Treatment device, treatment system and treatment method for treating water for an electrolyzer

Abstract

The invention relates to a treatment device (1) for treating water for an electrolyser (2), comprising: a pre-water supply (3) for providing pre-water (4); a vapour compression distiller (5), in particular a mechanical vapour compression distiller (5), for pre-purifying the supplied pre-water (4) wherein the vapour compression distiller (5) is configured to produce a distillate (6) and a concentrate (7) from the supplied pre-water (4); a concentrate discharge device (8) for discharging the concentrate; and a distillate supply device (9) for supplying at least part of the distillate to the electrolyzer (2) or to a cooling water reservoir (10) of the electrolyzer (2).

Description

Background Art

[0001] Typically, water electrolysis for hydrogen production is carried out within civilian infrastructure, in cities or industrial areas. However, the future of producing hydrogen in a carbon dioxide-neutral manner also requires electrolysis in remote areas, especially at sea (using wind energy) or in deserts (using solar or wind energy). In order to be able to perform electrolysis efficiently, pure water is required, and its purity even needs to be higher than that of drinking water. Therefore, it is necessary to have a water treatment plant that can treat highly saline and contaminated water in remote areas. Here, the water treatment for electrolysis is mainly achieved by reverse osmosis combined with ion exchange.

[0002] Currently known electrolysis systems, consisting of an electrolyzer and water treatment equipment, are only suitable to a limited extent for use in remote areas due to their high maintenance costs, which significantly increase operating costs. Furthermore, most electrolysis systems require chemical cleaning. Regular cleaning, while extending the service life, shortens maintenance intervals, leading to chemical emissions that pollute the environment and, therefore, jeopardize the sustainability of the electrolyzer's CO2-neutral concept. Summary of the Invention

[0003] The present invention proposes a treatment device for treating water for an electrolyzer, the treatment device comprising: a feed water supply (Vorlaufwasserspender) for providing feed water (Vorlaufwasser); a steam compression distiller, in particular a mechanical steam compression distiller, for pre-purifying the provided feed water, wherein the steam compression distiller is configured to produce a distillate and a concentrate from the provided feed water; a concentrate discharge device for discharging a first concentrate; and a distillate supply device for supplying at least a portion of the distillate to the electrolyzer or a cooling water reservoir of the electrolyzer.

[0004] In this context, feedwater can be contaminated water available in a region, such as a remote area. This contaminated water can be, for example, seawater, lake water, rainwater, or wastewater. This contaminated water is supplied to the treatment device via a feedwater reservoir or a feedwater pump, i.e., a feedwater supply. The feedwater supply can be any device capable of supplying feedwater to the treatment device.

[0005] Steam-compression stills are used to purify raw water, removing salts and other contaminants from it. The resulting distillate is very pure water. The operating principle of a steam-compression still is based on the compression of water vapor. Furthermore, the water vapor can be compressed using mechanical means such as a steam compressor. The resulting steam is directed to a heat exchange condenser, which converts the steam into water. The resulting distillate is partially discharged or stored, while the heat released by condensation is transferred to the raw water.

[0006] The distillate from the water treatment, ie the pure water, has a pH value of approximately 7. This protects the components of the treatment plant from scaling.

[0007] Mechanical vapor compression stills preferably produce distillate in the temperature range of 70° C. to 85° C. This has a positive effect on corrosion protection and reduces biological contamination.

[0008] The treatment device produces a distillate of sufficient quality in a simple manner to supply the electrolyser or the cooling water reservoir of the electrolyser, where the distillate can be used as process water and / or cooling water.

[0009] Advantageously, an electrodeionizer is provided for further purification of the distillate, wherein the electrodeionizer is connected downstream of the vapor compression still.

[0010] An electrodeionizer can form the second stage of water treatment in a treatment plant. The advantage of an electrodeionizer is that it produces ultrapure water and a second concentrate, a concentrated brine, from the distillate produced by the vapor compression still. "Post-purification" here should be understood as further increasing the purity of the distillate. This post-purification is necessary for the use of ultrapure water as process water in the electrolyzer to avoid compromising the electrolyzer's service life. The concentrated brine can be disposed of or re-supplied to the feedwater supply.

