Plant and process for producing liquefied hydrogen

Abstract

The invention relates to a liquefied hydrogen production plant comprising a gaseous hydrogen generator (2) configured to produce gaseous hydrogen, a liquefier (7), a supply line (6) connecting a gaseous hydrogen outlet of the gaseous hydrogen generator (2) to an inlet of the liquefier (7), the liquefier (7) comprising a cycle circuit refrigerator (8) configured to provide cold power and cool the gaseous hydrogen in the supply line (6) with a view to liquefying it, the plant (1) comprising at least one compressor (10) of the gaseous hydrogen produced by the gaseous hydrogen generator (2) and a buffer storage (9) configured to store the compressed gaseous hydrogen between the gaseous hydrogen generator (2) and the liquefier (7), the buffer storage (9) being connected to the supply line (6) via a set of bypass lines (19, 29),that is, the buffer storage (9) and the liquefier (7) are connected in parallel to the hydrogen gas outlet of the hydrogen gas generator (2).

Description

[0001] The invention relates to a plant and a method for producing liquefied hydrogen.

[0002] The invention relates more particularly to a liquefied hydrogen production installation comprising a gaseous hydrogen generator, for example an electrolyser, configured to produce gaseous hydrogen, a liquefier, a supply line connecting a gaseous hydrogen outlet of the gaseous hydrogen generator to an inlet of the liquefier, the liquefier comprising a cycle circuit refrigerator configured to provide cold power and cool the gaseous hydrogen from the supply line with a view to liquefying it, the installation comprising at least one compressor for the gaseous hydrogen produced by the gaseous hydrogen generator and a buffer storage configured to store the compressed gaseous hydrogen between the gaseous hydrogen generator and the liquefier.

[0003] Hydrogen production and hydrogen liquefaction from renewable energy require optimization and synergies between production (typically electrolysis) and liquefaction units.

[0004] Unlike electrolysers, for example, liquefiers have relatively low flexibility (limited flow rate change and / or start-up time).

[0005] Due to the intermittency of renewable energies, the amount of hydrogen produced can vary and this can therefore pose problems for the downstream liquefier. To solve this problem, it is known to provide buffer storage between production and liquefaction, see for example JP2020024064A2, CN107779906 or US2022316076.

[0006] This known solution is however imperfect because it increases the cost of installation without offering flexibility of use and optimal integration.

[0007] An aim of the present invention is to overcome all or part of the drawbacks of the prior art noted above.

[0008] To this end, the installation according to the invention, which also conforms to the generic definition given in the preamble above, is essentially characterized in that the buffer storage is connected to the supply line via a set of bypass lines, i.e. the buffer storage and the liquefier are connected in parallel to the hydrogen gas outlet of the hydrogen gas generator.

