Facility and method for the liquefaction of hydrogen

Abstract

The invention relates to a facility and a method for the liquefaction of hydrogen, comprising a hydrogen circuit (2) having an upstream end (21) intended to be connected to a source (23) of gaseous hydrogen and a downstream end (22) connected to at least one store (8), the facility (1) comprising a cold box (18) housing a set of heat exchangers (3, 4, 5, 6) in a heat exchange relationship with the hydrogen circuit (2), the facility (1) comprising a cooling device in a heat exchange relationship with at least part of the set of heat exchangers (3, 4), the facility (1) comprising a pipe (12) for collecting boil-off gas and equipped with at least one upstream end connected to the store (8) and / or a tank (19) to be filled, and a downstream end connected to the hydrogen circuit (2), inside the cold box (18), said downstream end of the collecting pipe (12) comprising, ahead of its connection to the hydrogen circuit (2), a portion in a heat exchange relationship with at least one heat exchanger (5, 6) of the set of heat exchangers (3, 4, 5, 6).

Description

[0001] The invention relates to an installation and a process for liquefying hydrogen.

[0002] The invention relates more particularly to a hydrogen liquefaction installation comprising a hydrogen circuit having an upstream end intended to be connected to a source of gaseous hydrogen and a downstream end connected to at least one cryogenic storage of liquefied hydrogen of the installation, the cryogenic storage being equipped with a withdrawal line configured to allow the supply of liquefied hydrogen to at least one tank to be filled, in particular a mobile tank, the installation comprising a cold box housing a set of heat exchanger(s) in heat exchange with the hydrogen circuit, the installation comprising a cooling device in heat exchange with at least part of the set of heat exchanger(s) configured to cool the hydrogen circuit, said cooling device comprising a cryogenic refrigerator with a cycle refrigeration gas in a working circuit,the cycle gas comprising at least one of the following: hydrogen, helium, the refrigerator working circuit comprising a cycle gas compression device, a cycle gas cooling device, a cycle gas expansion device and a cycle gas heating device, the installation comprising a vaporization gas recovery line having at least one upstream end connected to storage and / or intended to be connected to a tank to be filled and a downstream end connected to the hydrogen circuit.

[0003] Boil-off in truck loading systems and tanks in hydrogen liquefaction plants can result in losses of up to 15% of production.

[0004] These evaporation losses can of course be recovered, reheated, recompressed after storage, and reinjected into the liquefier. This requires a loss recirculation system and an appropriately sized liquefier.

[0005] Another solution to minimize the production of these vaporization gases is to subcool the liquid hydrogen produced.

[0006] The known solutions for recovering these vaporization gases can have drawbacks, as mentioned below. For example, some of the depressurization from the truck cannot be carried out to the plant's liquid storage via pressure equalization because the truck pressure may become lower than the storage pressure. The hydrogen is therefore lost or sent to a recovery system, as mentioned above. During truck refueling, it can happen that some cold vapors cannot return to the plant's liquid storage due to insufficient driving pressure. These vapors are then at risk of being lost.

[0007] The cold temperatures present in the storage tanks are generally insufficient to offset all the heat generated during truck loading operations. This leads to increased pressure within the tanks and a loss of hydrogen.

[0008] The return temperature of vapors from trucks being filled may be too high to be liquefied directly.

[0009] Depressurization is generally intermittent. The lines or pipes heat up between truck loads, and the gas returning to the liquefier is therefore hotter and more difficult to liquefy.

[0010] When the liquid storage capacity of the facility is relatively small, the storage pressure drops during truck loading. This necessitates the use of a liquid storage pressurization device, which involves vaporizing liquid hydrogen that will then need to be re-liquefied later.

