A method for the liquefaction of hydrogen is provided. The can include the steps of: precooling a hydrogen feed stream in a precooling cold box having a heat exchanger disposed therein to form a cooled hydrogen stream, wherein the heat exchanger is configured to cool down the feed stream within the precooling cold box by indirect heat exchange between the hydrogen feed stream and a precooling refrigerant; and withdrawing the cooled hydrogen stream from the precooling cold box; introducing the cooled hydrogen stream to a plurality of liquefaction cold boxes, wherein the cooled hydrogen stream liquefies within the plurality of liquefaction cold boxes by indirect heat exchange against a liquefaction refrigerant to form a product hydrogen stream in each of the plurality of liquefaction cold boxes, wherein the product hydrogen stream is in liquid form or pseudo-liquid form wherein there are M total precooling cold boxes and N total liquefaction cold boxes, wherein M is less than N.

A system for liquefying a gas includes a liquefaction heat exchanger having a feed gas inlet adapted to receive a feed gas and a liquefied gas outlet through which the liquefied gas exits after the gas is liquefied in the liquefying passage of the heat exchanger by heat exchange with a primary refrigeration passage. A mixed refrigerant compressor system is configured to provide refrigerant to the primary refrigeration passage. An expander separator is in communication with the liquefied gas outlet of the liquefaction heat exchanger, and a cold gas line is in fluid communication with the expander separator. A cold recovery heat exchanger receives cold vapor from the cold gas line and liquid refrigerant from the mixed refrigerant compressor system so that the refrigerant is cooled using the cold vapor.

A method and apparatus for separating air in which an oxygen-rich liquid stream is pumped and then heated within a heat exchanger to produce an oxygen product through indirect heat exchange with first and second boosted pressure air streams. The first boosted pressure air stream is cold compressed at an intermediate temperature of the heat exchanger, reintroduced into the heat exchanger at a warmer temperature and then fully cooled and liquefied. The second boosted pressure air stream, after having been partially cooled, is expanded to produce an exhaust stream that is in turn introduced into a lower pressure column producing the oxygen-rich liquid. The second boosted pressure air stream is partially cooled to a temperature no greater than the intermediate temperature at which the cold compression occurs so that both the first and second boosted pressure air streams are able to take part in the heating of the oxygen-rich stream.

A hybrid process of air separation and gas liquefaction, including dividing a compressed multicomponent refrigerant stream into a first portion and a second portion, introducing the first portion into a gas liquefaction system, thereby producing a first multicomponent refrigerant return stream, and introducing the second portion into an air separation system, thereby producing a second multicomponent refrigerant return stream. Wherein the first multicomponent refrigerant return stream and the second multicomponent refrigerant return are recompressed in a common compression system, thereby producing the compressed multicomponent refrigerant stream.

Various systems and methods for suppling cryogenic refrigeration to supercomputing applications such as quantum computing operations are provided. The disclosed systems and methods are flexible, efficient and scaleable to meet the cryogenic refrigeration requirements of many supercomputing applications. The disclosed systems and methods include: (i) a liquid nitrogen based integrated refrigeration system that integrates a nitrogen refrigerator with a refrigeration load circuit; (ii) a closed loop liquid nitrogen based refrigerator that provides cooling to the refrigeration load circuit via indirect heat exchange between liquid nitrogen in a nitrogen refrigerator and a separate refrigerant in a closed-loop refrigeration load circuit; and (iii) a liquid air based integrated refrigeration system that integrates an air intake system with a refrigerator and a refrigeration load circuit.

A method for recovering boil-off gas from a system including one or more liquefaction trains including transport trucks or loading bays, a gaseous hydrogen feed stream, a lower-temperature cold box, and a low-pressure hydrogen compressor. The method including collecting a boil-off gas stream from the transport trucks or loading bays, determining the pressure of the boil-off gas stream, and depending on the pressure, recycling the boo-off gas stream to predetermined destinations. Wherein the boil-off gas stream has either a low-pressure, having a pressure of less than 2 bara, or a medium-pressure, having a pressure equal to or greater than 2 bara.

According to the present invention, a method for cryogenic separation of air using an air separation unit comprising a rectification column is provided. Feed air is compressed, cooled and rectified in the rectification column obtaining an overhead gas, wherein a part of the overhead gas of the rectification column is condensed using fluid withdrawn from the rectification column, wherein the condensed overhead gas is used at least in part as a liquid reflux to the rectification column, wherein a first part of the fluid which is used for cooling the overhead gas of the rectification column is, after its use for cooling, compressed and reintroduced into the rectification column, and wherein a second part of the fluid which is used for cooling the overhead gas of the rectification column is, after its use for cooling, expanded and withdrawn from the air separation unit.

A small to mid-scale liquefied natural gas production system and method is provided. The disclosed liquefied natural gas production system employs a nitrogen-based refrigerant, at least one heat exchanger, three turbine/expanders and two or more refrigerant compression stages. The expansion ratio of one turbine/expander is appreciably lower than the expansion ratio of the other turbine/expanders such that the temperature of the exhaust stream from the turbine/expander with the lower expansion ratio is above the critical point temperature of the compressed natural gas containing feed stream but colder than -15° C.

A small to mid-scale liquefied natural gas production system and method is provided. The disclosed liquefied natural gas production system employs a nitrogen-based refrigerant, at least one heat exchanger, three turbine/expanders and two or more refrigerant compression stages. The expansion ratio of one turbine/expander is appreciably lower than the expansion ratio of the other turbine/expanders such that the temperature of the exhaust stream from the turbine/expander with the lower expansion ratio is above the critical point temperature of the compressed natural gas containing feed stream but colder than −15° C.

A small to mid-scale liquefied natural gas production system and method is provided. The disclosed liquefied natural gas production system employs a nitrogen-based refrigerant, at least one heat exchanger, three turbine/expanders and two or more refrigerant compression stages. The expansion ratio of one turbine/expander is appreciably lower than the expansion ratio of the other turbine/expanders such that the temperature of the exhaust stream from the turbine/expander with the lower expansion ratio is above the critical point temperature of the compressed natural gas feed stream but colder than −15° C.