Facility for producing dihydrogen

Abstract

The invention relates to a facility (1) for producing dihydrogen, the facility comprising a water purification device (2), a heating device (3) for converting the purified water into steam, and an electrolyser (4) configured to produce at least one stream of dihydrogen from the steam. The heating device (3) is preferably configured to recover waste heat. The invention also relates to a corresponding method.

Description

Hydrogen production facility

[0001] The present invention relates to the field of industrial production of dihydrogen.

[0002] The invention relates more specifically to installations implementing high-temperature electrolysis technologies known under the English name “Solid Oxide Electrolysis Cell (SOEC)”. State of the art

[0003] In the field of hydrogen production, it is known to carry out high-temperature electrolysis using an electrochemical device forming a reaction zone designed to convert water vapor into hydrogen. In other words, the electrochemical device carries out vapor-phase electrolysis using water vapor at a temperature that can be between 100°C and 850°C.

[0004] The reaction zone of a conventional electrolyser is formed by stacks of cells, each having an anode, a cathode and an electrolyte. High-temperature electrolysis decomposes water vapour to form, at the cathode of the cells, a flow of a fluid that includes dihydrogen.

[0005] There is a need to improve the efficiency of hydrogen production facilities and, in particular, to reduce their energy consumption.

[0006] To this end, the subject of the invention is a dihydrogen production installation comprising: a treatment device configured to treat a fluid so as to form a flow of this fluid in the liquid state, this flow being called "inlet flow", a heating device configured to heat the inlet flow so as to change the fluid of the inlet flow from the liquid state to the gaseous state, an electrochemical device configured to form one or more outlet flows from the inlet flow in the gaseous state, the outlet flow(s) including an outlet flow which comprises dihydrogen.

[0007] The fluid treated by said treatment device to form the inlet stream preferably comprises water.

[0008] Said treatment device is preferably configured to purify this fluid, in particular so that the properties of the fluid flow formed by this device are suitable for its use in the device, for example in terms of conductivity and quantity of ions and / or particles.

[0009] In one embodiment, one of said output streams formed by the electrochemical device comprises a so-called recovery fluid.

[0010] Said recovery fluid preferably comprises water not reacted in the electrochemical device.

[0011] In this embodiment, the installation may include a conduit configured to be able to convey this recovery fluid to the treatment device.

[0012] In one embodiment, the installation comprises a conduit configured to be able to convey to the treatment device a fluid such as water from an external source.

[0013] The aforementioned processing device may be a first processing device.

[0014] The installation may comprise one or more other treatment devices, in particular for treating one or more of the output streams formed by the electrochemical device.

[0015] Thus, the installation may comprise a second treatment device configured to extract from said output flow which comprises dihydrogen a so-called extraction fluid.

[0016] This extraction fluid preferably comprises water.

[0017] In one embodiment, the installation may comprise a conduit configured to be able to convey this extraction fluid to said first treatment device.

[0018] Alternatively or additionally, the installation may comprise a third treatment device configured to treat another of said output streams formed by the electrochemical device. In a non-limiting manner, this other output stream may comprise dioxygen.

[0019] Said third treatment device can be configured to extract from this other output flow a so-called extraction fluid.

[0020] The extraction fluid extracted by said third treatment device preferably comprises water.

[0021] In one embodiment, the installation may comprise a conduit configured to be able to convey to said first treatment device the extraction fluid extracted by said third treatment device.

[0022] In one embodiment, the heating device comprises at least one heat exchanger configured to transfer heat from an energy carrier to said input stream.

[0023] Without limitation, said energy vector may comprise a fluid containing heat from a fatal heat source.

[0024] The electrochemical device preferably comprises a solid oxide electrolyzer.

[0025] According to a first embodiment variant, the electrochemical device is configured to receive a sweeping gas.

[0026] According to a second embodiment, the electrochemical device is configured to operate without sweeping gas, the installation thus being able to be devoid of means for introducing a sweeping gas into the electrochemical device.

[0027] In one embodiment, the installation comprises one or more storage devices configured to respectively store one or more of said output streams formed by the electrochemical device.

[0028] According to another aspect, the invention also relates to a method for producing dihydrogen using an installation as defined above.

[0029] In a non-limiting manner, the method may comprise:treatment, using said treatment device, of a fluid preferably comprising water so as to form a flow of this fluid in the liquid state, this flow being called "input flow",heating, using said heating device, of the input flow to change the fluid of the input flow from the liquid state to the gaseous state,implementing the electrochemical device to form one or more output flows from the input flow in the gaseous state, the output flow(s) including an output flow which comprises dihydrogen.

[0030] Depending on the embodiments, the method may in particular comprise: an introduction into said (first) treatment device of said recovery fluid, and / or an introduction into said (first) treatment device of a fluid originating from said external source, and / or an introduction into said first treatment device of said extraction fluid originating from said second and / or said third treatment device, and / or a transfer of heat from said energy vector to said input flow, for example using said heating device and / or said heat exchanger.

[0031] Among other advantages, the invention makes it possible to: Optimize and maximize heat recovery from a heat source; Provide the electrochemical device with a continuous steam flow, including where appropriate in the event of significant fluctuation of the heat source; Provide at the outlet of the electrochemical device a flow of dihydrogen and a flow of dioxygen having appropriate purity and pressure, in particular for their storage; Provide at the outlet of the electrochemical device a flow of dihydrogen and a flow of dioxygen continuously, including where appropriate in the event of significant fluctuation of demand and / or of the heat source; Reduce the need for external electrical energy and consequently the environmental impact; Reduce the overall cost of producing dihydrogen; Increase the lifetime of the installation.

[0032] Other advantages and characteristics of the invention will appear on reading the detailed, non-limiting description which follows. Brief description of the figures

[0033] The following detailed description refers to the appended drawings in which:is a schematic view of an installation according to the invention, the installation comprising a water purification device, a heating device for forming a stream of water vapor with the purified water, an electrochemical device producing a stream of dihydrogen and a stream of dioxygen from the stream of water vapor, a device for treating the stream of dihydrogen and a device for treating the stream of dioxygen;is a schematic view of a heating device for an installation according to the invention, the heating device comprising a heat storage module and a heat exchanger for recovering heat from an energy vector, for example from a fluid coming from a waste heat source;lais a schematic view of a dihydrogen treatment device and a dihydrogen storage device for an installation according to the invention;lais a schematic view of a dioxygen treatment device and a dioxygen storage device for an installation according to the invention.; Detailed description of embodiments

[0034] An installation 1 in accordance with the invention is shown in.

[0035] Facility 1 is a hydrogen production facility.

[0036] In the non-limiting embodiment of the, the installation 1 comprises: a device 2 for treating a first fluid, the first fluid comprising in this example water, a device 3 for heating the first fluid, an electrochemical device 4, devices 5 and 6 for treating the flow leaving the electrochemical device 4, a device 7 for supplying the devices 2-6 with electrical energy, a fluid network.

[0037] In a non-limiting manner, the fluid network comprises in this example conduits 11, 12, 13 and 14 which are each connected to an inlet of the device 2 in order to be able to introduce respective fluids to form said first fluid.

[0038] In the example of the, the conduit 11 is connected to an external source (not shown) so as to be able to convey water coming from this external source to the device 2.

[0039] The conduits 12, 13 and 14 are each connected to an outlet of the devices 4, 5 and 6, respectively, in order to be able to convey to the device 2 a respective fluid leaving these devices (see further below).

[0040] The fluid network of installation 1 also includes conduits 15, 16, 17 and 18 fluidically connecting devices 2 to 6 to each other.

[0041] More specifically, the conduit 15 connects an outlet of the device 2 to an inlet of the device 3 in order to be able to introduce into the device 3 all or part of the first fluid leaving the device 2. The conduit 16 connects an outlet of the device 3 to an inlet of the device 4 in order to be able to introduce into the device 4 all or part of the first fluid leaving the device 3. The conduit 17 connects a first outlet of the device 4 to an inlet of the device 5 in order to be able to introduce into the device 5 all or part of a first outlet flow formed by the device 4. The conduit 18 connects a second outlet of the device 4 to an inlet of the device 6 in order to be able to introduce into the device 6 all or part of a second outlet flow formed by the device 4.

[0042] The device 2 of the installation 1 is configured to treat water which is introduced therein via one or more of the conduits 11 to 14, so that the properties of the water leaving the device 2 via the conduit 15, in particular in terms of conductivity and quantity of ions and / or particles which it contains, are adapted to its use in the device 3.

[0043] Device 2 is also called the “first treatment device”, or “purification device”.

[0044] Generally, the heating device 3 of the installation 1 is configured to pass the flow of the first fluid coming from the device 2, that is to say in this example the flow of purified water, from the liquid state to the gaseous state.

[0045] More particularly, the heating device 3 is in this example configured to form a flow of superheated steam from the flow of purified water.

[0046] To do this, the device 3 can recover heat from an energy vector formed from an external heat source, for example in the form of a flow of a second hot fluid in the gaseous or liquid state.

[0047] Alternatively or additionally, the device 3 can recover heat using electrical energy supplied by the device 7. The device 7 can be an electrical network and / or can comprise an electrical energy storage device.

[0048] The device 3 can therefore form a heat recovery device and can comprise for this purpose one or more pieces of equipment which can be chosen from a non-limiting list including an economizer, a recuperator, a heat exchanger, an electric heater, a degasser, a vaporizer, a superheater, a heat storage device, an electrical energy storage device and a heat pump.

[0049] Devices 2 and 3 thus together form a module known as the first fluid flow formation module, which constitutes an input flow for device 4 (see further below).

[0050] It is shown in a heating device 3 which is implemented in the installation 1 within the framework of a non-limiting embodiment.

[0051] In the example of the, the device 3 comprises a heat exchanger 21 configured to transfer heat from said second fluid, also called “heating fluid”, which circulates in this example in conduits 22, 23 and 24, to said first fluid which is in this example introduced into the exchanger 21 via the conduit 15 and which leaves it via the conduit 16 (see also).

[0052] In this embodiment, the device 3 comprises a heat storage module 25. The conduit 22 is configured to convey the heating fluid to the module 25 so that it can be introduced therein in whole or in part to store the heat it contains.

[0053] In this non-limiting example, the heat contained in the heating fluid comes from a fatal heat source (not shown) to which the conduit 22 can be connected.

[0054] The heating fluid is here introduced into the exchanger 21 via the conduit 23 and leaves via the conduit 24.

[0055] Of course, the device 3 is in no way limiting. For example, the device 3 may be without the heat storage module 25. For another example, according to different variants, said first and second fluids may circulate in the exchanger 21 in the same direction, or alternately in counter-current.

[0056] In another embodiment, not shown, the device 3 of the installation 1 is configured to transfer heat from a heating fluid via a transfer fluid such as water or thermal oil.

[0057] With reference to the, the electrochemical device 4 of the installation 1 is here a solid oxide electrolyser, forming a technology known under the Anglo-Saxon name “Solid Oxide Electrolysis Cell” (SOEC).

[0058] In a manner known per se, such an electrolyser 4 comprises one or more stacks of cells each forming a cathode, an anode and an electrolyte, so as to constitute a reaction zone.

[0059] The electrolyser 4 is in this example configured to carry out high-temperature electrolysis, that is to say to form, on the one hand, said first outlet flow of a fluid which comprises dihydrogen and, on the other hand, said second outlet flow of a fluid which comprises dioxygen, from a flow of water vapour having a temperature which can typically be between 100°C and 850°C.

[0060] The water vapor flow is in this example formed by the heating device 3.

[0061] In the embodiment of the, the electrochemical device 4 forms a third output stream which comprises water and which can be conveyed to the device 2 via the conduit 12.

[0062] In this example, the fluid comprising dihydrogen which is obtained by electrolysis is cooled within the electrochemical device 4. This cooling causes condensation of residual water present in this fluid. The residual water thus condensed forms said third outlet flow, said first outlet flow being formed by the remaining part of this fluid.

[0063] Still with reference to the, the device 5 of the installation 1, also called “second treatment device”, is configured to treat said first output flow which is conveyed from the device 4 to the device 5 by the conduit 17.

[0064] Similarly, the device 6 of the installation 1, also called “third treatment device”, is configured to treat said second output flow which is conveyed from the device 4 to the device 6 via the conduit 18.

[0065] In a non-limiting manner, the treatment carried out by each of the devices 5 and 6 may include operations of cooling and / or compression and / or purification of the corresponding flow, carried out by one or more corresponding treatment members.

[0066] Figures 3 and 4 show a treatment device 5, respectively 6, which can be implemented in the installation 1 within the framework of a non-limiting embodiment.

[0067] In the example of figures 3 and 4, each of the devices 5 and 6 comprises a purification unit 31 which comprises one or more technologies chosen from adsorption, absorption, membrane, distillation and conversion technologies.

[0068] Purification of the first outlet flow, i.e. the flow of fluid comprising dihydrogen, makes it possible in particular to remove from this flow impurities such as water and / or dioxygen and / or nitrogen and / or argon and / or carbon monoxide and / or carbon dioxide.

[0069] Purification of the second outlet flow, i.e. the flow of fluid comprising oxygen, makes it possible in particular to remove from this flow impurities such as water and / or nitrogen and / or argon and / or carbon monoxide and / or carbon dioxide.

[0070] In the example of figures 3 and 4, each of the devices 5 and 6 further comprises a compression unit 32, which makes it possible to compress the flow purified by the unit 31, in this example with a view to its storage in a storage device 33, or 34.

[0071] In this example, the units 31 and 32 of each of the devices 5 and 6 are configured to extract, by condensation, water present in the flow of dihydrogen (device 5) or dioxygen (device 6).

[0072] The water thus extracted can be conveyed from devices 5 and 6 to device 2 via conduits 13 and 14, respectively (see also).

[0073] Of course, one or more compression stages can be implemented before and / or after purification, depending in particular on the storage pressure to be achieved.

[0074] Each of the devices 5 and 6 may optionally comprise one or more additional purification and / or compression units (not shown), water also being able to be extracted from one or more of these additional units and conveyed to the device 2 in the manner described above.

[0075] For information purposes, the storage devices 33 and 34 which are respectively connected to the devices 5 and 6 may each comprise one or more tanks configured to store, respectively, dihydrogen in the gaseous state and dioxygen in the gaseous state, at pressures which may range from atmospheric pressure to 700 bars.

[0076] The installation 1 or any of its variants can thus be implemented to produce dihydrogen by appropriately using, according to techniques which are known as such, the different storage devices which can equip this installation, for example the heat storage module 25 (cf.), the dihydrogen storage device 33 (cf.), the dioxygen storage device 34 (cf.), and / or an electrical energy storage device forming for example the device 7 (cf.), depending on different parameters which can for example include the cost of electricity, the cost and availability of fatal heat, the need for dihydrogen and / or dioxygen, or even the filling level of one or more of the aforementioned storage devices.For another example, the invention can also be implemented to maximize the production of dihydrogen, or to extend the life of the installation or to be able to postpone a maintenance operation.

[0077] Advantageously, the installation 1 makes it possible to supply the heating device 3 with a flow of water treated by the device 2, itself supplied by one or more flows which can come selectively from an external source and / or from one or more of the devices 4, 5 and 6.

