Facility and method for hydrogen refrigeration

A plant for the refrigeration and liquefaction of hydrogen at cryogenic temperature, the plant comprising:

• a circuit of hydrogen to be cooled comprising an upstream end intended to be connected to a source of hydrogen and a downstream end connected to a cryogenic storage vessel configured to collect the cooled hydrogen;
• a first set of heat exchangers and a second set of heat exchangers arranged in series in heat exchange with the circuit of hydrogen to be cooled;
• a first cooling device in heat exchange with the first set of heat exchangers, the first cooling device comprising a refrigerator with a cycle of refrigeration of a first cycle gas;
• a second cooling device in heat exchange with the second set of heat exchangers, the second cooling device comprising a refrigerator with a cycle of refrigeration of a second cycle gas having a molar mass lower than 3 g/mol, the refrigerator of the second cooling device comprising, arranged in series in a cycle circuit:
• a member for compressing the second cycle gas, a heat exchanger for cooling the second cycle gas, one or more turbines or expansion valves in series and/or parallel for expanding the second cycle gas, and a member for reheating the expanded second cycle gas, the member for reheating the expanded second cycle gas being the second set of heat exchangers, the member for compressing the second cycle gas comprising at least one centrifugal compressor;
• a system for injection of at least one additional constituent having a molar mass of greater than 50 g/mol into the second cycle gas and mixing therewith before the second cycle gas enters the at least one centrifugal compressor;
• a member for purification of the mixture at the outlet of the compression member configured in order to remove the at least one additional constituent down to a predetermined residual content, the purification member being located upstream of the first set of heat exchangers and being configured to remove the at least additional constituent down to a residual content of less than 100 ppm upstream of the first set of heat exchangers, the purification member being a pressure swing adsorption (PSA) and/or temperature swing adsorption (TSA) system comprising at least two adsorbers;
• and
• a thermally insulated cold box harboring the first set of heat exchangers and the second set of heat exchangers, wherein the system for injecting and mixing an additional constituent and the purification member are located outside the thermally insulated cold box.