[0011] The document "BERSTAD DO ET AL: "Large-scale hydrogen liquefier utilizing mixed-refrigerant pre-cooling", INTERNATIONAL JOURNAL OF HYDROGEN ENERGY, ELSEVIER, AMSTERDAM, NL, vol. 35, no. 10, May 1, 2010 (2010-05-01), pages 4512-4523, (XP027028434, ISSN: 0360-3199) discloses a hydrogen liquefaction plant comprising a hydrogen circuit having an upstream end intended to be connected to a source of gaseous hydrogen and a downstream end connected to at least one cryogenic liquefied hydrogen storage of the plant, the cryogenic storage being equipped with a withdrawal line configured to allow the supply of liquefied hydrogen to a tank to be filled, the plant comprising a cold box housing a set of heat exchangers in heat exchange with the hydrogen circuit,the installation comprising a heat exchange cooling device with at least part of the heat exchanger assembly configured to cool the hydrogen circuit, said cooling device comprising a cryogenic refrigerator with a cycle gas refrigeration system in a working circuit, the cycle gas comprising helium, the refrigerator working circuit comprising a cycle gas compression element, a cycle gas cooling element, a cycle gas expansion element and a cycle gas heating element,

[0012] the installation comprising a vaporization gas recovery line having at least one upstream end connected to the storage and one downstream end, said downstream end of the recovery line having a portion in heat exchange with at least one exchanger of the heat exchanger assembly, the heat exchanger assembly of the cold box comprises a plurality of heat exchangers arranged in series between the upstream end and the downstream end of the hydrogen circuit, the hydrogen circuit makes a first pass in the last heat exchanger in series, downstream of this first pass the hydrogen circuit comprising an expansion device.

[0013] One aim of the present invention is to overcome all or part of the disadvantages of the prior art noted above.

[0014] To this end, the invention provides an installation according to claim 1 and a method according to claim 10.

[0015] Since the power required for hydrogen liquefaction is directly related to the pressure of gaseous hydrogen, this configuration allows for the liquefaction of gas at relatively high pressure.

[0016] This configuration allows the highest possible pressure to be maintained in the heat exchanger which cools the recovered vaporization gas (at the time of liquefaction) while limiting the pressure increase required in cases where the pressure is low in the storage facilities or trucks supplying this vaporization gas.

[0017] This architecture has a minimal impact on the liquefier's capacity.

[0018] Furthermore, embodiments of the invention are defined in the dependent claims.

[0019] Other features and advantages will become apparent upon reading the description below, which refers to the figures in which: Brève description des figures

[0020] The invention will be better understood upon reading the following description, given solely by way of example and made with reference to the accompanying drawings in which: [ Fig. 1 ] is a schematic and partial view illustrating a first example of the structure and operation of an installation in an initial configuration, [ Fig. 2 ] is a schematic and partial view illustrating a detail of the structure and operation of such an installation according to a first possible embodiment, [ Fig. 3 ] is a schematic and partial view illustrating this first example of installation in a second configuration, [ Fig. 4 ] is a schematic and partial view illustrating this first example of installation in a third configuration, [ Fig. 5 ] is a schematic and partial view illustrating this first example of installation in a fourth configuration, [ Fig. 6 ] is a schematic and partial view illustrating this first example of installation in a fifth configuration, [ Fig. 7 ] is a schematic and partial view illustrating this first example of installation in a sixth configuration, [ Fig. 8 ] is a schematic and partial view illustrating this first example of installation in a seventh configuration, [ Fig. 9 ] is a schematic and partial view illustrating the structure and operation of a second example implementation in a first configuration, [ Fig. 10 ] is a schematic and partial view illustrating this second example of installation in a second configuration, [ Fig. 11 ] is a schematic and partial view illustrating this second installation example in a third configuration, [ Fig. 12 ] is a schematic and partial view illustrating this second installation example in a fourth configuration, [ Fig. 13 ] is a schematic and partial view illustrating a detail of the structure and operation of another possible embodiment of the installation. Description détaillée

[0021] In all the figures, the same references refer to the same elements.

[0022] In this detailed description, the following embodiments are examples. Although the description refers to one or more embodiments, this does not mean that the features apply only to a single embodiment. Simple features from different embodiments can also be combined and / or interchanged to provide other embodiments.

