Hydrogen liquefaction installation and process

Abstract

The invention relates to a hydrogen liquefaction plant comprising a hydrogen supply circuit (3) to be cooled, a plurality of heat exchangers (4, 5, 6, 7, 17) arranged in heat exchange with the supply circuit (3), a first pre-cooling device (8), a second pre-cooling device (9) and a cooling system (10) in heat exchange with the set (4, 5) of exchangers, to lower the temperature of the hydrogen to a temperature below the critical temperature of hydrogen, the first pre-cooling device (8) comprising a closed-cycle refrigerator of a first cycle gas comprising at least three components, a first centrifugal compressor (18), a cooling unit (180), three phase separators (28, 48, 88) configured to separate the two-phase fluid,the refrigeration cycle refrigerator of the first pre-cooling device (8) comprising a first expansion element (78) configured to expand the liquid produced by one of the phase separators (48) and return this fluid to a first centrifugal compressor (18) via a passage through a heat exchanger of the exchanger assembly. Abbreviated figure: Fig. 1,

Description

Title of the invention: Installation and method for liquefying hydrogen

[0001] The invention relates to a plant and a method for liquefying hydrogen

[0002] The invention relates more particularly to a liquefaction installation of hydrogen comprising a hydrogen supply circuit to be cooled having an upstream end intended to be connected to a source of pressurized gaseous hydrogen at a first initial temperature and a downstream end intended to be connected to at least one member for collecting liquefied hydrogen, the installation comprising a plurality of heat exchangers arranged in series in heat exchange with the supply circuit, the installation comprising a first pre-cooling device in heat exchange with a first set of the heat exchanger(s), the first pre-cooling device being configured to lower the temperature of the hydrogen from the first temperature to a second temperature lower than the first temperature and between 120K and 163K,the installation comprising a second pre-cooling device in heat exchange with a second set of heat exchangers and configured to lower the temperature of the hydrogen from the second temperature to a third temperature lower than the second temperature and greater than or equal to 103K, the installation comprising a cooling system in heat exchange with a third set of heat exchangers and configured to lower the temperature of the hydrogen from the third temperature to a fourth temperature lower than the critical temperature of the hydrogen, for example lower than 25K, ,

[0003] A hydrogen liquefier generally comprises a pre-cooling section for bringing the hydrogen to an intermediate temperature of about 80K and a final section for cooling the hydrogen from about 80K to 30K. After cooling in both sections, the hydrogen liquefies.

[0004] It is known to use a refrigerant comprising several components including nitrogen and hydrocarbons in a closed cycle to cool the pre-cooling section.

[0005] For the liquefaction of hydrogen it is known to provide liquefiers using a pre-cooling system and a cooling system (refrigeration cycle comprising hydrogen and / or helium).

[0006] The document “Optimal operation of large-scale liquid hydrogen plant utilizing mixed fluid refrigeration System” (Krasae and al. International Journal of Hydrogen Energy, Vol 39, n°13 ISSN: 0360-3199) describes a liquefier whose pre-cooling system consists of a refrigerant mixing cycle (“MR”).

[0007] This solution is not satisfactory because it involves using a large number of components for the pre-refrigerant cycle.

[0008] Other known solutions consist of providing a pre-cooling system consisting of two cycles: a refrigerant mixing cycle and a nitrogen cycle.

[0009] It is advantageous to cool as much as possible in the pre-cooling section in order to limit the cooling to be carried out in the final section where the cooling is less efficient because it relies mainly on the sensible heat of the hydrogen. However, below a given temperature, there is a risk of demixing and / or freezing for the heaviest components of the cycle with the multi-component refrigerant.

[0010] For large capacity hydrogen liquefiers, known solutions have unsatisfactory energy performance.

[0011] An aim of the present invention is to overcome all or part of the drawbacks of the prior art noted above.

[0012] To this end, the installation according to the invention, moreover in accordance with the generic definition given in the preamble above, is essentially characterized in that the second pre-cooling device comprises a refrigerator with a refrigeration cycle of a second cycle gas consisting of nitrogen, the first pre-cooling device comprising a refrigerator with a closed refrigeration cycle of a first cycle gas comprising at least three components, at least one first component being more volatile than at least one second component, the at least one second component being more volatile than at least one third component, the refrigerator with a refrigeration cycle of the first pre-cooling device comprising a first centrifugal compressor of the first cycle gas, a cooling member of the first compressed cycle gas configured to produce a two-phase fluid, a first phase separator configured to separate the two-phase fluid,second compression members configured to compress the gas and the liquid coming from the first phase separator, a second phase separator configured to separate the two-phase fluid produced by the second compression members, a first pipe in heat exchange with a heat exchanger of the first assembly and configured to cool, partially condense gas produced by the second phase separator and transfer this partially condensed gas into a third phase separator of the refrigerator of the first pre-cooling device, the refrigeration cycle refrigerator of the first pre-cooling device comprising a first expansion member configured to expand the liquid produced by the second phase separator and return this fluid to the first centrifugal compressor via a passage in a heat exchanger of the first assembly.

