REDOX SHUTTLE ASSISTED ELECTRODEIONIZATION
The present disclosure is directed to an electrodialytic stack with a concentrate stream that moves through a concentrate flow path bounded by a central ion exchange membrane and a first outer ion exchange membrane. A dilute stream moves through a dilute flow path bounded by the central ion exchange membrane and a second outer ion exchange membrane. A redox shuttle loop is separated from the concentrate and dilute streams by the first and second outer ion exchange membranes, respectively. The outer ion exchange membranes are a different type than the central ion exchange membrane. Electrodes are operable to apply a voltage across the stack. At least one collection of ion exchange materials is located in at least one of the flow paths. The ion exchange materials migrate ions between the central ion exchange membrane and at least one of the outer ion exchange membranes.
1 . An electrodialytic stack comprising:
a concentrate flow path bounded by a central ion exchange membrane and a first outer ion exchange membrane of a different type than the central ion exchange membrane, wherein a concentrate stream moves through the concentrate flow path;
a dilute flow path bounded by the central ion exchange membrane and a second outer ion exchange membrane of a different type than the central ion exchange membrane, wherein a dilute stream moves through the dilute flow path;
a redox shuttle loop separated from the concentrate stream by the first outer ion exchange membrane and separated from the dilute stream by the second outer ion exchange membrane;
a first electrode and a second electrode operable to apply a voltage across the electrodialytic stack; and
at least one collection of ion exchange materials in at least one of the concentrate flow path and the dilute flow path, wherein the at least one collection of ion exchange materials migrates ions between the central ion exchange membrane and at least one of the first and second outer ion exchange membranes.
2 . The electrodialytic stack of claim 1 , wherein the at least one collection of ion exchange materials comprises a first collection of ion exchange materials located in the concentrate flow path and a second collection of ion exchange materials located in the dilute flow path.
3 . The electrodialytic stack of claim 1 , wherein the at least one collection of ion exchange materials comprises a cation exchange material and an anion ion exchange material.
4 . The electrodialytic stack of claim 1 , wherein the at least one collection of ion exchange materials comprises an ion exchange resin.
5 . The electrodialytic stack of claim 1 , wherein the at least one collection of ion exchange materials comprises a binder.
6 . The electrodialytic stack of claim 1 , wherein the at least one collection of ion exchange materials comprises at least one packed bed.
7 . The electrodialytic stack of claim 1 , wherein the at least one collection of ion exchange materials is incorporated into at least one of the first outer ion exchange membrane, the second outer ion exchange membrane, and the central ion exchange membrane.
8 . The electrodialytic stack of claim 1 , wherein the central ion exchange membrane comprises an anion exchange membrane and wherein the first and second outer ion exchange membranes comprise cation exchange membranes.
9 . The electrodialytic stack of claim 1 , wherein the central ion exchange membrane comprises a cation exchange membrane and wherein the first and second outer ion exchange membranes comprise anion exchange membranes.
10 . The electrodialytic stack of claim 1 , wherein the redox shuttle loop comprises a negatively charged redox active species.
11 . The electrodialytic stack of claim 1 , wherein the redox shuttle loop comprises ferrocyanide/ferricyanide ([Fe(CN) 6 ] 4− /[Fe(CN) 6 ] 3− ) or a negatively charged ferrocene derivative.
12 . The electrodialytic stack of claim 1 , wherein the redox shuttle loop comprises a positively charged redox active species.
13 . The electrodialytic stack of claim 1 , wherein the redox shuttle loop comprises bis(trimethylammoniopropyl) ferrocene/bis(trimethylammoniopropyl) ferrocenium ([BTMAP-Fc] 2+ /[BTMAP-Fc] 3+ ) or a positively charged ferrocene derivative.
14 . The electrodialytic stack of claim 1 , wherein the redox shuttle loop comprises:
a first redox stream separated from the concentrate stream by the first outer ion exchange membrane; and
a second redox stream separated from the dilute stream by the second outer ion exchange membrane.
15 . The electrodialytic stack of claim 14 , wherein the first redox stream is in fluid communication with the second redox stream.