[0023] The hydrogen liquefaction plant 1 illustrated in the [ Fig. 1 ] includes a hydrogen circuit 2 to be cooled / liquefied. This hydrogen circuit 2 has an upstream end 21 intended to be connected to a source 23 of gaseous hydrogen and a downstream end 22 connected to at least one cryogenic storage 8 of liquefied hydrogen produced by the installation 1.

[0024] Source 23 of gaseous hydrogen may include an electrolyzer, a gaseous hydrogen network and / or any other hydrogen production device.

[0025] The cryogenic storage unit 8 comprises, for example, a vacuum-insulated cryogenic tank and is equipped with at least one withdrawal line 11 configured to allow the supply of liquefied hydrogen to at least one tank 19 to be filled (for example, a truck-transported cryogenic tank 19). The installation 1 comprises a cold box 18, i.e., an insulated and preferably airtight cryogenic enclosure that houses at least part of the cryogenic liquefaction components forming a liquefier 31.

[0026] The cold box 18 houses in particular a set of heat exchanger(s) 3, 4, 5, 6 in thermal exchange and a cold part of the hydrogen circuit 2 in thermal exchange with these heat exchangers 3, 4, 5, 6.

[0027] Installation 1 further includes a heat exchange cooling device with at least part of the heat exchanger assembly(ies) 3, 4 configured to produce a cooling power which is used to cool the hydrogen circuit 2.

[0028] This cooling device preferably comprises a cryogenic refrigerator with a refrigeration cycle of a cycle gas in a working circuit. That is to say, the working circuit subjects the cycle gas to a thermodynamic cycle which brings this cycle gas to a cold end at a cryogenic temperature to provide cooling power.

[0029] The cycle gas comprises, for example, at least one of the following: hydrogen, helium. The working circuit of the refrigerator 7 comprises a cycle gas compression unit 9 (one or more compressors in series and / or parallel), a cycle gas cooling unit 3, 4, a cycle gas expansion unit 10 (turbine(s) and / or expansion valve(s)), and a cycle gas heating unit 6, 5, 4, 3. The gas cooling and heating units may include heat exchangers, and in particular counter-current heat exchangers that simultaneously heat and cool the cycle gas in the working circuit. The installation 1 further comprises at least one vaporization gas recovery line 12.This recovery line 12 is provided with at least one upstream end connected to the storage 8 and / or intended to be connected to a tank 19 to be filled and a downstream end connected to the hydrogen circuit 2 to recover the vaporization gas for the purpose of its liquefaction and mixing with the liquid hydrogen produced.

[0030] As illustrated in the [ Fig. 2 ], the downstream end of the recovery line 12 is connected to the hydrogen circuit 2 inside the cold box 18. Furthermore, prior to its connection to the hydrogen circuit 2, the downstream end of the recovery line 12 is in heat exchange with at least one exchanger 5, 6 of the heat exchanger assembly(ies) 3, 4, 5, 6 for the purpose of cooling it.

[0031] As illustrated, the cold box's heat exchanger assembly (3, 4, 5, 6) preferably comprises a plurality of heat exchangers arranged in series between the upstream end 21 and the downstream end 22 of the hydrogen circuit 2. The connection of the downstream end of the recovery line 12 with the hydrogen circuit 2 is located, for example, downstream of a first passage of the hydrogen circuit 2 through the last 6 heat exchanger in series.

[0032] As illustrated, this first passage of the hydrogen circuit 2 in the last heat exchanger 6 preferably includes a hydrogen catalysis section 29 configured to carry out the conversion of at least a portion of the Ortho hydrogen into Para hydrogen. Downstream of this first passage in the catalysis section 29 of the heat exchanger 6, the hydrogen circuit 2 preferably includes a pressure-reducing device 30 such as a pressure-reducing valve, for example.