[0009] Furthermore, embodiments of the invention may include one or more of the following features: the installation comprises a compressor located on the set of bypass pipe(s), the set of bypass pipe(s) comprises a return pipe configured to transfer hydrogen gas from the buffer storage to the supply pipe, the return pipe comprises at least one member for expanding the hydrogen gas among: an expansion valve, a turbine, a turbine coupled to an electric power generator or to a compressor to form a turbocharger, the refrigerator is of the cycle circuit type configured to produce cold power by subjecting a cycle gas to a thermodynamic cycle, the cycle circuit comprising a set of compressor(s) of the cycle gas, at least one member for cooling the compressed cycle gas and at least one member for expanding the compressed cycle gas,the cycle gas is hydrogen and the buffer storage is connected to the cycle circuit to supply the cycle circuit with hydrogen and / or to be supplied with hydrogen by the cycle circuit, the installation comprises at least one compressor of the hydrogen gas intended to supply the buffer storage which is also a compressor of the set of compressor(s) of the cycle gas, the supply line comprises several compressors arranged in series and / or in parallel configured to supply the buffer storage and / or the cycle circuit with compressed hydrogen, the set of compressor(s) of the cycle gas comprises several compressors arranged in series and / or in parallel, the installation comprising a supply line connecting the buffer storage to the inlet or outlet of at least one of the compressor(s) of the cycle gas and configured to allow supplying pressurized hydrogen gas into the cycle circuit,the installation comprises several liquefiers connected in parallel to the supply line and also connected in parallel to the buffer storage, the installation comprises a liquid hydrogen storage assembly(s) connected to one end of the supply line leaving the liquefier and configured to collect the hydrogen liquefied by the liquefier, the installation further comprising a filling circuit connected to the liquid hydrogen storage assembly(s) and configured to allow the filling of tank(s), the installation comprising a set of pipe(s) for recovering the vaporization gases generated at the liquid hydrogen storage assembly(s) and / or at the filling circuit, the set of pipe(s) for recovering the vaporization gases being connected to the supply circuit,the liquefier comprises a pre-cooling device in heat exchange with the supply line and configured to ensure pre-cooling of the gaseous hydrogen to an intermediate temperature before it is cooled by the refrigerator, the pre-cooling device comprising for example at least one of: a refrigeration cycle with nitrogen or with a refrigeration mixture, the refrigerators in parallel are of the cycle circuit type whose cycle gas is hydrogen and each configured to produce cold power by subjecting the cycle gas to a thermodynamic cycle, the buffer storage being connected in parallel to the cycle circuits of the refrigerators in parallel to supply the latter with hydrogen and / or to be supplied with hydrogen by the cycle circuits,the at least one expansion member of the compressed cycle gas comprises an expansion valve or turbine arranged on a pipe bypassing the supply circuit, downstream of a cryogenic purification device for the gaseous hydrogen to be liquefied, the storage pressure within the buffer storage is variable according to its filling rate between a determined maximum level and a minimum level which can be,

[0010] lower than the target pressure, (final compressor off). The invention also relates to a method for producing liquefied hydrogen using an installation according to any one of the characteristics above or below, comprising a step of supplying compressed gaseous hydrogen to the buffer storage when the gaseous hydrogen generator produces a quantity of hydrogen greater than a first threshold and a step of supplying the supply line with compressed gaseous hydrogen from the buffer storage when the gaseous hydrogen generator produces a quantity of hydrogen less than a second threshold.

[0011] According to other possible particularities: the method comprises a step of using compressed hydrogen supplied by the supply line and / or the buffer storage to supply a compression portion of a hydrogen cycle circuit of the refrigerator of the liquefier,- the method comprises a step of compressing the gaseous hydrogen in the supply line to a determined target pressure, for example equal to 60 bar, the final compression level of the compression portion of the cycle circuit being equal to this target pressure, the buffer storage is configured to store the gaseous hydrogen up to a determined maximum storage pressure which is higher than the target pressure, the buffer storage being configured to supply gas to the compression portion of the cycle circuit at the target pressure or at a pressure lower than the target pressure, the method comprises a step of storing, in a liquid hydrogen storage,of liquid hydrogen produced by the installation and possibly a step of filling tank(s) with liquid hydrogen from the liquid hydrogen storage, the method comprising a step of recovering vaporization gases generated during the storage step and / or during the filling step and a step of recycling the vaporization gas recovered in the supply line, the method comprises a step of producing electricity from the mechanical work provided by the expansion of the hydrogen withdrawn from the buffer storage.

[0012] 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.

[0013] Other features and advantages will become apparent upon reading the following description, given with reference to the figures in which: Brève description of figures

[0014] The invention will be better understood from reading the following description, given solely by way of example and with reference to the appended drawings in which: [ Fig. 1 ] is a schematic and partial view illustrating the structure and operation of an installation according to a first exemplary embodiment of the invention, [ Fig. 2 ] is a schematic and partial view illustrating the structure and operation of an installation according to a second exemplary embodiment of the invention, [ Fig. 3 ] is a schematic and partial view illustrating the structure and operation of an installation according to a third exemplary embodiment of the invention, [ Fig. 4 ] is a schematic and partial view illustrating the structure and operation of an installation according to a fourth exemplary embodiment of the invention, [ Fig. 5 ] is a schematic and partial view illustrating the structure and operation of an installation according to a fifth exemplary embodiment of the invention, [ Fig. 6 ] is a schematic and partial view illustrating the structure and operation of an installation according to a sixth exemplary embodiment of the invention, [ Fig. 7 ] is a schematic and partial view illustrating the structure and operation of an installation according to a seventh exemplary embodiment of the invention, [ Fig. 8 ] is a schematic and partial view illustrating the structure and operation of an installation according to an eighth exemplary embodiment of the invention. Description détaillée

[0015] In all figures, the same references refer to the same elements.

