Natural gas is a mixture of hydrocarbons with different molecular weights such as Ethane, Propane, Butane, etc. In NGL fractionation unit, heavier components in distillation towers such as De-Ethanizer, De-Propanizer, De-Butanizer, … would be separated. By separation of these components, in addition to producing value added products selling, control of hydrocarbon dew point has been occurred. NGL Fractionation will be usually done in different methods such as absorption as well as using cold box, in which nowadays the second method has been vastly utilized due to its further advantages.