What is the difference between regular gasoline and natural gas?

Marshall Brain

You Asked:

What is the difference between regular gasoline and natural gas? --- Sarah, St. Louis, Mo.

Marshall Brain Answers:

Let's start with their similarity. Both gasoline and natural gas are hydrocarbons. That means they are both made of hydrogen and carbon atoms bonded together.

The difference is the number of atoms in each molecule. With natural gas, the molecule is very small. There is one carbon atom with four hydrogen atoms bonded to it. Gasoline, on the other hand, is made of eight carbon atoms chained together with 18 hydrogen atoms bonded to the chain.

This means that natural gas is very light - lighter than air in fact - and always a gas at normal temperatures and pressures. Gasoline is much heavier and is always a liquid at normal temperatures and pressures.

Natural gas is also "cleaner" than gasoline from a carbon standpoint. In a natural gas molecule, there are four times as many hydrogen atoms as carbon atoms. In gasoline, the ratio is closer to 2-to-1.

The problem with natural gas from a vehicle standpoint is that it is harder to store than gasoline. Compressing natural gas requires energy, and a tank of compressed natural gas is much larger than a tank of gasoline that contains the same amount of energy.

More info on the formation and discovery of oil and natural gas: