Vertical water electrolyzer

Abstract

Vertical Water Electrolyzer The present invention relates to a device (2) for treating a mixture of water and a gas from a water electrolysis unit (52), comprising a separation module (4) configured to separate the gas from the water contained in the mixture, a first cooling module (6) for the gas from the separation module (4), and a second cooling module (8) for the water from the separation module (4), characterized in that the modules (4, 6, 8) are stacked one above the other so that the treatment device (2) forms a column. (Figure 1)

Description

Title of the invention: Vertical water electrolyzer

[0001] The present invention relates to the field of water electrolysis, which consists of dissociating water molecules into gaseous oxygen and hydrogen. The oxygen and hydrogen formed by water electrolysis can then be used as consumables in the chemical industry or transport. This dissociation is carried out using a direct electric current circulating in electrolysis reactors. Installations capable of carrying out this process industrially extend over large areas of land. The land area of ​​such an installation is therefore very large.

[0002] Furthermore, these installations make use of several modules which need to be connected together, which requires the presence of numerous pipes and therefore increases the risk of leakage, as well as the design and assembly time and the cost associated with this type of connection. These installations are therefore often massive and require space and time when it comes to installations capable of generating high flow rates of dihydrogen, in particular.

[0003] The invention firstly covers a device for treating a mixture of water and a gas originating from a water electrolysis block, comprising a separation module configured to separate the gas from the water contained in the mixture, a first module for cooling the gas originating from the separation module and a second module for cooling the water originating from the separation module, innovative in that the modules are superimposed on top of each other so that the treatment device forms a column.

[0004] The present invention essentially relates to a treatment device for separating a gas from water. The modules of the treatment device need to be fluidically interconnected with each other. These interconnections are often a source of leakage and design complexity. Indeed, the difficulty for those skilled in the art is to design an ergonomic, sealed and optimized system to reduce the size and the overall surface area of ​​such a treatment device.

[0005] The present invention describes a treatment device which makes it possible to address these problems, and in particular to ensure simplified water circulation within the treatment device. The superposition of the modules allows the reduction or elimination of pipes between the modules, which also makes it possible to reduce the risks of leakage, to simplify the design of the treatment device as a whole, and at the same time to avoid the presence of gas pockets.

[0006] According to another optional characteristic of the invention, the separation module is vertically interposed between the first cooling module and the second cooling module.

[0007] Advantageously, the arrangement of the modules makes it possible to increase the separation volume of the mixture, compared to a device of the prior art. The quality of the separation is thus improved. Indeed, the mixture can finish its separation in a part of the first cooling module as well as in a part of the second cooling module.

[0008] The position of the first cooling module relative to the separation module allows the liquid still associated with the gas at the inlet of the first cooling module to finish separating, partly due to the temperature change which occurs in the first cooling module.

[0009] The position of the second cooling module relative to the separation module allows the gas still associated with the liquid at the inlet of the second cooling module to finish separating and rise towards the first cooling module.

[0010] According to yet another characteristic of the invention, the separation module comprises a mixture inlet, a gas outlet on an upper part of the separation module and a water outlet on a lower part of the separation module.

[0011] The mixture inlet into the separation module is configured to receive the mixture at a temperature of 65°C. This mixture inlet is vertically arranged between the gas outlet and the water outlet. The gas bubbles suspended in the mixture rise in the separation module to reach the gas outlet while the liquid descends in the separation module to reach the water outlet.

[0012] According to another optional characteristic of the invention, an inlet of the first cooling module is fluidically connected to the gas outlet of the separation module and an inlet of the second cooling module is fluidically connected to the water outlet of the separation module.

[0013] According to another optional characteristic of the invention, the first cooling module comprises a first circuit configured to be traversed by the gas coming from the separation module and a second circuit configured to be traversed by a heat transfer fluid intended to cool this gas.

[0014] The gas outlet of the first cooling module is configured so that the gas reaches a temperature of 7°C, while the mixture which is admitted into the separation module is at 65°C. The heat transfer fluid thus has a temperature lower than that of the gas at the outlet of the first cooling module. This temperature may for example be less than or equal to 3°C.

[0015] According to another optional characteristic of the invention, the second cooling module comprises a first pass configured to be traversed by water from the separation module and a second pass configured to be traversed by a heat transfer fluid intended to cool the water.

