# US 11,299,808 B2 · Electrolysis unit and method for operating the electrolysis unit > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,299,808 B2 - Document ID: US11299808B2 - Status: Granted - Kind: B2 - Application number: 17/259,610 - Filed: 2019-07-08 - Published: 2021-09-23 - Granted: 2022-04-12 - Earliest claimed: 2018-07-27 - Assignees: Siemens Energy Global GmbH & Co. KG - Applicants: Siemens Energy Global GmbH & Co. KG - Inventors: Thomas Purucker; Stephan Rückert; Jochen Straub; Peter Utz - Web page: https://patentgrep.com/patent/US11299808B2 ## CPC - C25B 1/04: by electrolysis of water - C25B 9/05: Pressure cells - C25B 9/23: comprising ion-exchange membranes in or on which electrode material is embedded - C25B 9/70: Assemblies comprising two or more cells - C25B 13/00: Diaphragms; Spacing elements - C25B 15/081: {Supplying products to non-electrochemical reactors that are combined with the electrochemical cell, e.g. Sabatier reactor} - 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 electrolysis unit and to a method for electrochemically decomposing water into hydrogen and oxygen. The electrolysis unit has at least two electrolysis modules. The electrolysis unit also has exactly one first gas separation device for a first product gas including oxygen and exactly one second gas separation device for a second product gas including hydrogen. The first gas separation device is connected to the at least two electrolysis modules by respective first lines. The second gas separation device is connected to the at least two electrolysis modules by respective second lines. The at least two first lines have the same first length. The at least two second lines likewise have the same second length. ## Claims ### Claim 1 An electrolysis unit for the electrochemical dissociation of water (H2O) into hydrogen (H2) and oxygen (O2), comprising: at least two electrolysis modules; exactly one first gas separation device for a first product gas comprising oxygen, exactly one second gas separation device for a second product gas comprising hydrogen, wherein the first gas separation device is connected to each of the at least two electrolysis modules by means of a first conduit in each case and the second gas separation device is connected to each of the electrolysis modules by means of a second conduit in each case and the at least two first conduits have the same first length and the at least two second conduits have the same second length. ### Claim 2 (depends on 1) The electrolysis unit as claimed in claim 1, wherein an electrolysis module of the at least two electrolysis modules comprises at least two electrolysis cells and each electrolysis cell comprises an anode space having an anode and a cathode space having a cathode and the anode space is separated from the cathode space by means of a proton exchange membrane and the anode space is suitable for taking up water (H2O) and oxidizing it at the anode to give a first product comprising oxygen (O2) and the cathode space is suitable for taking up water (H2O) and reducing it at the cathode to give a second product comprising hydrogen (H2). ### Claim 3 (depends on 2) The electrolysis unit as claimed in claim 2, wherein the cathode space is connected to the second gas separation device and the anode space is connected to the first gas separation device. ### Claim 4 (depends on 1) The electrolysis unit as claimed in claim 1, wherein the first gas separation device and the second gas separation device are arranged inside one another, with the first or the second gas separation device being configured as an outer shell and a bottom and the other second or first gas separation device projecting as tube into the shell. ### Claim 5 (depends on 4) The electrolysis unit as claimed in claim 4, wherein the tube has a closing face in the direction of the bottom and the closing face is configured as a grid, as a perforated plate, or as a mesh. ### Claim 6 (depends on 4) The electrolysis unit as claimed in claim 4, wherein a cross section of the shell and/or of the tube is round or is a polygon. ### Claim 7 (depends on 1) The electrolysis unit as claimed in claim 1, wherein the first gas separation device is connected to a first pressure maintenance device and the second gas separation device is connected to a second pressure maintenance device. ### Claim 8 (depends on 1) The electrolysis unit as claimed in claim 1, wherein at least one pump is arranged between the first and/or second gas separation device and the electrolysis modules. ### Claim 9 (depends on 4) The electrolysis unit as claimed in claim 4 comprising: at least three electrolysis modules, wherein the electrolysis modules are arranged in a circle and the first and second gas separation devices are arranged centrally in the middle between the modules. ### Claim 10 (depends on 4) The electrolysis unit as claimed in claim 4, wherein the first and/or second gas separation device is connected to exactly one heat exchanger for cooling the water (H2O) which has been separated off. ### Claim 11 (depends on 4) The electrolysis unit as claimed in claim 4, wherein the first or second gas separation device is connected to exactly one water treatment device. ### Claim 12 (depends on 11) The electrolysis unit as claimed in claim 11, wherein the water treatment device comprises a pump, a cooling device, and an ion exchange device. ### Claim 13 (depends on 1) The electrolysis unit as claimed in claim 1, wherein the electrolysis module comprises a module end plate, which has an exterior covering surface, on each of two opposite sides and a first electrolysis module is electrically connected to a second electrolysis module in such a way that a contacting device contacts a covering surface of the first electrolysis module and a covering surface of the second electrolysis module to a large extent. ### Claim 14 A method for operating an electrolysis unit comprising: providing an electrolysis unit comprising at least two electrolysis modules, with water (H2O) being dissociated into hydrogen (H2) and oxygen (O2) in the electrolysis module, providing only one first gas separation device for a first product gas comprising oxygen, providing only one second gas separation device for a second product gas comprising hydrogen, wherein the first gas separation device is connected to each of the at least two electrolysis modules by means of a first conduit in each case and the second gas separation device is connected to each of the electrolysis modules by means of a second conduit in each case and the at least two first conduits comprise a same first length and the at least two second conduits comprise a same second length. ### Claim 15 (depends on 14) The method as claimed in claim 14, wherein the electrolysis unit is operated at a pressure in the range from 1 bar to 5 bar. ### Claim 16 (depends on 1) The electrolysis unit as claimed in claim 1, wherein the first gas separation device and the second gas separation device are arranged inside one another. ### Claim 17 (depends on 1) The electrolysis unit as claimed in claim 1, further comprising a central gas separation device comprising the first gas separation device and the second gas separation device, wherein a fluid-permeable wall permits fluid communication directly between respective interior volumes of the first gas separation device and the second gas separation device, and wherein the central gas separation device is configured to contain a fluid bath such that when the fluid bath is present the fluid-permeable wall is submerged therein. ### Claim 18 (depends on 1) The electrolysis unit as claimed in claim 1, wherein the central gas separation device is further configured such that when the fluid bath is present: respective portions of the interior volumes of the first gas separation device and the second gas separation device remain above the fluid bath; and no direct fluid communication is provided between the respective portions.