[0011] Furthermore, it is conceivable to provide an electrodialyser for pre-treatment of the feed water.

[0012] The electrodialyzer is fluidically connected to the vapor compression distiller and the feed water. The electrodialyzer can form the third stage of water treatment using a treatment plant. The feed water is mineralized by the concentrate concentrated in the electrodialyzer to prevent scaling of the treatment plant. The electrodialyzer product water is a solution with a low pH value, which primarily protects the vapor compression distiller from scaling. During electrodialyzer operation, the use of chemical descaling agents can be eliminated. This reduces maintenance intervals, thereby reducing labor and maintenance costs.

[0013] Furthermore, an external distillate storage is advantageously provided for additional storage of the distillate produced by the vapor compression still.

[0014] This enables the storage of distillate, which can be used in other processes or, after remineralization, as distillate for human consumption. This is particularly advantageous in remote areas where there are often no sources of distillate.

[0015] Furthermore, it is particularly advantageous if the treatment system is designed to be mobile, which enables the treatment device to be used independently of location and facilitates transport.

[0016] It is also conceivable to provide a heating device for the supply water, wherein the heating device is designed to heat the supply water to a temperature of 5 to 30° C., preferably 10 to 25° C.

[0017] This enables efficient treatment of the forewater in the vapor compression still, thereby shortening the start-up process for treating the forewater during cold starts.

[0018] In a second aspect, a treatment system is proposed, comprising the above-described treatment device and an electrolyzer and / or a cooling water reservoir for the electrolyzer.

[0019] The distillate from the treatment plant, after further treatment to ultrapure water, is particularly suitable for use as product water in the medium circuit because it is of extremely high purity, i.e., it is purer than the distillate. Furthermore, the distillate and / or product water can have a cooling function in the respective circuit through which they flow.

[0020] In a third aspect, a method for treating water, in particular process water, of an electrolyzer by means of the above-mentioned treatment device is proposed, the method comprising the following steps:

[0021] -Pre-water is provided by a pre-water supply device;

[0022] - pre-purification of the feed water by means of a steam compression distiller, wherein a distillate and a first concentrate are produced;

[0023] - discharging the first concentrate by means of a concentrate discharge device;

[0024] - supplying at least part of the distillate to the electrolyser or to a cooling water reservoir of the electrolyser by means of the distillate supply device.

[0025] By means of the method, a distillate of sufficient quality can be produced in a simple manner to supply the electrolyser or the cooling water reservoir of the electrolyser. Here, the distillate can be used as process water and / or cooling water.

[0026] Furthermore, an electrodeionizer can be provided, by which the distillate is further purified, producing a purified distillate and a second concentrate, wherein the purified distillate is supplied to the electrolyzer or the cooling water reservoir. In this case, the distillate supply is interrupted by the electrodeionizer, with the distillate being supplied first and the purified distillate being supplied secondarily.

[0027] Additional purification of the distillate increases the purity of the water. The purer the distillate, the more suitable it is for possible use in the electrolyser.

[0028] Furthermore, it is advantageous if at least part, in particular the entirety, of the second concentrate produced by the electrodeionizer is supplied to the feed water.

[0029] The second concentrate is used to prevent scaling of processing equipment components, particularly the vapor compression still. This reduces or even eliminates the use of chemicals, thereby lowering maintenance and labor costs.

[0030] A further advantage is that water from the electrolyser or from the cooling water reservoir of the electrolyser can be fed to the electrodeioniser for further purification.

[0031] This provides a purification step for the subsequent device, in this case the electrolyser. Thus, the product water or cooling water can be processed again or partially replaced, for example.

[0032] Additionally, it is conceivable to provide an electrodialyzer, by which the first concentrate of the steam-compression distiller is at least partially, in particular completely, demineralized, the demineralized water is discharged, and the minerals are supplied to the feed water. The electrodialyzer thus further separates the first concentrate of the steam-compression distiller into two products: an alkaline solution that is discharged and an acid solution that is fed back to the feed water.

[0033] Here, feedwater is pre-treated with acid generated by the electrodialyzer to prevent scaling of the treatment equipment, primarily the vapor compression still. This anti-scaling process eliminates the need for chemical descaling agents. This reduced or complete elimination of chemical use shortens maintenance intervals, reducing labor and maintenance costs.

