Method and apparatus for liquefying hydrogen

A process for the liquefaction of hydrogen integrated with the cryogenic separation of a first mixture of hydrogen and of another component, wherein:

• i) cooling the first mixture in an auxiliary heat exchanger down to at least 120K, the cooled first mixture is separated by partial condensation and/or by distillation and/or by stripping at a temperature below 120K in order to produce a flow rich in hydrogen containing at least one impurity at between 20 and 30 bar and the hydrogen-rich flow is purified at a cryogenic temperature of at most 103K in order to reduce its content of the at least one impurity in order to form a hydrogen-rich gas;
• ii) sending the hydrogen-rich gas originating from the apparatus for separation by distillation and/or stripping and/or partial condensation, the gas exiting from the separation apparatus at the temperature of at most 103K containing at least 99.9 mol % of hydrogen and at a pressure between 20 and 30 bar, to a hydrogen liquefier, without having heated the hydrogen-rich gas to a temperature above 0° C.;
• iii) cooling the hydrogen-rich gas from the temperature of at most 103K and at the pressure between 20 and 30 bar in a first heat exchanger of the liquefier;
• iv) cooling a hydrogen-rich flow in a second heat exchanger of the liquefier from a temperature of greater than 103K to form a cooled flow;
• and
• wherein the cooled flow is subsequently cooled in the second heat exchanger, the hydrogen-rich gas is mixed with the hydrogen-rich flow having substantially the same pressure and composition as the hydrogen-rich gas and cooled in the second heat exchanger down to the temperature of the hydrogen-rich gas in order to form a second mixture, and the second mixture is liquefied either in the first heat exchanger or after cooling in the first heat exchanger in order to form liquid hydrogen.

A hydrogen liquefaction apparatus having a liquefier, the hydrogen liquefaction apparatus comprising:

• a first heat exchanger;
• a separation apparatus configured to separate a mixed fluid using a means selected from the group consisting of distillation, stripping, partial condensation, and combinations thereof;
• means for sending a hydrogen-rich gas originating from the separation apparatus at a temperature of at most 103K containing at least 99.9 mol % of hydrogen and at a pressure between 20 and 30 bar to the hydrogen liquefier, without having heated the hydrogen-rich gas to a temperature above 0° C.;
• means for sending the hydrogen-rich gas to be cooled from the temperature of at most 103K and at the pressure between 20 and 30 bar in the first heat exchanger;
• a second heat exchanger;
• means for sending a hydrogen-rich flow to be cooled in the second heat exchanger;
• means for mixing the hydrogen-rich gas with the hydrogen-rich flow cooled in the second heat exchanger and having substantially the same pressure, temperature and composition as the hydrogen-rich gas in order to form a second mixture;
• and
• means for sending the second mixture to be liquefied in the first heat exchanger or after cooling in the first heat exchanger to be liquefied in order to form liquid hydrogen.