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.

Method for at least partially converting methane-containing gas, in particular boil-off gas, retained in a container, to a liquid state, the method comprising the subsequent steps of: feeding methane-containing gas from said container to a compressor, and increasing, by said compressor, a pressure of said fed methane-containing gas; feeding said increased pressurized methane-containing gas to a cooling unit for cooling said pressurized methane-containing gas; decreasing said pressure of said pressurized and cooled methane-containing gas, thereby obtaining methane-containing liquid and flash-off gas; feeding said methane-containing liquid and said flash-off gas to said container, wherein said flash-off gas is inputted into said container at or near a bottom part of said container for at least partly dissolving said flash-off gas into said methane-containing liquid. System for at least partially converting methane-containing gas, in particular boil-off gas, retained in a container, to a liquid state.

A system for cooling a gas with a mixed refrigerant includes a heat exchanger that receives and cools a feed of the gas so that a product is produced. The system includes a mixed refrigerant processing system having compression devices and aftercoolers as well as a low pressure accumulator and a high pressure accumulator. A cold vapor separator receives vapor from the high pressure accumulator and features a vapor outlet and a liquid outlet. Vapor from the cold vapor separator vapor outlet is cooled, expanded and directed to a primary refrigeration passage of the heat exchanger. Liquid from the liquid outlet of the cold vapor separator is subcooled, expanded and directed to the primary refrigeration passage. Liquid from the low pressure accumulator is subcooled, expanded and directed to the primary refrigeration passage. Liquid from the high pressure accumulator is subcooled, expanded and directed to the primary refrigeration passage.

Disclosed is a low-temperature refrigeration device comprising a working circuit that forms a loop and contains a working fluid the working circuit forming a cycle which includes, connected in series: a compression mechanism, a cooling mechanism, an expansion mechanism and a heating mechanism, 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, each cooling heat exchanger comprising a cooling fluid inlet and a cooling fluid outlet, characterized in that the cooling fluid outlet of one of the two cooling heat exchangers is connected to the cooling fluid inlet of the other cooling heat exchanger.

The present invention relates to a method and system for producing liquefied natural gas (LNG) from a stream of pressurized natural gas which involves a combination of mechanical refrigeration.

The invention relates to a heat exchanger system (1) for heat exchange between at least a first medium (M), in particular in the form of a hydrocarbon-rich phase, and a second medium (K), with at least first and second pipe space sections (101, 103; 103, 105) for accommodating the first medium (M), and with a first pipe space section connecting means (102; 104), via which the two pipe space sections (101, 103; 103, 105) are connected to one another in a flow-guiding manner. The first pipe space section (101; 103) is surrounded by a first shell space (201, 203), and the second pipe space section (103; 105) is surrounded by a second shell space (203, 205) for accommodating the second medium (K). The first shell space (201; 203) is defined by a first shell (301; 303) and the second shell space (203; 205) is defined by a second shell (303; 305).

A process for liquefying and subcooling a hydrocarbon-rich fraction, particularly natural gas, is described wherein, once cooled down, the fraction is subjected to a partial condensation to remove heavy hydrocarbons, particularly benzene, by the steps of: a) the liquefied hydrocarbon-rich fraction is subcooled in a separate heat exchanger (normal mode), b) the supply of the liquefied hydrocarbon-rich fraction to the heat exchanger is interrupted at the latest when a defined solid deposition value in the heat exchanger is reached (cleaning mode), c) the solid in the heat exchanger is melted with a defrost gas and drawn off from the heat exchanger and d) the liquefied hydrocarbon-rich fraction is subsequently returned to the heat exchanger.

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 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.

A system for removing selected components from a gas stream has a heat exchanger including a first cooling passage configured to receive a feed gas stream and to provide a cooled feed gas stream. An expander receives at least a portion of the cooled feed gas stream. A separation device receives an expanded fluid stream from the expander and separates the expanded fluid stream into a liquid stream containing selected components and a purified vapor stream having a purified vapor temperature. A compressor receives the purified vapor stream at approximately the purified vapor temperature and produces a compressed vapor stream that is returned to the heat exchanger.