Natural gas wells produce a slew of hydrocarbon liquids. When those liquids are separated from one another, one of the substances is natural gasoline. Not to be confused with gasoline, which is derived from refining petroleum, natural gasoline burns cleaner. It can run cars in its pure form, but is usually blended with regular gasoline to make the gas used in most cars. Natural gasoline can also be used to process other petroleum byproducts.
Natural gasoline and other natural gas liquids have to be processed at plants in machines called fractionators. Most processing plants are in the Gulf. That's where the United States gets most of its petroleum, which was the source of most petrochemicals before the U.S. natural gas industry took off.
Now that energy companies are drilling in natural gas plays, they're tapping into liquids that are lighter than oil, and easier to break into other valuable compounds and chemicals.