Patent ID: 6378330
Filing Date: 2002-04-30
Classification: F17C,F25J

Abstract:
A process for liquefying a pressurized gas stream rich in methane, which comprises the steps of:(a) withdrawing a first fraction of the pressured gas stream and entropically expanding the withdrawn first fraction to a lower pressure to cool and at least partially liquefy the withdrawn first fraction; (b) cooling a second fraction of the pressurized gas stream by indirect heat exchange with the expanded first fraction; (c) expanding the second fraction of the pressurized gas stream to a lower pressure, thereby at least partially liquefying the second fraction of the pressurized gas stream; and (d) removing the liquefied second fraction from the process as a pressurized product stream having a temperature above âˆ’112Â° C. (âˆ’170Â° F.) and a pressure at or above its bubble point pressure.