[0013] The combination of the first and second pre-cooling devices with the cooling system makes it possible to improve the performance of the installation. In particular, the composition of the first cycle gas and the association of the three phase separators of the first pre-cooling device makes it possible to improve the performance, in particular the energy performance of the installation, while using a limited number of components of the first cycle gas.

[0014] Furthermore, embodiments of the invention may include one or more of the following features: - the refrigeration cycle refrigerator of the first pre-cooling device comprises a fifth phase separator configured to receive the gas produced by the third phase separator of the refrigerator and expanded in an expansion member of the refrigerator of the first pre-cooling device, - the refrigeration cycle refrigerator of the first pre-cooling device comprises a fifth phase separator configured to receive the gas produced by the third phase separator of the refrigerator and expanded in an expansion member of the refrigerator of the first pre-cooling device, - the first cycle gas consists of a mixture of three to six components chosen from: nitrogen, methane, ethane or ethylene, propane or propene, butane or butene, pentane, - the refrigerator of the second pre-cooling device comprises, arranged in a cycle circuit, at least two centrifugal compressors in series configured to compress the second cycle gas, at least one expansion turbine of the second cycle gas coupled to a rotating shaft which is preferably also coupled to a compressor, the cycle circuit further comprising a thermosiphon device comprising a phase separator tank configured to receive at least one flow of the second cycle gas expanded by the at least one expansion turbine and return cycle gas to the compressors, - the first cycle gas consists of a mixture composed of at least one light component chosen from the group: nitrogen, methane, at least one medium component chosen from the group: ethane, ethylene, propane, propene, butane, butene and at least one heavy component which is pentane or, butane if the medium component is chosen from the group: ethane, ethylene, propane, propene.

[0015] The invention also relates to a method for liquefying hydrogen comprising the following steps: cooling a hydrogen flow to at least 20 bar abs and a first initial temperature to a second temperature of 163K or lower in at least a first line of heat exchanger(s) cooled by a first pre-cooling device, cooling the hydrogen flow from the second temperature to a third temperature of 103K or lower in at least one heat exchanger cooled by a second pre-cooling device, cooling the hydrogen flow from the third temperature to a temperature below the critical temperature of hydrogen, in particular below 25K in at least one heat exchanger cooled by a cooling system, liquefying the cooled hydrogen flow to the temperature below the critical temperature to obtain a liquid hydrogen flow, wherein, the second pre-cooling device is a refrigerator with a refrigeration cycle of a second cycle gas consisting of nitrogen, the first pre-cooling device being a refrigerator of a first closed refrigeration cycle using a first refrigerant comprising at least three components including at least one first component more volatile than at least one second component and at least one third component more volatile than the at least one second component, the first refrigeration cycle comprising at least two partial condensation stages at different temperatures higher than the second temperature, to separate the first refrigerant producing a gas enriched in its more volatile components and a liquid enriched in its less volatile components, the first refrigeration cycle comprising: compression in a centrifugal compressor where the entire flow of first refrigerant fluid is compressed from a pressure of between 1.1 bara and 10 bara, preferably between 1.5 and 6 bara, to a pressure of between 7 and 30 bara, preferably between 15 and 25 bara, cooling of the first refrigerant fluid to form a two-phase fluid, a separation of this two-phase fluid in a first phase separator, a centrifugal compression of the gas coming from the first phase separator and a pressurization of the liquid coming from the first phase separator up to a pressure of between 25 bara and 70 bara, preferably between 45 bara and 65 bara, sending this compressed gas and this pressurized liquid to a second phase separator, separating the compressed gas and the pressurized liquid in the second phase separator to form a gas and a liquid, • cooling of this gas produced by the second phase separator in the first heat exchange line to at least the second temperature to partially condense it, • sending this partially condensed gas to a third phase separator, • cooling and expansion of the liquid formed in the second phase separator via a valve or a turbine to form an expanded fluid and returning this expanded fluid to the first heat exchange line to heat up and form at least part of the compressed fluid in the centrifugal compressor.

