A system includes a heat exchanger including a first inlet for receiving a first pressurized gas stream and a first outlet for outputting a chilled gas stream produced by the heat exchanger cooling the first pressurized gas stream. The system also includes a turbo expander connected to the first outlet of the heat exchanger for receiving the chilled gas stream from the heat exchanger and producing a partially liquified gas stream, the partially liquified gas stream comprising vapors and LNG. The system further includes at least one separator connected to the turbo expander, wherein the partially liquified gas stream is fed into the at least one separator, and the at least one separator separates the vapors from the LNG.

A method is disclosed for start-up of a system for liquefying a feed gas stream comprising natural gas. The system has a feed gas compression and expansion loop, and a refrigerant system comprising a primary cooling loop and a sub-cooling loop. The feed gas compression and expansion loop is started up. The refrigerant system is pressurized. Circulation in the primary cooling loop is started and established. Circulation in the sub-cooling loop is started and established. A flow rate of the feed gas stream and circulation rates of the primary cooling loop and the sub-cooling loop are ramped up.

An engine-driven cryogenic cooling system for an aircraft includes a first air cycle machine, a second air cycle machine, and a means for condensing a chilled air stream into liquid air for an aircraft use. The first air cycle machine includes a plurality of components operably coupled to a gearbox of a gas turbine engine and configured to produce a cooling air stream based on a first engine bleed source of the gas turbine engine. The second air cycle machine is operable to output the chilled air stream at a cryogenic temperature based on a second engine bleed source cooled by the cooling air stream of the first air cycle machine.

A system and method for liquefying a hydrogen gas feed stream uses a high-pressure hydrogen stream from a storage source to provide refrigeration to the system. After providing refrigeration to the system, the hydrogen from the high-pressure storage source is at a pressure not lower than the pressure of a cold box feed stream of the system, where the cold box feed stream includes the hydrogen gas feed stream and at least one recycle stream, and is not recycled back through the system but instead exits the system.

A method for liquefying a feed gas stream. A refrigerant stream is cooled and expanded to produce an expanded, cooled refrigerant stream. Part or all of the expanded, cooled refrigerant stream is mixed with a make-up refrigerant stream in a separator, thereby condensing heavy hydrocarbon components from the make-up refrigerant stream and forming a gaseous expanded, cooled refrigerant stream. The gaseous expanded, cooled refrigerant stream passes through a heat exchanger zone to form a warm refrigerant stream. The feed gas stream is passed through the heat exchanger zone to cool at least part of the feed gas stream by indirect heat exchange with the expanded, cooled refrigerant stream, thereby forming a liquefied gas stream. The warm refrigerant stream is compressed to produce the compressed refrigerant stream.

A gas liquefaction apparatus includes at least a source-gas supply line that supplies source gas; a room-temperature heat exchanger, a preliminary-cooling heat exchanger, and a liquefaction/supercooling heat exchanger that are provided in series sequentially in the source-gas supply line and that cool the source gas; a separation drum that separates the source gas containing a condensate, which has been cooled by heat exchange up to a liquefaction temperature of the source gas or below, into a gas component and a liquefied component; and a refrigerant-gas supply line that uses a gas component separated by the separation drum as refrigerant gas to supply the refrigerant gas in a direction opposite to a supply direction of the source gas, in order of the liquefaction/supercooling heat exchanger, the preliminary-cooling heat exchanger, and the room-temperature heat exchanger.

Process for efficiently operating a natural gas liquefaction system with integrated heavies removal/natural gas liquids recovery to produce liquefied natural gas (LNG) and/or natural gas liquids (NGL) products with varying characteristics, such as, for example higher heating value (HHV) and/or propane content. Resulting LNG and/or NGL products are capable of meeting the significantly different specifications of two or more markets.

A method of constructing a plate fin heat exchanger includes joining a first side bar formed from a nickel-iron alloy to a first end of a fin element formed from a nickel-iron alloy through a first nickel-iron alloy bond, and joining a second side bar formed from a nickel-iron alloy to a second end of the fin element through a second nickel-iron alloy bond to create a first layer of the plate fin heat exchanger. The fin element defines a fluid passage.

A LNG liquefaction plant includes a propane recovery unit including an inlet for a feed gas, a first outlet for a LPG, and a second outlet for an ethane-rich feed gas, an ethane recovery unit including an inlet coupled to the second outlet for the ethane-rich feed gas, a first outlet for an ethane liquid, and a second outlet for a methane-rich feed gas, and a LNG liquefaction unit including an inlet coupled to the second outlet for the methane-rich feed gas, a refrigerant to cool the methane-rich feed gas, and an outlet for a LNG. The LNG plant may also include a stripper, an absorber, and a separator configured to separate the feed gas into a stripper liquid and an absorber vapor. The stripper liquid can be converted to an overhead stream used as a reflux stream to the absorber.

The invention relates to an integrated process and apparatus for liquefaction of natural gas and recovery of natural gas liquids. In particular, the improved process and apparatus reduces the energy consumption of a Liquefied Natural Gas (LNG) unit by using a portion of the already cooled overhead vapor from a fractionation column from an NGL (natural gas liquefaction) unit to, depending upon composition, provide, for example, reflux for fractionation in the NGL unit and/or a cold feed for the LNG unit, or by cooling, within the NGL unit, a residue gas originating from a fractionation column of the NGL unit and using the resultant cooled residue gas to, depending upon composition, provide, for example, reflux/feed for fractionation in the NGL and/or a cold feed for the LNG unit, thereby reducing the energy consumption of the LNG unit and rendering the process more energy-efficient.