Patent ID: 9121636
Filing Date: 2015-09-01
Classification: F25J

Abstract:
1. A process for removing a contaminant from a refrigerant employed in a closed-loop refrigeration cycle of a liquefied natural gas facility, the process comprising: withdrawing a first portion of the refrigerant following at least one expansion of the refrigerant in the closed-loop refrigeration cycle; withdrawing a second portion of the refrigerant in a predominantly liquid phase and upstream of the at least one expansion of the first portion of the refrigerant in the closed-loop refrigeration cycle; separating via a distillation column the first portion of the refrigerant into a contaminant-rich bottom stream and a contaminant-depleted overhead stream, wherein the distillation column includes a first indirect heat exchanger for heating liquids of the first portion of the refrigerant in a lower area of the distillation column using the second portion of the refrigerant and a second indirect heat exchanger for cooling vapors of the first portion of the refrigerant in an upper area of the distillation column using a cooled stream formed by expansion of the second portion of the refrigerant upon exiting the first indirect heat exchanger; expanding the overhead stream to form a cooled contaminant-depleted stream; and introducing the cooled stream upon exiting the second indirect heat exchanger and the cooled contaminant-depleted stream back into the closed-loop refrigeration cycle.