Turboexpander

A turboexpander (also referred to as turbo expander, expansion turbine or simply expander) is a centrigugal or axial flow turbine through which a high pressure gas is expanded to produce work that is typically used to drive a compressor. Because work is extracted from the expanding high pressure gas, the expansion is isentropic and the low pressure exhaust gas from the turbine is at a very low temperature, often as low as 200 K (-100 °F) or less.<ref>"Business Characteristics of the Natural Gas Conditioning Industry", Report GRI-93/0342</ref> Turbo expanders are very widely used as sources of refrigeration in industrial processes such as: the extraction of ethane as well as natural gas liquids (NGLs) from natural gas<ref>Flow sheet of demethanizer</ref>; the liquefaction of gases;<ref>BOC (NZ) publication: use search function for keyword "expansion"</ref><ref>US Department of Energy Hydrogen Program</ref><ref>Air Product Co. publication: use search function for keyword "expansion"</ref><ref>India Department of Atomic Energy publication: use search function for keyword "expansion"</ref> and other low-temperature processes.