Installation and process for the production of 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 feed 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 cooling power and cool the gaseous hydrogen from the feed line (6) for liquefaction, 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 feed line (6) via a set of bypass line(s) (19, 29),That is to say, the buffer storage (9) and the liquefier (7) are connected in parallel to the gaseous hydrogen outlet of the gaseous hydrogen generator (2). Abbreviated figure: Fig. 1,

Description

Title of the invention: Installation and process for the production of liquefied hydrogen

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

[0002] The invention relates more particularly to a liquefied hydrogen production plant comprising a gaseous hydrogen generator, for example an electrolyzer, configured to produce gaseous hydrogen, a liquefier, a feed 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 cooling power and cool the gaseous hydrogen from the feed line for liquefaction, the plant 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] The production of hydrogen and the liquefaction of hydrogen from renewable energy require optimization and synergies between the production (typically electrolysis) and liquefaction units.

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

[0005] Due to the intermittency of renewable energies, the quantity 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] One object of the present invention is to overcome all or part of the disadvantages 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 line(s), that is to say that the buffer storage and the liquefier are connected in parallel to the gaseous hydrogen outlet of the gaseous hydrogen generator.

[0009] Furthermore, embodiments of the invention may include one or more of the following features: - The installation includes a compressor located on the entire bypass pipe(s), - The entire bypass pipeline assembly includes a return pipeline configured to transfer gaseous hydrogen from the buffer storage to the feed pipeline, - the return line includes at least one gaseous hydrogen expansion device from among: an expansion valve, a turbine, a turbine coupled to an electric power generator or a compressor to form a turbocharger, - the refrigerator is of the cycle circuit type configured to produce cooling power by subjecting a cycle gas to a thermodynamic cycle, the cycle circuit comprising a set of cycle gas compressor(s), at least one cooling element for the compressed cycle gas and at least one expansion element for 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 be supplied with hydrogen by the cycle circuit, - the installation includes at least one compressor for the gaseous hydrogen intended to supply the buffer storage, which is also a compressor in the assembly of compressor(s) for the cycle gas, - The supply line comprises several compressors arranged in series and / or parallel, configured to supply the buffer storage and / or the cycle circuit with compressed hydrogen, - the cycle gas compressor assembly comprises several compressors arranged in series and / or in parallel, the installation including a supply line connecting the buffer storage to the inlet or outlet of at least one of the cycle gas compressor(s) and configured to allow the supply of pressurized gaseous hydrogen into the cycle circuit, - The installation includes several liquefiers connected in parallel to the supply line and also connected in parallel to the buffer storage. - The installation includes a set of liquid hydrogen storage unit(s) connected to one end of the feed line exiting the liquefier and configured to collect the hydrogen liquefied by the liquefier; the installation further includes a filling circuit connected to the liquid hydrogen storage system(s) configured to allow the filling of tank(s), the installation including a set of piping for the recovery of vaporization gases generated at the level of the liquid hydrogen storage system(s) and / or at the level of the filling circuitry, the set of piping for the recovery of vaporization gases being connected to the supply circuit, - the liquefier includes a pre-cooling device in heat exchange with the feed line and configured to ensure pre-cooling of the hydrogen gas to an intermediate temperature before its cooling by the refrigerator, the pre-cooling device including for example at least one of the following: a nitrogen refrigeration cycle or with a refrigeration mixture, - Parallel refrigerators are of the cycle circuit type, where the cycle gas is hydrogen, and each is configured to produce cooling power by subjecting the cycle gas to a thermodynamic cycle. The buffer storage is connected in parallel to the cycle circuits of the parallel refrigerators to supply them with hydrogen and / or to be supplied with hydrogen by the cycle circuits. - at least one compressed cycle gas expansion device includes an expansion valve or turbine arranged on a bypass line from 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 may be lower than the target pressure, (final compressor off).

