Light hydrocarbon recovery unit collects associated gas produced in gas or oil field (evaporating gas, surge tank gas and casing gas etc.) then liquefy to LNG, stable lighter hydrocarbon and dry gas which are valuable in market. Lighter hydrocarbon recovery units are mounted on one or more 7*2.3 skids. This configuration saves a lot in operating lifecycle and reduces equipment footprint, with quality of fabrication and reliability of project operating improved a lot. DCS or PLC is available to be enclosed to control the unit to ensure the quality and robust of operation. The recovery efficiency depends on the technology in different components. Recovery rate (account for C3) of propane refrigeration is approximate 45~80%, refrigerated oil absorption 80~92%, PSA 85~93%.