Production of chemical products using electrochemical flow systems and mediators and associated methods

Patent metadata

Field	Value
Publication number	US-11603597-B2
Application number	US-201916450847-A
Country	US
Kind code	B2
Filing date	Jun 24, 2019
Priority date	Aug 14, 2018
Publication date	Mar 14, 2023
Grant date	Mar 14, 2023

Abstract

Systems and methods for electrochemically producing chemical products are provided. In certain cases, the systems and methods described herein are capable of producing chemical products such as hydrogen peroxide in solutions with relatively low concentrations of electrolyte or other dissolved species at high efficiencies and/or low energetic cost. In some cases, redox mediators are used to spatially decouple direct electrochemical processes from the production of the chemical product.

First claim

What is claimed is:

1. A method for producing a chemical product, comprising:
applying, in an electrochemical cell, an electrical potential to a first electrode in contact with solution from a first fluid stream, the solution comprising a redox mediator, such that an active form of the redox mediator is generated;
contacting the solution from the first fluid stream with solution from a second fluid stream, the solution from the first fluid stream being essentially immiscible with the solution from the second fluid stream, wherein during the step of contacting the solution from the first fluid stream with the solution from the second fluid stream, at least a portion of the active form of the redox mediator is transferred from the solution from the first fluid stream to the solution from the second fluid stream; and
contacting the solution from the second fluid stream comprising the at least a portion of the active form of the redox mediator with solution from a third fluid stream after the at least a portion of the active form of the redox mediator is transferred to the solution from the second fluid stream from the solution from the first fluid stream, such that the active form of the redox mediator reacts with a reactant to produce the chemical product.

2. The method of claim 1 , comprising transporting the first fluid stream to a first module fluidically connected to the electrochemical cell such that the step of contacting the solution from the first fluid stream with the solution from the second fluid stream occurs in the first module.

3. The method of claim 1 , wherein the third fluid stream comprises the reactant.

4. The method of claim 1 , wherein the solution from the second fluid stream is essentially immiscible with the solution from the third fluid stream.

5. The method of claim 2 , comprising transporting the second fluid stream from the first module to a second module fluidically connected to the first module such that the step of contacting the solution from the second fluid stream with the solution from the third fluid stream occurs in the second module.

6. The method of claim 1 , wherein the chemical product produced is hydrogen peroxide and the reactant is oxygen gas.

7. The method of claim 1 , wherein the partition equilibrium of the active form of the redox mediator between the solution from the first fluid stream and the solution from the second fluid stream and/or the partition equilibrium of an inactive form of the redox mediator between the solution from the first fluid stream and the solution from the second fluid stream varies with the concentration of a phase transfer catalyst in the solution from the second fluid stream.

8. The method of claim 1 , wherein the redox mediator comprises an optionally-substituted quinone, and the active form of the redox mediator comprises the corresponding hydroquinone of the optionally-substituted quinone.

9. The method of claim 8 , wherein the optionally-substituted quinone and the corresponding hydroquinone of the optionally-substituted quinone have the structures of formula (1A) and formula (1B), respectively:

wherein groups R 1 , R 2 , R 3 , and/or R 4 can the same or different and are halo, hydroxyl, carboxylate/carboxylic acid, sulfonate/sulfonic acid, alkylsulfonate/alkylsulfonic acid, phosphonate/phosphonic acid, alkylphosphonate/alkylphosphonic acid, amino, quaternary ammonium, alkyl, heteroalkyl, alkoxy, glycoxy, polyalkyleneglycoxy, imino, polyimino, alkenyl, alkynyl, aryl, heteroaryl, heterocyclyl, nitro, nitrile, thiyl, and/or carbonyl groups, any of which is optionally substituted, or, any two adjacent groups of R 1 -R 4 can be joined together to form an optionally-substituted ring.

10. The method of claim 1 , wherein the redox mediator comprises an optionally-substituted anthraquinone, and the active form of the redox mediator comprises the corresponding hydroquinone of the optionally-substituted anthraquinone.

11. The method of claim 10 , wherein the optionally-substituted anthraquinone comprises one or more sulfonate groups, carboxylate groups, and/or phosphonate groups.

12. The method of claim 1 , wherein the electrochemical cell comprises a first electrode compartment and a second electrode compartment, the first electrode compartment comprising the first electrode, and the second electrode compartment comprising a second electrode.

13. The method of claim 12 , wherein the first electrode compartment and the second electrode compartment are separated by a bipolar membrane.

14. The method of claim 1 , comprising transporting solution from the first fluid stream that has already contacted solution from the second fluid stream back into the electrochemical cell.

15. The method of claim 12 , comprising performing the oxygen evolution reaction in the second electrode compartment.

16. The method of claim 2 , wherein the first module comprises a mixer-settler or comprises a hollow tubule comprising a porous wall.

17. The method of claim 1 , wherein the method is performed using a system comprising:
the electrochemical cell, wherein the electrochemical cell comprises the first electrode, a second electrode, a first inlet, and a first outlet; and
a first module fluidically connected to the electrochemical cell, wherein the first module comprises a first inlet, a first outlet, a second inlet, and a second outlet, and is configured to contact the solution from the first fluid stream with the solution from the second fluid stream, such that the active form of a redox mediator is transferred from the first fluid stream to the second fluid stream.

18. The method of claim 1 , wherein the method is performed using a system comprising:
the electrochemical cell, wherein the electrochemical cell comprises the first electrode, a second electrode, a first inlet, and a first outlet; and
a first module, wherein the first module comprises a first inlet, a first outlet, a second inlet, and a second outlet, wherein the first outlet of the electrochemical cell is fluidically connected to the first inlet of the first module, and wherein the first module comprises a mixer-settler and/or comprises a hollow tubule comprising a porous wall.

19. A method for producing a chemical product, comprising:
applying, in an electrochemical cell, an electrical potential to a first electrode in contact with solution from a first fluid stream, the solution comprising a redox mediator, such that an active form of the redox mediator is generated; and
contacting the solution from the first fluid stream with solution from a second fluid stream, the solution from the first fluid stream being essentially immiscible with the solution from the second fluid stream, such that the active form of the redox mediator reacts with a reactant to produce the chemical product,
wherein the partition equilibrium of the active form of the redox mediator between the solution from the first fluid stream and the solution from the second fluid stream and/or the partition equilibrium of an inactive form of the redox mediator between the solution from the first fluid stream and the solution from the second fluid stream varies with the concentration of a phase transfer catalyst in the solution from the second fluid stream.

20. The method of claim 19 , wherein the chemical product produced is hydrogen peroxide and the reactant is oxygen gas.

Assignees

• Massachusetts Inst Technology

Inventors

• Murray Alexander
• Voskian Sahag
• Hatton Trevor Alan
• Surendranath Yogesh

Classifications

• C01B15/01 Primary

  Hydrogen peroxide · CPC title

• C25B9/17

  Cells comprising dimensionally-stable non-movable electrodes; Assemblies of constructional parts thereof · CPC title

• C25B3/25

  Reduction · CPC title

• C25B1/30 Primary

  Peroxides · CPC title

• C25B9/19

  with diaphragms · CPC title