[0016] According to other possible particularities: - the process uses a fourth phase separator receiving the liquid produced by the second phase separator and the liquid produced by the third phase separator, - the process uses a fifth phase separator receiving the gas produced by the third phase separator and expanded, - the first cycle gas consists of a mixture of three to six components chosen from: nitrogen, methane, ethane or ethylene, propane or propene, butane or butene, pentane, - the first cycle gas comprises, in moles, between 10% and 50% of light component(s), between 30% and 70% of medium component(s) and between 10% and 35% of heavy component(s), the total being equal to 100%, - - the gas supplied by the second phase separator contains, in moles, less 20% of heavy component(s) and possibly at least 20% of light component(s), - the liquid supplied by the second phase separator contains at least 20% of heavy component(s) and possibly less than 20% of light component(s), - the gas supplied by the third phase separator contains less than 1% of heavy component(s) and preferably at least 30% of light component(s), - the liquid supplied by the third phase separator contains at least 5% of heavy component(s) and preferably less than 30% of light component(s), - the gas supplied by the second phase separator is cooled in the first heat exchanger line to a temperature between 10°C and -40°C, and preferably between +5°C and -20°C (or cooled between 120K and 163K) and supplies the third phase separator at this temperature, the liquid supplied by the second phase separator is cooled to a temperature between -30°C and -160°C, preferably between -50°C and -110°C, the liquid supplied by the third phase separator is cooled in the first heat exchanger line to a temperature of at most -50°C and is partially condensed before being sent to the fourth phase separator, cooling the hydrogen flow from the second temperature to a third temperature and / or cooling the hydrogen flow from the third temperature to a third temperature to a temperature below the critical temperature of hydrogen comprises cooling the hydrogen flow to an intermediate temperature of between 113K and 153K, preferably between 123K and 143K at which the hydrogen flow is sent to an adsorption purification unit operating at a cryogenic temperature and then optionally to a unit for catalytic conversion of ortho hydrogen into para hydrogen, to produce a hydrogen flow having a para hydrogen content of between 30% and 55% before being cooled again, the method comprises a production of pre-cooling power by the second pre-cooling device with the following steps: a centrifugal compression of the second cycle gas in at least two compressors arranged in series with an inlet pressure of between 1 and 5 bara, up to a pressure of between 10 and 50 bara and preferably between 15 and 25 bara, an expansion of the second compressed cycle gas and at a temperature of between 173K and 128K in at least one valve or turbine up to a pressure of between 1.1 and 2 bara, at least one expansion turbine optionally providing mechanical work for driving at least one compressor, the production of pre-cooling power by the second pre-cooling device comprises a transfer of the second expanded cycle gas into a phase separator tank of a thermosiphon type device and a return of the cycle gas from the tank to the inlet of the compressors, the expansion of the second compressed cycle gas to a pressure between 1.1 and 2 bara is carried out in two expansion turbines in series, the pressure of the second cycle gas entering the first of the turbines being between 15 and 50 bara, the temperature of the second cycle gas entering the second of the turbines preferably being between 143K and 103K, - the first cycle gas consists of a mixture of three components: CH4, C2H6 or C3H8, C5H10, for example, expressed in moles, 53% of CH4; 41% of C3H8, 6% of C5H10, or the first cycle gas consists of a mixture of four components from: CH4 and / or N2, C2H6 and / or C3H8, C5H10, for example, expressed in moles, 49% of CH4; 11% of C2H6, 31% of C3H8 and 9% of C5H10 or the first cycle gas consists of a mixture of CH4, C2H4, C3H8 and C5H12, for example in respective molar proportions of 24%, 39%, 22%, and 15% or in respective molar proportions of 6%, 33%, 26%, 35%, or the first cycle gas consists of a mixture of five components: N2; CH4, C2H6; C3H8; C5H10 for example in respective proportions in moles of 3%; 37%, 32%, 13% and 14% or in respective proportions in moles of 3%, 31%, 34%, 18%, 14%, or in respective proportions in moles of 3%, 33%, 37%, 13%, and 14%, - the cut-off temperature between the first (8) pre-cooling device and the second pre-cooling device (9), i.e. the temperature of the hydrogen flow between these two pre-cooling portions is between 148K and 123K, preferably between 138K and 133K.

[0017] The invention may also relate to any alternative device or method comprising any combination of the above or below features within the scope of the claims.

[0018] Other features and advantages will appear on reading the description below, given with reference to the figures in which: Brief description of the figures

[0019] The invention will be better understood on reading the following description given solely by way of example and with reference to the appended drawings in which:

[0020] [Fig. 1] is a schematic and partial view illustrating a first example of structure and operation of an installation according to the invention,

[0021] [Fig.2] is a schematic and partial view illustrating a second example of structure and operation of an installation according to the invention.

[0022] [Fig.3] is a schematic and partial view illustrating the structure and operation of a detail of a liquefaction installation according to the invention illustrating a first possible embodiment of a second pre-cooling device,

[0023] [Fig.4] is a schematic and partial view illustrating the structure and operation of a detail of a liquefaction installation according to the invention illustrating a second possible embodiment of a second pre-cooling device. Detailed description

[0024] In all the figures, the same references refer to the same elements.

[0025] In this detailed description, the following embodiments are examples. Well that the description refers to one or more embodiments, this does not mean that the features apply only to a single embodiment. Single features of different embodiments may also be combined and / or interchanged to provide other embodiments.

