System and method for redox-mediated electrodialysis

Patent metadata

Field	Value
Publication number	US-2024270611-A1
Application number	US-202218568009-A
Country	US
Kind code	A1
Filing date	Jun 30, 2022
Priority date	Jul 1, 2021
Publication date	Aug 15, 2024
Grant date	—

Abstract

A system for redox-mediated electrodialysis includes: a first electrode; a second electrode positioned in opposition to the first electrode; an anion exchange membrane and a cation exchange membrane positioned between the first and second electrodes; a feed channel for flow of a treating fluid, the feed channel extending between the anion and cation exchange membranes; an additional membrane or pair of membranes between the first and second electrodes, the additional membrane or pair of membranes defining a collection channel on one or both sides of the feed channel for collecting anions and cations removed from the treating fluid, the additional membrane or pair of membranes including an anion exchange membrane and/or a cation exchange membrane; and a redox channel for flow of a redox fluid, the redox channel containing the first and second electrodes and being separated from the feed and/or collection channels by the anion and/or cation exchange membranes.

First claim

1 . A method for redox-mediated electrodialysis, the method comprising:
providing a system including:
a first electrode;
a second electrode positioned in opposition to the first electrode;
an anion exchange membrane and a cation exchange membrane disposed between the first and second electrodes;
a feed channel extending between the anion and cation exchange membranes; and
a redox channel containing the first and second electrodes and being separated from the feed channel by the anion and cation exchange membranes;
flowing a redox solution comprising a redox couple through the redox channel; flowing a treating fluid comprising one or more biomolecules and an ionic species through the feed channel, the ionic species including anions and cations; applying a voltage, the first electrode becoming positively charged and the second electrode becoming negatively charged, the redox couple undergoing oxidation near the first electrode and reduction near the second electrode, whereby the anions in the feed channel are drawn through the anion exchange membrane and the cations in the feed channel are drawn through cation exchange membrane, while the one or more biomolecules remain in the feed channel, thereby purifying the treating fluid.

2 . The method of claim 1 , wherein the one or more biomolecules comprise a protein, peptide, carboxylate, organic acid, glycoside, carbohydrate, DNA, and/or RNA.

3 . The method of claim 2 , wherein the protein comprises a whey protein.

4 . (canceled)

5 . The method of claim 1 , wherein the redox couple is selected from the group consisting of: V 2+ /V 3+ , VO 2− /VO 2 + , Zn/Zn 2+ , Fe 2+ /Fe 3+ , [Fe(CN) 6 ] 4− /[Fe(CN) 6 ] 3− , Quinone derivatives, TEMPO derivatives, and ferrocene derivatives.

6 . The method of claim 1 , wherein the redox fluid includes an organic solvent.

7 . The method of claim 1 , wherein the redox redox couple is selected from the group consisting of: [Fe(bpy) 3 ] 2+ /[Fe(bpy) 3 ] 3+ , CoCp 2 /CoCp 2 + , ferrocene/ferrocenium, and V(acac) 3 /[V(acac) 3 ] + .

8 . (canceled)

9 . The method of claim 1 , wherein the redox channel includes the redox couple at a concentration in a range from about 30 mM to about 100 mM.

10 . The method of claim 1 , wherein the voltage is 1.2 V or less.

11 . (canceled)

12 . The method of claim 1 , wherein purifying the treating fluid comprises removing at least about 95% of the ionic species from the treating fluid.

13 - 14 . (canceled)

15 . The method of claim 1 , wherein the treating fluid is a waste stream from bio, food or pharmaceutical manufacturing.

16 - 17 . (canceled)

18 . The method of claim 1 , further comprising, after purifying the treating fluid:
flowing a collection fluid through the feed channel; and reversing the voltage, the first electrode becoming negatively charged and the second electrode becoming positively charged, the redox couple undergoing oxidation near the second electrode and reduction near the first electrode, whereby the anions and cations previously removed from the treating fluid are drawn through the anion and cation exchange membranes and into the collection fluid, the feed channel thereby functioning as a collection channel for the ionic species.

19 - 22 . (canceled)

23 . A system for redox-mediated electrodialysis, the system comprising:
a first electrode; a second electrode positioned in opposition to the first electrode; an anion exchange membrane and a cation exchange membrane positioned between the first and second electrodes; a feed channel for flow of a treating fluid, the feed channel extending between the anion and cation exchange membranes; an additional membrane or pair of membranes between the first electrode and second electrodes, the additional membrane or pair of membranes defining a collection channel on one or both sides of the feed channel for collecting anions and cations removed from the treating fluid, the additional membrane or pair of membranes including an anion exchange membrane and/or a cation exchange membrane; and a redox channel for flow of a redox fluid, the redox channel containing the first and second electrodes and being separated from the feed and/or collection channels by two of the anion and cation exchange membranes.

24 . The system of claim 23 , wherein the collection channels constitute portions of a salt collection channel for recombination of the anions and cations removed from the treating fluid.

25 . The system of claim 23 , including up to n of the anion and cation exchange membranes alternately positioned between the first and second electrodes, n being an integer, preferably an odd integer.

26 . The system of claim 23 , further comprising a stack of two or more of the first electrodes and a stack of two or more of the second electrodes, each stack including two or more of the first or second electrodes.

27 . The system of claim 23 , wherein the redox channel is configured for continuous circulation of the redox fluid.

28 . (canceled)

29 . The system of claim 23 , further comprising one or more pumps connected to the feed, redox, and/or collection channels.

30 . The system of claim 23 , wherein the first and second electrodes comprise carbon.

31 . The system of claim 23 , wherein each of the anion exchange membranes comprises a polymer film including positively-charged functional groups, and
wherein each of the cation exchange membranes comprises a polymer film including negatively-charged functional groups.

Assignees

• Univ Illinois
• Nat Univ Kongju Ind Univ Coop Found

Inventors

• Su Xiao
• Kim Nayeong
• Elbert Johannes
• Kim Choonsoo

Classifications

• C02F2201/4618

  Supplying or removing reactants or electrolyte · CPC title

• C02F2201/46135

  Voltage · CPC title

• C02F2101/30

  Organic compounds · CPC title

• C02F2001/46133

  characterised by the material · CPC title

• C02F1/4693 Primary

  electrodialysis · CPC title