[0078] Of course, the invention is not limited to the examples which have just been described. For example, in a variant embodiment not shown, the installation 1 can be configured to use a portion of the fluid treated by the device 5 as an oxidant and a portion of the fluid treated by the device 6 as fuel in an additional heating device (not shown). Such an additional heating device can be configured to supply heat to the heating device 3 and / or steam to the electrochemical device 4.

[0079] The electrochemical device 4 of the installation of the invention may be configured to operate without sweeping gas. Alternatively, the installation may comprise means (not shown) for introducing into the electrochemical device 4 a flow of a sweeping gas such as air or nitrogen, or even water in the gaseous state, in order to balance the pressure within the device 4 and facilitate the evacuation of the oxygen which accumulates there.

[0080] In variants of the, the treatment device 2 can be configured to be supplied only by a fluid coming from an external source, or only by a fluid leaving one or more pieces of equipment of the installation, for example from one or more of the devices 4, 5 and 6 in the example of the.

[0081] The installation of the invention can of course include numerous conventional pieces of equipment which are not described above, for example one or more pumps, one or more compressors, one or more fans, one or more flow control valves, one or more ejectors, etc.

Claims

Installation (1) for producing dihydrogen comprising:a treatment device (2) configured to treat, preferably to purify, a fluid preferably comprising water so as to form a flow of this fluid in the liquid state, this flow being called "inlet flow", so as to adapt the properties of the fluid in terms of the quantity of ions and / or particles that it contains,a heating device (3) configured to heat the inlet flow so as to change the fluid of the inlet flow from the liquid state to the gaseous state,an electrochemical device (4) configured to form one or more outlet flows from the inlet flow in the gaseous state, the outlet flow(s) including an outlet flow which comprises dihydrogen. Installation (1) according to claim 1, in which one of said output flows formed by the electrochemical device (4) comprises a so-called recovery fluid which preferably comprises water which has not reacted in the electrochemical device (4), the installation (1) comprising a conduit (12) configured to be able to convey this recovery fluid to the treatment device (2). Installation (1) according to claim 1 or 2, comprising a conduit (11) configured to be able to convey to the treatment device (2) a fluid such as water from an external source. Installation (1) according to any one of claims 1 to 3, in which the treatment device (2) is a first treatment device, the installation (1) comprising: a second treatment device (5) configured to extract from said output flow which comprises dihydrogen a so-called extraction fluid which preferably comprises water, the installation (1) comprising a conduit (13) configured to be able to convey this extraction fluid to said first treatment device (2), and / or a third treatment device (6) configured to extract from another of said output flows formed by the electrochemical device (4) a so-called extraction fluid which preferably comprises water, this other output flow preferably comprising dioxygen, the installation (1) comprising a conduit (14) configured to be able to convey this extraction fluid to said first treatment device (2). Installation (1) according to any one of claims 1 to 4, wherein the heating device (3) comprises at least one heat exchanger (21) configured to transfer heat from an energy vector to said input flow. Installation (1) according to claim 5, wherein said energy vector comprises a fluid containing heat from a fatal heat source. Installation (1) according to any one of claims 1 to 6, in which the electrochemical device (4) comprises a solid oxide electrolyser. Installation (1) according to any one of claims 1 to 7, in which the electrochemical device (4) is configured to receive a sweeping gas. Installation (1) according to any one of claims 1 to 8, comprising one or more storage devices (33, 34) configured to respectively store one or more of said output streams formed by the electrochemical device (4). A method for producing dihydrogen using a plant (1) according to any one of claims 1 to 9, the method comprising:treatment, using said treatment device (2), of a fluid preferably comprising water so as to form a flow of this fluid in the liquid state, this flow being called "inlet flow", so as to adapt the properties of the fluid in terms of the quantity of ions and / or particles it contains,heating, using said heating device (3), of the inlet flow to change the fluid of the inlet flow from the liquid state to the gaseous state,implementing the electrochemical device (4) to form one or more outlet flows from the inlet flow in the gaseous state, the outlet flow(s) including an outlet flow which comprises dihydrogen.

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