[0026] The hydrogen liquefaction installation 1 illustrated in [Fig.l] comprises a circuit 3 for supplying hydrogen to be cooled having an upstream end intended to be connected to a source 2 of pressurized hydrogen gas at a first initial temperature and a downstream end 23 intended to be connected to at least one member 30 for collecting the liquefied hydrogen. The source 2 of gaseous hydrogen may comprise, for example, an electrolyzer. The hydrogen collection member 30 may comprise, for example, at least one cryogenic storage.

[0027] The installation 1 preferably comprises a plurality of heat exchangers 4, 5, 6, 7, 17 arranged in series in heat exchange with the supply circuit 3.

[0028] The installation 1 comprises a first pre-cooling device 8 in heat exchange with a first set 4, 5 among the heat exchangers (in this illustrated example the first two heat exchangers 4, 5). The first pre-cooling device 8 is configured to produce and supply cold power and transfer it to the supply circuit 3 to lower the temperature of the hydrogen from the first temperature to a second temperature lower than the first temperature and lower than or equal to 163K, for example up to 120K (second temperature between 120K and 163K for example).

[0029] The installation 1 comprises a second pre-cooling device 9 in heat exchange with a second set 4, 5, 6 among the heat exchangers (in this example illustrated the first three heat exchangers 4, 5, 6). The second pre-cooling device 9 is configured to produce and supply cold power and transfer it to the supply circuit 3 to lower the temperature of the hydrogen from the second temperature to a third temperature lower than the second temperature and for example less than or equal to 103K and for example up to 80K (third temperature for example between 113K and 65K, preferably between 103K and 80K).

[0030] The second pre-cooling device 9 is a refrigeration cycle refrigerator management of a second cycle gas consisting of nitrogen (i.e. essentially nitrogen and possibly traces of impurities).

[0031] As illustrated, the installation 1 further comprises a cooling system 10 in heat exchange with a third set 4, 5, 6, 7, 17 among the heat exchanger(s) (in this illustrated example five heat exchangers). The cooling system 10 is a cryogenic refrigerator configured to produce cold power at at least one cold end of its cycle and provide this cold power to lower the temperature of the hydrogen from the third temperature to a fourth temperature below the critical temperature of the hydrogen, for example below 25K.

[0032] The first pre-cooling device 8 is a refrigerator with a closed refrigeration cycle of a first cycle gas comprising at least three components (mixture of refrigerants "MR"), at least one first component being more volatile than at least one second component, the at least one second component being more volatile than at least one third component. This refrigerator with a refrigeration cycle of the first pre-cooling device 8 comprises at least one first centrifugal compressor 18 of the first cycle gas, a member 180 for cooling the first compressed cycle gas (for example a heat exchanger cooled by a heat transfer fluid, such as water for example). The first compressed and cooled cycle gas produces a two-phase fluid. The first pre-cooling device 8 (or refrigerator 8) comprises a first phase separator 28 configured to separate this two-phase fluid.The first pre-cooling device 8 comprises conduits transferring the gas and the liquid produced by the first phase separator 28 to respective second compression members 38, 58 (compressor 38 and pump 58) configured to compress respectively the gas and the liquid coming from the first phase separator 28. Preferably, the compression 38 of the gas coming from the first phase separator 28 is of the centrifugal type. This compression 38 and the pressurization 58 of the liquid coming from the first phase separator 28 can bring the fluids up to a pressure of between 25 bara and 70 bara, preferably between 45 bara and 65 bara.

[0033] The cycle circuit 21 of the first pre-cooling device 8 comprises a second phase separator 48 configured to receive the fluid flows produced by the second compression members 38, 58 and to separate the resulting two-phase fluid. The cycle circuit 21 of the first pre-cooling device 8 comprises a first pipe 68 having an upstream end connected to the gaseous part of the second phase separator 48. This first pipe 68 is in heat exchange with at least one heat exchanger 4, 5 of the first set of exchangers and configured to cool, partially condense gas produced by the second phase separator 48. A downstream end of this first pipe 68 is connected to a third cycle circuit separator 88 of the first pre-cooling device 8 to transfer this partially condensed gas there (possibly via an expansion valve 188).

[0034] For example, the gas supplied by the second phase separator 48 is cooled in the first line 68, of heat exchanger(s) 4, 5 to a temperature between 120K and 163K. In the embodiment of [Fig.l], the third separator 88 operates at a temperature lower than the temperature of the fourth separator 108.

[0035] The cycle circuit 21 of the first pre-cooling device 8 comprises a second pipe 98 having an upstream end connected to the liquid part of the second phase separator 48. This second pipe 98 is in heat exchange with at least one heat exchanger 4, 5 of the first set of exchangers.

[0036] The liquid supplied by the second phase separator 48 is for example cooled to a temperature between -30°C and -160°C, preferably between -50°C and -110°C.

[0037] This second pipe 98 preferably comprises a first expansion member 78 such as a valve configured to expand the liquid produced by the second phase separator 48 before returning this fluid to the first centrifugal compressor 18 via a passage in a heat exchanger of the first assembly 4, 5. As illustrated in [Fig. 1] and described in more detail below, after expansion in the first expansion member 78 and before returning to the heat exchanger(s) 4, 5, the liquid supplied by the second phase separator 48 can pass into a possible fourth phase separator 108 of the cycle circuit of the first pre-cooling device 8.