[0016] 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. Single features of different embodiments may also be combined and / or interchanged to provide other embodiments.

[0017] The illustrated liquefied hydrogen production installation 1 comprises a gaseous hydrogen generator 2, for example an electrolyzer, configured to produce gaseous hydrogen, a liquefier 7 and a supply line 6 connecting an outlet of the gaseous hydrogen generator 2 to an inlet of the liquefier 7.

[0018] In the following, the hydrogen gas generator 2 is designated an electrolyzer. Of course, as a variant or in combination, this hydrogen gas generator 2 may comprise a reforming device, in particular an auto-thermal reforming device (“ATR”).

[0019] The liquefier 7 includes a cycle circuit refrigerator 8 configured to provide cold power and cool the hydrogen gas in the supply line 6 for liquefaction.

[0020] The installation 1 comprises at least one compressor 10 of the gaseous hydrogen produced by the electrolyser 2 and at least one buffer storage 9 configured to store the compressed gaseous hydrogen between the electrolyser 2 and the liquefier 7.

[0021] According to an advantageous feature, the buffer storage 9 is connected to the supply pipe 6 via a set of bypass pipe(s) 19, 29, i.e. the buffer storage 9 and the liquefier 2 are connected in parallel to the gaseous hydrogen outlet of the electrolyser 2.

[0022] This architecture allows for better interoperability between electrolyzer 2 and liquefier 7.

[0023] The buffer storage 9 is preferably a high-pressure gas storage allowing compressed hydrogen to be stored when the electrolyser 2 is producing at full capacity and hydrogen to be returned, for example, when the production of hydrogen by the electrolyser 2 is insufficient (renewable energy not readily available, for example).

[0024] As illustrated in [ Fig. 1 ] at least one compressor 10 may be located on the set of bypass lines 19.

[0025] Further, the bypass line assembly may include a first line 19 configured to fill the buffer storage 9 and a return line 29 configured to transfer hydrogen gas from the buffer storage 9 to the supply line 6.

[0026] The restitution pipe 29 preferably comprises at least one member 39 for expanding the gaseous hydrogen from among: an expansion valve, a turbine, a turbine coupled to an electric power generator or to a compressor to form a turbocharger.

[0027] Thus, the recovery of hydrogen gas stored under pressure can be carried out when the availability of hydrogen is low. A 39 electricity production turbine can be used to produce electricity during this restitution period (cf. [ Fig. 2 ]).

[0028] As illustrated in particular in [ Fig. 4 ] And [ Fig. 8 ], the refrigerator 8 ensuring the cooling of the hydrogen with a view to its liquefaction may comprise a refrigerator of the cycle circuit 16 type configured to produce cold power by subjecting a cycle gas comprising for example helium and / or hydrogen to a thermodynamic cycle. The cycle circuit 16 of such a refrigerator 8 typically comprises a set of compressors of the cycle gas, at least one member 13 for cooling the compressed cycle gas (one or more heat exchangers) and at least one member 15 for expanding the compressed cycle gas (valve(s) and / or turbine(s)). In the example of the [ Fig. 8 ], the refrigerator cycle circuit 16 is separate from the supply line 6. In addition, this cycle circuit 16 is closed. After compression 11 at room temperature, the cycle gas is cooled in a first heat exchanger assembly 13 (to a first temperature, for example of the order of 80K). The cycle gas is then expanded (valve 15) and produces cold power which is supplied to the supply line 6 in a colder heat exchanger 14 (typically around 20K). The cycle gas which provided the cold power is returned to compression and heats up by cooling the cycle gas flow which is going to be expanded. By returning to compression, the cycle gas also cools the supply line 6 in the opposite direction (typically countercurrently).

