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 method for operating a heat exchanger, in which a first operating mode is carried out in first time periods, and a second operating mode is carried out in second time periods that alternate with the first time periods; in the first operating mode a first fluid flow is formed at a first temperature level, is fed into the heat exchanger in a first region at the first temperature level, and is partially or completely cooled in the heat exchanger; in the first operating mode a second fluid flow is formed at a second temperature level, is fed into the heat exchanger in a second region at the second temperature level, and is partially or completely heated in the heat exchanger. A corresponding arrangement and a system with such an arrangement are also covered by the present invention.

A cryogenic fluid containment system is disclosed. The system can store a fluid such as hydrogen at a cryogenic temperature and pressure. As the fluid naturally warms, boil-off fluid is produced by the fluid and can be directed to a backup power system that is configured to consume the boil-off fluid. The boil-off fluid being extracted from the cryogenic fluid containment system causes additional boil-off fluid to be generated from the fluid and refrigerate the fluid within the cryogenic fluid containment system. Additionally, the boil-off fluid can be monitored over time such that as the boil-off fluid accumulates within the storage tank, a boil-off controller can determine whether the boil-off fluid is to be extracted from the storage tank. The boil-off controller can enable the fluid to be maintained below a pressure threshold within the storage tank.

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.

A hydrogen liquefaction apparatus is provided. The apparatus can include: one or more precooling zones; a plurality of liquefaction zones; a precooling refrigeration cycle configured to provide refrigeration to the precooling zone; and a cold end refrigeration cycle configured to provide refrigeration to the plurality of liquefaction zones, wherein the cold end refrigeration cycle comprises a common recycle compression system, wherein there are M total one or more precooling zones and N total liquefaction zones, wherein M is less than N.

Process and plant for the production of liquid hydrogen with a liquefier that has a variable cooling power dependent on the electrical power consumed. The liquefier is supplied with electricity by a first source of electricity at least one additional source of electricity that provides an intermittent or variable amount of electricity over time. Liquid hydrogen is produced at first thermodynamic conditions when the liquefier is supplied with a predetermined nominal electrical energy level and produced at subcooled conditions, with respect to the first thermodynamic conditions, when electricity supplied to the liquefier exceeds the nominal level.

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.

Methods and systems for vaporizing and recovering LNG are provided. One method includes: a) heating at least a portion of the LNG to provide a boil-off gas stream and a liquid quench stream; b) routing the boil-off gas stream and the liquid quench stream to a quench system, wherein the quench system cools the boil-off gas stream to provide a quenched stream; and c) compressing the quenched stream to provide a compressed quenched stream.

A small scale natural gas liquefaction plant is integrated with an LNG loading facility in which natural gas is liquefied using a multi-stage gas expansion cycle. LNG is then loaded onto an LNG truck or other LNG transport vehicle at the loading facility using a differential pressure control system that uses compressed boil off gas as a motive force to move the LNG from the LNG storage tank to the LNG truck so as to avoid the use of an LNG pump and associated equipment as well as to avoid venting of boil off vapors into the environment.