Patent ID: 7591150
Filing Date: 2009-09-22
Classification: F25J

Abstract:
1. A method of producing liquid natural gas, the method comprising: providing a source of unpurified natural gas and flowing a portion of the unpurified natural gas from the source; dividing the portion of unpurified natural gas into at least a process stream and a cooling stream; flowing the process stream sequentially through a compressor and a first side of at least one heat exchanger; flowing the cooling stream sequentially through an expander and a second side of the at least one heat exchanger; sensing a temperature of the process stream after it exits the first side of the at least one heat exchanger; flowing substantially all of the process stream from the first side of the at least one heat exchanger to the second side of the at least one heat exchanger if a sensed temperature is warmer than a specified temperature; and flowing at least a portion of the process stream from the first side of the at least one heat exchanger to a gas-liquid separator if the sensed temperature is colder than the specified temperature.