[0034] A further advantage is that the second portion of the pre-cleaned distillate is supplied to an external distillate storage, which enables the distillate to be provided to other processes or persons in remote areas.

[0035] Furthermore, the feed water is advantageously preheated to a temperature of 5 to 30° C., preferably 10 to 25° C. This enables efficient treatment of the feed water in the vapor compression still, thereby saving energy and efficiently treating the feed water.

[0036] Other advantages, features and details of the present invention will be apparent from the following description, in which embodiments of the present invention are described in detail with reference to the accompanying drawings. The features mentioned in the claims and the description may constitute essential features of the present invention alone or in any combination. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] The accompanying drawings show:

[0038] Figure 1 is a schematic diagram of a processing device;

[0039] Figure 2 is a schematic diagram of the processing system;

[0040] Figure 3A schematic diagram of the method. DETAILED DESCRIPTION

[0041] Figure 1 A treatment device 1 for treating water for an electrolyzer 2 is shown, comprising: a forewater supply 3 for providing forewater 4; a steam compression distiller 5, in particular a mechanical steam compression distiller 5, for pre-purifying the provided forewater 4, wherein the steam compression distiller 5 is configured to produce a distillate 6 and a first concentrate 7 from the provided forewater 4; a concentrate discharge device 8 for discharging the first concentrate 7; and a distillate supply device 9 for supplying at least part of the distillate 7 to the electrolyzer 2 or a cooling water reservoir 10 of the electrolyzer 2.

[0042] according to Figure 1 Treatment unit 1 is equipped with an electrodeionizer 11 for further purification of distillate 6. During the purification process, the electrodeionizer separates high-purity distillate 6 into a second concentrate 12. Distillate 6 is supplied to electrolyzer 2 or its cooling water reservoir 10 via distillate supply device 9. Second concentrate 12 contains acid and is supplied to pre-water 4 for pre-processing or discharged from treatment unit 1. The electrodeionizer is functionally connected downstream of vapor compression distiller 5.

[0043] To prevent scaling of the treatment device 1, in particular the vapor compression distiller 5, an electrodialyser 13 is provided. This electrodialyser utilizes the first concentrate 7 of the vapor compression distiller 5. This produces a second concentrate 12 with a low pH value, which is supplied to the pre-water 4 and water which is discharged.

[0044] Furthermore, an external distillate storage 15 is provided for additionally storing the distillate 6 produced by the vapor compression still 5 .

[0045] Furthermore, the processing system 17 is configured to be movable.

[0046] In order to efficiently treat the pre-water 4, especially to heat the pre-water faster during cold start, a heating device 16 for the pre-water 4 is provided in the treatment device 1. The heating device 16 is configured to heat the pre-water 4 to a temperature of 5 to 30°C.

[0047] Figure 2 A processing system 17 is shown having Figure 1 The treatment device 1 and the electrolyser 2 and / or the cooling water reservoir 10 of the electrolyser 2 are shown.

[0048] Figure 3 and Figure 1 A method 100 for treating water for an electrolyser 2 using the treatment device 1 is shown, the method comprising the following steps:

[0049] - Providing 110 front water 4 from the front water supplier 3;

[0050] - pre-purification 120 of the forewater 4 by means of a vapor compression distiller 5 , wherein a distillate 6 and a first concentrate 7 are produced;

[0051] - discharging 130 the first concentrate 7 by means of the concentrate discharge device 8 ;

[0052] - supplying 140 at least part of the distillate 6 to the electrodeionizer 11 and another part to the external distillate storage 15;

[0053] Repurification 150 of the distillate 6 by means of the electrodeionizer 11 , wherein a repurified distillate 18 and a second concentrate 12 are produced;

[0054] The re-purified distillate 18 is supplied 160 to the electrolyzer 2 or to the cooling water reservoir 10 of the electrolyzer 2 by means of the distillate supply device 9 .

[0055] In this case, a portion of the second concentrate 12 is discharged 170 from the entire treatment device 1 , and another portion is supplied 180 again to the feedwater 4 for pre-processing.

[0056] Furthermore, the electrolyser 2 or the cooling water reservoir 10 of the electrolyser 2 can supply 190 water to the electrodeioniser 11 for re-purification, which is Figure 2 It is shown schematically in FIG.

