Described herein are methods and systems for the liquefaction of natural gas to produce a LNG product. The methods and systems use an apparatus for separating a flash gas from a liquefied natural gas (LNG) stream to produce a LNG product and recovering refrigeration from the flash gas. The apparatus includes a shell casing enclosing a heat exchange zone comprising a coil wound heat exchanger, and a separation zone. The heat exchange zone is located above and in fluid communication with the separation zone. Flash gas is separated from the LNG product in the separation zone and flows upwards from the separation zone into the heat exchange zone where refrigeration is recovered from the separated flash gas.

Implementations described and claimed herein provide systems and methods for removing nitrogen during liquefaction of natural gas. In one implementation, a nitrogen rejection unit is used in an LNG facility to remove nitrogen from natural gas during an LNG liquefaction process. The nitrogen rejection unit contains at least two columns and at least one 3-stream condenser, 2-stream condenser or a two 2-stream condenser.

A thermodynamic system containing a working fluid is disclosed. The thermodynamic system comprises at least a working fluid collection vessel (11) adapted to contain a liquid phase and a gaseous phase of the working fluid in thermodynamic equilibrium. A chilling arrangement (51) is functionally coupled to the fluid collection vessel (11) and adapted to remove heat from the working fluid collected in the working fluid collection vessel (11) and thereby reduce pressure in said thermodynamic system. Also disclosed are methods for depressurizing a thermodynamic system containing a working fluid in liquid/gas equilibrium.

A split mixed refrigerant (MR) natural gas liquefication system, where low-pressure (LP) and medium pressure (MP) MR compressors are driven by a first gas turbine and a propane compressor and a high-pressure (HP) MR compressor is driven by a second gas turbine, is disclosed. The split MR liquefication system is configured to adjust the characteristics of the HP MR compressor to require less power when less power is available and more power when more power is available compared to the system's design point. Such adjustments allow for shifting the balance of power between the propane compressor and the HP MR compressor to improve LNG production efficiency.

Implementations described and claimed herein provide systems and methods for processing liquefied natural gas (LNG). In one implementation, a feed gas is received and partially condensed into a two-phase stream by expanding the feed gas. A liquid containing fouling components is removed from the two-phase stream. A vapor generated from the two-phase stream is compressed into a compressed feed gas. The compressed feed gas is directed into a feed chiller heat exchanger. The compressed feed gas is free of the fouling components.

An air-cooled heat exchanger (6) arranged in a gas processing facility for performing a liquefaction process of natural gas is configured to supply cooling air to a tube (63) through which a fluid to be cooled is caused to flow, to thereby cool the fluid to be cooled, and a mist supply section (7) is configured to supply mist obtained by spraying demineralized water, to thereby cool the cooling air. Further, the mist supply section (7) is configured to spray the demineralized water from a lateral position on an upstream side of an intake.

Implementations described and claimed herein provide systems and methods for processing liquefied natural gas (LNG). In one implementation, a solvent is injected into a feed of natural gas at a solvent injection point. A mixed feed is produced from a dispersal of the solvent into the feed of natural gas. The mixed feed contains heavy components. A chilled feed is produced by chilling the mixed feed. The chilled feed includes a vapor and a condensed liquid. The condensed liquid contains a fouling portion of the heavy components condensed by the solvent during chilling. The liquid containing the fouling portion of the heavy components is separated from the vapor. The vapor is directed into a feed chiller heat exchanger following separation of the liquid containing the fouling portion of the heavy components from the vapor, such that the vapor being directed into feed chiller heat exchanger is free of freezing components.

Compression train for a natural gas liquefaction process. The compression train includes a driver machine and only one centrifugal compressor machine driven in rotation by the driver machine; the compressor is configured to compress a refrigerant gas with a molecular weight less than 30 g/mol from a suction pressure to a discharge pressure; the ratio between discharge and suction pressures is higher than 10. A LNG plant including a compression train.

The compression train includes an engine, a first centrifugal compressor driven by the engine and a second centrifugal compressor driven by the engine; the first centrifugal compressor is housed inside one case; the second centrifugal compressor is housed inside one case; the first centrifugal compressor has a first inlet fluidly connected to a line of high molecular weight gas, in particular higher than 40; the second centrifugal compressor has a second inlet fluidly connected to a line of low molecular weight gas, in particular between 20 and 30; the second centrifugal compressor is arranged to provide a compression ratio higher than 10:1.

Disclosed is a liquefied natural gas production train, comprising at least one integrated process unit having a structural frame forming multiple process equipment floors. The at least one integrated process unit extends in vertical direction, wherein a height of the at least one integrated process unit is substantially equal to or larger than a width and a length of the at least one integrated process unit. The disclosure also provides a method of producing liquefied natural gas, using the LNG production train.