[0038] As described above, the possible fourth phase separator 108 can be configured to recover the liquid produced by the second phase separator 48 and expanded by the first expansion member 78 and to also be supplied with the liquid produced by the third phase separator 88 via an appropriate conduit.

[0039] For example, the liquid supplied by the third phase separator 88 can be cooled in the exchanger(s) 5 (first heat exchanger line 4) to a temperature of at most -50°C and is partially condensed before being sent to the fourth phase separator 108.

[0040] The first cycle gas consists of a mixture of three to six components chosen from: nitrogen, methane, ethane or ethylene, propane or propene, butane or butene, pentane.

[0041] This first cycle gas preferably consists of a mixture composed of at least one light component chosen from the group: nitrogen, methane, at least one medium component chosen from the group: ethane, ethylene, propane, propene, butane, butene and ... minus one heavy component which is pentane or butane if the medium component is chosen from the group: ethane, ethylene, propane, propene.

[0042] The first cycle gas comprises, for example, in moles, between 10% and 50% of light component(s), between 30% and 70% of medium component(s) and between 10% and 35% of heavy component(s), the total being equal to 100%.

[0043] Thus, in operation, the entire flow rate of first refrigerant fluid can be compressed 18 from a pressure of between 1.1 bara and 10 bara, preferably between 1.5 and 6 bara, to a pressure of between 7 and 30 bara, preferably between 15 and 25 bara.

[0044] The gas supplied by the second phase separator 48 may advantageously contain, in moles, less than 20% of heavy component(s) and possibly at least 20% of light component(s).

[0045] Similarly, the liquid supplied by the second phase separator 48 may contain at least 20% of heavy component(s) and possibly less than 20% of light component(s).

[0046] Similarly, the gas supplied by the third phase separator 88 may contain less than 1% of heavy component(s) and preferably at least 30% of light component(s).

[0047] Furthermore, the liquid supplied by the third phase separator 88 may contain at least 5% of heavy component(s) and preferably less than 30% of light component(s).

[0048] When the first cycle gas consists of a mixture of three components: CH4, C2H6 or C3H8, C5H10, it can be composed in the following proportions expressed in moles: 53% CH4; 41% C3H8, 6% C5H10.

[0049] When the first cycle gas consists of a mixture of four components from among: CH4 and / or N2, C2H6 and / or C3H8, C5H10, it can be composed in the following proportions expressed in moles: 49% of CH4; 11% of C2H6, 31% of C3H8 and 9% of C5H10. Alternatively, the first cycle gas can consist of a mixture of four components from among: CH4, C2H4, C3H8 and C5H12, for example in respective proportions in moles of 24%, 39%, 22%, and 15% or in respective proportions in moles of 6%, 33%, 26%, 35%.

[0050] When the first cycle gas consists of a mixture of five components from: or the first cycle gas consists of a mixture of five components: N2; CH4, C2H6; C3H8; C5H10, it can be composed in the following respective proportions expressed in moles: 3%; 37%, 32%, 13% and 14% or in respective proportions of 3%, 31%, 34%, 18%, 14%, or in respective proportions of 3%, 33%, 37%, 13%, and 14%.

[0051] This structure of the first pre-cooling device 8 provides efficiency energy with a limited number of components of the mixture constituting the first cycle gas.

[0052] The second nitrogen cycle pre-cooling device 9 is shown schematically in [Fig.l] and may comprise any suitable structure and operation. For example, the nitrogen undergoes a thermodynamic cycle with compression then cooling 4, 5 then expansion (valve(s) and / or turbine(s)) 29 and reheating 6, 5, 4.

[0053] As illustrated in [Fig. 3], the second pre-cooling device 9 may comprise or consist of a cycle circuit refrigerator. This cycle circuit may comprise at least two centrifugal compressors 19 in series configured to compress the second cycle gas (nitrogen). The compression inlet pressure may be between 1 and 5 bara, and the outlet pressure may be between 10 and 50 bara and preferably between 15 and 25 bara. After passing through one or more exchangers 4, 5 of the installation, the compressed and cooled nitrogen (for example to a temperature between 173K and 128K) may be expanded in at least one expansion turbine 29 which may be coupled to a rotating shaft also coupled to a compressor 19 of the cycle. The nitrogen is for example expanded to a pressure between 1.1 and 2 bara.

[0054] This second pre-cooling device 9 may further comprise a thermosiphon device comprising a phase separator tank 39 configured to receive at least one flow of the second cycle gas expanded by the at least one expansion turbine 29 and return cycle gas to the compressors 19 (via a counter-current passage in the exchanger(s) 6, 5, 4 for its reheating). As illustrated, the separator tank 39 may also be supplied with fluid taken from the cycle before the expansion 29. At this location the nitrogen is for example at a temperature between -130°C and -145°C.