[0033] Similarly, the downstream end of the recovery line 12 preferably includes a vaporization gas flow expansion device 20 located between the portion in heat exchange with the heat exchanger(s) 5, 6 of the heat exchanger assembly(ies) and the connection to the hydrogen circuit 2.

[0034] As illustrated, downstream of the connection, the hydrogen circuit 2, which has received the cooled and expanded vaporized gas, can make a second pass through the last heat exchanger 6 for additional cooling. This second heat exchange is preferably located in another section of the heat exchanger 6 that does not include a catalytic section.

[0035] As illustrated, downstream of this second pass through the last heat exchanger 6, the hydrogen circuit 2 may include a hydrogen flow expansion device 23. This expansion device 23 is, for example, a final expansion device in the cold box and includes, for example, an expansion valve and / or a cryogenic expansion turbine. The fluid thus expanded is liquefied and can then be supplied to cryogenic storage via suitable piping.

[0036] This configuration avoids the expansion of gaseous hydrogen, which would tend to heat it. According to the configuration above, the recovered gaseous hydrogen is expanded in two stages within the liquefier. First, it expands at the outlet of the last catalytic heat exchanger 6, then during a second pass through the exchanger 6 without catalytic conversion, and finally, it undergoes a final expansion to the final pressure level intended for storage 8.

[0037] THE [ Fig. 1 ] And [ Fig. 3 ] has [ Fig. 8 ] illustrate different configurations or operations that can be implemented by installation 1.

[0038] As illustrated, the recovery line 12 preferably comprises a first upstream end connected to an upper end of the storage tank 8 and a second upstream end intended to be connected to the upper end of a mobile tank 19. For example, the first and second upstream ends of the recovery line 12 are connected to the downstream end of the recovery line via two separate pipe branches 121, 122, respectively. These two branches 121, 122 may be fitted with their respective valve(s) 221, 222.

[0039] Furthermore, the downstream end 22 of the hydrogen circuit may have two ends connected respectively to the lower and upper part of the storage via respective valve(s) 201, 202 to fill the storage 8 in its liquid phase or in its gaseous phase.

[0040] Furthermore, as illustrated, the withdrawal line 11 may have an upstream end connected to the storage tank 8 (lower section) and preferably equipped with a valve 111, and two downstream ends. The first downstream end, equipped with a valve 112, may be designed to be detachably connected to a tank to be filled with liquid (lower section). The second downstream end of the withdrawal line 11 may be equipped with a valve 113 and may be connected to the second upstream end of the gas recovery line 12 (branch 122).

[0041] This fluidic link between the withdrawal line 11 and branch 122 allows liquid to be injected into the reservoir 19 at the level of its upper part (filling by rain for example).

[0042] In the various configurations illustrated, closed valves are shown in black while open valves are shown in white.

[0043] In the configuration of the [ Fig. 1 There is no mobile tank to fill.

[0044] The hydrogen from source 23 is liquefied by the liquefier 31 and distributed to the storage tank(s) 8 via the piping of circuit 2. The mobile tank(s) gas recovery valves 222 are closed. Hydrogen can be supplied to the storage tank at its lower end. The hydrogen supplied by the liquefier 31 can be subcooled to maintain the pressure of the storage tank(s) 8 and to counteract thermal ingress. The pressure of the storage tank 8 can be regulated by the valves 201 and 202, which allow for filling from the bottom and / or the top. As illustrated, the valve 221 at the first downstream end of the vaporization gas recovery line from the storage tank 8 can be opened to keep this line 121, 12, cool.

[0045] In the configuration of the [ Fig. 3 A mobile tank 19, to be filled, is connected to the first downstream end of the withdrawal line 11. This tank 19 is also connected to the second upstream end of the recovery line 12 (branches 122).

