Enhanced methane flash system for natural gas liquefaction
AssigneeConocoPhillips Company
InventorsNed Baudat, Anthony Eaton, Philip Ritchie, Paul Hahn, Jame Yao, Rong-Jwyn Lee
Life of this patent
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Abstract
Natural gas liquefaction system employing an open methane cycle wherein the liquefied natural gas is flashed immediately upstream of the liquefied natural gas storage tank and boil off vapors from the tank are returned to the open methane cycle.
Claims95
1-39. (canceled)
A process for liquefying a natural gas stream, said process comprising the steps of:
- (a) cooling the natural gas stream in a first refrigeration cycle employing a first refrigerant;
- (b) cooling the natural gas stream in a second refrigeration cycle employing a second refrigerant;
- (c) cooling the natural gas stream in a third refrigeration cycle employing a third refrigerant;
- and
- (d) cooling the natural gas stream in a multi-stage expansion cycle comprising at least 3 expansion stages, said multi-stage expansion cycle comprising 2 or fewer phase separators.
A process for liquefying a natural gas stream, said process comprising the steps of:
- (a) cooling the natural gas stream via indirect heat exchange with a first predominantly methane stream or group of streams to thereby provide a first cooled stream;
- (b) separating at least a portion of the first cooled stream into a first separated stream and a second separated stream;
- (c) compressing at least a portion of the first separated stream in a compressor;
- and
- (d) cooling at least a portion of the second separated stream via indirect heat exchange with a second predominantly methane stream or groups of streams to thereby form a second cooled stream.
A process for liquefying a natural gas stream, said process comprising the steps of:
- (a) reducing the pressure of the natural gas stream to thereby provide a first pressure-reduced stream comprising less than about 5 mole percent vapor;
- (b) splitting at least a portion of the first pressure-reduced stream into a first split stream and a second split stream, each of said first and second split streams comprising less than about 5 mole percent vapor;
- (c) conducting at least a portion of the first split stream to a liquefied natural gas storage tank;
- and
- (d) heating at least a portion of the second split stream by indirect heat exchange with a first predominantly methane stream to thereby provide a first warmed stream.
An apparatus for liquefying a natural gas stream, said apparatus comprising:
- a methane economizer for providing indirect heat exchange between a plurality of predominantly methane streams via a plurality of heat exchanger passes, said methane economizer comprising a first heat exchanger pass for cooling at least a portion of the natural gas stream;
- and
- a multi-stage methane expansion cycle for receiving at least a portion of the cooled natural gas stream from the first heat exchanger pass, said methane expansion cycle comprising at least 3 expanders for sequentially reducing the pressure of the natural gas stream, said methane expansion cycle comprising 2 or less phase separators.
A liquefied natural gas product produced via the process of claim 1
A liquefied natural gas product produced via the process of claim 16.
A liquefied natural gas product produced via the process of claim 23.
A computer simulation process comprising using a computer to simulate the process of claim 1.
A computer simulated process comprising using a computer to simulate the process of claim 16.
A computer simulation process comprising using a computer to simulate the process of claim 23.
Dependencies are inferred from the claim text.