What’s the Difference Between Propane and Natural Gas?

by | Feb 4, 2016 | Answer Man, Blog, Propane | 0 comments

What's the difference between natural gas and propane?We talk about propane and natural gas almost as if they’re interchangeable.  While both fuels are very similar, they are not identical and are most certainly not interchangeable.  Both are used for cooking, heating, and powering vehicles for transport, but their sources, physical makeup, and associated costs make all the difference (literally).

The Physical Difference

Natural gas is mostly methane that’s been pressurized into a liquid.  But natural gas also consists of multiple other gases including propane.  This is because natural gas is a naturally occurring fuel that is collected and has a very simple refining process.  Natural gas is simply cleaned before use to make it more efficient.

On the other hand, propane is a refined fuel.  Propane is a hydrocarbon, like butane and ethane, that is part of other materials.  These hydrocarbons are found in natural gas and petroleum, making propane the result of refining processes for both materials.


  • Can be stored as a liquid
  • Produce carbon monoxide
  • A low emission fuels

The two fuels are spoken of interchangeably because of how similar they are.  Both are stored in large above ground tanks or in refillable, portable bottles.  And while both fuels burn relatively cleanly for the environment, propane requires more oxygen in its mixture than natural gas.  To meet this, pressurized propane tanks contain less overall propane and more oxygen by volume than a natural gas tank does.  This is fine as Propane requires less fuel to achieve the same amount of energy release.

An unfortunate similarity is that both fuels released deadly carbon monoxide.  When any hydrocarbon is burned, the liberated carbon atoms bond with oxygen used in the fire to create carbon monoxide.  This is why you should never burn anything in an enclosed space.  Always make sure that you can vent harmful fumes away from the area.


  • Propane is heavier
  • Propane is more energy-efficient
  • Natural gas is slightly cleaner
  • Natural gas is cheaper

When it comes to safety, it’s important to remember that propane is heavier than air while natural gas is lighter than air.  While both will easily dissipate into the air, they can concentrate into dangerous levels in enclosed spaces.  This makes propane more dangerous, as it collects along the floor of the room rather than seeking higher exits.  This collection of gases leaves it at greater risk of explosion or an increased likelihood for suffocation if the leak is undetected.

As we mentioned before, less propane is required to generate the same BTU output as natural gas, but each canister is contains less propane to begin with since a larger amount of oxygen is needed for propane to burn properly.  Both fuels burn cleanly, but natural gas is a cleaner burning fuel.  Many outdoor grill enthusiasts prefer natural gas grills over propane because of the difference in clean burning.  Some believe that the extra exhaust from propane affects the food itself, but many agree that’s part of the charm of outdoor grilling.

Which should you choose?  Natural gas is often connected via city lines, but can be shipped and stored in tanks much like propane.  Overall, the price of natural gas is less than that of propane.  The efficiency of propane often balances out the difference in costs so the choice of which is better remains for you to decide.

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