A liquefaction system is capable of sequentially or simultaneously liquefying multiple feed streams of hydrocarbons having different normal bubble points with minimal flash. The liquefying heat exchanger has separate circuits for handling multiple feed streams. The feed stream with the lowest normal boiling point is sub-cooled sufficiently to suppress most of the flash. Feed streams with relatively high normal boiling points are cooled to substantially the same temperature, then blended with bypass streams to maintain each product near its normal bubble point. The system can also liquefy one stream at a time by using a dedicated circuit or by allocating the same feed to multiple circuits.

Low-temperature refrigeration device arranged in a frame and comprising a working circuit forming a loop and containing a working fluid, the working circuit forming a cycle comprising in series: a compression mechanism, a cooling mechanism, an expansion mechanism and a heating mechanism, the device comprising a refrigeration heat exchanger intended to extract heat from at least one member by exchanging heat with the working fluid, the mechanisms for cooling and reheating the working fluid comprising a common heat exchanger in which the working fluid transits in counter-flow in two separate transit portions of the working circuit, the compression mechanism comprising at least two compressors and at least one motor for driving the compressors, the working fluid expansion mechanism comprising at least one rotary turbine, the device comprising at least one drive motor comprising a drive shaft, one end of which drives a compressor and the other end of which is coupled to a turbine, the motor being attached to the frame at at least one fixed point, the common heat exchanger being attached to the frame at at least one fixed point, the two counter-flow transit portions of the common heat exchanger being orientated in a longitudinal direction of the frame, the drive shaft of the drive motor being orientated in a direction parallel or substantially parallel to the longitudinal direction and the turbine and the compressor being arranged relatively longitudinally such that the turbine is located longitudinally on the side corresponding to the relatively cold end of the common heat exchanger when the device is being operated and the compressor is located longitudinally on the side corresponding to the relatively hot end of the common heat exchanger when the device is being operated.

Disclosed is a low-temperature refrigeration device which is arranged in a frame and comprises a working circuit that forms a loop and contains a working fluid, the working circuit forming a cycle comprising, connected in series: a compression mechanism, a cooling mechanism, an expansion mechanism and a heating mechanism, wherein the mechanisms for cooling and heating the working fluid comprise a common heat exchanger in which the working fluid flows in opposite directions in two separate transit portions of the working circuit, the device further comprising a refrigeration heat exchanger for extracting heat from at least one member by exchanging heat with the working fluid flowing in the working circuit, the compression mechanism comprising two separate compressors, the mechanism for cooling the working fluid comprising two cooling heat exchangers which are arranged respectively at the outlet of the two compressors and ensure heat exchange between the working fluid and a cooling fluid, wherein the frame extends in a longitudinal direction and comprises a lower base intended to be mounted on a support, the cooling heat exchangers are located in the frame about the common heat exchanger, i.e. the cooling heat exchangers are not located below the common heat exchanger between the common heat exchanger and the lower base of the frame.

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.

A method for processing a gas mixture containing nitrogen and methane, the gas mixture being at least partly liquefied using a mixed refrigerant circuit and is expanded in a storage tank, wherein: formed in the storage tank are a liquid phase, which is depleted in nitrogen and enriched with methane relative to the gas mixture, and a vapour phase, which is enriched with nitrogen and depleted in methane relative to the gas mixture; at least some of the vapour phase is compressed, at least partly liquefied, and subjected to low-temperature rectification; and formed in the low-temperature rectification are a top gas rich in nitrogen and lean in methane, and a bottom liquid lean in nitrogen and rich in methane. The invention provides that the partial liquefaction of the vapour phase is caused by cooling by means of heat exchange using the mixed refrigerant circuit.

A liquefaction system and method for producing liquefied natural gas (LNG) is provided. The liquefaction system may include a heat exchanger to cool natural gas to LNG, a first compressor to compress and combine first and second portions of a single mixed refrigerant from the heat exchanger, a first cooler to cool the single mixed refrigerant from the first compressor to a first liquid phase and a gaseous phase, and a first liquid separator to separate the first liquid phase from the gaseous phase. The liquefaction system may also include a second compressor to compress the gaseous phase, a second cooler to cool the compressed gaseous phase to a second liquid phase and the second portion of the single mixed refrigerant, a second liquid separator to separate the second liquid phase from the second portion of the single mixed refrigerant, and a pump to pressurize the first liquid phase.

The invention relates to a liquefied gas storage facility, in particular for liquid hydrogen, comprising a liquefied gas tank intended to contain gas in liquid form and a gaseous phase, a device for cooling the contents of the tank, the cooling device comprising at least a first refrigerator with a cycle for refrigerating a cycle gas, said first refrigerator comprising, arranged in series in a cycle circuit: a member for compressing the cycle gas, a member for cooling the cycle gas, a member for expanding the second cycle gas and a member for reheating the expanded cycle gas, the cooling device comprising a first heat transfer fluid loop comprising a first end exchanging heat with a cold end of the first refrigerator and a second end comprising a first heat exchanger located in the tank, the first heat transfer fluid loop comprising a member for circulating the heat transfer fluid, characterized in that the first heat exchanger exchanges heat directly with the inside of the tank, that is to say that the first heat exchanger exchanges heat directly with the fluid which surrounds it in the tank.

A system for the regeneration of nitrogen energy within a closed loop cryogenic system is described. A liquid nitrogen storage is provided in fluid communication with a first flow line. A pump pumps liquid nitrogen from the liquid nitrogen storage to the first flow line. At least one cryogenic cooling loop is provided in fluid communication with the first flow line. The cryogenic cooling loop has an nitrogen intake and a nitrogen outlet with the nitrogen outlet being positioned downstream of the nitrogen intake. The cryogenic cooling loop has a heat exchanger between the nitrogen intake and the nitrogen outlet. A turbo expander used for re-cooling the nitrogen flowing through the first flow line and the at least one cryogenic cooling loop has an inlet and an outlet. The inlet is provided in fluid communication with the first flow line. The turbo expander is connected to a power source. A second flow line connects the outlet of the turbo expander to the liquid nitrogen storage.

A process for cooling a hydrocarbon-rich fraction, in particular natural gas, against a refrigerant circuit. In this process, the compressed refrigerant is divided into three refrigerant substreams. Whereas the first substream is work-producingly expanded in a warm expander and the second substream is work-producingly expanded in a cold expander, the third substream is work-producingly expanded at the lowest temperature level. The result therefrom is that the operating point of the cold expander is shifted in such a manner that the refrigeration output of the two expanders is situated in a ratio between 40/60 and 60/40.

A process for producing liquefied natural gas and liquid carbon dioxide comprising: Step a): separating a natural gas feed gas into a CO.sub.2-enriched gas stream and a CO.sub.2-depleted natural gas stream; Step b): liquefying the CO.sub.2-depleted natural gas stream in a liquefaction unit comprising at least a main heat exchanger and a system for producing frigories, said liquefaction unit comprising at least one refrigeration cycle fed by a refrigerant stream; Step c): simultaneous liquefying of the CO.sub.2-enriched gas stream resulting from step a) in a CO.sub.2 liquefaction unit; wherein the refrigeration necessary for the liquefaction of the CO.sub.2-enriched gas stream and for the liquefaction of the natural gas is supplied by said frigorie-producing system of the liquefaction unit and in that the refrigeration necessary for the liquefaction of the CO.sub.2-enriched gas stream originates from a portion of said refrigerant stream supplying the refrigeration cycle of said liquefaction unit.