# US 2021/0172074 A1 · Electrolysis unit and electrolyser

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- Number: US 2021/0172074 A1
- Document ID: US20210172074A1
- Status: Published application
- Kind: A1
- Application number: 16/762,754
- Filed: 2018-09-21
- Published: 2021-06-10
- Earliest claimed: 2017-11-24
- Assignees: Siemens Aktiengesellschaft
- Applicants: Siemens Aktiengesellschaft
- Inventors: Alexander Hahn; Hagen Hertsch; Stephan Rückert; Thomas Purucker; Alexander Spies; Jochen Straub; Richard Wagner
- Web page: https://patentgrep.com/patent/US20210172074A1

## CPC

- C25B 1/04: by electrolysis of water
- C25B 9/19: with diaphragms
- C25B 9/23: comprising ion-exchange membranes in or on which electrode material is embedded
- C25B 9/75: having bipolar electrodes
- C25B 13/00: Diaphragms; Spacing elements
- C25B 15/083: {Separating products}
- C25B 15/087: {Recycling of electrolyte to electrochemical cell}
- Y02E 60/36: Hydrogen production from non-carbon containing sources, e.g. by water electrolysis
- Y02P 20/133: Renewable energy sources, e.g. sunlight
- C25B: ELECTROLYTIC OR ELECTROPHORETIC PROCESSES FOR THE PRODUCTION OF COMPOUNDS OR NON-METALS; APPARATUS THEREFOR (anodic or cathodic protection C23F13/00; single-crystal growth C30B)
- Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02P: CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS

## Abstract

An electrolytic device and to a method for operating an electrolysis of water with at least one electrolysis cell, the electrolysis cell having an anode compartment having an anode and a cathode compartment having a cathode. The anode compartment is separated from the cathode compartment by a proton exchange membrane. The anode compartment is suitable for holding water and oxidising the water on the anode to form a first product including oxygen and the cathode compartment is suitable for holding water and reducing the water on the cathode to a second product including hydrogen. Furthermore, the electrolysis device includes a first gas precipitation device for precipitation of oxygen, the first gas precipitation device for carrying out a natural water circulation being arranged above the electrolysis cell.

## Claims

### Claim 1

An electrolysis device for the electrolysis of water, comprising:
at least one electrolysis cell, wherein the electrolysis cell comprises an anode space having an anode and a cathode space having a cathode, wherein the anode space is separated from the cathode space by means of a proton exchange membrane, and the anode space is suitable for receiving water and oxidizing it at the anode to give a first product comprising oxygen and the cathode space is suitable for receiving water and reducing it at the cathode to give a second product comprising hydrogen;
a first gas separating apparatus for separation of oxygen;
wherein the first gas separating apparatus is arranged above the electrolysis cell for performing a natural circulation of water.

### Claim 2 (depends on 1)

The electrolysis device as claimed in claim 1, further comprising:
a first line which is connected to an upper section of the anode space and to the first gas separating apparatus, and
a second line which is connected to the first gas separating apparatus and to a lower section of the anode space.

### Claim 3 (depends on 1)

The electrolysis device as claimed in claim 1, further comprising:
a second gas separating apparatus for separation of hydrogen;
a third line which is connected to an upper section of the cathode space and to the second gas separating apparatus;
a fourth line which is connected to the second gas separating apparatus and to a lower section of the anode space and/or cathode space, wherein the second gas separating apparatus is arranged above the electrolysis cell for performing a natural circulation of water.

### Claim 4 (depends on 3)

The electrolysis device as claimed in claim 3,
wherein a first heat exchanger is arranged in the second line and/or a second heat exchanger is arranged in the fourth line.

### Claim 5 (depends on 4)

The electrolysis device as claimed in claim 4,
wherein the first heat exchanger and the second heat exchanger are thermally coupled.

### Claim 6 (depends on 4)

The electrolysis device as claimed in claim 4,
wherein the first heat exchanger and the second heat exchanger are coupled so as to allow transfer of material.

### Claim 7 (depends on 3)

The electrolysis device as claimed in claim 3,
wherein the second line and the fourth line are connected via a connection line for water equalization.

### Claim 8 (depends on 1)

A method for operating an electrolysis device for electrolysis of water as claimed in claim 1, the method comprising:
producing in an electrolysis cell an oxygen-comprising first product and a hydrogen-comprising second product by means of electrolysis at a functional membrane from water as a starting material,
circulating of the starting material, wherein the first product and/or the second product is effected in the form of a natural water circulation.

### Claim 9 (depends on 8)

The method as claimed in claim 8,
wherein a prevailing operating pressure is atmospheric pressure.