Abstract: Method of cooling a hydrocarbon stream (10) such as natural gas, the method at least comprising the steps of (a) heat exchanging the hydrocarbon stream (10) against a first refrigerant stream (20) to provide a cooled hydrocarbon stream (30) and an at least partly evaporated refrigerant stream (40); (b) compressing the at least partly evaporated refrigerant stream (40) using one or more compressors (14, 16, 18) to provide a compressed refrigerant stream (50, 60, 70); (c) cooling the compressed refrigerant stream (50, 60, 70) after one or more of the compressors against ambient to provide a cooled compressed refrigerant stream (70a); (d) dynamically expanding the cooled compressed gaseous refrigerant stream (70a) to provide an expanded refrigerant stream (80); and (e) further cooling the expanded refrigerant stream (80) to provide an at least partially condensed refrigerant stream.

Abstract: A method of controlling one or more refrigerant compressors (12) for one or more gaseous streams (10) at a normal operating temperature. At least one refrigerant compressor (12) has a vapour recirculation line (30). A compressor feed stream (10a) is provided from a combination of a vapour recirculation stream (30) from the vapour recirculation line (30) and an at least partly evaporated refrigerant stream (8). The compressor feed stream (10a) is passed through a suction drum (11) to provide a compressor gaseous stream (10), which is passed through the refrigerant compressor (s) (12). The inlet temperature T1 of the compressor gaseous stream (10) is determined, and cooling of a refrigerant stream is controlled in response to temperature T1 to provide the compressor gaseous stream (10) at the normal operating temperature of at least one refrigerant compressor (12).

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: The invention provides a process for producing purified natural gas, the process comprising the steps of: expanding a pressurised natural gas stream comprising at least 4 ppmv of mercaptans and supplying it to a first separation column, in which the natural gas stream is separated into a gaseous overhead stream enriched in methane and a first fraction enriched in mercaptans; withdrawing the gaseous overhead stream enriched in methane from the separation column to obtain the purified natural gas; with drawing the fraction enriched in mercaptans from the separation column; removing mercaptans from the first fraction enriched in mercaptans.

Abstract: A method and apparatus for liquefying a hydrocarbon stream (10) such as natural gas. The method comprises the steps of: (a) compressing the hydrocarbon stream (10) using one or more compressors (12) driven by one or more steam turbines (14) to provide a compressed hydrocarbon stream (20); (b) heat exchanging the compressed hydrocarbon stream (20) against one or more refrigerant streams (40) to fully condense the compressed hydrocarbon stream (20) and provide a liquefied hydrocarbon stream (30) and one or more warmed refrigerant streams (50); (c) compressing at least one of the warmed refrigerant stream(s) (50) of step (b) using one or more compressors (18) driven by one or more gas turbines (22); and (d) at least partly driving one or more of the steam turbines (14) of step (a) using steam provided by one or more of the gas turbines (22) of step (c).

Abstract: Method of cooling a hydrocarbon stream (10) such as natural gas, the method at least comprising the steps of (a) heat exchanging the hydrocarbon stream (10) against a first refrigerant stream (20) to provide a cooled hydrocarbon stream (30) and an at least partly evaporated refrigerant stream (40); (b) compressing the at least partly evaporated refrigerant stream (40) using one or more compressors (14, 16, 18) to provide a compressed refrigerant stream (50, 60, 70); (c) cooling the compressed refrigerant stream (50, 60, 70) after one or more of the compressors against ambient to provide a cooled compressed refrigerant stream (70a); (d) dynamically expanding the cooled compressed gaseous refrigerant stream (70a) to provide an expanded refrigerant stream (80); and (e) further cooling the expanded refrigerant stream (80) to provide an at least partially condensed refrigerant 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 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 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.

Abstract: The present invention relates to a refrigerant circuit (1), in particular for use in a liquefaction plant, the refrigerant circuit (1) at least comprising: —a refrigerator (2) having an inlet (21) for refrigerant (10) at a refrigeration pressure, and at least five outlets (22, 23, 24, 25, 26, . . . ) for evaporated refrigerant (20, 30, 40, 50, 60, . . . ) evaporated at different pressure levels, the at least five outlets (22, 23, 24, 25, 26, . . . ) being preferably intended for refrigerants evaporated at increasing pressures from the first outlet (22) to the fifth (26) and optional higher outlets; —a first compressor (3) having one or more inlets for receiving evaporated refrigerant from the refrigerator and an outlet (34) that can be connected to the inlet (21) of the refrigerator (2); and—a second compressor (4) having one or more inlets for receiving evaporated refrigerant from the refrigerator and an outlet (44) that can be connected to the inlet (21) of the refrigerator (2).

Abstract: The present invention relates to a method for the liquefaction of a hydrocarbon-rich stream, preferably a natural gas containing stream, by heat exchanging against a refrigerant (1a-d). The liquid refrigerant (19) is evaporated using heat from the hydrocarbon-rich stream, thereby obtaining an evaporated refrigerant (3a-d). The evaporated refrigerant (3a-d) is subsequently compressed (5), cooled (10) against ambient thereby fully condensing the compressed refrigerant. Next, the fully condensed compressed refrigerant (12) is further sub-cooled (14) by indirect heat exchange against an auxiliary refrigerant being cycled in an auxiliary refrigerant. Then the subcooled refrigerant (16) is expanded (18) thereby forming the liquid refrigerant (19).

Abstract: The present invention relates to a refrigerant circuit (1), in particular for use in a liquefaction plant, the refrigerant circuit (1) at least comprising: a refrigerator (2) having an inlet (21) for refrigerant (10) and at least one outlet (22) for refrigerant (20) evaporated in the refrigerator (2); a compressor (3) having an inlet (31) for receiving the evaporated refrigerant (20) from the refrigerator (2) and an outlet (34) for compressed refrigerant (11a); a cooler (5) having an inlet (81) for compressed refrigerant (110a) and an outlet (82) for cooled compressed refrigerant (120a); a stream splitter (6) suitable for splitting the cooled compressed refrigerant (120a) in at least two streams (10a, 130a); a first valve (7), a second valve (8) and a first relief valve (9).

Abstract: The invention relates to a mixing device for the homogenization of temperatures and/or concentrations in a fluid flow, having a hollow element, for conducting the fluid flow, which hollow element has: (a) a first insert positioned within the hollow element and defining an excentric passage; (b) a second insert positioned within the hollow element upstream of the first insert, wherein the second insert has a central opening; (c) a third insert positioned in the hollow element downstream of the first insert and the second insert, which third insert has at least two openings, which are evenly distributed along a concentric circle within said third insert; and (d) a fourth insert positioned in the hollow element between the first insert and the third insert, wherein the fourth insert has at least two radially extending first deflectors.