[0046] After connecting tank 19 to the withdrawal line 11 and the gas recovery line 12, the pressure in tank 19 (for example, between 3 and 10 bar) can be reduced to a level below the pressure P8 in storage 8 (for example, a few millibars below P8). This is done to allow liquid to be filled from storage to tank 19 by differential pressure (without a pump). The hydrogen in tank 19 is generally predominantly gaseous (1 to 10% liquid phase) and at a temperature between 100 K and 25 K. The first portion of the recovered hot hydrogen can be sent to a recovery system 32 via a parallel line equipped with a valve 322. When the temperature in tank 19 has dropped to a predetermined level, for example, between 50 K and 30 K, the gas can be returned to the liquefier (valve 222 open).This gaseous hydrogen will be liquefied in the liquefier 31 as described previously and can return to storage 8 as long as the pressure in the tank 19 is greater than the pressure of storage 8 (plus the pressure losses of the circuits).

[0047] To finalize the depressurization of tank 19, it may be necessary to lower its pressure below the pressure of storage 8. Several possibilities are available. In one option, the depressurization of tank 19 can be carried out towards the recovery system 32 (see [ Fig. 4 ]. According to another possibility, pressure balancing can be achieved between reservoir 19 and storage 8 (see [ Fig. 5 ] : valves 222 and 221 open) followed by pressurization of the storage by the liquefier (valve 201 open cf. [ Fig. 5 ]). That is to say, the gas is transferred from the reservoir 19 to the storage via branches 122 and then 121 of the recovery line 12.

[0048] At the end of this first sequence, tank 19 reached a pressure P19 lower than the pressure P8 of storage 8.

[0049] Next, as illustrated in the [ Fig. 6 [ ], tank 19 can be filled with liquid. Liquid hydrogen can be transferred from storage 8 into the upper part of tank 19 via the withdrawal line 11 and the valve 113 of the branch connected to the gas recovery line.

[0050] The liquid from storage 8 can be sufficiently cold to maintain pressure P19 in tank 19 by condensing the vapors there. The pressure in storage 8 can be maintained by injecting liquid hydrogen from the liquefier into the vapor phase of the storage (top-filling via branch 121 of the gas recovery line 12 with valve 221 open). This hydrogen can come from the hydrogen circuit 2, which has been expanded and heated in a heat exchanger. The corresponding cold can therefore be recovered inside the liquefier 31 during this phase rather than injecting heat into storage 8 via a pressurization unit (PBU).

[0051] At the end of this sequence, tank 19 can still have a pressure P19 close to the pressure P8 of storage 8. Tank 19 is filled beyond half of its capacity (for example between 85% and 95% of its capacity) but its pressure should preferably be reduced in order to be able to take to the road and not lose hydrogen during the journey.

[0052] The pressure of tank 19 for road use may be dependent on local regulations.

[0053] This depressurization can be achieved, for example, by venting to the recovery system 32 (valve 322 open). The pressure in tank 19 can be reduced, for example, to 1.5 bar. Simultaneously, the system can continue to control the pressure in storage 8, for example, by injecting subcooled liquid hydrogen at the top and / or bottom of storage 8 by controlling valves 202 and 201. See [ Fig. 7 ].

[0054] There [ Fig.8 ] illustrates a variant implementation that differs from the [ Fig. 1 only in that the branch 122 of the recovery line 12 intended for recovering vaporized gas from the tank 19 includes a compression unit 24 such as a cryogenic type compressor (a cold compressor configured to compress vapors at temperatures between 25 and 100 K). As illustrated, a bypass line 124 from the compressor 24 and a set of valve(s) 224, 324 may be provided to allow or prevent the passage of all or part of the flow through the compressor 24.

[0055] This compression unit 24 allows better recovery of vapors from the reservoir 19 onto the vapor recovery line 12 towards the liquefier 31.

[0056] This compression unit 24 increases the pressure of the recovered hydrogen vapors for collection in storage 8 and / or the liquefier 31 during phases where the pressures available in tank 19 are insufficient to ensure this transfer by pressure differential. The advantage of a cryogenic compressor 24 compared to a conventional ambient-temperature compressor is its reduced size due to the higher density of cold hydrogen. The cold temperature of the hydrogen is maintained during compression, and the compressed cold hydrogen can be easily collected in storage 8 or sent to the liquefier 31 for re-liquefaction.

