Turboexpander
（重定向自Expansion turbine）
![Figure 1: Schematic diagram of a turboexpander driving a compressor.](/Images/godic/202501/12/ExpansionTurbine4733.png")
![Figure 2: A schematic diagram of a demethanizer extracting hydrocarbon liquids from natural gas.](/Images/godic/202501/12/Demethanizer4733.PNG")
![Figure 3: Schematic diagram of power generation system using a turboexpander.](/Images/godic/202501/12/Expansion_turbine_power_generation4733.png")
![Figure 4: Schematic diagram of a refrigeration system using a turboexpander, compressor and a motor.](/Images/godic/202501/12/Expansion_turbine+compressor_refrigeration_system4733.png")
A turboexpander, also referred to as a turbo-expander or an expansion turbine, is a centrifugal or axial flow turbine through which a high pressure gas is expanded to produce work that is often used to drive a compressor.
Because work is extracted from the expanding high pressure gas, the expansion is approximated by an isentropic process (i.e., a constant entropy process) and the low pressure exhaust gas from the turbine is at a very low temperature, −150 °C or less depending upon the operating pressure and gas properties. Partial liquefaction of the expanded gas is not uncommon.