Apparatus for carrying out electrolysis, and electrolysis method

Abstract

The invention relates to an apparatus (1) for carrying out electrolysis, the apparatus comprising: a vessel (2) for holding a liquid (3), in particular a liquid electrolyte (4); and an inductive element (12) having a core (13), in particular a closed core and preferably a soft-magnetic core, for guiding a magnetic flux (φ), and a primary winding (14) for inducing an electrical voltage (Ui) in particular directly into the liquid (2) during operation of the apparatus (1); wherein the vessel (2) has a concentration section (15) and a circulation section (16) which is connected to a first end (20) and a second end (21) of the concentration section (15) and is guided at least partially around the inductive element (12), wherein the concentration section (15) is designed, during operation of the apparatus (1), to increase an electrical current density (J) of an electrical current (Ii) caused by the induced electrical voltage (Ui) in comparison with the circulation section (16). The invention also relates to an electrolysis method.

Description

[0001] Device for carrying out electrolysis and electrolysis process

[0002] The invention relates to a device for carrying out an electrolysis, comprising: a vessel for holding a liquid, in particular a liquid electrolyte; and an inductive element with a particularly closed and preferably soft-magnetic core for guiding a magnetic flux and a primary winding in order to induce an electrical voltage, in particular directly into the liquid, during operation of the device.

[0003] Furthermore, the invention relates to an electrolysis process with a device for carrying out an electrolysis, wherein an alternating voltage is applied to a primary winding of the device.

[0004] Electrolysis is a chemical process in which an electric current forces a redox reaction in an electrolyte, producing reaction products from the substances contained in the electrolyte. Electrolysis is used on a large scale in the industrial production of hydrogen and chlorine, among other things.

[0005] A well-known variant of electrolysis is direct current electrolysis. In this process, direct current is passed between two electrodes immersed in an electrolyte. Electrolysis produces reaction products at the electrodes from the substances contained in the electrolyte. Since the chemical reactions in direct current electrolysis take place at the electrodes, and the electrodes are thus integrated into the chemical process, the electrodes in direct current electrolysis are consumable parts that decompose and must therefore be replaced regularly.

[0006] An alternative electrolysis method uses alternating current. Although alternating current electrolysis typically yields lower oxyhydrogen gas yields than direct current electrolysis, it offers the advantage that, by generating an alternating electrical current in the electrolyte, electrodes and thus their regular replacement are no longer required.

[0007] An electrolysis process based on alternating current is described in document RU 81 189 U1, which discloses a complex electrolysis device. A direct current component is superimposed on the alternating current component.

[0008] The documents RU 215 527 Ul and WO 2011 / 038432 Al respectively.

[0009] US 2023 / 0012657 A1 each discloses an electrolysis process using alternating current. However, the described processes still require electrodes, which decompose and must be replaced.

[0010] US 2021 / 0156037 A1 relates to an electrolysis device with several coils arranged around a housing. A vertical flow channel is arranged within the housing, in which an electrolyte is exposed to an alternating magnetic field. An electrostatic field is generated using additional electrodes. Further excitation is generated using an LED array.

[0011] Further devices in connection with electrolysis are known from EP 3 981 897 A1 and WO 2022 / 124711 A1.

[0012] In light of these statements, it is an object of the present invention to at least partially mitigate or even completely eliminate the disadvantages of the prior art. Preferably, the object of the present invention is to provide a simply constructed device for carrying out electrolysis and a highly efficient electrolysis process based on alternating current.

[0013] This object is achieved by an electrolysis device according to claim 1 and by an electrolysis method according to claim 13.