[0057] The configuration of the [ Fig. 8 ] corresponds to the configuration of the [ Fig. 1 The hydrogen from circuit 2 is liquefied by the liquefier 31 and distributed to storage 8. This hydrogen can be subcooled to control and maintain the pressure in storage 8 and to counteract thermal ingress. This pressure in storage 8 can be regulated via valves 202 and 201 (top / bottom filling). As illustrated, valve 221 on the vaporization gas recovery branch of storage 8 can be opened to keep this line cool. Valves 222 and 322 on the vaporization gas recovery branch of tanks 19 are closed. Compressor 24 is preferably stopped.

[0058] There [ Fig. 9 ] illustrates a depressurization configuration of a tank 19 to be filled which corresponds to the configuration of the [ Fig. 3 Note that in this embodiment shown, the draw-off line 11 is not connected to the upper part of the tank (via branch 122), but of course it could be.

[0059] After connecting the tank to the gas extraction and recovery lines 11 and 12, the pressure (e.g., from 3 to 10 bar) in tank 19 can be reduced below the storage pressure 8. The hydrogen in tank 19 is generally predominantly gaseous (1 to 10% liquid phase) and at a temperature, for example, between 100K and 25K. A first portion of the recovered hot hydrogen can be sent to the recovery system 32 (valve 322 open). Once the temperature of the gas in tank 19 has dropped (for example between 50K and 30K), the recovered gas can be sent to the liquefier 31 (pipe 12, valves 222, 224 open). This hydrogen will be liquefied as described previously (passage(s) through the exchanger 6 and expansion) and then will supply the storage 8 as long as the pressure in tank 19 remains higher than the pressure in storage 8 (plus the pressure losses of the circuits concerned).Compressor 24 is preferably not used in this first depressurization phase but can be cooled by the vapors returning to the liquefier 31. As illustrated in [. Fig. 10 To finalize the depressurization of tank 19, its pressure can be lowered below the pressure of storage tank 8. Compressor 24 can be used to draw vapors from tank 19 and send them to storage tank 8. The return line to liquefier 31 can be closed during this phase. The pressure in storage tank 8 can still be regulated by valves 202 and 201. Therefore, gas is transferred from tank 19 to storage tank 8.

[0060] At the end of this step, tank 19 has reached a pressure lower than the pressure of storage 8. This represents the main part of filling tank 19 with liquid. Liquid hydrogen is transferred from storage 8 to tank 19 via the withdrawal line 11 (valve 111 open). The pressure of storage 8 can be maintained by injecting hydrogen from the liquefier 31 (valves 201 and / or 202). The pressure of tank 19 can be maintained below the pressure of storage 8 by means of the compressor 24. Cf. [ Fig. 10 ].

[0061] At the end of this step, tank 19 may still be at a pressure close to that of storage 8. The fill level of tank 19 is relatively high (for example, between 85% and 95%), but its pressure may need to be reduced to allow transport and avoid hydrogen loss during the journey. This transport pressure may depend on local regulations. Compressor 24 can reduce this pressure in tank 19 to the required starting pressure (without using valve 332 to the recovery system or avoiding hydrogen loss during transport). The gas from tank 19 is pumped to storage 8 (see [ Fig. 12 ]).

[0062] The 24-unit cold compressor can also be used to reduce the pressure of storage tank 8 without requiring a supply of subcooled hydrogen. This increases the liquefier's production capacity.

[0063] There [ Fig. 13 ] illustrates an alternative embodiment of the circuit returning the recovered vaporization gases within the cold box 18 of the liquefier 31. For the sake of simplification, only a portion of the cold box 18 and the circuits have been shown in the [ Fig. 13 The method of implementation of the [ Fig. 13 ] differs from that of the [ Fig. 2 ] in that the downstream end of the recovery line 12 includes, upstream of the connection to the hydrogen circuit 2, a catalytic section 25 (for example a catalytic pot) configured to carry out the conversion of at least a part of the Para hydrogen into Ortho hydrogen.