16 . An ion transfer system comprising:
at least one ion transfer module comprising:
a modular dilute inlet in fluid communication with a modular dilute outlet; and
a modular concentrate inlet in fluid communication with a modular concentrate outlet; and
at least one redox shuttle assisted electrodeionization stack comprising:
a concentrate flow path comprising a concentrate inlet in fluid communication with a concentrate outlet, the concentrate flow path bounded by a central ion exchange membrane and a first outer ion exchange membrane of a different type than the central ion exchange membrane, wherein a concentrate stream moves through the concentrate flow path;
a dilute flow path comprising a dilute inlet in fluid communication with a dilute outlet, the dilute flow path bounded by the central ion exchange membrane and a second outer ion exchange membrane of a different type than the central ion exchange membrane, wherein a dilute stream moves through the dilute flow path;
a feed flow path in fluid communication with at least one of the concentrate inlet and the dilute inlet, the feed flow path fluidly couplable to at least one of the concentrate outlet, the dilute outlet, the modular dilute outlet, and the modular concentrate outlet;
a redox shuttle loop separated from the concentrate stream by the first outer ion exchange membrane, the redox shuttle loop separated from the dilute stream by the second outer ion exchange membrane;
a first electrode and a second electrode operable to apply a voltage across the at least one redox shuttle assisted electrodeionization stack; and
at least one collection of ion exchange materials in at least one of the concentrate flow path and the dilute flow path, wherein the at least one collection of ion exchange materials migrates ions between the central ion exchange membrane and at least one of the first and second outer ion exchange membranes.
17 . The ion transfer system of claim 16 , wherein the at least one ion transfer module comprises a second redox shuttle assisted electrodeionization stack.
18 . The ion transfer system of claim 16 , wherein the at least one ion transfer module comprises a redox shuttle assisted electrodialytic stack.
19 . The ion transfer system of claim 16 , wherein the at least one ion transfer module comprises a reverse osmosis system.
20 . The ion transfer system of claim 16 , wherein the at least one ion transfer module comprises an electrodeionization system.
21 . A method comprising:
inputting a concentrate stream into a concentrate flow path of an electrodialytic stack, the concentrate flow path bounded by a first outer ion exchange membrane and a central ion exchange membrane;
inputting a dilute stream into a dilute flow path of the electrodialytic stack, the dilute flow path bounded by a second outer ion exchange membrane and the central ion exchange membrane;
circulating a redox shuttle loop around the first and second outer ion exchange membranes;
applying a voltage across the electrodialytic stack; and
migrating ions between the central ion exchange membrane and at least one of the first and second outer ion exchange membranes via at least one collection of ion exchange materials in at least one of the concentrate flow path and the dilute flow path.
22 . The method of claim 21 , wherein the at least one collection of ion exchange materials comprises a first collection of ion exchange materials located in the concentrate flow path and a second collection of ion exchange materials located in the dilute flow path.
23 . The method of claim 21 , wherein the at least one collection of ion exchange materials comprises a cation exchange material and an anion exchange material.
24 . The method of claim 21 , wherein the at least one collection of ion exchange materials comprises an ion exchange resin.
25 . The method of claim 21 , wherein the at least one collection of ion exchange materials comprises at least one packed bed.
26 . The method of claim 21 , wherein the at least one collection of ion exchange materials is incorporated into at least one of the first outer ion exchange membrane, the second outer ion exchange membrane, and the central ion exchange membrane.
27 . The method of claim 21 , wherein the central ion exchange membrane comprises an anion exchange membrane and wherein the first and second outer ion exchange membranes comprise cation exchange membranes.
28 . The method of claim 21 , wherein the central ion exchange membrane comprises a cation exchange membrane and wherein the first and second outer ion exchange membranes comprise anion exchange membranes.
29 . The method of claim 21 , wherein the redox shuttle loop comprises a negatively charged redox active species.
30 . The method of claim 21 , wherein the redox shuttle loop comprises ferrocyanide/ferricyanide ([Fe(CN) 6 ] 4− /[Fe(CN) 6 ] 3− ) or a negatively charged ferrocene derivative.
31 . The method of claim 21 , wherein the redox shuttle loop comprises a positively charged redox active species.
32 . The method of claim 21 , wherein the redox shuttle loop comprises bis(trimethylammoniopropyl) ferrocene/bis(trimethylammoniopropyl) ferrocenium ([BTMAP-Fc] 2+ /[BTMAP-Fc] 3+ ) or a positively charged ferrocene derivative.