[0014] According to the invention, in a device of the type mentioned at the outset, the vessel has a concentration section and a circulation section which is connected to a first and a second end of the concentration section and is guided at least partially around the inductive element, the concentration section being designed to increase, during operation of the device, an electrical current density of an electrical current caused by the induced electrical voltage compared to the circulation section. Preferably, the concentration section is designed to increase, in particular to maximize, the current density in the concentration section compared to the entire remainder of the vessel.With the aid of the device according to the invention, an alternating voltage and thus an alternating current can be induced directly in the liquid by applying an alternating voltage to the primary winding, whereby electrolysis of the liquid takes place. Because the alternating current is induced directly in the liquid, in contrast to direct current electrolysis, no electrodes are required. The electrolysis takes place directly in the liquid. Replacing electrodes due to decomposition of the electrodes is therefore not necessary. The electrolysis of the liquid primarily takes place in the concentration section. However, electrolysis can also take place sporadically at other points in the vessel. The invention is based on the knowledge that a high electrical current density is advantageous for electrode-free electrolysis based on alternating current and leads to electrolysis.The concentration section is designed and arranged in the device in such a way that during operation of the device a high current density, preferably of at least 5 A / mm. 2, is generated. In a preferred variant of the invention, the current density during operation of the device in the concentration section is highest compared to the current density of the induced current in the other sections of the vessel. The high current density can be generated in particular by narrowing the vessel in the concentration section. The current density can be approximately determined from the number of turns of the primary winding (essentially corresponds to a transformation ratio), the current intensity in the primary winding and an effective area, in particular a cross-sectional area, of the concentration section. The number of turns is, for example, between 1 and 100. The cross-sectional area of ​​the concentration section is, for example, between 3 mm 2 and 20 mm 2. The current strength in the primary winding can be between 1 A and 100 A, for example. The concentration section is preferably arranged centrally in the vessel. The circulation section, through its arrangement around the inductive element and its connection to the first and second ends of the concentration section, enables an electrical voltage loop and thus an electrical current flow around the inductive element. Preferably, the concentration section and the circulation section for the liquid form a closed loop around the inductive element. A voltage can be induced and a current can flow in this loop. The concentration section can, in particular, be elongated. Preferably, the concentration section is straight, i.e., not curved, when viewed in a section, in particular a longitudinal section. The concentration section can have substantially the same width over its entire length.In one embodiment of the invention, the concentration section is tubular. The circulation section is in fluid communication with the concentration section at the first and second ends. This allows the liquid to flow from the circulation section into the concentration section and back into the latter. The vessel is preferably made of plastic, in particular electrolyte-resistant plastic. The vessel preferably has a volume of at least 10 1. The concentration section is preferably guided through a recess in the inductive element. The primary winding can be wound continuously around the core, preferably along the entire length of the core. The core of the inductive element is preferably made of nanocrystalline material. By applying an alternating voltage to the primary winding, a magnetic flux is generated in the core, which leads to an induced voltage in the liquid.The liquid thus forms, in analogy to a transformer, the secondary winding.

[0015] All location and direction information in this disclosure relates to the intended use of the device, in which electrolysis is carried out. A longitudinal axis of the concentration section is preferably arranged substantially parallel to the acceleration due to gravity. In a preferred variant of the invention, the concentration section has a constriction in the vessel. In this way, the electrical current density in the concentration section is increased compared to the current density in the circulation section and the electrolysis is focused in the concentration section. The constriction can in particular represent the narrowest point of the vessel for the liquid. In the constriction, the vessel preferably has the smallest cross-sectional area for the liquid. The cross-sectional area is preferably a substantially horizontal cross-sectional area.

[0016] It is preferred if the concentration section, viewed in a section, in particular a cross-section or a longitudinal section, has a smaller width than the circulation section. It is particularly preferred if the concentration section has the smallest width of all sections of the vessel.

[0017] In one embodiment of the invention, it is provided that, viewed in a section, in particular a cross-section or longitudinal section, the circulation section has two circulation regions guided around the inductive element, wherein the two circulation regions are each connected to a first and a second end of the concentration section. Preferably, the circulation regions are located on opposite sides of the concentration section, viewed in the section. The circulation regions themselves are preferably in fluid communication with one another at an upper side and at a lower side of the vessel, each via a connecting section of the circulation section. The circulation regions are also in fluid communication with the concentration section, preferably at the upper side and at the lower side of the vessel, in particular via the connecting sections of the circulation section.Preferably, the width of the concentration section, as seen in the section, is smaller than the width of the circulation regions. It is particularly preferred if the width of the concentration section is reduced by at least a factor of two compared to the width of the circulation regions. The width can correspond to a diameter of the concentration section or of the circulation regions. In one embodiment of the invention, it is provided that a tapered section of the circulation section, which tapers conically in the direction of the concentration section, adjoins the first end and / or the second end of the concentration section and via which the circulation section is connected to the concentration section. Viewed in the above-mentioned section, the width of the concentration section is thus smaller than the width of the end region of the tapered section(s) facing away from the concentration section.Viewed in the mentioned section, the circulation regions can be connected to the concentration section via the above-mentioned connecting sections and the tapered section at the first end and at the second end, respectively.

