System and method for generation of gases

Patent metadata

Field	Value
Publication number	US-2021017654-A1
Application number	US-201916982507-A
Country	US
Kind code	A1
Filing date	Mar 20, 2019
Priority date	Mar 20, 2018
Publication date	Jan 21, 2021
Grant date	—

Abstract

Provided are electrochemical cells and methods for generating hydrogen gas and oxygen gas.

First claim

1 . An electrochemical system for generating hydrogen gas and/or oxygen gas, the system comprising:
two or more electrochemical thermally activated chemical (ETAC) cells, each configured for holding an aqueous solution and comprising at least one electrode assembly, each having a cathode electrode and an anode electrode, said two or more ETAC cells being configured to generate hydrogen gas in the presence of electrical bias, and generate oxygen gas in the absence of bias, and a control unit configured to operate the two or more cells in accordance with a predetermined operational pattern.

2 . The system according to claim 1 , the system comprising:
two or more ETAC cells, each configured for holding an aqueous solution and comprising at least one electrode assembly, each having a cathode electrode and an anode electrode, said cathode electrode being configured to affect reduction of water in said aqueous solution in response to an applied electrical bias, to thereby generate hydrogen gas and hydroxide ions, said anode electrode being capable of reversibly undergoing oxidation in the presence of hydroxide ions, and undergoing reduction in the absence of bias, to generate oxygen gas, and a control unit configured to operate the two or more cells in accordance with a predetermined operational pattern.

3 . An electrochemical system for generating oxygen gas, the system comprising:
two or more ETAC cells, each configured for holding an aqueous solution optionally containing hydroxide ions, and comprising at least one electrode assembly, the at least one electrode assembly comprising a cathode electrode and an anode electrode, said anode electrode being configured to undergo reduction in the absence of electrical bias to generate oxygen gas, and a control unit configured to operate the two or more cells in accordance with a predetermined operational pattern.

4 . The system according to claim 1 comprising a heat source or a heat exchanger.

5 . The system according to claim 1 , wherein the predetermined operational pattern permits one or more operation cycle of the system.

6 . The system according to claim 1 wherein the operational pattern provides for each cell in the two or more cells an output in a form of at least one of mode selector and operational parameter selector.

7 . The system according to claim 1 wherein the operational pattern provides an output comprising at least one of (i) applied bias, (ii) timing for operation, and (iii) duration of operation of each of the two or more cells.

8 . The system according to claim 7 , wherein the operational pattern further provides a temperature value for each of the two or more cells.

9 . The system according to claim 1 being operable in a hydrogen gas generation mode or an oxygen gas generation mode or in a continuous hydrogen gas generation mode.

10 . The system according to claim 9 , wherein the continuous mode comprises, in a first operation cycle, generation of hydrogen gas in at least one of the two or more cells, in parallel to generation of oxygen gas in at least one different cell of the two or more cells and in a second operation cycle, generation of hydrogen gas in the at least one different cell of the two or more cells, in parallel to generation of oxygen gas in the at least one of the two or more cells.

11 . The system according to claim 1 , wherein the operational pattern permits operation of two or more of the cells at the same bias, at the same timing of operation or different timing of operation and for the same or different duration and optionally at same or different temperature.

12 . The system according to claim 1 , wherein the two or more cells are separated, having essentially no fluid or gas communication.

13 . The system according to claim 1 , further comprising at least one inlet and at least one outlet configured to allow circulation of the aqueous solution and of the gas in the system.

14 . The system according to claim 13 , wherein the at least one inlet is for receiving an aqueous solution into the two or more cells and at least one outlet for evacuating an aqueous solution and/or a gas from the two or more cells.

15 . The system according to claim 14 wherein at least two of said two or more cells are non-partitioned cells.

16 . The system according to claim 1 , wherein the electrode assembly is selected from mono-polar assembly, bi-polar assembly, flat assembly and rolled assembly.

17 . The system according to claim 1 comprising at least one reservoir.

18 .- 19 . (canceled)

20 . The system according to claim 1 comprising at least one phase separator configured to extract the gas.

21 .- 22 . (canceled)

23 . The system according to claim 1 , wherein the applied electric bias between the cathode and the anode electrodes in each of the at least one electrode assembly is at least 1.23V when measured at 25° C.

24 .- 26 . (canceled)

27 . A method of generating hydrogen gas, the method comprising:
in a system comprising two or more electrochemical thermally activated chemical (E-TAC) cells, each containing an aqueous solution and comprising an electrode assembly having a cathode electrode and an anode electrode, applying an electric bias in at least one of said two or more cells at a first time point to affect reduction of water and generate hydrogen gas; and applying an electric bias at a different time point in at least another of said two or more cells to affect reduction of water and generate hydrogen gas.

28 . (canceled)

29 . A method of generating hydrogen gas and/or oxygen gas, the method comprising:
in a system comprising two or more electrochemical thermally activated chemical (E-TAC) cells, each containing an aqueous solution and each comprising an electrode assembly having a cathode electrode and an anode electrode, applying electrical bias to at least two of said two or more cells to generate hydrogen gas therein; discontinuing bias in one or more of said at least two cells to induce generation of oxygen gas, wherein the method is operable in accordance with a predetermined operational pattern.

30 .- 43 . (canceled)

Assignees

• Technion Res & Development Found Ltd

Inventors

• Grader Gideon
• Shter Gennady
• Dotan Hen
• Rothschild Avner
• Landman Avigail

Classifications

• Y02P20/133

  Renewable energy sources, e.g. sunlight · CPC title

• Y02E60/36

  Hydrogen production from non-carbon containing sources, e.g. by water electrolysis · CPC title

• C25B1/02

  Hydrogen or oxygen · CPC title

• C25B15/02

  Process control or regulation · CPC title

• C25B9/70

  Assemblies comprising two or more cells · CPC title