I have done blog posts in the past about what is natural gas and how natural gas was formed. Because natural gas is a very important element to our every day lives, it is interesting to see how natural gas has formed over many years and how it was even first discovered. For this blog, I wanted to actually pry open natural gas as a whole and really get into what is inside it. What makes up natural gas? What are the components of it? Better yet, how does each component do its part?
Chemical Composition of Natural Gas
| Compound | Symbol | Percent in Natural Gas |
| Methane | CH4 | 60-90 |
| Ethane | C2H6 | 0-20 |
| Propane | C3H8 | 0-20 |
| Butane | C4H10 | 0-20 |
| Carbon Dioxide | CO2 | 0-8 |
| Oxygen | O2 | 0-0.2 |
| Nitrogen | N2 | 0-5 |
| Hydrogen Sulfide | H2S | 0-5 |
| Rare Gases | A, He | 0-2 |
The truth is, the exact composition of natural gas is different depending on the location. Each well has a different gas composition and different amounts of each component. Natural gas is a naturally occurring mixture or premixed combustion. Natural gas is a combustible mixture of hydrocarbon gases. What is a hydrocarbon you ask? A hydrocarbon is an organic compound of hydrogen and carbon called petroleum. While natural gas is formed primarily of methane, it also includes ethane, propane, butane, and pentane. Below, you can see a typical composition of natural gas.
When there is almost pure methane, natural gas is considered “dry” gas. When the heavier hydrocarbons are present, the gas is considered “wet.” The gas that we get as consumers is made up of almost entirely pure methane. Yes, natural gas is already composed of mostly methane but the gas still must go through processing to remove the hydrocarbons before it reached the consumer. This means that the ethane, propane, butane, and pentanes must be removed. However just because these elements are removed, this does not mean that they are worthless and wasteful.
There is a term that groups together these hydrocarbons that are removed from natural gas. This term is coined Natural Gas Liquids or NGLs. These NGLs can be sold and are valuable by-products of natural gas. NGLs are sold separately and can be used for many different things in many different ways. This includes but is not limited to enhancing oil recovery in oil wells, sources of energy, and providing raw materials for oil refineries or petrochemical plants.
At Croft, we have equipment to fit your processing needs. Check out our FCS and JTS which removed hydrocarbons from the gas stream.
*Updated May 2020 by a CROFT representative
https://www.uniongas.com/about-us/about-natural-gas/Chemical-Composition-of-Natural-Gas
https://www.theglobeandmail.com/opinion/answering-a-truly-burning-question/article5381010/
http://naturalgas.org/naturalgas/processing-ng/