[0055] The embodiment of the second pre-cooling device 9 illustrated in [Fig.4] differs from that of [Fig.3] only in that the refrigerator comprises three centrifugal compressors 19 in series and two expansion turbines 29 in series. The first and second turbines 29 can be coupled respectively to the second and third compressors 19.

[0056] At the inlet of the first turbine 29 the nitrogen is for example at a temperature between -100 and -130°C. At the outlet of the second turbine 29 the nitrogen is for example at a temperature between -130 and -170°C.

[0057] In operation, cooling the hydrogen 3 from the second temperature to the third temperature and / or cooling the hydrogen flow 3 from the third temperature to a third temperature to a temperature below the critical temperature of the hydrogen may comprise cooling up to an intermediate temperature between 113K and 153K, preferably between 123K and 143K. At this intermediate temperature the hydrogen flow can be sent to an adsorption purification unit 11 operating at a cryogenic temperature and then possibly to a catalytic conversion unit of ortho hydrogen into para hydrogen, to produce a hydrogen flow having a para hydrogen content between 30% and 55% before being cooled again.

[0058] This partially converted hydrogen can continue its cooling until its liquefaction ensured by the cooling system 10. It can be converted (ortho to para) even more along the heat exchanger line(s) 7 downstream. It can undergo a final expansion 100 downstream (valve(s) or turbine(s)).

[0059] The embodiment of [Fig. 2] differs from that of [Fig. 1] only in that the refrigeration cycle refrigerator of the first pre-cooling device 8 comprises a fifth phase separator 118. The cycle circuit is configured so that the fifth phase separator 118 is supplied with the gas produced by the third phase separator 88 of the refrigerator via a heat exchange with at least one heat exchanger 4, 5 and expanded in an expansion member 128. As illustrated, the gas and the liquid produced by the fifth phase separator 118 can supply the fourth phase separator 108 via a heat exchange with at least one heat exchanger 5.

[0060] In this embodiment, for example, the gas supplied by the second phase separator 48 is cooled in the first line 68 of heat exchanger(s) 4 to a temperature between 10°C and -40°C, and preferably between +5°C and -20°C and feeds the third phase separator 88 at this temperature. In this embodiment, the fifth separator 118 operates at a lower temperature than the fourth separator 108 which itself operates at a lower temperature than the third separator 88.

[0061] The cooling system 10 is illustrated schematically for the sake of simplification. This may be composed of a cryogenic cycle refrigerator whose cycle gas comprises or is made up of at least one of: hydrogen, helium. The cycle gas is subjected to a thermodynamic cycle (compression 101, cooling 4, 5, 6, expansion 102, reheating 7, 6, 5, 7) to provide cold power at at least one end of the cycle.

[0062] All or part of the heat exchangers 4, 5, 6, 7, 17 may be multi-pass exchangers (co-current or counter-current) to ensure the simultaneous heating and cooling of the flow(s).

[0063] At least the cold parts of the first and second pre-cooling devices can be arranged in a first insulated cold box. At least the cold parts of the cooling device can be arranged in a second box cold isolated.

[0064] The cut-off temperature between the first 8 pre-cooling device and the second 9 pre-cooling device, i.e. the temperature of the hydrogen flow between these two pre-cooling portions, may be between 148K and 123K, preferably between 138K and 133K.

[0065] The cut-off temperature between the second 9 pre-cooling device and the cooling system 10, i.e. the temperature of the hydrogen flow between these two pre-cooling portions, may be between 93K and 73K, preferably between 88K and 81K.

[0066] The centrifugal compression(s) may have several compression stages.

[0067] The relaxation(s) provided by valve(s) and / or turbine(s).

[0068] In the example illustrated, the pre-cooling and cooling consists of two pre-cooling devices 8, 9 and a cooling device 10. Of course, other cooling devices (and possibly pre-cooling) can be envisaged (refrigeration loop(s) for example).

