Natural gas Some of these gases include heptane, pentane, propane and other hydrocarbons with molecular weights above methane (). The natural gas transmission lines extend to the natural gas processing plant or unit which removes the higher molecular weighted hydrocarbons to produce natural gas with energy content between . The processed natural gas may then be used for residential, commercial and industrial uses. Natural gas flowing in the distribution lines is called mid-stream natural gas and is often used to power engines which rotate compressors. These compressors are required in the transmission line to pressurize and re-pressurize the mid-stream natural gas as
Liquefied natural gas Twomey received patents for a process for large scale liquefaction of natural gas. The intention was to store natural gas as a liquid so it could be used for shaving peak energy loads during cold snaps. Because of large volumes it is not practical to store natural gas, as a gas, near atmospheric pressure. However, if it can be liquefied it can be stored in a volume 600 times smaller. This is a practical way to store it but the gas must be stored at −260 °F (−162 °C). There are two processes for liquefying natural gas in large quantities.