A cooling circuit for a system for supplying and cooling a gas in a floating structure having a tank, the cooling circuit having a coolant flowing through it and including a main loop having: a compression device; a heat exchanger; an internal heat exchanger; and a turbocompressor, the cooling circuit includes a regulating branch connected to the main loop, the regulating branch having a valve that is configured to control the flow of coolant within the regulating branch, the main loop including a pressure sensor, the valve controlling the amount of coolant present in the main loop according to the pressure measured by the pressure sensor.

A semi-closed loop system for producing liquefied natural gas (LNG) that combines certain advantages of closed-loop systems with certain advantages of open-loop systems to provide a more efficient and effective hybrid system. In the semi-closed loop system, the final methane refrigeration cycle provides significant cooling of the natural gas stream via indirect heat transfer, as opposed to expansion-type cooling. A minor portion of the LNG product from the methane refrigeration cycle is used as make-up refrigerant in the methane refrigeration cycle. A pressurized portion of the refrigerant from the methane refrigeration cycle is employed as fuel gas. Excess refrigerant from the methane refrigeration cycle can be recombined with the processed natural gas stream, rather than flared.

A process and apparatus for liquefying a gas stream comprising hydrocarbons and sour species is provided in which the sour species are removed in liquefied form as the sweetened gas stream is progressively cooled to liquefaction temperatures. The process involves cooling the gas stream in a manner to produce a cooled gas stream comprising gaseous hydrocarbons and residual sour species. The cooled gas stream is then treated with a cold solvent to deplete the cooled gas stream of residual sour species. The resulting cooled sweetened gas stream is then further cooled to produce liquid hydrocarbons.

Provided is a natural gas processing facility for the liquefaction or regasification of natural gas. The facility includes a primary processing unit, e.g., refrigeration unit, for warming natural gas or chilling natural gas to at least a temperature of liquefaction. The facility also has superconducting electrical components integrated into the facility. The superconducting electrical components incorporate superconducting material so as to improve electrical efficiency of the facility by at least one percent over what would be experienced through the use of conventional electrical components. The superconducting electrical components may be one or more motors, one or more generators, one or more transformers, switch gears, one or more electrical transmission conductors, variable speed drives, or combinations thereof.

The invention relates to a device (200) for liquefying a gas (51), the device comprising: a circuit (55) for conveying gas to be liquefied, the circuit comprising at least one heat exchanger (204) for exchanging heat between the gas (51) to be liquefied and a refrigerant flow (52) comprising at least dihydrogen refrigerant; a closed refrigeration circuit (210) configured to convey the refrigerant flow,
the closed refrigeration circuit comprising a means (215) for maintaining an internal composition of the dihydrogen refrigerant at a ratio of parahydrogen to orthohydrogen that is lower or higher than the ratio corresponding to a natural equilibrium composition in the refrigerant flow closed circuit, the means (215) comprising a catalytic reactor (220) configured to convert some of the orthohydrogen from the dihydrogen refrigerant flow into parahydrogen or vice versa.

Gas liquefaction process, preferably natural gas in a small-scale plant that includes compression cycles, refrigeration with various refrigerants and expansion, and a small-scale plant that includes of 4 loops to carry it out.

A system and method for cooling a gas using a mixed refrigerant includes a compressor system and a heat exchange system, where the compressor system may include an interstage separation device or drum with no liquid outlet, a liquid outlet in fluid communication with a pump that pumps liquid forward to a high pressure separation device or a liquid outlet through which liquid flows to the heat exchanger to be subcooled. In the last situation, the subcooled liquid is expanded and combined with an expanded cold temperature stream, which is a cooled and expanded stream from the vapor side of a cold vapor separation device, and subcooled and expanded streams from liquid sides of the high pressure separation device and the cold vapor separation device, or combined with a stream formed from the subcooled streams from the liquid sides of the high pressure separation device and the cold vapor separation device after mixing and expansion, to form a primary refrigeration stream.

A framed, low-temperature refrigeration device is provided, which includes a working circuit that forms a loop and contains a working fluid, the working circuit forming a cycle that includes 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 include a common heat exchanger in which the working fluid flows in opposite directions in two separate transit portions of the working circuit. The device may also include a refrigeration heat exchanger for extracting heat from at least one member by exchanging heat with the working fluid flowing in the working circuit, wherein the compression mechanism includes two separate compressors, wherein the mechanism for cooling the working fluid includes 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 includes 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.

The liquefaction system comprises a high-temperature refrigerant circuit and a low-temperature refrigerant circuit. The system further comprises a first high-temperature heat exchanger, wherein the feed gas is in heat exchange with a first stream of vaporizing first refrigerant and is cooled thereby, and a second high-temperature heat exchanger, wherein compressed first refrigerant of the first refrigerant circuit and compressed second refrigerant of the second refrigerant circuit are in heat exchange with a second stream of vaporizing first refrigerant and are cooled thereby. A low-temperature heat exchanger is further provided, wherein cooled feed gas from the first high-temperature heat exchanger and cooled second refrigerant from the second high-temperature heat exchanger are further cooled and liquefied in heat exchange with a flow of vaporizing second refrigerant.

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.