[0018] To remove gases, particularly oxyhydrogen gases, it is advantageous if a longitudinal axis of the concentration section is arranged essentially vertically. The oxyhydrogen gases produced during electrolysis can rise upwards and thus be transported out of the concentration section. In order to separate the hydrogen from the oxygen in a hydrogen-oxygen mixture as oxyhydrogen gas, a ceramic element can be used, for example. Such a ceramic element can be arranged, for example, on the upper side of the device, in particular at a discharge opening to be described further below. The ceramic element can act as a membrane for certain gas molecules, particularly for hydrogen molecules. For this purpose, the ceramic element can have pores which, due to their size, only allow hydrogen molecules to pass through. This allows the hydrogen to be separated from the oxygen.

[0019] It is advantageous if the concentration section is guided through a recess in the inductive element. The recess is preferably an opening delimited by the core and the primary winding arranged thereon, in particular a through-opening. The opening can, for example, have a round or square shape. The core of the inductive element is guided at least partially or completely around the recess and thus enables the guidance of a magnetic flux around the recess and thus around the concentration section. In one embodiment of the invention it can be provided that a main extension plane of the inductive element is arranged essentially horizontally. In particular an area delimited by the recess can be oriented essentially horizontally. The core of the inductive element is preferably arranged horizontally.

[0020] A particularly compact and efficient embodiment of the device results when a longitudinal axis of the concentration section is arranged substantially at right angles to a main extension plane of the inductive element, preferably wherein the concentration section penetrates the main extension plane of the inductive element. The concentration section can penetrate the main extension plane of the inductive element, in particular by means of the recess. It is particularly preferred if the longitudinal axes of the circumferential regions, viewed in section, also run at right angles to the main extension plane of the inductive element and preferably penetrate it.

[0021] It is advantageous if the vessel has a discharge opening, particularly on its upper side, for discharging a gas, preferably an oxyhydrogen gas. If the longitudinal axis of the concentration section is oriented substantially vertically, gas produced during electrolysis can advantageously rise from the liquid and be discharged through the discharge opening.

[0022] In one embodiment of the invention, the vessel has a supply opening, particularly on its underside, for supplying the liquid. The supply opening can be connected to a storage container for the liquid via a supply line. In a further embodiment of the invention, the vessel can also have a drainage opening. The vessel can be continuously rinsed with the liquid through the supply opening and the drainage opening during operation of the device.

[0023] In a preferred embodiment of the invention, the vessel can be designed to be rotationally symmetrical about an axis of symmetry. The core of the inductive element can also be designed to be rotationally symmetrical about the axis of symmetry. The axis of symmetry preferably coincides with the longitudinal axis of the concentration section.

[0024] A particularly advantageous variant with regard to the level of the electrical voltage induced in the liquid results when the inductive element is substantially completely surrounded by the vessel. In other words, the inductive element, with the exception of leads for the primary winding, is arranged substantially completely within the vessel. For this purpose, the vessel can have a preferably central vessel recess for the inductive element. The circumferential section surrounds the inductive element substantially by 360°.

[0025] The object stated at the outset is also achieved by an electrolysis method in which a device for carrying out an electrolysis is used and an alternating voltage is applied to a primary winding of the device, the device for carrying out an electrolysis being designed as described above.

[0026] The features, advantages and effects described in connection with the device for carrying out electrolysis are transferable to the electrolysis process according to the invention. In the electrolysis process, an alternating voltage is applied to the primary winding, whereby an alternating magnetic flux is generated in the core of the inductive element, which induces an alternating electrical voltage and thus an alternating electrical current directly into the liquid. The alternating current causes electrolysis in the liquid. The electrolysis preferably takes place primarily in the concentration section. A direct current or direct voltage component is not provided in the liquid during normal operation of the device. The electrolysis is preferably generated exclusively by an alternating current or an alternating voltage in the liquid.If the vessel has a supply opening and preferably also a discharge opening, the vessel can be continuously supplied with fresh electrolyte and rinsed during operation of the device. Advantageously, the vessel is also cleaned as a result. The device according to the invention and the method according to the invention are particularly robust. The liquid therefore does not have to be as chemically pure as in the prior art methods. For this reason, water, for example salt water, in particular seawater, can be used as the electrolyte. Industrial wastewater can also be used as the electrolyte.

[0027] It is advantageous if the frequency of the alternating voltage is between 50 Hz and 100 kHz.

[0028] In one embodiment of the invention, a gas, in particular an oxyhydrogen gas, is discharged or ignited. The latter is particularly advantageous for decomposing undesirable components of the electrolyte.

[0029] The invention is described in more detail below with reference to figures, to which it is not intended to be limited. They show:

[0030] Fig. 1 is an exemplary overall view of an apparatus for carrying out electrolysis;

[0031] Fig. 2 is a longitudinal section through the device according to Fig. 1; and

[0032] Fig. 3 shows a cross section through the device according to Fig. 1.

