Abstract: In a method and apparatus for treating a hydrocarbon stream having methane, at least a part of the hydrocarbon stream and a main refrigerant stream are cooled by indirect heat exchanging against a pre-cooling refrigerant. The pre-cooled hydrocarbon stream is passed to a first inlet of an extraction column, and an effluent stream is discharged from the extraction column. The effluent stream and at least a part of the pre-cooled main refrigerant stream are passed to a further heat exchanger, where they are both cooled thereby providing a cooled methane-enriched hydrocarbon stream and at least one cooled main refrigerant stream. The passing of the effluent stream to the further heat exchanger and the passing of the pre-cooled hydrocarbon stream to the first inlet of the extraction column includes indirectly heat exchanging the effluent stream against the pre-cooled hydrocarbon stream.

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 (14) 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) which is used to cool (22) a hydrocarbon stream (70). 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 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 first liquefied hydrocarbon stream is provided from a first source and a second liquefied hydrocarbon stream is provided from a second source. The second liquefied hydrocarbon stream has been liquefied by cooling solely against a first cooled nitrogen-based stream. The first and second liquefied hydrocarbon streams are gasified to produce a gasified hydrocarbon stream, thereby cooling a gaseous nitrogen-based stream against the gasifying first and second liquefied hydrocarbon streams to provide a second cooled nitrogen-based stream.

Abstract: A wet hydrocarbon stream having at least methane and water, provided at a temperature equal to a first temperature, is cooled thereby lowering the temperature to a second temperature. In a water removal device a wet disposal stream having water is withdrawn from the wet hydrocarbon stream, at the second temperature. An effluent stream having the wet hydrocarbon stream from which the wet disposal stream has been removed, is discharged from the water removal device and passed to a further heat exchanger. A refrigerant stream is also passed to the further heat exchanger, and both the effluent stream and the refrigerant stream are cooled in the further heat exchanger by indirect heat exchanging against an evaporating refrigerant fraction. The effluent stream is heated by indirectly heat exchanging against the wet hydrocarbon stream. The cooling of the wet hydrocarbon stream includes this indirectly heat exchanging.

Abstract: In a method and apparatus for treating a hydrocarbon stream having methane, at least a part of the hydrocarbon stream and a main refrigerant stream are cooled by indirect heat exchanging against a pre-cooling refrigerant. The pre-cooled hydrocarbon stream is passed to a first inlet of an extraction column, and an effluent stream is discharged from the extraction column. The effluent stream and at least a part of the pre-cooled main refrigerant stream are passed to a further heat exchanger, where they are both cooled thereby providing a cooled methane-enriched hydrocarbon stream and at least one cooled main refrigerant stream. The passing of the effluent stream to the further heat exchanger and the passing of the pre-cooled hydrocarbon stream to the first inlet of the extraction column includes indirectly heat exchanging the effluent stream against the pre-cooled hydrocarbon stream.

Abstract: A wet hydrocarbon stream (510) comprising at least methane and water, provided at a temperature equal to a first temperature, is cooled thereby lowering the temperature to a second temperature. In a water removal device (525) at least one wet disposal stream (590) comprising water is withdrawn from the wet hydrocarbon stream, at the second temperature. An effluent stream (560), comprising the wet hydrocarbon stream from which the at least one wet disposal stream (590) has been removed, is discharged from the water removal device (525) and passed to a further heat exchanger (535). At least one refrigerant stream (210) is also passed to the further heat exchanger (535), and both the effluent stream (560) and the refrigerant stream (210) are cooled in the further heat exchanger (535) by indirect heat exchanging against an evaporating refrigerant fraction (230).

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: A first liquefied hydrocarbon stream is provided from a first source and a second liquefied hydrocarbon stream is provided from a second source. The second liquefied hydrocarbon stream has been liquefied by cooling solely against a first cooled nitrogen-based stream. The first and second liquefied hydrocarbon streams are gasified to produce a gasified hydrocarbon stream, thereby cooling a gaseous nitrogen-based stream against the gasifying first and second liquefied hydrocarbon streams to provide a second cooled nitrogen-based stream.

Abstract: A refrigerant stream is provided at a refrigerant pressure, and passed through at least three heat exchange steps operating at different pressures. A hydrocarbon stream is passed through at least two of these heat exchange steps to provide a cooled stream. A fraction of the refrigerant stream is expanded and evaporated at each heat exchange step to a different pressure, to provide a first evaporated refrigerant stream at a first evaporation pressure, and at least two other evaporated refrigerant streams at evaporation pressures lower than the first. The first evaporated refrigerant stream is compressed through a highest-pressure compressor to provide at least a fraction of the refrigerant stream at the refrigerant pressure, and the other evaporated refrigerant streams are compressed through at least two parallel lower pressure compressors to provide two or more part-compressed refrigerant streams, all of which part-compressed refrigerant streams are passed through the highest pressure compressor.

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 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 (14) 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) which is used to cool (22) a hydrocarbon stream (70). 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 hydrocarbon feed stream is separated in one or more separators to provide a hydrocarbon stream and at least one methane-lean stream comprising a first ethane-rich header feed stream. The hydrocarbon stream is heat exchanged with at least one refrigerant stream to provide at least one cooled hydrocarbon stream and at least one at least partially evapourated refrigerant stream. The first ethane-rich header feed stream is passed to at least one fuel gas header, from which header fuel gas is removed as at least one fuel gas stream.

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: A refrigerant stream is passed through at least one heat exchanger to provide a first at least partially evaporated stream and a second at least partially evaporated stream. A first compressor feed stream is provided from the first partially evaporated stream, and a second compressor feed stream is provided from the second partially evaporated stream. The first compressor feed stream is passed through a first refrigerant compressor and the second compressor feed stream through a second compressor, to provide first and second compressed streams, which are combined at a common pressure. The first refrigerant compressor is controlled by heating the second at least partially evaporated stream or the second compressor feed stream, or vice versa.