A method and apparatus for liquefying a natural gas feed stream and removing nitrogen therefrom to produce a nitrogen-depleted LNG product, in which a natural gas feed stream is passed through main heat exchanger to produce a first LNG stream, which is separated to form a nitrogen-depleted LNG product and a recycle stream composed of nitrogen-enriched natural gas vapor, and in which the recycle stream is passed through main heat exchanger to produce a first LNG stream, separately from and in parallel with the natural gas feed stream, to produce a first at least partially liquefied nitrogen-enriched natural gas stream that is separated to provide a nitrogen-rich vapor product.

The present invention relates to a gas storage apparatus and method, and more specifically to liquid air energy storage and its use to facilitate both Demand Side Reduction (DSR) and the use of reduced-cost electricity by industrial compressed-air users. A related electricity generating apparatus and method is also disclosed. The apparatus and method use a first sensible heat coolth store and second latent heat coolth store to first reduce the gas in temperature and then to change it into a liquid phase. Coolth top up devices are also disclosed.

Liquefier arrangements configured for co-production of both liquid natural gas (LNG) and liquid nitrogen (LIN) configured to operate in two distinct operating modes are provided.

The present invention relates to a refrigerant composition. According to the invention it is envisioned that the composition comprises comprising an inert gas selected from nitrogen, argon, neon and a mixture thereof, and a mixture of at least two C.sub.1-C.sub.5 hydrocarbons. The present invention further relates to the use of the refrigerant composition in a method for liquefying a gaseous substance, particularly hydrogen or helium.

A method of producing LNG. According to the method, a natural gas stream is compressed using first and second compressors. A cooler cools the natural gas stream so that the second compressor produces a cooled, compressed natural gas stream, which is liquefied in a liquefaction process. The liquefaction process uses a refrigerant compressor configured to compress a stream of refrigerant used to chill, condense, or liquefy the cooled, compressed natural gas stream. Using a heat recovery steam generation (HRSG) system, heat is recovered from a power source of the refrigerant compressor. A stream of pressurized steam is generated from the recovered heat. At least one of the first and second compressors is powered using at least part of the stream of pressurized steam.

An apparatus for reliquefaction of boil-off gas for a vessel, comprises: a compression unit for compressing the boil-off gas discharged from the storage tank; and a heat exchanger for heat-exchanging the compressed boil-off gas compressed by the compression unit with the boil-off gas discharged from the storage tank; a first expansion means for dividing the boil-off gas passing through the heat exchanger into at least two flows including a first flow and a second flow, and expanding the divided first flow; a first intercooler for cooling the second flow remaining after the division of the first flow by using the first flow expanded by the expansion means as a refrigerant; and a receiver for receiving a second flow having passed through the first intercooler, in which a downstream pressure of the compression unit is controlled by a flow discharged from the receiver.

Certain embodiments of the invention relate to a facility for refrigerating hydrogen to cryogenic temperatures, and in particular for liquefying hydrogen, comprising a circuit for hydrogen to be refrigerated comprising an upstream end to be connected to a hydrogen source, and a downstream end connected to a refrigerated hydrogen collection member, the refrigeration facility comprising a set of one or more heat exchangers in thermal exchange with the circuit of hydrogen to be refrigerated, the facility comprising a device for refrigerating by heat exchange with the set of one or more heat exchangers, the refrigerating device comprising a refrigerator with a refrigeration cycle of a cycle gas such as hydrogen, at least one portion of the hydrogen circuit, of the set of one or more exchangers and of the refrigerating device being housed in a vacuum-insulated cold box, the facility comprising in the cold box, at least one ejector the suction inlet of which is connected to the gas phase of a fluid capacity and the motor fluid intake inlet of which is connected to at least one among: the pressurized cycle gas of the refrigerator, the hydrogen of the hydrogen circuit refrigerated in the set of one or more heat exchangers.

Liquefier arrangements configured for flexible co-production of both liquid natural gas (LNG) and liquid nitrogen (LIN) are provided. Each liquefier arrangement comprises separate and independent nitrogen recycle circuits or loops, including a warm recycle circuit and a cold recycle circuit with a means for diverting nitrogen refrigerant between the two recycle circuits or loops. The warm recycle circuit includes a booster loaded warm turbine, a warm booster compressor and warm recycle compression whereas the cold recycle circuit includes a booster loaded cold turbine, a cold booster compressor and a separate cold recycle compression.

Described herein are systems and processes of removing contaminants in a liquid nitrogen (LIN) stream used to produce liquefied natural gas (LNG). Greenhouse gas contaminants are removed from the LIN using a greenhouse gas removal unit. The LNG is compressed prior to being cooled by the LIN.

Liquefier arrangements configured for co-production of both liquid natural gas (LNG) and liquid nitrogen (LIN) configured to operate in two distinct operating modes are provided.