[0064] In addition, the recovery line 12 includes a bypass portion 26 and a set of valve(s) 27, 28 configured to ensure or not the passage of the vaporization gas flow into the catalysis section 25.

[0065] The specification required for hydrogen liquefiers 31 is to achieve a minimum conversion rate of around 95% Para for the hydrogen at the liquefier outlet. The presence of a catalyst in the last heat exchanger(s) 5, 6 generally allows for a conversion rate between 98% and 100%, depending on the hydrogen pressure.

[0066] The hydrogen gas returning from the tanks 19 to be filled comes from the vaporization of liquid and is generally composed of hydrogen in the form of Para in a proportion between 98% and 100%.

[0067] In some cases, installation 1 is not suitable for recovering excessively hot hydrogen vapors because this can disrupt the operation of liquefier 31.

[0068] These recovered vapors can be cooled using the inverse Ortho to Para conversion of that carried out in the liquefier for the flow of circuit 2 hydrogen.

[0069] Thus, for example, these recovered vaporization gases can have a temperature between 50K and 25K. The higher this temperature, the further the hydrogen is from its equilibrium point at that temperature (20K for 98% Para hydrogen), and the more the Para to Ortho conversion will cool the hydrogen. The vapors are therefore converted from the Para to the Ortho form, then liquefied in the heat exchanger / expander 20 (heat exchanger 6), and are subsequently mixed with the hydrogen in circuit 2 before being fed into storage tank 8 (as described previously). The use of such a catalytic converter 25 is generally only necessary when the gaseous hydrogen arrives sufficiently hot (for example, at the beginning of the depressurization of the tank 19 being filled) and under sufficient pressure (typically between 3 and 10 bar).The bypass system 26, 27, and in particular the valve(s), can be configured to ensure passage through the conversion catalyst based on the gas return temperature, which can be measured by a temperature sensor 33 in the recovery line 12. Thus, when the measured temperature becomes sufficiently low or the pressure drops in the recovery line (end of tank 19 depressurization), the circuit valve 28 is closed and the direct feed valve 27 to the heat exchanger 6 is opened to reduce the system pressure drop.

[0070] This control of the depressurization of tank 19 limits the flow rate relative to the capacity of the liquefier (a control on the outlet temperature of the reliquefied gas exchanger may be provided).

[0071] Of course, this embodiment can be applied to the embodiments and steps above.

[0072] Furthermore, the above examples are not exhaustive. Thus, for example, the installation could include several storage tanks 8 and / or several filling and recovery lines 11 for vaporized gases.

[0073] A 24-hour cold compressor could be placed in parallel with the recovery line, for transferring the gas to the liquefier, particularly in cases where several tanks are treated simultaneously.

