The difference between propane, or liquid petroleum gas (LPG), and natural gas comes down to their portability, compression, energy efficiency, and cost. However, there is generally no difference when it comes to performance in appliances for heating, cooking, or drying. The mixture of natural gas is comprised of propane, along with other gases like methane, butane, ethane, and pentane.
One difference in the physical properties of propane and natural gas is how easily they liquefy and transport. Propane turns into a liquid at —46° F (-43° C), so it's easy to compress and carry in a portable tank. You can buy compressed propane at most gas stations. It's decompressed by a valve at the source of use, such as a barbeque grill. Yet natural gas doesn't compress as easily. It usually comes to your home from a utility company along dedicated lines to power things like a central heating system, clothes dryer, and water heater.
Propane is heavier than air which is heavier than natural gas. Both natural gas and propane will dissipate into the air if they are released in an open enough environment and both can pose an explosive risk if they concentrate enough and are ignited. However, because propane is heavier, it tends to fall to the ground, collect, and pose a greater explosive risk. On the other hand, because natural gas is lighter than air, it tends to rise and dissipate into the air, posing less of an explosive risk.