[0029] As illustrated, the liquefier 7 may comprise at least one pre-cooling device 12 in heat exchange with the supply line 6 and the cycle circuit 16 and configured to ensure pre-cooling of the gaseous hydrogen to an intermediate temperature (80K) before its cooling by the refrigerator 8. This pre-cooling device 12 comprises for example at least one of: a nitrogen refrigeration cycle or with a refrigeration mixture in heat exchange with a pre-cooling exchanger assembly 13 (for example in a first pre-cooling cold box).

[0030] In the example of the [ Fig. 4 ], the cycle gas is hydrogen (i.e. of the same nature as the gas to be liquefied). In this configuration, the buffer storage 9 can be connected to the cycle circuit 16 to supply the cycle circuit 16 with hydrogen and / or to possibly be supplied with hydrogen by the cycle circuit. That is to say that the cycle circuit 16 can be open.

[0031] This configuration makes it possible to share components of the installation 1. Thus, at least one compressor 10 of the gaseous hydrogen intended to supply the buffer storage 9 can also be a compressor of the set of compressor(s) 10, 11 of the cycle gas (cf. [ Fig. 3] ou [Fig. 4 ]). Thus, a part of the supply line 6 can also constitute a portion of the cycle circuit 16.

[0032] This is also illustrated in the [ Fig. 4 ] where the cycle circuit 16 of the refrigerator 8 may be partly common with the supply line 6. Thus, for example, downstream of a pre-cooling exchanger 13, the supply line 6 may comprise a cryogenic purification system 25 (of the TSA type for example) then an expansion member 36 (valve for example) for expansion with a view to liquefaction (cooling 14 below the critical temperature). Downstream, the supply line 6 may supply liquefied hydrogen to a storage 18 of liquid hydrogen.

[0033] As illustrated, downstream of the device 25 for cryogenic purification of the gaseous hydrogen to be liquefied, the installation 1 may comprise a bypass pipe provided with an expansion member 15 (valve for example) and connected to the rest of the cycle circuit 16. That is to say that the cycle circuit 16, after compression 11 at non-cryogenic temperature, may comprise a passage in the supply pipe 6 in which the cycle gas is pre-cooled 13 then purified 25 then expanded 15 before providing its cold power to the supply pipe 6 and returning to the compression 11 (by giving up its frigories in the heat exchangers while heating up). That is, the compression pressure in the cycle circuit 16 and the pressure in the feed line 6 can be set to the same level and these flows can be mixed in a portion of the feed line 6 up to the outlet of the cryogenic purification device 25.Downstream of this cryogenic purification 25, part of the hydrogen is expanded 36 for liquefaction while another part is used as high pressure cycle gas.

[0034] As illustrated in [ Fig. 3 ], the supply line 6 may comprise several compressors 10 arranged in series (and / or in parallel) configured to supply the buffer storage 9 and / or the cycle circuit 16 with compressed hydrogen.

[0035] For example, the compression can be staged between an initial pressure of the order of atmospheric pressure and a pressure level greater than 60 bar, for example greater than 100 bar, in particular greater than 200 bar to supply the buffer storage 9. At the outlet of an intermediate compression stage (target pressure level, for example at 60 bar) the supply line 6 supplies for example the cycle circuit 16 of the refrigerator 8. Downstream of this intermediate compression stage, the bypass line 19 can compress with at least one additional compressor 10 the hydrogen to supply the buffer storage 9 at a pressure which can be higher.

[0036] As schematically illustrated in [ Fig. 3 ], the restitution line 29 can feed (with expansion 39 if necessary) the supply line 6 downstream of the intermediate compression stage. Similarly, a line 139 can be provided allowing the buffer storage 9 to transfer fluid to the inlet of the intermediate compression stage (or an upstream compression stage), to feed the supply line 6 further upstream at a lower pressure (for example when the pressure in the buffer storage 9 is relatively low).

[0037] The pressure within the buffer storage 9 can be variable depending on its filling rate between a determined maximum level (for example 250 bara) and a minimum level and for example a pressure level which can be lower than the target pressure of the cycle circuit, (final compressor(s) 10 switched off).

[0038] This allows the buffer storage 9 to be used down to a relatively low pressure, for example 5 bara. Using the full pressure of the buffer storage 9 allows its size to be reduced (typically by 10% to 25% for the same quantity of hydrogen stored).