[0033] Fig. 1 shows an overall view, reduced to the essentials, of an exemplary embodiment of a device 1 for carrying out an electrolysis according to the invention. The device 1 has a vessel 2 for holding a liquid 3, in particular an electrolyte 4. The vessel 2 can, for example, have a volume of between 10 l and 60 l. In the illustration shown, the vessel 2 has a lateral outer surface 5 which is essentially in the shape of a cylinder jacket, to which a cover surface 7 adjoins on an upper side 6 of the vessel 2, which cover surface forms a funnel-shaped connection 8 with a discharge opening 9 for discharging an oxyhydrogen gas 52. On an underside 10 of the vessel 2, a feed opening 50 is provided for feeding the liquid 3 into the interior of the vessel 2. The vessel 2 is elongated in the illustration shown.In the embodiment shown, a longitudinal axis 11 of the vessel 2 also forms an axis of symmetry for the vessel 2.

[0034] Fig. 2 shows a longitudinal section through the device 1 along the longitudinal axis 11. In Fig. 2 it can be seen that the device

[0035] 1 has an inductive element 12 with a soft magnetic core 13 for guiding a magnetic flux cp. The core 13 can be circular around the longitudinal axis 11. A main extension plane E12 of the inductive element 12, in particular of the core 13, is arranged horizontally. A primary winding 14 is wound around the core 13. By applying an electrical alternating voltage to the primary winding 14, a magnetic flux cp, in particular an alternating magnetic flux, is induced in the core 13, which in turn induces an alternating voltage U± and consequently an alternating current I± directly into the liquid 3 in the vessel 2. In this way, electrolysis is induced in the liquid 3 without the need for electrodes, as is the case with direct current electrolysis.

[0036] The vessel 2 has, as can also be seen in the cross section according to Fig. 3, a preferably vertically arranged concentration section 15 and a circulation section 16. The concentration section 15 is arranged substantially in the middle of the vessel 2 and can be tubular. The concentration section 15 is elongated and preferably arranged along the longitudinal axis 11 of the vessel 2. In other words, in the illustration shown, the longitudinal axis 11 of the vessel

[0037] 2 and the longitudinal axis of the concentration section 15 are identical. The length of the concentration section can be, for example, between 10 mm and 200 mm. The concentration section is guided through a recess 17 in the form of an opening 18 in the inductive element 12 or the core 13, so that the concentration section 15 intersects the main extension plane E12 of the inductive element 12. The vessel 2 preferably penetrates the opening 18 exactly once with the concentration section 15. Further penetrations of the vessel 2 through the opening 18 are preferably not provided. The concentration section 15 has a constriction 19 in the vessel 2. In the illustration shown, the constriction 19 is at the level of the surrounding core 13. The constriction 19 extends over the entire length of the concentration section 15. The constriction 19 has the smallest cross-sectional area of ​​the vessel 2 for the liquid 3.The electrolysis of the liquid 3 takes place predominantly in the concentration section 15, which, due to its position and cross-sectional area Ais, has the highest current density J of the alternating current li. The current density J is calculated from the current intensity in the primary winding 14, the number of turns N of the primary winding, and the cross-sectional area A15 of the concentration section 15.

[0038] At a first end 20 and a second end 21 of the concentration section 15 there is in each case a tapered section 22 of the circulation section 16 which converges conically in the direction of the concentration section 15. The axis of symmetry of the tapered sections 22 coincides with the longitudinal axis 11 of the vessel 2. The concentration section 15 is connected to the circulation section 16 by the two tapered sections 22. The circulation section 16 has, as seen in the longitudinal section according to Fig. 2, two opposite circulation regions 23 which are in fluid communication with one another and with the corresponding tapered section 22 on the top side 6 and on the bottom side 10 of the vessel 2 via a connecting section 24. In the longitudinal section according to Fig. 2 considers the first end 20 with the second end 21 of the concentration section 15.This allows the liquid 3 to flow in a circle through the concentration section 15 and the circulation section 16. The circulation regions 23 are elongated. The circulation regions 23 are part of a substantially hollow, cylindrical part 51 of the vessel 2 (see Fig. 3). The longitudinal axes 25 of the circulation regions 23 are arranged parallel to the longitudinal axis 11 of the vessel 2. Between the circulation regions 23 and the concentration section 15 there is a vessel recess 26 in which the inductive element 12 is received. The vessel recess 26 surrounds the concentration section 15. The alternating voltage Ui runs along the circulation regions 23 and the concentration section 15. Accordingly, the induced current Ii also flows along the circulation regions 23 and the concentration section 15. The direction of the voltage U± and the current I± changes with the frequency of the alternating voltage applied to the primary winding 14.

