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.

Hydrogen is liquefied through a process utilizing refrigeration from hydrogen at one, two, or three different pressures as well as a nitrogen refrigeration cycle. One or more stages of catalyst are used to convert ortho-hydrogen to para-hydrogen as the hydrogen is cooled and liquefied. Subcooled liquid hydrogen feeds the final stage of ortho-hydrogen to para-hydrogen conversion to reduce or eliminate vaporization of the hydrogen during the exothermic ortho-hydrogen to para-hydrogen conversion.

A process for liquefying a process gas that includes introducing a heat transfer fluid into an active magnetic regenerative refrigerator apparatus that comprises a single stage comprising dual multilayer regenerators located axially opposite to each other.

A process for liquefying a process gas comprising: introducing a heat transfer fluid into an active magnetic regenerative refrigerator apparatus that comprises (i) a high magnetic field section in which the heat transfer fluid flows from a cold side to a hot side through at least one magnetized bed of at least one magnetic refrigerant, (ii) a first no heat transfer fluid flow section in which the bed is demagnetized, (iii) a low magnetic or demagnetized field section in which the heat transfer fluid flows from a hot side to a cold side through the demagnetized bed, and (iv) a second no heat transfer fluid flow section in which the bed is magnetized; continuously diverting a bypass portion of the heat transfer fluid from the cold side of the low magnetic or demagnetized field section into a bypass flow heat exchanger at a first cold inlet temperature; and continuously introducing the process gas into the bypass flow heat exchanger at a first hot inlet temperature and discharging the process gas or liquid from the bypass flow heat exchanger at a first cold exit temperature; wherein the temperature difference between bypass heat transfer first cold inlet temperature and the process gas first cold exit temperature is 1 to 5 K.

A system comprising: (a) a liquid natural gas compression module having a compressed liquid natural gas conduit; (b) an active magnetic regenerative refrigerator H.sub.2 liquefier module; (c) at least one H.sub.2 gas source fluidly coupled to the active magnetic regenerative refrigerator H.sub.2 liquefier module via an H.sub.2 gas conduit; and (d) a heat exchanger that receives the compressed liquid natural gas conduit and the H.sub.2 gas conduit.

The invention relates to an integrated process for continuous production of liquid hydrogen, comprising (a) producing gaseous hydrogen by electrolysis; and (b) liquefying said gaseous hydrogen in a hydrogen liquefaction unit, which liquefaction unit is powered by energy essentially from renewable sources; and, (c) when additional power is needed, using electrical energy generated in a process in which electrical energy and hydrogen are co-generated by an integrated electrolysis process comprising: (d) electrolysing a metal salt or mixture of metal salts and water into the corresponding metal or metals, acid or acids, and oxygen (electricity storage phase), and (e) producing gaseous hydrogen and recovering electricity in a regeneration reaction of the metal (s) and acid(s) of step (d) (regeneration phase); wherein at least part of the gaseous hydrogen generated in step (e) is used in step (b) of the process.

The present invention pertains to a cooling method for liquefying a feed gas, comprising the steps of providing a cooling cycle with a refrigerant stream; dividing the refrigerant stream into a first partial stream and a second partial stream; expanding the first partial stream in a first expansion device; and transferring cooling energy from the expanded first partial stream to a feed gas stream to be cooled, particularly comprising hydrogen and/or helium. Further the method comprises the steps of guiding the expanded first partial stream to a suction inlet of an ejector; and guiding the second partial stream to a propellant inlet of the ejector such that, upon expanding the second partial stream in the ejector, the expanded first partial stream is compressed and merged with the expanded second partial stream.

A process for liquefying a process gas that includes introducing a heat transfer fluid into an active magnetic regenerative refrigerator apparatus that comprises a single stage comprising dual multilayer regenerators located axially opposite to each other.

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, the fluid can be directed to a portion of a liquefaction system that is configured to perform a cooling technique on the fluid. The cooling techniques may be Joule-Thomson cooling techniques. The liquefaction system may be equipped to perform both non-Joule-Thomson cooling techniques and Joule-Thomson cooling techniques. The system is configured to direct fluid to an appropriate portion of the liquefaction system, which may be based at least in part upon a Joule-Thomson coefficient of the fluid.

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.