[0016] The second cooling module is configured so that the outlet water reaches a temperature of 60°C. The heat transfer fluid thus has a temperature lower than that of the outlet water from the second cooling module. This temperature may, for example, be less than or equal to 45°C.

[0017] According to another optional characteristic of the invention, the treatment device comprises a module for purifying the water coming from the second cooling module, the purification module constituting the column by being positioned vertically under the second cooling module.

[0018] For example, the purification module may be an ion exchange resin, which, when water passes through it, exchanges cations or anions and allows the water to return to a target conductivity.

[0019] Given the position of the purification module in the treatment device, the water subjected to gravity passes through the purification module under the sole effect of its weight. This is particularly advantageous because it allows the circulation pump located downstream of the assembly to be charged.

[0020] According to another optional characteristic of the invention, the column resulting from the superposition of the modules measures between 9 and 15 meters in height and the floor area occupied by this column is between 0.96m2 and 1.44m2, or 1.2m2 + / - 20%. Nevertheless, other column dimensions are conceivable without departing from the scope of the invention.

[0021] The invention also covers a water electrolyser comprising at least one such first treatment device, the mixture treated by the first treatment device being a mixture of water and dioxygen, the electrolyser comprising a second device for treating a mixture of water and dihydrogen, the second treatment device comprising at least one separation member configured to separate the dihydrogen from the water contained in the mixture, a first member for cooling the dihydrogen from the separation member and a member for purifying the water from the separation member, the water electrolyser comprising at least one water electrolysis block configured to deliver the mixture of water and dioxygen and the mixture of water and dihydrogen.

[0022] Such a water electrolyzer provides both dioxygen and dihydrogen. Two treatment devices are therefore necessary for the production of these gases, one for dihydrogen and one for dioxygen.

[0023] According to another optional characteristic of this electrolyser, the members of the second treatment device are superimposed on top of each other so that the second treatment device forms a column.

[0024] The two treatment devices being arranged in the form of a column, this design makes it possible to reduce the footprint of the water electrolyser according to the invention.

[0025] According to another characteristic of the invention, the water electrolyser comprises at least one pump configured to circulate the water from at least one of the columns to the electrolysis block, said pump being fluidically arranged between the column and the electrolysis block.

[0026] Since the water electrolyser block is not included in the columns, it is necessary to supply it with water so as to form, with the treatment device(s), one or more water circulation loops. The pump is therefore configured to push the water from the columns into the water electrolysis block. The column arrangement of the treatment device in such a water electrolyser makes it possible to limit the use of several pumps since the hydrostatic head of the water is used to generate a circulation of the water flow. The main pump is therefore always in charge, which ensures a positive NPSH (acronym for Net Positive Suction Head) and which prevents cavitation of said pump.

[0027] Other characteristics and advantages of the invention will become apparent from the following description on the one hand, and from several exemplary embodiments given for informational and non-limiting purposes with reference to the attached schematic drawings on the other hand, in which:

[0028] [Fig-1] is a diagram of a treatment device according to the invention;

[0029] [Fig.2] is a diagram of the treatment device according to the invention comprising a water purification module;

[0030] [Fig.3] is a diagram of a water electrolyser according to the invention.

[0031] [Fig. 1] represents a treatment device 2 comprising a combination of four modules and a base 36, more particularly a separation module 4, a first cooling module 6, a second cooling module 8 as well as a collection module 9 for the treated water. The modules are here cylindrical volume elements, for example of circular section.

[0032] The separation module 4 is interposed between the first cooling module 6 and the second cooling module 8. The general direction of extension of the modules is vertical, these modules being arranged directly above each other.

[0033] The separation module 4 comprises an inlet 10 and two outlets 12, 14. The inlet 10 of the separation module 4 is used by a mixture of water and a gas, for example dioxygen or dihydrogen resulting from electrolysis of water.

[0034] The separation module 4 is configured to allow the gas present in this mixture to rise while the liquid descends in the separation module 4. A gas outlet 12 is therefore located on the upper part 16 of the cooling module 6. A water outlet 14 is located on a wall of the treated water collection module 9. Within the separation module 4, a level of water in the liquid state is present.

[0035] The treatment device 2 also comprises a first cooling module 6 placed vertically directly above the separation module 4. The cooling module 6 comprises a first circuit 20. The arrangement of these two modules allows the gas from the separation module 4 to pass through the first circuit 20 of the cooling module 6.