[0010] The invention also relates to a process for producing liquefied hydrogen using an installation according to any one of the above or below characteristics, 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 features: - the process includes a step of using compressed hydrogen supplied by the feed line and / or buffer storage to supply a compression portion of a hydrogen cycle circuit of the refrigerator liquefier - the process includes a step of compressing gaseous hydrogen in the feed line to a predetermined 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 gaseous hydrogen up to a predetermined 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 process includes a storage step, in liquid hydrogen storage(s), of liquid hydrogen produced by the installation and possibly a filling step of tank(s) with liquid hydrogen from the liquid hydrogen storage, the process including a step of recovering vaporization gases generated at the storage step and / or during the filling step and a step of recycling the recovered vaporization gas into the feed line, - the process includes a stage of electricity production from the mechanical work provided by the expansion of 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 from the following description, made with reference to the figures in which: Brief description of the figures

[0014] 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:

[0015] [Fig. 1] is a schematic and partial view illustrating the structure and function of an installation according to a first example of an embodiment of the invention,

[0016] [Fig.2] is a schematic and partial view illustrating the structure and function of an installation according to a second embodiment of the invention,

[0017] [Fig.3] is a schematic and partial view illustrating the structure and function of an installation according to a third embodiment of the invention,

[0018] [Fig.4] is a schematic and partial view illustrating the structure and function of an installation according to a fourth embodiment of the invention,

[0019] [Fig.5] is a schematic and partial view illustrating the structure and function of an installation according to a fifth embodiment of the invention,

[0020] [Fig.6] is a schematic and partial view illustrating the structure and operation of an installation according to a sixth embodiment of the invention,

[0021] [Fig.7] is a schematic and partial view illustrating the structure and operation of an installation according to a seventh embodiment of the invention,

[0022] [Fig.8] is a schematic and partial view illustrating the structure and operation of an installation according to an eighth embodiment of the invention. Detailed description

[0023] In all figures, the same references refer to the same elements.

[0024] 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.

[0025] 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.

[0026] In the following, the gaseous hydrogen generator 2 is referred to as the electrolyzer. Of course, alternatively or in combination, this gaseous hydrogen generator 2 may include a reforming device, in particular an auto-thermal (“ATR”).

[0027] The liquefier 7 includes a cycle circuit refrigerator 8 configured to provide cooling power and cool the gaseous hydrogen from the supply line 6 for liquefaction.

[0028] Installation 1 includes at least one compressor 10 of the gaseous hydrogen produced by the electrolyzer 2 and at least one buffer storage 9 configured to store the compressed gaseous hydrogen between the electrolyzer 2 and the liquefier 7.

[0029] According to an advantageous feature, the buffer storage 9 is connected to the supply line 6 via a set of bypass line(s) 19, 29, i.e. the buffer storage 9 and the liquefier 2 are connected in parallel to the gaseous hydrogen outlet of the electrolyzer 2.

[0030] This architecture allows for better interoperability between the electrolyzer 2 and the liquefier 7.

[0031] The buffer storage 9 is preferably a high-pressure gaseous storage allowing compressed hydrogen to be stored when the electrolyzer 2 is producing at full capacity and hydrogen to be released, for example, when the production of hydrogen by the electrolyzer 2 is insufficient (for example, low renewable energy availability).

[0032] As illustrated in [Fig.1], at least one compressor 10 can be located on the bypass pipe(s) assembly 19.

[0033] In addition, the set of bypass lines may include a first line 19 configured to fill the buffer storage 9 and a return line 29 configured to transfer gaseous hydrogen from the buffer storage 9 to the feed line 6.

[0034] The delivery line 29 preferably includes at least one gaseous hydrogen expansion device 39 from among: an expansion valve, a turbine, a turbine coupled to an electric power generator or a compressor to form a turbocharger.

[0035] Thus, the recovery of gaseous hydrogen stored under pressure can be carried out when hydrogen availability is low. A power-generating turbine 39 can be used to produce electricity during this recovery period (see [Fig. 2]).

[0036] As illustrated in particular in [Fig.4] and [Fig.8], the refrigerator 8 ensuring the cooling of hydrogen for the purpose of its liquefaction may include a 16-cycle circuit type refrigerator configured to produce cooling power by subjecting a cycle gas comprising, for example, helium and / or hydrogen to a thermodynamic cycle.

[0037] The cycle circuit 16 of such a refrigerator 8 typically includes a set of cycle gas compressors, at least one compressed cycle gas cooling device 13 (one or more heat exchangers) and at least one compressed cycle gas expansion device 15 (valve(s) and / or turbine(s)).

[0038] In the example of [Fig. 8], the refrigerator cycle circuit 16 is separate from the supply line 6. Furthermore, this cycle circuit 16 is closed. After compression 11 at ambient temperature, the cycle gas is cooled in a first heat exchanger assembly 13 (to a first temperature, for example, of around 80 K). The cycle gas is then expanded (valve 15) and produces cooling power, which is supplied to the supply line 6 in a cooler heat exchanger 14 (typically around 20 K). The cycle gas that provided the cooling power is returned to compression and warms up, cooling the cycle gas flow that is about to be expanded. Returning to compression, the cycle gas also cools the supply line 6 in the opposite direction (typically counter-currently).