Claims

1. A hydrogen liquefaction installation comprising a hydrogen circuit (2) having an upstream end (21) intended to be connected to a source (23) of gaseous hydrogen and a downstream end (22) connected to at least one cryogenic storage (8) for liquefied hydrogen of the installation, the cryogenic storage (8) being provided with a withdrawal line (11) configured to allow the supply of liquefied hydrogen to at least one reservoir (19) to be filled, in particular a mobile reservoir, the installation (1) comprising a cold box (18) housing a set of heat exchanger(s) (3, 4, 5, 6) in thermal exchange with the hydrogen circuit (2), the installation (1) comprising a cooling device in thermal exchange with at least a part of the set of heat exchanger(s) (3, 4) configured to cool the hydrogen circuit (2), said cooling device comprising a cryogenic refrigerator (7) with a refrigeration cycle of a cycle gas in a working circuit, the cycle gas comprising at least one of: hydrogen, helium, the working circuit of the refrigerator (7) comprising a compression member (9) for the cycle gas, a cooling member (3, 4) for the cycle gas, an expansion member (10) for the cycle gas and a reheating member (6, 5, 4, 3) for the cycle gas, the installation (1) comprising a boil-off gas recovery line (12) provided with at least one upstream end connected to the storage (8) and / or intended to be connected to a reservoir (19) to be filled and a downstream end connected to the hydrogen circuit (2), inside the cold box (18), said downstream end of the recovery line (12) comprising, prior to its connection to the hydrogen circuit (2), a portion in thermal exchange with at least one exchanger (5, 6) of the set of heat exchanger(s) (3, 4, 5, 6), the set of heat exchanger(s) (3, 4, 5, 6) of the cold box (18) comprising a plurality of heat exchangers arranged in series between the upstream end (21) and the downstream end (22) of the hydrogen circuit (2), the hydrogen circuit (2) making a first pass in the last heat exchanger (6) in series, downstream of this first pass the hydrogen circuit (2) comprising an expansion member (30) such as an expansion valve for example, the connection of the downstream end of the recovery line (12) with the hydrogen circuit (2) being located downstream of the first pass of the hydrogen circuit (2) in the last heat exchanger (6) in series and downstream of the expansion member (30), downstream of the connection, the hydrogen circuit (2) which has received the cooled and expanded boil-off gas making a second pass in the last heat exchanger (6) for additional cooling, and, downstream of this second pass in the last heat exchanger (6), the hydrogen circuit (2) comprising an expansion member (23) for the hydrogen flow, and in that the downstream end of the recovery line (12) comprises an expansion member (20) for the boil-off gas flow located between the portion in thermal exchange with the at least one exchanger (5, 6) of the set of heat exchanger(s) (3, 4, 5, 6) and the connection to the hydrogen circuit (2).

2. The installation according to claim 1, characterized in that the first pass of the hydrogen circuit (2) in the last heat exchanger (6) in series comprises a hydrogen catalysis section (29) configured to carry out the conversion of at least a part of the Ortho hydrogen into Para hydrogen.

3. The installation according to claim 1 or 2, characterized in that the second pass in the last heat exchanger (6) does not comprise a catalysis section for Ortho hydrogen into Para hydrogen.

4. The installation according to any one of claims 1 to 3, characterized in that said expansion member (23) of the hydrogen circuit (2) located downstream of the second pass in the last heat exchanger (6), comprises at least one from among: an expansion valve, a turbine.

5. The installation according to any one of claims 1 to 4, characterized in that the downstream end of the recovery line (12) comprises, upstream of the connection to the hydrogen circuit (2), a catalysis section (25) configured to carry out the conversion of at least a part of the Para hydrogen into Ortho hydrogen.

6. The installation according to claim 5, characterized in that the downstream end of the recovery line (12) comprises a bypass portion (26) and a set of valve(s) (27, 28) configured to ensure or not the passage of the boil-off gas flow in said catalysis section (25).

7. The installation according to any one of claims 1 to 6, characterized in that the recovery line (12) comprises a compression member (24) such as a cryogenic-type compressor.

8. The installation according to any one of claims 1 to 7, characterized in that the recovery line (12) comprises a first upstream end connected to the storage (8) and a second upstream end intended to be connected to a mobile reservoir (19).

9. The installation according to claims 7 and 8, characterized in that the first and second upstream ends of the recovery line (12) are connected to the downstream end of the recovery line (12) via respectively two distinct line branches and in that the compression member (24) is located in the line branch of the second upstream end of the recovery line (12).

10. A method for hydrogen liquefaction using an installation according to any one of claims 1 to 9, comprising a step of recovering boil-off gas via the recovery line (12), a step of cooling this recovered boil-off gas in the cold box (18), a step of expanding this boil-off gas in the cold box (18), a step of mixing this expanded boil-off gas with the hydrogen flow to be cooled.

11. The method for hydrogen liquefaction according to claim 10, comprising at least one from among: a step of expanding the mixture of boil-off gas and the hydrogen flow to be cooled, a step of expanding the mixture of boil-off gas and the hydrogen flow to be cooled.

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