[0036] The first cooling module 6 comprises a second circuit 22 configured to be traversed by a heat transfer fluid, for example a heat transfer liquid, which has a lower temperature than that of the gas which flows through the first circuit 20. This exchange of calories between the heat transfer fluid and the gas makes it possible to reduce the temperature of the gas at the outlet of the first cooling module 6, and thus promotes the condensation of the water still present in this portion of the module. The second circuit 22 is illustrated symbolically but it is understood that it occupies the entire section of the first cooling module 6.

[0037] The treatment device 2 comprises a second cooling module 8. This second cooling module 8 is positioned vertically directly under the separation module 4. This second cooling module 8 comprises two passes 24, 26 which exchange heat with each other. A first pass 24 is fluidically connected to the collection module 9 of the treated water and is configured to be traversed by the water in the liquid state coming from the separation module 4. Because the liquid is heavier than the gas, the latter passes from end to end through the second cooling module 8.

[0038] The second pass 26 is configured to be traversed by a heat transfer fluid, advantageously a heat transfer liquid. The heat transfer fluid at the inlet of the second pass 26 has a lower temperature than that of the water at the inlet of the first pass 24. Indeed, the heat exchange between these two fluids allows the water to exit the second cooling module 8 at a lower temperature than the temperature at which it entered. The second pass 26 is illustrated symbolically but it is understood that it occupies the entire section of the second cooling module 8.

[0039] The treated water collection module 9 is fluidically connected to the pass 24 of the second cooling module 8 and is configured to form a buffer zone for the water in the liquid state before exiting the column via the liquid outlet 14.

[0040] The base 36 is arranged under the treated water collection module 9, it is therefore, according to the vertical arrangement of the treatment device 2, at the lowest point of the treatment device 2. The role of the base 36 is to carry the different constituent modules of the processing device 2. Base 36 is therefore the base of the column.

[0041] The modules 4, 6, 8 and 36 are superimposed on each other and made integral by means of flanges 30. A flange 30 is a metal ring arranged on the periphery of a cylinder which delimits the module concerned. The role of this flange is to ensure the mechanical connection and the sealing between these modules. A flange is arranged on each upper and lower edge of the modules 4, 6, 8, 36 and it extends over the entire periphery of the modules 4, 6, 8, 36. The modules 4, 6, 8, 36 are screwed together two by two, by means of perforations which the flanges 30 of each module 4, 6, 8, 36 comprise. The fixing of the flanges 30 makes it possible to ensure a water and gas seal between the modules 4, 6, 8, 36.

[0042] [Fig. 2] is a representation of the processing device 2 according to another exemplary embodiment. This processing device comprises all the means and components described in relation to [Fig. 1] and reference will be made to the description of the latter for the elements which retain an identical reference between [Fig. 1] and [Fig. 2].

[0043] This treatment device 2 comprises, in addition to the other modules, a water purification module 34. The purification module 34 is placed vertically under the second cooling means 8 described previously.

[0044] The purification module 34 has a flange 30 and is secured to the second cooling module 8 by means of its upper flange 30.

[0045] The purification module 34 may for example be a resin exchanger which has the specific feature of comprising a solid material, often in granular form. The material present in the purification module is capable of capturing ions (cation or anion) from the liquid passing through it, here the water coming from the second cooling module 8.

[0046] The purification module 34 is fluidically connected to the second cooling module 8. The liquid coming from the separation module 4 being charged with ions, the purification module 34 makes it possible to reduce this ion charge and to return to a state of low water conductivity. Given the arrangement of the purification module 34, the latter is crossed by the water by the sole force of gravity. The water can thus pass through the resin without it being necessary to put it under pressure by means of a pump dedicated to this purpose. When the liquid leaves the purification module 34, it has become pure water again.

[0047] [Fig. 3] is a diagram showing a water electrolyzer 38 according to the invention. Two treatment devices 32, 40 constituting this water electrolyzer are illustrated in [Fig. 3]. The first treatment device 32 comprises the elements described previously, in particular in [Fig. 2]. The first treatment device 32 is configured to separate water from oxygen.