[0057] To prevent scaling of the treatment device 1, in particular of the vapor compression distiller 5, a further demineralization 200 is provided by means of an electrodialyser 13. The alkaline water 19 is then discharged 210 and the acidic water 14 is supplied to the pre-water 4.

[0058] To provide distillate 6 to humans or other processes, a second portion of the pre-cleaned distillate 6 is supplied 230 to an external distillate storage 15 .

[0059] Furthermore, in order to accelerate the cold start of the method 100 for treating the forewater, a heating device 16 is provided, by which the forewater 4 is preheated to a temperature of 5 to 30° C. at 240° C.

Claims

1. A treatment device (1) for treating water for an electrolyser (2), the treatment device comprising: A front water supplier (3) for providing front water (4); a steam compression distiller (5), in particular a mechanical steam compression distiller (5), for pre-purifying the provided forewater (4), wherein the steam compression distiller (5) is configured to produce a distillate (6) and a first concentrate (7) from the provided forewater (4); a concentrate discharge device (8) for discharging the first concentrate (7); and A distillate supply device (9) is used to supply at least part of the distillate to the electrolyzer (2) or a cooling water reservoir (10) of the electrolyzer (2).

2. The processing device (1) according to claim 1, characterized in that An electrodeionizer (11) is provided for re-purifying the distillate (6), wherein the electrodeionizer (11) is connected downstream of the steam compression distiller (5).

3. The processing device (1) according to claim 1 or 2, characterized in that An electrodialyser (13) is provided for repurifying the first concentrate (7) of the vapor compression distiller (5) and for pre-processing the forewater (4).

4. The processing device (1) according to any one of the preceding claims, characterized in that An external distillate storage (15) is provided for additionally storing the distillate (6) produced by the vapor compression distiller (5).

5. The processing device (1) according to any one of the preceding claims, characterized in that The processing device (1) is configured to be movable.

6. The processing device (1) according to any one of the preceding claims, characterized in that A heating device (16) is provided for the front water (4), wherein the heating device (16) is designed to heat the front water (4) to a temperature of 5 to 30° C., preferably 10 to 25° C.

7. A treatment system (17) comprising a treatment device (1) according to any one of the preceding claims and an electrolyser (2) and / or a cooling water reservoir (10) for the electrolyser (2).

8. A method (100) for treating water for an electrolyser (2) using the treatment device (1) according to any one of claims 1 to 6, the method comprising the following steps: - providing (110) front water (4) from the front water supplier (3); - pre-purification (120) of the forewater (4) by means of a steam compression distiller (5), wherein a distillate (6) and a first concentrate (7) are produced; - discharging (130) the first concentrate (7) by means of a concentrate discharge device (8); - supplying (160) at least part of the distillate (6) to the electrolyser (2) or to a cooling water reservoir (10) of the electrolyser (2) by means of a distillate supply device (9).

9. The method according to claim 8, characterized in that An electrodeionizer (11) is provided, by which the distillate (6) is re-purified (150), wherein a re-purified distillate (18) and a second concentrate (12) are produced, wherein the re-purified distillate (18) is supplied (160) to the electrolyzer (2) or the cooling water reservoir (10).

10. The method according to claim 9, characterized in that The second concentrate (12) produced by the electrodeionizer (11) is at least partially, in particular entirely, supplied (180) to the forewater (4).

11. The method according to any one of claims 8 to 10, characterized in that The electrolyzer (2) or the water in the cooling water reservoir (10) of the electrolyzer (2) is supplied to the electrodeionizer (11) for repurification (190).

12. The method according to any one of claims 8 to 11, characterized in that An electrodialyser (13) is provided, by which the first concentrate (7) of the steam compression distiller (5) is at least partially, in particular completely, demineralized (200), demineralized water (19), in particular alkaline solution, is discharged, and minerals, in particular acid solution, are supplied (220) to the front water (4).

13. The method according to any one of claims 8 to 12, characterized in that A second portion of the pre-purified distillate (6) is supplied (230) to an external distillate storage (15).

14. The method according to any one of claims 8 to 13, characterized in that The front water (4) is preheated (240) to a temperature of 5 to 30°C, preferably 10 to 25°C.

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