Hahn
Is There a Difference Between Propane vs LPG?
Many of the gas appliances sold in Australia are manufactured overseas.
So, you get it home, open the box, start to read the owner’s manual and there it is!
It says that the appliance is made for use with Propane.
But where do you buy Propane in Australia?
Propane vs LPG
Propane is LPG but not all LPG is propane.
LPG – Liquefied Petroleum Gas – is flammable hydrocarbon gas liquefied through pressurisation.
Propane is classified as LPG, along with butane, isobutane and mixtures of these gases.
LPG comes from natural gas processing and oil refining.
LPG is frequently used for fuel in heating, cooking, hot water and vehicles.
The Name Game
The bad news is that this causes a lot of confusion and concern.
The good news is that Propane is readily available in Australia, we just call it LPG.
Propane is LPG, so no worries!
Propane is the gas that is supplied to virtually all homes and most businesses that purchase LPG in Australia.
LPG is supplied in gas bottles that are either exchanged or refilled on site by LPG tankers.
When used for a BBQ, it can be refilled or exchanged for a full one in a swap scheme.
These are typically 9kg bottles. SWAP'n'GO BBQ gas bottles are a good example of a swap system.
In Australia, LPG goes by a number of names including LPG, LPG gas, bottled gas, Propane, BBQ gas, camping gas and LP gas, so it can be quite confusing.
However, it’s all the same gas.
7 Important LPG Facts
1. LPG is the acronym for Liquefied Petroleum Gas or Liquid Petroleum Gas.
2. LPG is a group of flammable hydrocarbon gases, including propane, that are liquefied through pressurisation and commonly used as fuel.
3. LPG comes from natural gas processing and petroleum refining.
4. There are a number of gases that fall under the “LPG” label, including propane, butane and isobutane (i-butane), as well as mixtures of these gases.
5. LPG gases can all be compressed into liquid at relatively low pressures.
6. LPG is frequently used for fuel in heating, cooking, hot water and vehicles, as well as for refrigerants, aerosol propellants and petrochemical feedstock.
7. LPG (propane) is generally stored, as a liquid, in steel vessels ranging from small BBQ gas bottles to larger gas cylinders and storage tanks.
Propane (LPG) is Not Natural Gas
Propane is not to be confused with Natural Gas, which is primarily Methane.
When Natural Gas is initially extracted from the ground it may also contain Ethane, Propane, Butane, Pentane and Pentanes Plus.
Most of these are usually stripped out for other specific applications before it is passed along through the pipelines.
Impurities are also removed, including water and sulphur.
The chemical formula for Methane is CH4 (Methane molecule model shown).
How Does LPG Work?
LPG is stored under pressure, as a liquid, in a gas bottle.
It turns back into gas vapour when you release some of the pressure in the gas bottle by turning on your gas appliance.
Almost all of the uses for LPG involve the use of the gas vapour, not the liquefied gas.
What is LPG Used For?
LPG has hundreds, if not thousands, of uses.
The uses most people can name are LPG around the home, in their cars or LPG for business.
It is used in leisure time activities including caravans, boats, recreational vehicles, hot air balloons and camping.
Business and industry use LPG for a multitude of processes including steam boilers, kilns, ovens and LPG forklifts.
Crop and produce drying, heating greenhouses, hot water for dairies, irrigation pumps and heating animal enclosures are just some of the agricultural applications for LPG.
There are also many, many more LPG applications, including autogas, power generation and the hospitality industry.
What is LPG made of: LPG Composition
Propane is LPG but not all LPG is propane.
The gases that fall under the “LPG” label, including ethane, ethylene, propane, propylene, normal butane, butylene, isobutane and isobutylene, as well as mixtures of these gases.
In Australia, we are lucky that our LPG is Propane because it has some advantages over Butane, which is also considered LPG.
(Propane molecule model shown)
The most important advantage is that Propane works better in cold weather.
LPG is a liquid under pressure in the gas bottle.
It turns to vapour when you turn on the appliance and relieve some of the pressure, but only if it is above its boiling point.
Propane boils at around -42°C, so it would need to be really cold for it to not vapourise.
Butane, on the other hand, boils at about -1°C, so you could wake up on a cold winter morning with no working gas.
No fun at all!
And Then There is Butane
Now, if you are reading this blog from another country, LPG may not be just Propane for you.
It could be butane. (Butane molecule model shown)
Some countries get a mixture of Propane and Butane.
Other countries, like the UK, sell butane and propane separately.
Both are hydrocarbon gases and both are a Liquefied Petroleum Gas, so the mixture of the two still meets the definition of LPG.
For the tech heads out there, their chemical formulas are C3H8, for Propane, and C4H10, for Butane.
Autogas is Different
The exception to the rule is “autogas”, which is what you buy at the servo for your LPG powered car.
Autogas can be pure Propane or it can be a mixture or Propane and Butane.
Either should work equally well, as the Propane component is typically 60% or more.
Now a bit of trivia...
In the USA they also use Propane but they also call it “Propane” and seldom use the term LPG.
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The information in this article is derived from various sources and is believed to be correct at the time of publication. However, the information may not be error free and may not be applicable in all circumstances.