Patent ID: 7310971
Filing Date: 2007-12-25
Classification: F25J,F28F,Y10S

Abstract:
1. A process for liquefying a natural gas stream, said process comprising: (a) cooling the natural gas stream in at least one upstream heat exchanger of an upstream refrigeration cycle via indirect heat exchange with an upstream refrigerant; (b) using a refluxed heavies removal column to remove heavy hydrocarbon components from the cooled natural gas stream; (c) cooling the heavies-reduced natural gas stream in a methane refrigeration cycle via indirect heat exchange with a predominately methane refrigerant; (d) cooling a portion of the predominately methane refrigerant via indirect heat exchange with the upstream refrigerant in a first core-in-kettle heat exchanger to thereby provide a cooled predominately methane stream, wherein the first core-in-kettle heat exchanger operates in parallel with said at least one upstream heat exchanger; (e) employing at least a portion of the cooled predominately methane stream as a reflux stream in the refluxed heavies removal column; (f) cooling at least a portion of the predominately methane refrigerant via indirect heat exchange with the upstream refrigerant in a second core-in-kettle heat exchanger; (g) discharging a first gas-phase portion of the upstream refrigerant from the first heat exchanger; (h) discharging a second liquid-phase portion of the upstream refrigerant from the second heat exchanger; and (i) facilitating indirect heat exchange between the first gas-phase portion and the second liquid-phase portion; said first and second core-in-kettle heat exchangers being positioned in a stacked configuration with one of the heat exchangers locate above the other heat exchanger.