An expander and motor-compressor unit is disclosed. The unit includes a casing and an electric motor arranged in the casing. A compressor is arranged in the casing and drivingly coupled to the electric motor through a central shaft. Furthermore, a turbo-expander is arranged for rotation in the casing and is drivingly coupled to the electric motor and to the compressor through the central shaft.

Plant and method for liquefying a flow of gas, having a cooling circuit that includes at least one exchanger (5) for cooling the gas, and at least one expansion turbine (6) which is mounted on a rotary axle which is supported by at least one bearing (7) of the gas-static type, the cooling circuit (2) also including a pressurized gas injection conduit that is configured to supply pressurized gas to the bearing (7) in order to provide support to the rotary axle, the plant (1) further includes a recovery conduit (9) that is configured to recycle at least a portion of the gas which has been used to support the rotary axle of the bearing (7) with a view to liquefying the gas.

A method of liquefying a contaminated hydrocarbon-containing gas stream includes cooling the stream in a first heat exchanger and cooling the cooled stream in an expander to obtain a partially liquefied stream. The method further includes separating the partially liquefied stream in a separator to obtain a gaseous stream and a liquid stream. The liquid stream is expanded to obtain a multiphase stream containing at least a vapour phase, a liquid phase and a solid phase. The multiphase stream is separated in a separator to obtain a gaseous stream and a slurry stream. The slurry stream is separated in a solid/liquid separator to obtain a liquid hydrocarbon stream and a concentrated slurry stream. The gaseous stream is passed through the first heat exchanger to obtain a heated gaseous stream. The heated gaseous stream is compressed and combined with the contaminated hydrocarbon-containing gas stream.

The present invention provides a method of liquefying a contaminated hydrocarbon-containing gas stream: (a) providing a CO2 contaminated hydrocarbon-containing gas stream (20); (b) cooling the contaminated hydrocarbon-containing gas stream to obtain a partially liquefied stream (70); (c) separating the partially liquefied stream obtaining a liquid stream (90); (d) cooling the liquid stream (90) in a direct contact heat exchanger (200) obtaining a multiphase stream (201) containing at least a liquid phase and a solid CO2 phase; (e) separating the multiphase stream in a solid-liquid separator (202) obtaining a CO2 depleted liquid stream (141); (f) passing the CO2 depleted liquid stream (141) to a further cooling, pressure reduction and separation stage to generate a further CO2 enriched slurry stream (206); (g) passing at least part of the further CO2 enriched slurry stream (206) to the direct contact heat exchanger (200) to provide cooling duty to and mix with the liquid stream (90).

Herein pipeline pressure, temperature and NGL constituents are manipulated for the transportation and optional storage in a pipeline system of natural gas mixtures or rich mixtures for delivery of chilled Products for downstream applications. Pressure reduction from a last compression section delivers internally chilled Products for reduced capital and operating costs. A high lift compressor station before the pipeline terminus provides pressure differential for Joule-Thompson chilling of the pipeline contents. The chilling step can be retrofitted to existing pipeline systems, and the chilling steep can include a turbo expander or the like for recovery of pipeline pressure energy for power generation. For like throughout, with this higher pressure operation, the effects of enhanced NGL content results in a reduction in diameter of the pipeline by at least one standard size. Substantial overall reduction in energy consumption and associated CO2 emissions is thereby achieved through integrated pipeline/processing applications.

Cryogenic energy storage systems, and particularly methods for capturing cold energy and re-using that captured cold energy, are disclosed. The systems allow cold thermal energy from the power recovery process of a cryogenic energy storage system to be captured effectively, to be stored, and to be effectively utilised. The captured cold energy could be reused in any co-located process, for example to enhance the efficiency of production of the cryogen, to enhance the efficiency of production of liquid natural gas, and/or to provide refrigeration. The systems are such that the cold energy can be stored at very low pressures, cold energy can be recovered from various components of the system, and/or cold energy can be stored in more than one thermal store.

The invention relates to a method and system of preparing a lean methane-containing gas stream (22), comprising: feeding a hydrocarbon feed stream (10) into a separator (100); withdrawing from the separator (100) a liquid bottom stream (12); passing the liquid bottom stream (12) to a stabilizer column (200); withdrawing from the stabilizer column (200) a stabilized condensate stream (13) enriched in pentane, withdrawing from the stabilizer column (200) a stabilizer overhead stream (14) enriched in ethane, propane and butane; splitting the stabilizer overhead stream (14) according to a split ratio into a main stream portion (15) and a slip stream portion (16), passing the slip stream portion (16) to a fractionation unit (300) to obtain an ethane enriched stream (17) and a bottom stream enriched in propane and butane (18).

Liquefier includes first compression section which is driven by a superconducting motor and which compresses a substance in a gaseous state. Cooling circuit includes: second compression section which is driven by the motor when first compression section is being driven by the motor and which compresses a refrigerant; first heat exchange section which cools the refrigerant by causing heat exchange between a substance in a tank and the compressed refrigerant; second expansion section which brings the refrigerant down to or below a critical temperature of a superconducting material by expanding the cooled refrigerant; and second heat exchange section which imparts cold heat of the refrigerant to the substance by causing heat exchange between the substance in the tank and the refrigerant after cooling a superconducting magnet, and supplies the refrigerant brought down to or below the critical temperature by second expansion section to the motor and cools the superconducting magnet.

A system and method for cryogenic purification of a hydrogen, nitrogen, methane and argon containing feed stream to produce a methane free, hydrogen and nitrogen containing synthesis gas and a methane rich fuel gas, as well as to recover an argon product stream, excess hydrogen, and excess nitrogen is provided. The disclosed system and method are particularly useful as an integrated cryogenic purifier in an ammonia synthesis process in an ammonia plant. The excess nitrogen is a nitrogen stream substantially free of methane and hydrogen that can be used in other parts of the plant, recovered as a gaseous nitrogen product and/or liquefied to produce a liquid nitrogen product.

A device for recovering variable low-temperature gas includes a low temperature stabilizing system, a compression system, an expansion refrigeration system, and a heat exchange system, which are connected to each other by pipelines, where the low temperature stabilizing system is composed of a liquid storage unit, a liquid delivery unit, a liquid jet gasification mixing unit, and a control unit, for regulating the temperature of low-temperature gas; a liquid outlet channel of the liquid storage unit is connected to a liquid inlet channel of the liquid delivery unit, a liquid outlet channel of the liquid delivery unit is connected to a liquid inlet channel of the liquid jet gasification mixing unit, and the compression system is composed of a raw material compressor and a circulating compressor; and a gas outlet channel of the raw material compressor is connected to a gas inlet channel of the circulating compressor.