PERFORMING AN ELECTROLYSIS

Abstract

A method for performing an electrolysis using an electrolysis stack having multiple electrolysis cells, wherein each of the electrolysis cells has: an anode space with an anode, a cathode space with a cathode, a membrane that separates the anode space and the cathode space from each other, and a recombination catalyst. The method includes feeding an electrolysis medium to the electrolysis stack and determining a flow rate at which the electrolysis medium is fed to the electrolysis stack, providing electrical energy to the electrolysis stack for performing the electrolysis with the electrolysis medium fed to the electrolysis stack, and determining a degree of degradation of the membranes based on the determined flow rate of the electrolysis medium.

Claims

1. A method for performing electrolysis using an electrolysis stack having multiple electrolysis cells, wherein each of the electrolysis cells comprises: an anode space with an anode, a cathode space with a cathode, a membrane that separates the anode space and the cathode space from each other, a recombination catalyst, wherein the method comprises: feeding an electrolysis medium to the electrolysis stack and determining a flow rate at which the electrolysis medium is fed to the electrolysis stack, providing electrical energy to the electrolysis stack for performing the electrolysis with the electrolysis medium fed to the electrolysis stack, determining a degree of degradation of the membranes based on the determined flow rate of the electrolysis medium,

2. The method according to claim 1, wherein the method further comprises: issuing a warning, interrupting the electrolysis and/or performing maintenance on the membranes, in case the determined degree of degradation of the membranes exceeds a threshold value.

3. The method according to claim 1, wherein the electrical energy is provided to the electrolysis stack depending on the determined degree of degradation of the membranes.

4. The method according to claim 1, wherein a maintenance of the electrolysis stack is scheduled based on the determined degree of degradation of the membranes.

5. The method according to claim 1, wherein the electrolysis medium comprises water and the recombination catalysts are configured for recombining oxygen and hydrogen to water.

6. The method according to claim 1, wherein the recombination catalysts comprise a chemical composition involving platinum.

7. The method according to claim 1, wherein the recombination catalysts are arranged within the anode space of the respective electrolysis cell.

8. An arrangement comprising: an electrolysis stack having multiple electrolysis cells, wherein each of the electrolysis cells comprises: an anode space with an anode, a cathode space with a cathode, a membrane that separates the anode space and the cathode space from each other, a recombination catalyst, an electrolysis medium feed fluidly connected to the electrolysis stack, a flow meter for measuring a flow rate of the electrolysis medium through the electrolysis medium feed, a control unit that is connected electrically to the electrolysis stack for providing electrical energy to the electrolysis stack for performing the electrolysis with the electrolysis medium fed to the electrolysis stack with the electrolysis medium feed, connected electrically to the flow meter for receiving a measurement signal from the flow meter, and configured for determining a degree of degradation of the membranes based on the measurement signal received from the flow meter.

9. The arrangement according to claim 8, wherein the control unit is further configured for: issuing a warning, interrupting the electrolysis and/or issuing a signal indicating that maintenance on the membranes is supposed to be performed, in case the determined degree of degradation of the membranes exceeds a threshold value.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0069] In the following the invention will be described with respect to the figures. The figures show preferred embodiments, to which the invention is not limited. The figures and the dimensions shown therein are only schematic. The figures show:

[0070] FIG. 1 is an arrangement according to the invention,

[0071] FIG. 2 is a detailed view of a first embodiment of the electrolysis stack of the arrangement of FIG. 1, and

[0072] FIG. 3 is a detailed view of a second embodiment of the electrolysis stack of the arrangement of FIG. 1.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

[0073] FIG. 1 shows an arrangement 1 comprising an electrolysis stack 2. The electrolysis stack 2 is shown in more detail in FIGS. 2 and 3. Therein, two embodiments of the electrolysis stack 2 are shown. Since in FIG. 1 the degree of detail is lower than in FIGS. 2 and 3, the electrolysis stack 2 of FIG. 1 could be either of the electrolysis stacks 2 shown in FIGS. 2 and 3.

[0074] The arrangement 1 further comprises an electrolysis medium feed 10 fluidly connected to the electrolysis stack 2 and a flow meter 11 for measuring a flow rate of the electrolysis medium through the electrolysis medium feed 10.

[0075] Via the electrolysis medium feed 10 water can be fed to the electrolysis stack 2 as an electrolysis medium. In the shown example, the electrolysis medium feed 10 is realized as a single feed that provides the water to both anode spaces and cathode spaces of the electrolysis stack 2.

