JPWO2021236979A5

JPWO2021236979A5 -

Info

Publication number: JPWO2021236979A5
Application number: JP2022567220A
Authority: JP
Publication date: 2024-04-17

Claims

1. An electrochemically driven carbon dioxide separator (EDCS) for separating carbon dioxide from a carbon dioxide-containing gas, said EDCS comprising:
a cell, the cell comprising:
two electrodes capable of operating as anodes or cathodes, the two electrodes comprising a charge storage compound and an anion exchange polymer, the charge storage compound capable of reacting to form hydroxide when operating as the cathode, and reacting to consume hydroxide when operating as the anode;
a membrane adjacent to and separating the two electrodes, the membrane comprising an anion exchange polymer;
a channel within the membrane adapted for the inflow of a carbon dioxide-containing gas; and a channel adapted for the outflow of carbon dioxide, the channel defining an opening in contact with the electrode, which is the anode.
a channel adapted for the outflow of carbon dioxide and defining an opening in contact with the electrode, said electrode being the cathode;
The cell, during operation,
Hydrogen produced at the cathode is transported to the membrane;
the carbon dioxide-containing gas contacts the membrane, and the carbon dioxide reacts with hydroxide ions to form bicarbonate ions, carbonate ions, or bicarbonate and carbonate ions;
the bicarbonate ions, carbonate ions, or bicarbonate and carbonate ions are transported through the membrane to the anode electrode;
the bicarbonate ions, carbonate ions, or bicarbonate and carbonate ions react at the anode electrode to form carbon dioxide and water;
The carbon dioxide is adapted to be released from the EDCS through the channel adapted for carbon dioxide outflow from the electrode serving as the anode.

1. An electrochemically driven carbon dioxide separator (EDCS) for separating carbon dioxide from a carbon dioxide-containing gas, said EDCS comprising:
a cell, the cell comprising:
two electrodes capable of operating as anodes or cathodes, said two electrodes comprising nickel hydroxide, optionally in a partially oxidized state, and an anion exchange polymer;
two electrodes, the nickel hydroxide being capable of reacting to form hydroxide when acting as the cathode and to consume hydroxide when acting as the anode;
a membrane adjacent to and separating the two electrodes, the membrane comprising an anion exchange polymer;
a channel adapted for the outflow of carbon dioxide or the inflow of a carbon dioxide-containing gas and defining an opening in contact with the electrode that will become the anode; and a channel adapted for the outflow of carbon dioxide or the inflow of a carbon dioxide-containing gas and defining an opening in contact with the electrode that will become the cathode,
The cell, during operation,
Hydroxide is produced at the cathode electrode;
the carbon dioxide-containing gas contacts the cathode electrode, and the carbon dioxide reacts with hydroxide ions to form bicarbonate ions, carbonate ions, or bicarbonate and carbonate ions;
the bicarbonate ions, carbonate ions, or bicarbonate and carbonate ions are transported through the membrane to the anode electrode;
The bicarbonate ions, carbonate ions, or bicarbonate and carbonate ions are adapted to react at the anode electrode to form carbon dioxide and water.

The EDCS further comprises a power supply for supplying current to the electrodes, the power supply being adapted to alternately reverse the direction of current such that each electrode can be operated in turn as the anode and as the cathode ; or
3. The EDCS of claim 1 or 2, further comprising a power source for supplying current to the electrodes and an electrical switch coupled to the power source and the electrodes, the electrical switch adapted to alternately reverse a direction of current to enable each electrode to operate in turn as the anode and as the cathode.

3. The EDCS of claim 1 or 2 , further comprising a current collector adjacent each of the electrodes.

3. The EDCS of claim 1 or 2 , wherein the charge storage compound comprises a metal hydroxide, a metal oxyhydroxide, a metal oxide, or a hydrogen storage alloy.

6. The EDCS of claim 5 , wherein the charge storage compound comprises nickel hydroxide, manganese dioxide, partially charged nickel hydroxide, or lanthanum nickel hydride.

3. The EDCS of claim 1 or 2, further comprising an ionomer layer between the membrane and each of the two electrodes extending along an edge of each of the two electrodes to a current collector, the ionomer layer adapted to seal carbon dioxide released from the electrode serving as the anode within the electrode serving as the anode and the channel for the outflow of carbon dioxide from the electrode serving as the anode .

The EDCS of claim 7 , wherein the ionomer layer comprises an anion exchange polymer.

3. The EDCS of claim 1 or 2, wherein the anion exchange polymer of the two electrodes, the anion exchange polymer of the membrane, and/or the anion exchange membrane of the ionomer layer independently comprise a polymer backbone that is free of quaternary ammonium or imidazolium groups and ether groups.

