Editing Ethane (section)

==Production==
After [[methane]], ethane is the second-largest component of [[natural gas]]. Natural gas from different gas fields varies in ethane content from less than 1% to more than 6% by volume. Prior to the 1960s, ethane and larger molecules were typically not separated from the methane component of natural gas, but simply burnt along with the methane as a fuel. Today, ethane is an important [[petrochemical]] [[feedstock]] and is separated from the other components of natural gas in most well-developed gas fields. Ethane can also be separated from [[petroleum gas]], a mixture of gaseous hydrocarbons produced as a byproduct of [[petroleum refining]].

Ethane is most efficiently separated from methane by liquefying it at cryogenic temperatures. Various refrigeration strategies exist: the most economical process presently in wide use employs a [[turboexpander]], and can recover more than 90% of the ethane in natural gas. In this process, chilled gas is expanded through a [[turbine]], reducing the temperature to approximately {{cvt|−100|°C|F}}. At this low temperature, gaseous methane can be separated from the liquefied ethane and heavier hydrocarbons by [[distillation]]. Further distillation then separates ethane from the [[propane]] and heavier hydrocarbons.