A method and apparatus for producing liquefied natural gas. A portion of a natural gas stream is cooled in a first heat exchanger and re-combined with the natural gas stream, and heavy hydrocarbons are removed therefrom to generate a separated natural gas stream and a separator bottom stream. Liquids are separated from the separator bottom stream to form an overhead stream, which is cooled and separated to form a recycle gas stream. The recycle gas stream is compressed. A first portion of the compressed recycle gas stream is directed through the first heat exchanger and directed to the separator as a column reflux stream. The separated to natural gas stream is used as a coolant in the first heat exchanger to thereby generate a pretreated natural gas stream, which is compressed and liquefied.

The present invention relates to a refrigerant composition comprising neon and hydrogen. The present invention further relates to the use of the refrigerant composition in liquefying gaseous substances such as hydrogen or helium.

A system and method for increasing the efficiency of natural gas liquefaction processes by using a hybrid cooling system and method. More specifically, a system and method for converting a transcritical precooling refrigeration process to a subcritical process. In one embodiment, the refrigerant is cooled to sub-critical temperature using an economizer. In another embodiment, the refrigerant is cooled to a sub-critical temperature using an auxiliary heat exchanger. Optionally, the economizer or auxiliary heat exchanger can be bypassed when ambient temperatures are sufficiently low to cool the refrigerant to a sub-critical temperature. In another embodiment, the refrigerant is isentropically expanded.

A cooling system includes a compressor configured to pressurize carbon dioxide to form pressurized carbon dioxide, a mixer configured to generate mixed refrigerant in which the pressurized carbon dioxide and solvent in a liquid state, a depressurization apparatus provided downstream from the mixer and configured to depressurize the mixed refrigerant, a separator configured to separate carbon dioxide in a gas state from the mixed refrigerant, a heat exchanger configured to exchange heat between the mixed refrigerant cooled through depressurization and a fluid to be cooled, and a second heat exchanger configured to cool the carbon dioxide or the mixed refrigerant using vaporized carbon dioxide or the mixed refrigerant.

The device (600) for liquefying a natural gas comprises: a first centrifugal compressor (605), a fractionating means (110), a second centrifugal compressor (610), a first heat exchange body (115), a second heat exchange body (120) and a return conduit (125) leading to the first compressor, upstream of an inlet (116) in the first exchange body, a third heat exchange body (420), a third centrifugal compressor (620), the first and third centrifugal compressors being actuated by a single common turbine (630), a casing (635) common to the first compressor and the third compressor, a cooling means (430) and a transfer conduit (435) leading to the third exchange body.

The invention relates to an installation and a process for production of a cryogenic fluid, in particular of liquefied hydrogen, comprising, positioned in at least one cold box, a set of heat exchangers in thermal exchange with the circuit for hydrogen to be cooled, the installation comprising a device for pre-cooling, which is configured to pre-cool the circuit for gas to be cooled to a first determined temperature, and a device for cryogenic cooling which is configured to cool the circuit for gas to be cooled to a second determined temperature, lower than the first temperature, the cycle gas cooling unit and/or the cycle gas heating unit comprise(s) one or more first cycle heat exchangers distinct from the first part of the pre-cooling heat exchangers of the circuit for the gas to be cooled, these first cycle heat exchangers also being cooled by thermal exchange with the pre-cooling fluid circuit of the pre-cooling device.

A natural gas liquefying apparatus includes: a precooling unit, which is a treatment unit configured to precool natural gas; a liquefying unit, which is a treatment unit configured to liquefy the natural gas; a refrigerant cooling unit, which is a treatment unit configured to cool a liquefying refrigerant; a compression unit configured to compress vaporized refrigerants; and a pipe rack including air-cooled coolers arrayed and arranged on an upper surface. The treatment units and the compression unit are separately arranged in a first arrangement region and a second arrangement region arranged opposed to each other across a long side of the pipe rack. The pipe rack interposed between the first and second arrangement regions has a region in which no air-cooled cooler is arranged in order to arrange a plurality of pipes, through which refrigerants are allowed to flow, in a direction of a short side of the pipe rack.

A method and system for liquefying a methane-rich high-pressure feed gas stream using a first heat exchanger zone and a second heat exchanger zone. The feed gas stream is mixed with a refrigerant stream to form a second gas stream, which is compressed, cooled, and directed to a second heat exchanger zone to be additionally cooled below ambient temperature. It is then expanded to a pressure less than 2,000 psia and no greater than the pressure to which the second gas stream was compressed, and then separated into a first expanded refrigerant stream and a chilled gas stream. The first expanded refrigerant stream is expanded and then passed through the first heat exchanger zone such that it has a temperature that is cooler, by at least 5 F., than the highest fluid temperature within the first heat exchanger zone.

A method and apparatus for producing liquefied natural gas. A pretreated natural gas stream is compressed in at least two serially arranged compressors to a pressure of at least 1,500 psia and cooled. The resultant cooled compressed natural gas stream is expanded in at least one work producing natural gas expander to a pressure less than 2,000 psia and no greater than the pressure to which natural gas stream has been compressed, thereby forming a chilled natural gas stream that is separated into a refrigerant stream and a non-refrigerant stream. The refrigerant stream is warmed in a heat exchanger through heat exchange with one or more process streams associated with pretreating the natural gas stream, thereby generating a warmed refrigerant stream. The warmed refrigerant stream and the non-refrigerant stream are then liquefied.

Disclosed is a device for liquefying a fluid, comprising a fluid circuit to be cooled, the device comprising a heat exchanger assembly in heat exchange with the fluid circuit to be cooled, at least one first cooling system in heat exchange with at least a portion of the heat exchanger assembly, the first cooling system being a refrigerator having a cycle for refrigerating a cycle gas mainly comprising helium, said refrigerator comprising in series in a cycle circuit: a mechanism for compressing the cycle gas, at least one member for cooling the cycle gas, a mechanism for expanding the cycle gas, and at least one member for reheating the expanded cycle gas, wherein the compression mechanism includes at least four compression stages in series composed of a centrifugal compressor assembly, the compression stages being mounted on shafts that are rotationally driven by a motor assembly, the expansion mechanism comprising at least three expansion stages in series composed of a set of centripetal turbines, the at least one member for cooling the cycle gas being configured to cool the cycle gas at the outlet of at least one of the turbines, and wherein at least one of the turbines is coupled to the same shaft as at least one compression stage so as to feed the mechanical work produced during the expansion to the compression stage.