Abstract: The invention relates to a liquid natural gas plant for producing liquefied natural gas. The liquid natural gas plant comprises two or more parallel treatment and liquefaction trains, each train comprising a cooling stage arranged to receive a cleaned natural gas stream from a gas treatment stage, an NGL-extraction unit for extracting natural gas liquids, thereby generating a light natural gas stream. The liquid natural gas plant comprises an additional liquefaction train, comprising an additional cooling stage arranged to receive an additional feed stream for generating additional liquefied natural gas. The additional feed stream comprises two or more side streams taken from the light natural gas taken from the respective light natural gas streams of the one or more parallel treatment and liquefaction trains.

Abstract: A method and apparatus for cooling a hydrocarbon stream such as natural gas. An initial hydrocarbon stream is passed through a first separator to provide an initial overhead stream and a mixed hydrocarbon feed stream. The initial overhead stream is cooled to provide a cooled hydrocarbon stream such as LNG, and at least a C1 overhead stream and one or more C2, C3 and C4 overhead streams are separated from the mixed hydrocarbon feed stream. At least a fraction of at least one of the group comprising: the C2 overhead stream, the C3 overhead stream and the C4 overhead stream is cooled with the C1 overhead stream to provide a cooled stream, which is further cooled against at least a fraction of the cooled, preferably liquefied, hydrocarbon stream to provide an at least partly liquefied cooled 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: Method of liquefying a hydrocarbon stream from a feed stream including (a) passing the feed stream through a first cooling stage having at least two heat exchangers and against a component refrigerant in a first refrigerant circuit, to provide a cooled hydrocarbon stream; (b) passing the cooled hydrocarbon stream through a second cooling stage against a second refrigerant in a second refrigerant circuit, to provide a liquefied hydrocarbon stream; (c) passing the second refrigerant through one of the heat exchangers of the first cooling stage. The heat exchangers of the first cooling stage are shell and tube heat exchangers having two or more tube circuits. The first refrigerant circuit includes a refrigerant compressor and the second refrigerant circuit includes a refrigerant compressor. The refrigerant compressor of the first refrigerant circuit and the refrigerant compressor of the second refrigerant circuit are interconnected and are arranged to be driven by a common driver.

Abstract: A method of liquefying a hydrocarbon stream such as natural gas from a feed stream, the method at least comprising the steps of: (a) providing a feed stream (10); (b) dividing the feed stream (10) of step (a) to provide at least a first feed stream (20) comprising at least 90 mass % of the initial feed stream (10), and a second feed stream (30); (c) liquefying the first feed stream (20) of step (b) at a pressure between 20-100 bar to provide a first liquefied natural gas (LNG) stream (40); (d) cooling the second feed stream (30) of step (b) to provide a cooled feed stream (50); (e) combining the first LNG stream (40) of step (c) with the cooled feed stream (50) of step (d) to provide a combined LNG stream (60); (f) reducing the pressure of the combined LNG stream (60) of step (e); and (g) passing the combined LNG stream (60) of step (f) through a flash vessel (12) to provide a product LNG stream (70) and a gaseous stream (80).

Abstract: A multi-phase hydrocarbon stream (145) is treated to provide a treated liquid hydrocarbon stream (165), such as a liquefied natural gas (LNG) stream. The multi-phase hydrocarbon stream (145) is passed to a first gas/liquid separator (150), wherein it is separated at a first pressure to provide a first separator hydrocarbon vapour stream (205) and a first separator bottoms stream (155). The first separator bottoms stream (155) is then separated in a second gas/liquid separator (160) at a second pressure that is lower than the first pressure, to provide a second separator hydrocarbon vapour stream (175) and a treated liquid hydrocarbon stream (165). The second separator hydrocarbon vapour stream (175) is compressed in an overhead stream compressor (180) to provide a stripping vapour stream (185) which is passed to the first gas/liquid separator (150).

Abstract: Method and apparatus for cooling a stream in a heat exchanger against a refrigerant fluid being cycled in a refrigerant circuit. The cycling of the refrigerant fluid includes feeding a first refrigerant fluid into an axial compressor and compressing it to obtain a compressed first refrigerant fluid. The compressed first refrigerant fluid is then fed into a centrifugal compressor, with a second refrigerant fluid. The compressed first refrigerant fluid and the second refrigerant fluid are compressed in the centrifugal compressor, thereby obtaining a compressed refrigerant fluid mixture. The compressed refrigerant fluid mixture is cooled in a heat exchanger and subsequently separated into at least two streams. The at least two streams are evaporated at different pressure levels of a heat exchanger in heat exchanging contact with the stream to be cooled, and from the at least two evaporated streams the first and second refrigerant fluids are retrieved.