[0039] In Fig. 2 it can be seen that the width of the concentration section B1 is smaller than the respective width B23 of the circulation areas 23.

[0040] In Fig. 2, the discharge opening 9 for discharging oxyhydrogen gas can also be seen on the top side 6. The resulting oxyhydrogen gas rises in the liquid 3 and can be discharged via the discharge opening 9. The supply opening 50, through which the vessel can be supplied with fresh liquid 3, can be seen on the bottom side 10.

[0041] Fig. 3 shows a cross-section through the device 1, which runs parallel to the main extension plane E12. The circulation region has a hollow cylindrical cross-section in Fig. 3. In Fig. 3 it can be seen that the circulation regions 23 visible in the longitudinal section according to Fig. 2 are part of the circulation section 16 and form components of the essentially hollow cylindrical part 51 of the vessel 2. The circulation section 16 and the core 13 are arranged concentrically around the concentration section 15.

Claims

Claims:

1. Device (1) for carrying out electrolysis, comprising: a vessel (2) for holding a liquid (3), in particular a liquid electrolyte (4); and an inductive element (12) with a particularly closed and preferably soft-magnetic core (13) for guiding a magnetic flux (cp) and a primary winding (14) in order to induce an electrical voltage (U±), in particular directly, into the liquid (2) during operation of the device (1);characterized in that the vessel (2) has a concentration section (15) and a circulation section (16) which is connected to a first (20) and a second end (21) of the concentration section (15) and is guided at least partially around the inductive element (12), wherein the concentration section (15) is designed to increase an electrical current density (J) of an electrical current (I±) caused by the induced electrical voltage (U±) in comparison to the circulation section (16) during operation of the device (1); 2. Device (1) according to claim 1, characterized in that the concentration section (15) has a constriction (19) of the vessel (2).

3. Device (1) according to claim 1 or 2, characterized in that the concentration section (15) has a smaller width than the circulation section when viewed in a section, in particular a cross-section or longitudinal section.

4. Device (1) according to one of claims 1 to 3, characterized in that, viewed in a section, in particular a cross-section or longitudinal section, the circulation section (16) has two circulation regions (23) guided around the inductive element (12), wherein the two circulation regions (23) are each connected to the first (20) and a second end (21) of the concentration section (15).

5. Device (1) according to one of claims 1 to 3, characterized in that characterized in that a tapered section (22) of the circulation section (16) converges conically in the direction of the concentration section (15) and connects to the first end (20) and / or the second end (21) of the concentration section (15), via which tapered section(s) the circulation section (16) is connected to the concentration section (15).

6. Device (1) according to one of claims 1 to 5, characterized in that the concentration section (15) is guided through a recess (17) of the inductive element (12).

7. Device (1) according to one of claims 1 to 6, characterized in that a main extension plane (E12) of the inductive element (12) is arranged substantially horizontally.

8. Device (1) according to one of claims 1 to 7, characterized in that a longitudinal axis (11) of the concentration section (15) is arranged substantially at right angles to a main extension plane (E12) of the inductive element (12), preferably wherein the concentration section (15) penetrates the main extension plane (E12) of the inductive element (12).

9. Device (1) according to one of claims 1 to 8, characterized in that the vessel (2) has, in particular on an upper side (6), a discharge opening (9) for discharging a gas, preferably an oxyhydrogen gas (52).

10. Device (1) according to one of claims 1 to 9, characterized in that the vessel (2) has, in particular on a bottom side (10), a supply opening (50) for supplying the liquid (3).

11. Device (1) according to one of claims 1 to 10, characterized in that the vessel (2) is rotationally symmetrical about an axis of symmetry.

12. Device (1) according to one of claims 1 to 11, characterized in that the inductive element (12) is substantially completely surrounded by the vessel (2).

13. Electrolysis method with a device (1) for carrying out an electrolysis, wherein an alternating voltage is applied to a primary winding (14) of the device (1), characterized in that it is designed to carry out an electrolysis according to one of claims 1 to 12.

14. Electrolysis process according to claim 13, characterized in that water, for example salt water, is used as the electrolyte (4).

15. Electrolysis process according to claim 13 or 14, characterized in that a gas, in particular an oxyhydrogen gas (52), is discharged or ignited.

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