[0048] A second treatment device 40 is part of the water electrolyser 38. According to an exemplary embodiment, the second treatment device 40 comprises a separation member 44, a cooling member 46, a purification member 48, a collection member 49 for the treated water and finally a support 50. These members 44, 46, 48, 49 and the support 50, just as in the first treatment device 32, are superimposed vertically, with from top to bottom, the cooling member 46, then the separation member 44, the purification member 48, the collection member 49 for the treated water and finally the support 50. The members 44, 46, 48, 49 and the support 50 are made integral two by two by means of a flange 30 similar to the flanges 30 present on the modules 4, 6, 8, 36 of the first treatment device 32. The support 50 of the second treatment device 40 is similar to the base 36 of the first processing device 32, as described in [Fig.2].

[0049] The second treatment device 40 comprises a water outlet 15 fluidly connected to the collection member 49 of the treated water. The water outlet 15 is similar to the water outlet 14, according to the description of [Fig. 1]. The separation member 44 of the second treatment device 40 comprises an access 11 for a water / dihydrogen mixture, the access 11 is similar to the inlet 10, according to the description of the description of [Fig. 1].

[0050] [Fig. 3] shows a second treatment device 40 organized vertically in the form of a column, but the invention relating to the water electrolyser 38 is constituted as soon as at least one of the treatment devices 32, 40 is organized in a column. The treatment devices 32 and 40 can for example measure between 9 and 15 meters high while having a footprint of between 0.96m2 and 1.44m2.

[0051] The water electrolyzer 38 illustrated in [Fig. 3] also comprises a water electrolysis block 52 configured to carry out non-spontaneous chemical reactions through the use of a direct electric current flowing between two electrodes placed opposite each other. These chemical reactions cause a dissociation of the water molecules into gaseous oxygen and hydrogen. This oxygen is transported by the water loop to the first treatment device 32 in order to separate it from the water and recover it. The hydrogen is transported by the water loop to the second treatment device 40 in order to separate it from the water and recover it.

[0052] The water electrolysis block 52 comprises a first channel 54 configured to be traversed by water. When the water passes through the first channel 54, it is electrolyzed, thus forming the mixture of water and dioxygen mentioned above. The first channel 54 is fluidically connected with the inlet 10 of the first treatment device 32. This connection makes it possible to supply the first treatment device 32 with a water / dioxygen mixture.

[0053] A second channel 56 is part of the water electrolysis block 52. This second channel 56 is configured to be traversed by water in order to assist in the evacuation of the mixture of water and dihydrogen. The second channel 56 is fluidically connected with the access 11 of the second treatment device 40. This connection makes it possible to supply the second treatment device 40 with a water / dihydrogen mixture.

[0054] The first treatment device 32 comprises a water inlet 58 fluidly connected to the treated water collection module 9. Thus, the water treated by the purification module 34 is mixed with water coming from outside the electrolyser, in the treated water collection module 9. It is thus possible to supplement the water loops of the two treatment devices 32, 40 with water.

[0055] The water electrolyser 38 comprises a pump 60, hereinafter referred to as the first pump 60a, disposed between the water outlet 14 of the second treatment device 32 and a filter 62. The filter 62 makes it possible to filter the water treated by the purification module 34 and the water added to the second treatment device 32 via the water inlet 58. The water passing through the filter 62 is then sent into the water electrolysis unit 52 via the first pump 60a. An outlet of the filter 62 is connected to an inlet of the first channel 54 of the electrolysis unit 52.

[0056] A pump 60, hereinafter called 60b, is part of the water electrolyser 38, this second pump 60b being placed between a water outlet 15 of the second treatment device 40 and the electrolysis block 52, in particular an inlet of the second channel 56. This second pump 60b sends the water treated by the second treatment device 40 into the water electrolysis block 52.

[0057] The water level present in the second treatment device 40 configured to produce dihydrogen increases faster than that present in the first treatment device 32, which is configured to produce dioxygen. It may therefore be necessary to balance the water level between the two columns. Thus, a bypass pipe 66 extends between the water outlet 15 of the purification member 48 and the inlet of the filter 62. This bypass pipe 66 therefore makes it possible to balance the water levels by transferring a portion of the excess water accumulated in the second treatment device 40 to the water loop which passes through the first treatment device 32.