Abstract: Method of, and apparatus for, rejecting nitrogen from a hydrocarbon stream to provide a fuel gas stream. A hydrocarbon stream is at least partially liquefied and subsequently expanded. The expanded hydrocarbon stream is fractionated in a fractionation column to provide an nitrogen-rich hydrocarbon stream and a nitrogen-lean hydrocarbon stream. The nitrogen-rich hydrocarbon stream is partially condensed in a condenser by cooling against a refrigerant circulated in a dedicated first refrigerant circuit, and phase-separated to provide a nitrogen-rejection stream and a nitrogen-lean reflux stream which is returned to the fractionation column. The nitrogen-lean hydrocarbon stream is partially vaporized and phase-separated to provide a vapour stream that is returned to the fractionation column and a liquefied nitrogen-lean hydrocarbon stream that is subjected to sub-cooling. The fuel gas stream is generated from the sub-cooled nitrogen-lean hydrocarbon stream.

Abstract: Method and apparatus for liquefying a hydrocarbon stream such as natural gas from a feed stream. The method comprises at least the steps of: first cooling the feed stream (10) against a first cooling refrigerant being cycled in a first cooling refrigerant circuit (100), wherein the first cooling refrigerant comprises >90 mol % propane, second cooling the cooled gas stream (20) to obtain a liquefied stream (60) against a first mixed refrigerant being cycled in a first mixed refrigerant circuit (200), wherein said second cooling is in two or more heat exchangers (42, 44), at least two of which are operating at different pressures and sub-cooling the liquefied stream (60) against a second mixed refrigerant or against a nitrogen refrigerant being cycled in a sub-cooling refrigerant circuit (300), thereby obtaining a sub-cooled hydrocarbon stream (70).

Abstract: A condensed mixed hydrocarbon feed stream (10), recovered from an initial feed stream (8), is fractionated into one ore more fractionated streams. In this process, the condensed mixed hydrocarbon feed stream (10) is separated into at least a first part-feed stream (20) and a second part-feed stream (30). The first part-feed stream (20) is passed into a first gas/liquid separator (14), to provide at least a first fractionated stream in the form of a first gaseous overhead stream (40). A first bottom liquid stream (50) provided by the first gas/liquid separator (14) is passed into a second gas/liquid separator (22) to provide at least a second fractionated stream in the form of a second gaseous overhead stream (70), which is cooled by heat exchange (26) against the second part-feed stream (30).

Abstract: A method and apparatus for cooling a hydrocarbon stream such as natural gas. An initial hydrocarbon stream is passed through a first separator to provide an initial overhead stream and a mixed hydrocarbon feed stream. The initial overhead stream is cooled to provide a cooled hydrocarbon stream such as LNG, and at least a C1 overhead stream and one or more C2, C3 and C4 overhead streams are separated from the mixed hydrocarbon feed stream. At least a fraction of at least one of the group comprising: the C2 overhead stream, the C3 overhead stream and the C4 overhead stream is cooled with the C1 overhead stream to provide a cooled stream, which is further cooled against at least a fraction of the cooled, preferably liquefied, hydrocarbon stream to provide an at least partly liquefied cooled stream.

Abstract: A method and apparatus for cooling and separating a hydrocarbon stream such as natural gas. The method comprises providing a hydrocarbon stream, cooling the hydrocarbon stream (10) to provide a partially liquefied hydrocarbon stream, passing at least a fraction of the partially liquefied hydrocarbon stream into a distillation column through a first inlet, providing a lower feed stream, providing a refrigerant circuit comprising at least a refrigerant stream, heating the lower feed stream against the refrigerant stream to provide a heated lower feed stream and a cooled refrigerant stream, passing the heated lower feed stream into the distillation column through a second inlet lower than the first inlet, and separating the partially liquefied hydrocarbon stream in the distillation column to provide at least a first overhead gaseous stream and a first bottom liquid stream.

