Petroleum
Petroleum, or crude oil, is a mixture of molecular substances that results from the decaying of plants and animals. Over thousands of years, as massive amounts of dead plant and animal materials accumulates and decays, the earth processes will decompose it into several organic molecules. These molecules range from very small to very large hydrocarbons that are typically called alkanes. This mixture of alkanes cannot be used as it is pumped out of the ground. Rather, it needs to separated into parts in order to be used.
The parts of petroleum are used for fuel and building things. A brief overview of what petroleum is used for is in the image to the right: As you can see, most of petroleum is used as a fuel, Gasoline is the largest component, while other fuels (diesel, fuel oil, jet fuel, etc.) make up nearly 93 % of the uses. The other 7% is used as building materials, which we will talk about later. |
Used as Fuel
After separation, the fuel is burned in a combustion reaction. As we have talked about, combustion reactions take a hydrocarbon and burn in the presence of oxygen to make carbon dioxide and water. This reaction releases energy. The burning of octane, which is the primary ingredient in gasoline, looks like this:
After separation, the fuel is burned in a combustion reaction. As we have talked about, combustion reactions take a hydrocarbon and burn in the presence of oxygen to make carbon dioxide and water. This reaction releases energy. The burning of octane, which is the primary ingredient in gasoline, looks like this:
Where is the Petroleum?
Petroleum is a thick liquid that is found underground. It comes out as a black/green liquid. Petroleum is found all over the planet in reservoirs that are underground. Some of these reservoirs are under the ocean floor, and we have built huge platforms that drill under the ocean floor to retrieve the petroleum. To the left is an example of one of these platforms. Below is a world map showing large reserves of petroleum. |