[0039] Thus, the buffer storage 9 may be configured to store hydrogen gas up to a determined maximum storage pressure (e.g. 250 bar) which is higher than the target pressure (e.g. 60 bar) but the buffer storage 9 may be configured to supply gas to the compression portion of the cycle circuit (and / or to the supply line 6) at the target pressure or at a pressure lower than the target pressure. As also illustrated in [ Fig. 3 ], a cycle circuit line can return cycle gas to compression (at an intermediate stage with or without compression 11 if applicable).

[0040] As schematically illustrated in [ Fig. 5 ], another user 26 of the compressed hydrogen gas can be connected as a bypass to the supply line 6 (in parallel to the inlet of the liquefier and in parallel to the buffer storage 9). In addition, an additional line 161 or loop with a compressor 11 can be provided to supply the cycle circuit 16 with hydrogen at the intermediate pressure (60 bar). Similarly, another supply line 17 can connect the buffer storage 9 to the inlet or outlet of at least one of the compressor(s) 11 of the cycle gas and can be configured to allow pressurized hydrogen gas to be supplied to the cycle circuit 16 at a determined pressure level.

[0041] As schematically illustrated in [ Fig. 7 ], the installation 1 may comprise at least one storage 18 of liquid hydrogen connected to a downstream end of the supply pipe 6 leaving the liquefier 7. The storage 18 is of the cryogenic type and configured to collect the hydrogen liquefied by the liquefier 7.

[0042] The installation 1 may comprise a filling circuit 20 connected to the liquid hydrogen storage 18 and configured to allow the filling of tank(s) 21, for example mobile tanks (typically delivery truck). The installation 1 comprises for this purpose a set of pipe(s) 22, 23, 24 for recovering the vaporization gases generated at the liquid hydrogen storage 18 and / or at the filling circuit 20 (for example to recover the vaporization gas from the tanks 21 to be filled). This set of pipe(s) 22, 23, 24 for recovering the vaporization gases is connected to the supply circuit 6 to recycle, if necessary, the vaporization gas recovered in the supply pipe 6 (if necessary with compression 111).

[0043] Thus, intermediate pressure vaporization gas can be recovered at the start of depressurization of the trucks / ships 21, this vaporization gas can be mixed with the hydrogen from the supply line 6 with or without an intermediate compressor 11 depending on the pressure level.

[0044] As schematically illustrated in [ Fig. 6 ], the installation 1 may comprise several liquefiers 7 connected in parallel to the supply pipe 6 and also connected in parallel to the buffer storage 9.

[0045] The processes described above and below can therefore be applied (simultaneously or not) to all or part of the liquefiers in parallel.

[0046] The invention allows the installation to be adapted to production fluctuations (intermittent renewable energy, for example) with integration offering maximum synergies.

Claims

1. Liquefied hydrogen production facility comprising a gaseous hydrogen generator (2), for example an electrolyzer (2), configured to produce gaseous hydrogen, a liquefier (7), a supply line (6) connecting a gaseous hydrogen outlet of the gaseous hydrogen generator (2) to an inlet of the liquefier (7), the liquefier (7) comprising a cycle circuit refrigerator (8) configured to provide cold power and cool the gaseous hydrogen in the supply line (6) for liquefaction thereof, the facility (1) comprising at least one compressor (10) for the gaseous hydrogen produced by the gaseous hydrogen generator (2) and a buffer storage (9) configured to store the compressed gaseous hydrogen between the gaseous hydrogen generator (2) and the liquefier (7), the buffer storage (9) being connected to the supply line (6) via a set of line(s) (19, 29) of derivation,that is to say that the buffer storage (9) and the liquefier (7) are connected in parallel to the hydrogen gas outlet of the hydrogen gas generator (2), the refrigerator (8) being of the cycle circuit (16) type configured to produce cold power by subjecting a cycle gas to a thermodynamic cycle, the cycle circuit (16) comprising a set of compressor(s) (10, 11) of the cycle gas, at least one member (13) for cooling the compressed cycle gas and at least one member (15) for expanding the compressed cycle gas, , characterized in that the cycle gas is hydrogen and in that the buffer storage (9) is connected to the cycle circuit (16) to supply the cycle circuit (16) with hydrogen and / or to be supplied with hydrogen by the cycle circuit.

