An integrated industrial unit is provided, which can include: a nitrogen source configured to provide liquid nitrogen; a hydrogen source; a hydrogen liquefaction unit, wherein the hydrogen liquefaction unit comprises a precooling system, and a liquefaction system; and a liquid hydrogen storage tank, wherein the precooling system is configured to receive the gaseous hydrogen from the hydrogen source and cool the gaseous hydrogen to a temperature between 75 K and 100 K, wherein the precooling system comprises a primary refrigeration system and a secondary refrigeration system, wherein the liquefaction system is in fluid communication with the precooling system and is configured to liquefy the gaseous hydrogen received from the precooling system to produce liquid hydrogen, wherein the liquid hydrogen storage tank is in fluid communication with the liquefaction system and is configured to store the liquid hydrogen received from the liquefaction system.

A hydrogen feed stream is introduced into a primary refrigeration system of a precooling system and cooling the hydrogen stream to a first precooling temperature. From there, the precooled hydrogen stream is then introduced to a secondary refrigeration system of the precooling system and cooling the precooled hydrogen stream to a second temperature. Next, the cooled hydrogen stream is then liquefied in the liquefaction system to produce liquid hydrogen. The refrigeration is provided by expansion of a pressurized gaseous nitrogen stream and vaporization of a liquid nitrogen stream that is sourced from a nearby air separation unit.

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.

Disclosed techniques include gas liquefaction using hybrid processing. A gas is compressed adiabatically to produce a compressed gas at a first pressure. The compressing a gas adiabatically is accomplished using one or more compressing stages. Heat is extracted from the compressed gas at a first pressure. The heat that is extracted is collected in a thermal store. The compressed gas at a first pressure is further compressed. The further compressing is accomplished using a first liquid piston compressor. The further compressing produces a compressed gas at a second pressure. The first liquid piston compressor is cooled using a liquid spray. The compressed gas at a second pressure is cooled using a heat exchanger. The cooling accomplishes liquefaction of the compressed gas at a second pressure. The gas that was liquefied is stored for future use. The gas that was liquefied is used to perform work.

The present invention pertains to a method for filling a transport tank with a product medium in a liquid state in a gas liquefaction plant, comprising a step of supplying the product medium in the liquid state from a storage tank (18) of the gas liquefaction plant to the transport tank. The method is characterized in that it further comprises a step of discharging the product medium in a gaseous state from the transport tank into the storage tank (18).

A method and system for liquefying a methane-rich high-pressure feed gas stream using a first heat exchanger zone and a second heat exchanger zone. The feed gas stream is mixed with a refrigerant stream to form a second gas stream, which is compressed, cooled, and directed to a second heat exchanger zone to be additionally cooled below ambient temperature. It is then expanded to a pressure less than 2,000 psia and no greater than the pressure to which the second gas stream was compressed, and then separated into a first expanded refrigerant stream and a chilled gas stream. The first expanded refrigerant stream is expanded and then passed through the first heat exchanger zone such that it has a temperature that is cooler, by at least 5° F., than the highest fluid temperature within the first heat exchanger zone.

A pre-cool refrigeration circuit includes a pre-cool compressor configured to receive and compress pre-cool refrigerant vapor from a pre-cool heat exchanger, a pre-cool cooling device configured to receive and cool compressed pre-cool refrigerant from the pre-cool compressor, a pre-cool expansion device configured to receive and expand compressed and cooled pre-cool refrigerant from the pre-cool cooling device, and a pre-cool separation device configured to receive expanded pre-cool refrigerant from the pre-cool expansion device at a reduced pressure so as to lower a boiling point of the expanded pre-cool refrigerant and to separate the expanded pre-cool refrigerant into a pre-cool refrigerant vapor stream and a pre-cool refrigerant liquid stream. A primary refrigeration circuit includes a first primary compressor configured to receive and compress a primary refrigerant vapor from a liquefier heat exchanger and the pre-cool heat exchanger, a primary cooling device configured to receive and cool compressed primary refrigerant from the first primary compressor. The primary cooling device is in fluid communication with the pre-cool heat exchanger and the liquefier heat exchanger. A first primary expansion device is configured to receive and expand compressed and cooled primary refrigerant from the liquefier heat exchanger, with the first primary expansion device having an outlet in fluid communication with the liquefier heat exchanger and the pre-cool heat exchanger.

Systems and methods are described for increasing capacity and efficiency of a nitrogen refrigerant boil-off gas recovery system for a natural gas storage tank. Boil-off gas is condensed against two-phase nitrogen in a condensing heat exchanger having an inner vessel through which the boil-off gas flows and an outer vessel through which the two phase nitrogen flows. Logic controls maintain storage tank pressure and power consumption within preferred levels by adjusting the pressure of the two-phase nitrogen in the heat exchanger. Additional logic controls maintain the temperature difference between the nitrogen streams entering into and returning from the cold end of a second heat exchanger by controlling the position of an expansion valve on the return circuit.

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.

A technology liquefies natural gas. The natural gas liquefaction method pre-cools treated natural gas by ethane evaporation, sub-cools liquefied gas using cooled nitrogen as a refrigerant, reduces liquefied gas pressure, separates non-liquefied gas and diverts liquefied natural gas. Before pre-cooling the natural gas is compressed, ethane is evaporated during the multi-stage pre-cooling of liquefied gas with simultaneous evaporation of ethane using cooled ethane as a refrigerant. Ethane generated by evaporation is compressed, condensed and used as a refrigerant during the cooling of liquefied gas and nitrogen, with nitrogen being compressed, cooled, expanded and fed to the natural gas sub-cooling stage. The natural gas liquefaction unit contains a natural gas liquefaction circuit, an ethane circuit and a nitrogen circuit. The natural gas liquefaction circuit includes a natural gas compressor, a cooler unit, ethane vaporizers, a closed-end subcooling heat exchanger, and a separator, connected in series.