[0039] As illustrated, the liquefier 7 may include at least one precooling device 12 in heat exchange with the supply line 6 and the cycle circuit 16 and configured to provide precooling of the gaseous hydrogen to an intermediate temperature (80K) before its cooling by the refrigerator 8. This pre-cooling device 12 includes, for example, at least one of the following: a nitrogen refrigeration cycle or a refrigeration mixture in heat exchange with a pre-cooling exchanger assembly 13 (for example in a first cold pre-cooling box).

[0040] In the example of [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 be supplied with hydrogen by the cycle circuit. That is to say, the cycle circuit 16 can be open.

[0041] This configuration allows for the sharing of 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 (see [Fig. 3] or [Fig. 4]). Thus, a portion of the supply line 6 can also constitute a portion of the cycle circuit 16.

[0042] This is also illustrated in [Fig. 4] where the refrigerator cycle circuit 16 of the refrigerator 8 may be partially shared with the supply line 6. Thus, for example, downstream of a pre-cooling exchanger 13, the supply line 6 may include a cryogenic purification system 25 (of the TSA type, for example) and then a pressure-reducing device 36 (e.g., a valve) for liquefaction (cooling 14 below the critical temperature). Downstream, the supply line 6 may supply liquefied hydrogen to a liquid hydrogen storage tank 18.

[0043] As illustrated, downstream of the cryogenic hydrogen gas purification device 25 to be liquefied, the installation 1 may include a bypass line equipped with a pressure-reducing device 15 (for example, a valve) and connected to the rest of the cycle circuit 16. That is to say, the cycle circuit 16, after compression 11 at non-cryogenic temperature, may include a passage in the supply line 6 in which the cycle gas is pre-cooled 13, then purified 25, then pressure-reduced 15 before supplying its cooling power to the supply line 6 and returning to the compression 11 (releasing its cooling capacity in the heat exchangers as it warms up).

[0044] That is to say, the compression pressure in the cycle circuit 16 and the pressure in the supply line 6 can be set to the same level, and these flows can be mixed in a portion of the supply line 6 up to the outlet of the cryogenic purification device 25. Downstream of this cryogenic purification 25, a portion of the hydrogen is expanded 36 for liquefaction, while another portion is used as a high-pressure cycle gas.

[0045] As illustrated in [Fig.3], the supply line 6 may include 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.

[0046] For example, the compression can be staged between an initial pressure on the order of atmospheric pressure and a pressure level above 60 bar, for example above 100 bar, in particular above 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 feeds, for example, the refrigerator cycle circuit 16. Downstream of this intermediate compression stage, the bypass line 19 can compress the hydrogen with at least one additional compressor 10 to supply the buffer storage 9 at a pressure that may be higher.

[0047] As schematically illustrated in [Fig. 3], the return line 29 can supply (with expansion valve 39 if necessary) the feed line 6 downstream of the intermediate compression stage. Similarly, a line 139 can be provided allowing the buffer storage 9 at the inlet of the intermediate compression stage (or an upstream compression stage) to supply the feed line 6 further upstream at a lower pressure (for example, when the pressure in the buffer storage 9 is relatively low).

[0048] The pressure within the buffer storage 9 can vary according to its filling rate between a determined maximum level (for example 250 bara) and a minimum level and for example a pressure level which may be lower than the target pressure of the cycle circuit, (final compressor(s) 10 off).

[0049] 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).

[0050] Thus, the buffer storage 9 can be configured to store gaseous hydrogen up to a predetermined maximum storage pressure (e.g. 250 bar) which is higher than the target pressure (e.g. 60 bar) but the buffer storage 9 can 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.

[0051] As also illustrated in [Fig.3], a line of the cycle circuit can return cycle gas to the compression (to an intermediate stage with or without compression 11 as appropriate).

[0052] As schematically illustrated in [Fig.5], another user 26 of the compressed gaseous hydrogen can be connected in bypass of the supply line 6 (in parallel with the inlet of the liquefier and in parallel with the buffer storage 9).