2. Installation according to claim 1, characterized in that it comprises a compressor (10) located on the set of bypass pipe(s) (19, 29).

3. Installation according to claim 1 or 2, characterized in that the set of bypass pipe(s) (19, 29) comprises a restitution pipe (29) configured to transfer gaseous hydrogen from the buffer storage (9) to the supply pipe (6).

4. Installation according to claim 3, characterized in that the restitution pipe (29) comprises at least one member (39) for expanding the gaseous hydrogen among: an expansion valve, a turbine, a turbine coupled to an electric power generator or to a compressor to form a turbocharger.

5. Installation according to any one of claims 1 to 4, characterized in that that it comprises at least one compressor (10) of gaseous hydrogen intended to supply the buffer storage (9) which is also a compressor of the set of compressor(s) (10, 11) of the cycle gas.

6. Installation according to any one of claims 1 to 5, characterized in thatthe supply line (6) comprises several compressors (10) arranged in series and / or in parallel configured to supply the buffer storage (9) and / or the cycle circuit (16) with compressed hydrogen.

7. Installation according to claim 6 characterized in that the set of compressor(s) (10, 11) of the cycle gas comprises several compressors (10, 11) arranged in series and / or in parallel, the installation (1) comprising a supply pipe (17) connecting the buffer storage (9) to the inlet or outlet of at least one of the compressor(s) (11) of the cycle gas and configured to allow the supply of pressurized hydrogen gas into the cycle circuit (16).

8. Installation according to any one of claims 1 to 7, characterized in that it comprises several liquefiers (7) connected in parallel to the supply pipe (6) and also connected in parallel to the buffer storage (9).

9. Installation according to any one of claims 1 to 8, characterized in that it comprises a liquid hydrogen storage assembly (18) connected to one end of the supply pipe (6) leaving the liquefier (7) and configured to collect the hydrogen liquefied by the liquefier (7), the installation (1) further comprising a filling circuit (20) connected to the liquid hydrogen storage assembly (18) and configured to allow the filling of tank(s) (21), the installation (1) comprising a set of pipe(s) (22, 23, 24) for recovering the vaporization gases generated at the liquid hydrogen storage assembly (18) and / or at the filling circuit (20), the set of pipe(s) (22, 23, 24) for recovering the vaporization gases being connected to the supply circuit (6).

10. Process for producing liquefied hydrogen using an installation according to any one of claims 1 to 9, characterized in that it comprises a step of supplying compressed gaseous hydrogen to the buffer storage (9) when the gaseous hydrogen generator (2) produces a quantity of hydrogen greater than a first threshold and a step of supplying the supply line (6) with compressed gaseous hydrogen from the buffer storage (9) when the gaseous hydrogen generator (2) produces a quantity of hydrogen less than a second threshold.

11. Method according to claim 10, characterized in that it comprises a step of using compressed hydrogen supplied by the supply line (6) and / or the buffer storage (9) to supply a compression portion of a hydrogen cycle circuit of the refrigerator (8) of the liquefier (7).

12. Method according to claim 11, characterized in thatit comprises a step of compressing the gaseous hydrogen in the supply line (6) to a determined target pressure, for example equal to 60 bar, and in that the final compression level of the compression portion of the cycle circuit is equal to this target pressure.

13. Method according to claim 12, characterized in that the buffer storage (9) is configured to store hydrogen gas up to a determined maximum storage pressure which is higher than the target pressure, the buffer storage (9) being configured to supply gas to the compression portion of the cycle circuit at the target pressure or at a pressure lower than the target pressure.

14. Method according to any one of claims 10 to 13, characterized in thatit comprises a step of storing, in a liquid hydrogen storage(s) (18), liquid hydrogen produced by the installation (1) and possibly a step of filling tank(s) (21) with liquid hydrogen from the liquid hydrogen storage (18), the method comprising a step of recovering vaporization gas generated during the storage step and / or during the filling step and a step of recycling the vaporization gas recovered in the supply pipe (6).

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