Apparatus for the liquefaction of natural gas and methods relating to same
First Claim
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.
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Accused Products
Abstract
An apparatus and method for producing liquefied natural gas. A liquefaction plant may be coupled to a source of unpurified natural gas, such as a natural gas pipeline at a pressure letdown station. A portion of the gas is drawn off and split into a process stream and a cooling stream. The cooling stream passes through an expander creating work output. A compressor may be driven by the work output and compresses the process stream. The compressed process stream is cooled, such as by the expanded cooling stream. The cooled, compressed process stream is expanded to liquefy the natural gas. A gas-liquid separator separates a vapor from the liquid natural gas. A portion of the liquid gas is used for additional cooling. Gas produced within the system may be recompressed for reintroduction into a receiving line or recirculation within the system for further processing.
139 Citations
40 Claims
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1. A method of producing liquid natural gas, the method comprising:
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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. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27)
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28. A liquefaction plant comprising:
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a first flow path defined and configured for sequential delivery of a first stream of natural gas through a compressor and a first side of at least one heat exchanger; a second flow path defined and configured for sequential delivery of a second stream of natural gas through an expander and a second side of the at least one heat exchanger; at least two paths including a cooling path and a liquid production path formed from the first flow path at a location subsequent an intended flow of the first stream of natural gas through the first side of the at least one heat exchanger, wherein the cooling path is defined and configured to selectively direct a flow of gas to the second side of the at least one heat exchanger and wherein the liquid production path is defined and configured to selectively direct a flow of gas to a gas-liquid separator. - View Dependent Claims (29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40)
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Specification