[0053] In addition, an extra line 161 or loop with a compressor 11 may be provided to supply the cycle circuit 16 with hydrogen at the intermediate pressure (60 bar). Similarly, another supply line 17 may connect the buffer storage 9 to the inlet or outlet of at least one of the cycle gas compressor(s) 11 and be configured to supply pressurized gaseous hydrogen to the cycle circuit 16 at a predetermined pressure level.

[0054] As schematically illustrated in [Fig.7], the installation 1 may include at least one liquid hydrogen storage 18 connected to a downstream end of the feed line 6 coming out of the liquefier 7. The storage 18 is of the cryogenic type and configured to collect the hydrogen liquefied by the liquefier 7.

[0055] The installation 1 may include 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 a delivery truck). The installation 1 includes for this purpose a set of lines 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 lines 22, 23, 24 for recovering the vaporization gases is connected to the supply circuit 6 to recycle, where applicable, the vaporization gas recovered in the supply line 6 (where applicable, with compression 111).

[0056] Thus, vaporization gas at intermediate pressure can be recovered at the beginning of depressurization of trucks / ships 21, this vaporization gas can be mixed with hydrogen from the supply line 6 with or without intermediate compressor 11 depending on the pressure level.

[0057] As schematically illustrated in [Fig.6], the installation 1 may include several liquefiers 7 connected in parallel to the supply line 6 and also connected in parallel to the buffer storage 9.

[0058] The processes described above and below can therefore be applied (simultaneously or not) to all or part of the liquefiers in parallel.

[0059] The invention allows the installation to adapt to production fluctuations (intermittent renewable energy for example) with an integration offering maximum synergies.

Claims

Demands

1. A liquefied hydrogen production plant comprising a gaseous hydrogen generator (2), for example an electrolyzer (2), configured to produce gaseous hydrogen, a liquefier (7), a feed 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 cooling power and cool the gaseous hydrogen from the feed line (6) for liquefaction, 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 feed line (6) via a set of piping(s) (19, 29) of derivation,that is to say that the buffer storage (9) and the liquefier (7) are connected in parallel to the outlet of the gaseous hydrogen of the gaseous hydrogen generator (2), the refrigerator (8) being of the type with a cycle circuit (16) configured to produce cooling power by subjecting a cycle gas to a thermodynamic cycle, the cycle circuit (16) comprising a set of cycle gas compressor(s) (10, 11), at least one compressed cycle gas cooling device (13) and at least one compressed cycle gas expansion device (15), 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 bypass pipe(s) assembly (19, 29).

3. Installation according to claim 1 or 2, characterized in that the bypass pipe(s) assembly (19, 29) includes a return 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 return conduit (29) comprises at least one component (39) of expansion of gaseous hydrogen through: an expansion valve, a turbine, a turbine coupled to an electric power generator or a compressor to form a turbocharger.

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

6. Installation according to any one of claims 1 to 5, characterized in that the 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 cycle gas compressor assembly (10, 11) comprises several compressors (10, 11) arranged in series and / or in parallel, the installation (1) comprising a supply line (17) connecting the buffer storage (9) to the inlet or outlet of at least one of the cycle gas compressor(s) (11) and configured to allow the supply of pressurized gaseous hydrogen 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 line (6) and also connected in parallel to the buffer storage (9).

9. An installation according to any one of claims 1 to 8, characterized in that it comprises a set of liquid hydrogen storage tank(s) (18) connected to one end of the supply line (6) exiting 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 tank(s) (18) and configured to allow the filling of tank(s) (21), the installation (1) comprising a set of lines (22, 23, 24) for recovering the vaporization gases generated at the liquid hydrogen storage tank(s) (18) and / or at the filling circuit (20), the set of lines (22, 23, 24) of vaporization gas recovery being connected to the supply circuit (6).

10. A 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 an amount of hydrogen greater than a first threshold and a step of supplying the feed line (6) with compressed gaseous hydrogen from the buffer storage (9) when the gaseous hydrogen generator (2) produces an amount of hydrogen less than a first threshold.

11. A 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. A method according to claim 11, characterized in that it comprises a step of compressing gaseous hydrogen in the feed 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. A method according to claim 12, characterized in that the buffer storage (9) is configured to store gaseous hydrogen up to a determined maximum storage pressure which is greater 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. A method according to any one of claims 10 to 13, characterized in that it comprises a step of storing, in a liquid hydrogen storage (18), liquid hydrogen produced by the installation (1) and optionally a step of filling tank(s) (21) with liquid hydrogen from the liquid hydrogen storage (18), 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 recovered vaporization gas into the feed line (6).

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