Abstract: A method of cooling a hydrocarbon stream such as natural gas from a feed stream (10), the method at least comprising the steps of: (a) passing the feed stream (10) and a first refrigerant stream (20) through a cooling stage (100) including one or more heat exchangers (12a, 12b) to provide a cooled hydrocarbon stream (30); and (b) circulating the first refrigerant stream (20) around a first refrigerant circuit (110) which includes one or more compressors (14), one or more coolers (16, 18) after the compressor (s), and a refrigerant accumulator (22) after the cooler (s); wherein there are no further coolers between the refrigerant accumulator (22) and the heat exchanger or the first of more than one heat exchanger (12a, 12b).

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: Method of liquefying a hydrocarbon stream such as natural gas from a feed stream (10), the method at least comprising the steps of: (a) circulating a first refrigerant stream (70) in a first refrigerant circuit (110); (b) cooling the first refrigerant stream (70) in one or more heat exchangers (14) of a first cooling stage (100) to provide a cooled first refrigerant stream (20); (c) passing at least part of the cooled first refrigerant stream (20) through one or more expanders to provide one or more expanded cooled first refrigerant streams (30); (d) passing the or at least one of the expanded cooled first refrigerant streams (30) and the feed stream (10) through the first one or more heat exchangers (14) to provide a cooled hydrocarbon stream (40); (e) passing the cooled hydrocarbon stream (40) through a second cooling stage (200) against a second refrigerant stream (50) to provide a liquefied hydrocarbon stream (60); wherein at least one expander is an expansion turbine (12) whose work energy created in ste

Abstract: Method of liquefying a hydrocarbon stream such as natural gas from a feed stream (10), the method at least comprising the steps of: (a) passing the feed stream (10) through a first cooling stage (100a, 100b) having at least two heat exchangers (112) and against a first single component refrigerant in a first refrigerant circuit (110a, 110b), to provide a cooled hydrocarbon stream (30); (b) passing the cooled hydrocarbon stream (30) through a second cooling stage (200) against a second refrigerant in a second refrigerant circuit (210a, 210b), to provide a liquefied hydrocarbon stream (40); (c) passing the second refrigerant through one or more of the heat exchangers (112) of the first cooling stage (100a, 110b); wherein the heat exchangers of the first cooling stage (100a, 100b) are shell and tube heat exchangers (112) having two or more tube circuits, the feed stream (10) passing through the tube circuit in each shell and tube heat exchanger (112) and the second refrigerant passing through another tube circui

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 method of liquefying natural gas from a feed stream (10) comprising at least the steps of: passing the feed stream (10) against a mixed refrigerant being cycled through a heat exchanger (12), to provide an at least partly liquefied hydrocarbon stream (20) having a temperature below ?100° C.; outflowing the mixed refrigerant as a liquid and vapour outflow refrigerant stream (80) and passing it through a first separator (18) to provide a vapour refrigerant stream (90) and a liquid refrigerant stream (110); recycling without substantial heat exchange the liquid refrigerant stream (110) into the heat exchanger (12); compressing and cooling the vapour refrigerant stream (90) to provide a cooled compressed stream (100) having a temperature below 0° C. and recycling it into the heat exchanger (12).

Abstract: A hydrocarbon stream is liquefied in a method wherein a feed stream is provided, from which feed stream a first stream and a second stream are produced. The first stream is liquefied in a main liquefaction system to provide a first liquefied stream, while the second stream is cooled separately to provide a cooled second stream. The first liquefied stream is combined with the cooled second stream to produce a combined stream, which is separated in a gas/liquid separator into a liquefied hydrocarbon product stream and a gaseous stream. The gaseous stream is warmed to a temperature of above ?40° C. by heat exchanging against any other stream used in the method, wherein the warming of the gaseous stream employs at least heat exchanging against the second stream to provide at least part of the cooling of the second stream.

Abstract: A method of liquefying a hydrocarbon stream such as natural gas from a feed stream, the method at least comprising the steps of: (a) providing a feed stream (10); (b) dividing the feed stream (10) of step (a) to provide at least a first feed stream (20) comprising at least 90 mass % of the initial feed stream (10), and a second feed stream (30); (c) liquefying the first feed stream (20) of step (b) at a pressure between 20-100 bar to provide a first liquefied natural gas (LNG) stream (40); (d) cooling the second feed stream (30) of step (b) to provide a cooled feed stream (50); (e) combining the first LNG stream (40) of step (c) with the cooled feed stream (50) of step (d) to provide a combined LNG stream (60); (f) reducing the pressure of the combined LNG stream (60) of step (e); and (g) passing the combined LNG stream (60) of step (f) through a flash vessel (12) to provide a product LNG stream (70) and a gaseous stream (80).