[0058] The bypass line 66 may comprise a pump 60, hereinafter called third pump 60c, for circulating water between the water outlet 15 of the second treatment device 40 and the filter 62. The portion of the bypass line 66 between the filter 62 and the third pump 60c comprises a valve 70 for controlling the circulation of water within the bypass line 66, depending on the need for balancing between the two water loops. It should be noted that the pump 60c is optional. Indeed, the second treatment device 40 being higher in pressure thanks to the pressure difference between the dihydrogen side (for example 10 barg) and the dioxygen side (for example 7 or 3 barg), the pressure difference The flow rate is sufficient to push the water from the water outlet 15 to the oxygen-side circulation loop upstream of the filter 62.

[0059] In a variant of the invention, the bypass pipe 66 may comprise a separation module configured to separate any gas residues present in the water at the discharge 15. The separation module is advantageously coupled to a degassing device, connected to a vent network allowing the discharge of degassed dihydrogen residues to the atmosphere. Such a separation module arranged between the second treatment device 40 and the first treatment device 32 makes it possible to limit the transfer of dihydrogen to the first treatment device 32 in the case where dihydrogen remains in the water at the discharge 15. Of course, the invention is not limited to the examples which have just been described and numerous adjustments can be made to these examples without departing from the scope of the invention.

[0060] The invention, as just described, achieves the aim it set itself, and makes it possible to propose a column-shaped water treatment device and a water electrolyzer making it possible to reduce the footprint for the generation of dihydrogen and dioxygen. Variants not described here could be implemented without departing from the context of the invention, provided that, in accordance with the invention, they comprise a water treatment device in accordance with the invention, that is to say at least partly in the form of a vertical column.

Claims

Claims

1. Device (2) for treating a mixture of water and a gas coming from a water electrolysis block (52), comprising a separation module (4) configured to separate the gas from the water contained in the mixture, a first cooling module (6) for the gas coming from the separation module (4) and a second cooling module (8) for the water coming from the separation module (4), characterized in that the modules (4, 6, 8) are superimposed on top of each other so that the treatment device (2) forms a column.

2. A treatment device (2) according to claim 1, wherein the separation module (4) is vertically interposed between the first cooling module (6) and the second cooling module (8).

3. Treatment device (2) according to any one of claims 1 or 2, wherein the separation module (4) comprises a mixture inlet (10), a gas outlet (12) on an upper part (16) of the separation module 4 and a water outlet (14) on a lower part (18) of the separation module (4).

4. Treatment device (2) according to the preceding claim, wherein an inlet of the first cooling module (6) is fluidically connected to the gas outlet (12) of the separation module (4) and an inlet of the second cooling module (8) is fluidically connected to the water outlet (14) of the separation module (4).

5. Treatment device (2) according to any one of the preceding claims, in which the first cooling module (6) comprises a first circuit (20) configured to be traversed by the gas coming from the separation module (4) and a second circuit (22) configured to be traversed by a heat transfer fluid intended to cool the gas.

6. Treatment device (2) according to any one of the preceding claims, in which the second cooling module (8) comprises a first pass (24) configured to be traversed by the water coming from the separation module (4) and a second pass (26) configured to be traversed by a heat transfer fluid intended to cool the water.

7. Treatment device (2) according to any one of the preceding claims, comprising a module for purifying the water (34) from of the second cooling module (8), the purification module (34) being positioned vertically under the second cooling module (8).

8. Treatment device (2) according to any one of the preceding claims, in which the superposition of the modules measures between 9 and 15 meters high and the floor area of the superposition of the modules is between 0.96m2 and 1.44m2.

9. A water electrolyzer (38) comprising at least one first treatment device (32) according to any one of the preceding claims, the mixture treated by the first treatment device (32) being a mixture of water and dioxygen, the water electrolyzer (38) comprising a second treatment device (40) for treating a mixture of water and dihydrogen, the second treatment device (40) comprising at least one separation member (44) configured to separate the dihydrogen from the water contained in the mixture, a first cooling member (46) for the dihydrogen from the separation member (44) and a purification member (48) for the water from the separation member (44), the water electrolyzer (38) comprising at least one water electrolysis block (52) configured to deliver the mixture of water and dioxygen and the mixture of water and dihydrogen.

10. Water electrolyzer (38) according to the preceding claim, in which the members (44, 46, 48) of the second treatment device (40) are superimposed on top of each other so that the second treatment device (40) forms a column.

11. Water electrolyzer (38) according to the preceding claim, comprising at least one pump (60, 60a, 60b) configured to circulate water from at least one of the columns to the electrolysis block (52), said pump (60, 60a, 60b) being fluidically arranged between the column and the electrolysis block (52).

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