Patent ID: 8424340

Claim:
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 to thereby produce a cooled natural gas stream comprising predominately methane; (b) introducing said cooled natural gas stream into a refluxed heavies removal column; (c) using said refluxed heavies removal column to remove heavy hydrocarbon components from said cooled natural gas stream to thereby produce a heavies-reduced natural gas stream and a heavies-rich stream; (d) cooling said heavies-reduced natural gas stream in a methane refrigeration cycle via indirect heat exchange with a predominately methane refrigerant; (e) cooling a portion of said predominately methane refrigerant via indirect heat exchange with said upstream refrigerant in an upper core-in-kettle heat exchanger to thereby provide a cooled predominately methane stream, wherein said upper core-in-kettle heat exchanger operates in parallel with said at least one upstream heat exchanger; (f) employing at least a portion of said cooled predominately methane stream as a reflux stream in said refluxed heavies removal column; and (g) cooling at least a portion of said predominately methane refrigerant via indirect heat exchange with said upstream refrigerant in a lower core-in-kettle heat exchanger, said upper and lower core-in-kettle heat exchangers being positioned in a stacked configuration with the upper heat exchanger located above the lower heat exchanger, wherein an economizer is generally disposed adjacent to and therebetween, wherein the predominately methane refrigerant is delivered to the upper core-in-kettle heat exchanger prior the lower core-in-kettle heat exchanger, upon exiting the upper core-in-kettle heat exchanger the predominately methane refrigerant is then delivered to the lower core-in-kettle heat exchanger.