Claims

Claims

1. Hydrogen liquefaction installation comprising a circuit (3) for supplying hydrogen to be cooled having an upstream end intended to be connected to a source (2) of pressurized gaseous hydrogen at a first initial temperature and a downstream end (23) intended to be connected to at least one member (30) for collecting the liquefied hydrogen, the installation (1) comprising a plurality of heat exchangers (4, 5, 6, 7, 17) arranged in series in heat exchange with the supply circuit (3), the installation (1) comprising a first pre-cooling device (8) in heat exchange with a first set (4, 5) among the heat exchanger(s), the first pre-cooling device (8) being configured to lower the temperature of the hydrogen from the first temperature to a second temperature lower than the first temperature and between 120K and 163K,the installation (1) comprising a second pre-cooling device (9) in heat exchange with a second set (4, 5, 6) among the heat exchangers and configured to lower the temperature of the hydrogen from the second temperature to a third temperature lower than the second temperature and between 103K and 80K, the installation (1) comprising a cooling system (10) in heat exchange with a third set (4, 5, 6, 7, 17) among the heat exchangers and configured to lower the temperature of the hydrogen from the third temperature to a fourth temperature lower than the critical temperature of the hydrogen, for example lower than 25K, in which the second pre-cooling device (9) comprises a refrigerator with a refrigeration cycle of a second cycle gas consisting of nitrogen,the first pre-cooling device (8) comprising a refrigerator with a closed refrigeration cycle of a first cycle gas comprising at least three components including at least one first component more volatile than at least one second component, the at least one second component being more volatile than at least one third component, the refrigerator with a refrigeration cycle of the first pre-cooling device (8) comprising a first centrifugal compressor (18) of the first cycle gas, a member (180) for cooling the first compressed cycle gas configured to produce a two-phase fluid, a first phase separator (28), configured to separate the two-phase fluid, second compression members (38, 58) configured to compress the gas and the liquid coming from the first phase separator (28), a second phase separator (48) configured to separate the two-phase fluid produced by the second compression members (38, 58), a first pipe (68) in heat exchange with a heat exchanger of the first assembly (4, 5) and configured to cool, partially condense gas produced by the second phase separator (48) and transfer this partially condensed gas into a third phase separator (88) of the refrigerator of the first pre-cooling device (8),the refrigeration cycle refrigerator of the first pre-cooling device (8) comprising a first expansion member (78) configured to expand the liquid produced by the second phase separator (48) and return this fluid to the first centrifugal compressor (18) via a passage in a heat exchanger of the first assembly (4, 5), in which the refrigeration cycle refrigerator of the first pre-cooling device (8) comprises a fourth phase separator (108) configured to recover the liquid produced by the second phase separator (48) and expanded by the first expansion member (78) and to also be supplied with the liquid produced by the third phase separator (88).,

2. Installation according to claim 1, characterized in that the refrigeration cycle refrigerator of the first pre-cooling device (8) comprises a fifth phase separator (118) configured to receive the gas produced by the third phase separator (88) of the refrigerator and expanded in an expansion member (128) of the refrigerator of the first pre-cooling device (8).

3. Installation according to any one of claims 1 to 2, characterized in that the first cycle gas consists of a mixture of three to six components chosen from: nitrogen, methane, ethane or ethylene, propane or propene, butane or butene, pentane.

4. Installation according to any one of claims 1 to 3, characterized in that the refrigerator of the second pre-cooling device (9) comprises, arranged in a cycle circuit, at least two centrifugal compressors (19) in series configured to compress the second cycle gas, at least one turbine (29) for expanding the second cycle gas coupled to a rotating shaft which is preferably also coupled to one of the compressors (19), the cycle circuit

5. further comprising a thermosiphon device comprising a phase separator tank (39) configured to receive at least one flow of the second cycle gas expanded by the at least one expansion turbine (29) and return cycle gas to the compressors (19). A method of liquefying hydrogen comprising the following steps: - cooling a hydrogen flow (3) having a pressure of at least 20 bar abs and a first initial temperature to a second temperature of 163K or lower in at least a first line (4, 5) of heat exchanger(s) cooled by a first pre-cooling device (8), - cooling the hydrogen flow (3) from the second temperature to a third temperature of 103K or lower in at least one heat exchanger (4, 5, 6) cooled by a second pre-cooling device (9), - cooling the hydrogen flow (3) from the third temperature to a temperature below the critical temperature of hydrogen, in particular below 25K in at least one heat exchanger (6, 7, 17) cooled by a cooling system (10), liquefying the hydrogen flow (3) cooled to the temperature below the critical temperature to obtain a liquid hydrogen flow, wherein the second pre-cooling device (9) is a refrigerator with a refrigeration cycle of a second cycle gas consisting of nitrogen, - the first pre-cooling device (8) being a refrigerator of a first closed refrigeration cycle using a first refrigerant fluid comprising at least three components including at least one first component more volatile than at least one second component and at least one third component more volatile than the at least one second component, the first refrigeration cycle comprising at least two partial condensation stages at different temperatures higher than the second temperature, to separate the first refrigerant fluid by producing a gas enriched in its more volatile components and a liquid enriched in its less volatile components, the first refrigeration cycle comprising: compression in a centrifugal compressor (18) where the entire flow of first refrigerant fluid is compressed from a pressure of between 1.1 bara and 10 bara, preferably between 1.5 and 6 bara, to a pressure of between 7 and 30 bara, preferably between 15 and 25 bara, cooling (180) of the first refrigerant fluid to form a two-phase fluid, separating this two-phase fluid in a first phase separator (28), centrifugal compression of the gas coming from the first phase separator (28) and pressurizing (58) the liquid coming from the first phase separator (28) to a pressure of between 25 bara and 70 bara, preferably between 45 bara and 65 bara, sending this compressed gas and this pressurized liquid to a second phase separator (48), separating the compressed gas and the pressurized liquid in the second phase separator (48) to form a gas and a liquid, cooling this gas produced by the second phase separator (48) in the first heat exchange line (4) to at least the second temperature to partially condense it, sending this partially condensed gas into a third phase separator (88), cooling and expanding the liquid formed in the second phase separator (48) via a valve (78) or a turbine to form an expanded fluid and returning this expanded fluid to the first heat exchange line (4) to heat up and form at least part of the compressed fluid in the centrifugal compressor (18), the method using a fourth phase separator (108) receiving the liquid produced by the second phase separator (48) and the liquid produced by the third phase separator (88).

