Abstract:
The present invention provides a method of cooling a hydrocarbon stream, such as a method of liquefying a natural gas stream to provide a liquefied natural gas stream and an apparatus therefore, the method comprising at least the steps of : (a) heat exchanging a hydrocarbon stream (10) against one or more refrigerant streams (20) to provide a cooled hydrocarbon stream (30) and one or more at least partly evapourated refrigerant streams (40); (b) compressing the one or more at least partly evapourated refrigerant streams (40) in at least one refrigerant compressor (150) to provide one or more compressed refrigerant streams (60); (c) driving one or more turbines (200) to directly mechanically drive the at least one refrigerant compressor (150) and provide one or more hot discharge streams (220, 460) from the one or more turbines (200); and (d) thermally desalinating a salinated water stream (280) in a thermal desalination unit (250) with at least a part of the heat energy derived from at least one of the one or more hot discharge streams (220, 460) to provide a desalinated water stream (260).
Abstract:
A method and apparatus for liquefying a gaseous hydrocarbon stream such as natural gas. The method comprises at least the steps of providing a feed stream (10) and dividing the feed stream (10) of step to provide at least a first stream (20) and a second stream (30). The first stream (20) is liquefied using heat exchange against a liquid nitrogen stream (40) to provide a first liquefied hydrocarbon stream (60) and an at least partly evaporated nitrogen stream (70). The second stream (20) is cooled and liquefied by heat exchanging against the at least partly evaporated nitrogen stream (70) to provide a second cooled hydrocarbon stream (80).
Abstract:
A refrigerant stream (10) is provided at a refrigerant pressure, and passed through at least three heat exchange steps (12, 14, 16, 18) operating at different pressure levels. A hydrocarbon stream (20) is passed through at least two of these heat exchange steps to provide a cooled hydrocarbon stream (30). A fraction of the refrigerant stream (10) is expanded and evaporated at each heat exchange step (12, 14, 16, 18) to a different pressure, to provide a first evaporated refrigerant stream (40) at a first evaporation pressure, and at least two other evaporated refrigerant streams (50, 60, 70) at evaporation pressures lower than the first evaporation pressure. The first evaporated refrigerant stream (40) is compressed through a highest-pressure compressor stage (22) to provide at least a fraction of the refrigerant stream (10) at the refrigerant pressure, and the other evaporated refrigerant streams (50, 60, 70) are compressed through at least two parallel lower pressure compressor stages (24, 26, 28) to provide two or more part-compressed refrigerant streams (50a, 60a, 70a), all of which part-compressed refrigerant streams (50a, 60a, 70a) being passed through the highest pressure compressor stage (22).
Abstract:
A mixed refrigerant stream (10) comprising a first mixed refrigerant is passed through one or more heat exchangers (12) to provide a cooled mixed refrigerant stream (20). At least a fraction of a cooling stream (30) comprising a second mixed refrigerant is expanded to provide one or more expanded cooling streams (40a), at least one of which may be passed through one or more of the heat exchangers (12), to cool the mixed refrigerant stream (10) thereby providing the cooled mixed refrigerant stream (20). The temperature (T1) and the flow (F1) of at least part of the cooled mixed refrigerant stream (20) is monitored, and the flow (F2) of the cooling stream (30) is controlled using the flow F1 and the temperature T1.
Abstract:
A first liquefied hydrocarbon stream (10) is provided from a first source (12) and a second liquefied hydrocarbon stream (20) is provided from a second source (22). The second liquefied hydrocarbon stream (20) has been liquefied solely by cooling against a first cooled nitrogen-based stream (40). The first and second liquefied hydrocarbon streams (10,20) are gasified to produce a gasified hydrocarbon stream (11,21,51), thereby cooling a gaseous nitrogen-based stream (30) against the gasifying first and second liquefied hydrocarbon streams (10,20) to provide a second cooled nitrogen-based stream (40).
Abstract:
A method and apparatus for liquefying a gaseous hydrocarbon stream such as natural gas. The method comprises at least the steps of providing a feed stream (10) and dividing the feed stream (10) to provide at least a first stream (20) and a second stream (30). The first stream (20) is liquefied using heat exchange against a liquid nitrogen stream (40) to provide a first liquefied hydrocarbon stream (60) and an at least partly evaporated nitrogen stream (70). The second stream (20) is cooled and liquefied by heat exchanging against the at least partly evaporated nitrogen stream (70) to provide a second cooled hydrocarbon stream (80).
Abstract:
A method and apparatus for cooling two or more liquefied hydrocarbon streams. First (30) and second (30a) liquefied hydrocarbon streams are provided and combined thereby providing a combined liquefied hydrocarbon stream (40). The combined liquefied hydrocarbon stream (40) is further cooled against a refrigerant thereby providing a further cooled liquefied hydrocarbon stream (50) such as liquefied natural gas (LNG).
Abstract:
Method and apparatus for producing a cooled hydrocarbon stream (60). The method employs cooling, at at least two consecutive pressure levels, a first stream and a first mixed refrigerant stream, using portions of the first mixed refrigerant from the first mixed refrigerant stream in first and second heat exchangers (125, 145); first and second expansion devices (135, 165); and a first compressor (105) to provide the first mixed refrigerant stream. The cooling process is controlled using an advanced process controller based on model predictive control to determine simultaneously control actions for a set of manipulated variables in order to optimise at least one of a set of parameters whilst controlling at least one of a set of controlled variables. The set of manipulated variables comprises: the composition of the mixed first refrigerant, the setting of the first expansion device (135), and the setting of the second expansion device (165).
Abstract:
The present invention provides a method of cooling a hydrocarbon stream, such as a method of liquefying a natural gas stream to provide a liquefied natural gas stream and an apparatus therefore, the method comprising at least the steps of : (a) heat exchanging a hydrocarbon stream (10) against one or more refrigerant streams (20) to provide a cooled hydrocarbon stream (30) and one or more at least partly evapourated refrigerant streams (40); (b) compressing the one or more at least partly evapourated refrigerant streams (40) in at least one refrigerant compressor (150) to provide one or more compressed refrigerant streams (60); (c) driving one or more turbines (200) to directly mechanically drive the at least one refrigerant compressor (150) and provide one or more hot discharge streams (220, 460) from the one or more turbines (200); and (d) thermally desalinating a salinated water stream (280) in a thermal desalination unit (250) with at least a part of the heat energy derived from at least one of the one or more hot discharge streams (220, 460) to provide a desalinated water stream (260).
Abstract:
A first liquefied hydrocarbon stream (10) is provided from a first source (12) and a second liquefied hydrocarbon stream (20) is provided from a second source (22). The second liquefied hydrocarbon stream (20) has been liquefied solely by cooling against a first cooled nitrogen-based stream (40). The first and second liquefied hydrocarbon streams (10,20) are gasified to produce a gasified hydrocarbon stream (11,21,51), thereby cooling a gaseous nitrogen-based stream (30) against the gasifying first and second liquefied hydrocarbon streams (10,20) to provide a second cooled nitrogen-based stream (40).