[0076] Within the electrolysis stack 2, an electrolysis can be performed with the water. The water remaining in the anode spaces can be guided together with the anode product, i.e. oxygen, from the electrolysis stack 2 to an anode separator 17. From the anode separator 17 the gaseous oxygen can be extracted via an oxygen outlet 19 and the liquid water can be fed back to the electrolysis stack 2. In order to compensate for losses of the water, new water can be introduced into the anode separator 17 via a water feed 22.

[0077] The water remaining in the cathode spaces of the electrolysis stack 2 can be guided together with the cathode product, i.e, hydrogen, from the electrolysis stack 2 to a cathode separator 18. From the cathode separator 18 the gaseous hydrogen can be extracted via a hydrogen outlet 20 and the liquid water can be extracted via a water outlet 21.

[0078] Also, the arrangement 1 comprises a control unit 12 that is [0079] connected electrically to the electrolysis stack 2 for providing electrical energy to the electrolysis stack 2 for performing the electrolysis with the electrolysis medium fed to the electrolysis stack 2 with the electrolysis medium feed 10, [0080] connected electrically to the flow meter 11 for receiving a measurement signal from the flow meter 11, and [0081] configured for determining a degree of degradation of membranes 8 based on the measurement signal received from the flow meter 11.

[0082] With the arrangement 1, an electrolysis can be performed using the electrolysis stack 2. The method comprises: [0083] feeding an electrolysis medium to the electrolysis stack 2 and determining a flow rate at which the electrolysis medium is fed to the electrolysis stack 2, [0084] providing electrical energy to the electrolysis stack 2 for performing the electrolysis with the electrolysis medium fed to the electrolysis stack 2, [0085] determining a degree of degradation of the membranes 8 based on the determined flow rate of the electrolysis medium.

[0086] FIG. 2 shows a detailed view of a first embodiment of the electrolysis stack 2 of the arrangement 1 of FIG. 1. Therein, it can be seen that the electrolysis stack 2 comprises multiple electrolysis cells 3. Each of the electrolysis cells 3 has an anode space 4 with an anode 6, a cathode space 5 with a cathode 7. The anode 6 of the left electrolysis cell 3 and the cathode 7 of the right electrolysis cell 3 are configured as outer electrodes 13. These can be considered to be the electrodes of the electrolysis stack 2. The remaining anodes 6 and cathodes 7 are realized in pairs by means of a respective bipolar plate 14.

[0087] Further, the electrolysis cells 3 each comprise a membrane 8 that separates the anode space 4 and the cathode space 5 from each other. Also, a respective recombination catalyst 9 is arranged within each of the anode spaces 4. The recombination catalyst 9 is mixed with an electrolysis catalyst 16 configured for enhancing the electrolysis. In the cathode spaces 5, only an electrolysis catalyst 16 is provided. Both the recombination catalysts 9 and the electrolysis catalysts 16 are held by a respective support 15. For clarity, only the recombination catalyst 9, the support 15 and the electrolysis catalysts 16 of the right electrolysis cell 3 are indicated with respective reference numerals.

[0088] FIG. 3 shows a detailed view of a second embodiment of the electrolysis stack 2 of the arrangement 1 of FIG. 1. In contrast to the embodiment of FIG. 2, herein the recombination catalysts 9 are provided distinctly from the electrolysis catalyst 16 of the respective electrolysis cell 3.

LIST OF REFERENCE NUMERALS

[0089] 1 arrangement

[0090] 2 electrolysis stack

[0091] 3 electrolysis cell

[0092] 4 anode space

[0093] 5 cathode space

[0094] 6 anode

[0095] 7 cathode

[0096] 8 membrane

[0097] 9 recombination catalyst

[0098] 10 electrolysis medium feed

[0099] 11 flow meter

[0100] 12 control unit

[0101] 13 outer electrode

[0102] 14 bipolar plate

[0103] 15 support

[0104] 16 electrolysis catalyst

[0105] 17 anode separator

[0106] 18 cathode separator

[0107] 19 oxygen outlet

[0108] 20 hydrogen outlet

[0109] 21 water outlet

[0110] It will be understood that many additional changes in the details, materials, steps and arrangement of parts, which have been herein described in order to explain the nature of the invention, may be made by those skilled in the art within the principle and scope of the invention as expressed in the appended claims. Thus, the present invention is not intended to be limited to the specific embodiments in the examples given above.