6. Method according to claim 5 characterized in that it uses a fifth phase separator (118) receiving the gas produced by the third phase separator (88) and expanded (128).

7. Process according to any one of claims 5 to 6, characterized in that the first cycle gas consists of a mixture of three to six components chosen from: nitrogen, methane, ethane or ethylene, propane or propene, butane or butene, pentane.

8. Method according to any one of claims 5 to 7 characterized in that the first cycle gas consists of a mixture composed of at least one light component chosen from the group: nitrogen, methane, at least one medium component chosen from the group: ethane, ethylene, propane, propene, butane, butene and at least one heavy component which is pentane or, butane if the medium component is chosen from the group: ethane, ethylene, propane, propene.

9. Process according to claim 8 characterized in that the first cycle gas comprises, in moles, between 10% and 50% of light component(s), between 30% and 70% of medium component(s) and between 10% and 35% of heavy component(s), the total being equal to 100%.

10. A method according to any one of claims 5 to 9, characterized in that the cooling of the hydrogen flow (3) from the second temperature to a third temperature comprises cooling the hydrogen flow to an intermediate temperature between 113K and 153K, preferably between 123K and 143K at which the hydrogen flow is sent to an adsorption purification unit (11) operating at a cryogenic temperature and then optionally to a unit for catalytic conversion of ortho hydrogen into para hydrogen, to produce a hydrogen flow having a para hydrogen content between 30% and 55% before being cooled again.

11. Method according to any one of claims 5 to 10, characterized in that it comprises a production of pre-cooling power by the second pre-cooling device (9) with the following steps: a centrifugal compression of the second cycle gas in at least two compressors (19) arranged in series from an inlet pressure of between 1 and 5 bara, up to a pressure of between 10 and 50 bara and preferably between 15 and 25 bara, an expansion of the second compressed cycle gas and at a temperature of between 173K and 128K in at least one valve or turbine (29) up to a pressure of between 1.1 and 2 bara, at least one expansion turbine (29) optionally providing mechanical work for driving at least one compressor (19).

12. Method according to claim 11, characterized in that the production of pre-cooling power by the second pre-cooling device (9) comprises a transfer of the second expanded cycle gas into a phase separator tank (39) of a thermosiphon type device and a return of the cycle gas from the tank (39) to the intake of the compressors (19).

13. Method according to claim 11 or 12, characterized in that the expansion of the second compressed cycle gas to a pressure of between 1.1 and 2 bara is carried out in two expansion turbines (29) in series, the pressure of the second cycle gas entering the first of the turbines (29) being between 15 and 50 bara, the temperature of the second cycle gas entering the second of the turbines preferably being between 143K and 103K.

14. A method according to any one of claims 5 to 13, characterized in that the first cycle gas consists of a mixture of three components: CH4, C2H6 or C3H8, C5H10, for example, expressed in moles, 53% of CH4; 41% of C3H8, 6% of C5H10, or the first cycle gas consists of a mixture of four components from: CH4 and / or N2, C2H6 and / or C3H8, C5H10, for example, expressed in moles, 49% of CH4; 11% of C2H6, 31% of C3H8 and 9% of C5H10 or the first cycle gas consists of a mixture of CH4, C2H4, C3H8 and C5H12, for example in respective molar proportions of 24%, 39%, 22%, and 15% or in respective molar proportions of 6%, 33%, 26%, 35%, or the first cycle gas consists of a mixture of five components: N2; CH4, C2H6; C3H8; C5H10 for example in respective molar proportions of 3%;37%, 32%, 13% and 14% or in respective mole proportions of 3%, 31%, 34%, 18%, 14%, or in respective mole proportions of 3%, 33%, 37%, 13%, and 14%.;

15. Method according to any one of claims 5 to 14, characterized in that the cut-off temperature between the first (8) pre-cooling device and the second pre-cooling device (9), i.e. the temperature of the hydrogen flow between these two pre-cooling portions is between 148K and 123K, preferably between 138K and 133K.

16. Method according to any one of claims 5 to 15, characterized in that the cut-off temperature between the second (9) pre-cooling device and the cooling system (10), i.e. the temperature of the hydrogen flow between these two pre-cooling portions is between 93K and 73K, preferably between 88K and 81K.

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