The anion exchange polymer of the two electrodes, the anion exchange polymer of the membrane, and/or the anion exchange membrane of the ionomer layer may be independently selected from the group consisting of poly(arylpiperidinium), alkylammonium-functionalized poly(arylalkylene), substituted-imidazolium-functionalized poly(arylalkylene), alkylammonium-functionalized poly(styrene), substituted-imidazolium-functionalized poly(styrene), alkylammonium-functionalized poly(styrene-co-divinylbenzene), substituted-imidazolium-functionalized poly(styrene-block-ethylene-co-butadiene-block-styrene), alkylammonium ... 3. The EDCS of claim 1 or 2, comprising a substituted imidazolium-functionalized poly(styrene-block-ethylene-co-butadiene-block-styrene), an alkylammonium-functionalized poly(ethylene), a substituted imidazolium-functionalized poly(ethylene), an alkylammonium-functionalized poly(tetrafluoroethylene), a substituted imidazolium-functionalized poly(tetrafluoroethylene), an alkylammonium-functionalized poly(ethylene-co-tetrafluoroethylene), a substituted imidazolium-functionalized poly(ethylene-co-tetrafluoroethylene), a polyethyleneimine, a poly(diallylammonium), a polydiallyldimethylammonium , or a combination thereof.

3. The EDCS of claim 1 or 2, wherein the anion exchange polymer of the two electrodes, the anion exchange polymer of the membrane, and/or the anion exchange membrane of the ionomer layer independently comprise poly(arylpiperidinium) or polydiallyldimethylammonium .

the membrane comprises a plurality of said channels for the passage of the carbon dioxide-containing gas into the membrane ; or
the membrane comprises a void volume for the carbon dioxide-containing gas to diffuse through the membrane; or
3. The EDCS of claim 1 or 2, further comprising a check valve configured to release carbon dioxide generated in the anode electrode from the EDCS through the channel for the outflow of carbon dioxide from the anode electrode .

13. The EDCS of claim 12 , further comprising a fan for blowing the carbon dioxide containing gas through the channel for entry of the carbon dioxide containing gas within the membrane.

3. The EDCS of claim 1 or 2 , wherein the carbon dioxide containing gas is air.

3. The EDCS of claim 1 or 2 , further comprising a stack of one or more additional cells electrically connected in series and a manifold adapted for the outflow of carbon dioxide from each of the electrodes that become the anodes.

16. The EDCS of claim 15 , wherein the ionomer layer surrounds each of the two electrodes and the channel for the outflow of carbon dioxide.

The current collector is a bipolar plate between each cell instead of two current collector plates;
a current collector plate at each end of the stack.

20. The EDCS of claim 17 , wherein the bipolar plate is configured to provide the channels for the exit of carbon dioxide.

20. The EDCS of claim 18 , wherein the channels for outflow of carbon dioxide are perpendicular to the channels in the membrane for the CO2-containing air.

3. A battery system comprising a metal-air battery and the EDCS according to claim 1 or 2 , wherein the carbon dioxide-containing gas is air, and the air is supplied to the EDCS to reduce the concentration of the carbon dioxide, and then the air with the reduced concentration of carbon dioxide is directed to a cathode inlet of the metal-air battery.

3. A method for separating carbon dioxide from a carbon dioxide-containing gas, comprising: supplying the carbon dioxide-containing gas to an EDCS according to claim 1 or 2 ; and driving an electric current through the EDCS.

22. The method of claim 21 , wherein the current is driven through the EDCS in a first phase where one of the two electrodes becomes the anode and the other of the two electrodes becomes the cathode, and in a second phase where a current is driven where one of the two electrodes becomes the cathode and the other of the two electrodes becomes the anode.

23. The method of claim 22, wherein the EDCS voltage is monitored at a constant current such that each of the first and second stages continues for a sufficient time to convert most or all of the nickel hydroxide in the anode to nickel oxyhydroxide and most or all of the nickel oxyhydroxide in the cathode to nickel hydroxide before reversing polarity of the one or more cells.

24. The method of claim 23 , wherein the polarity of the one or more cells is reversed when the voltage of the EDCS is within a range of about 0.5 to about 1.0 V per cell.

22. The method of claim 21, further comprising monitoring a ratio of nickel oxyhydroxide to the sum of nickel hydroxide and nickel oxyhydroxide for the two electrodes combined, which when multiplied by 100 indicates a cell average state of charge (SOC), and triggering an intervention when the ratio reaches a desired threshold set below 0.5 or when the battery average SOC reaches a desired threshold below 50 %.

24. The method of claim 23, further comprising monitoring a total charge passed through each of the first and second stages, and triggering an intervention when the total charge passed through one of the first and second stages falls below a predetermined fraction of a nominal electrode capacity.

The intervention includes extending the stage of operation until a higher voltage threshold is reached , or
The intervention includes extending a stage of the operation until a predetermined amount of charge has passed, or
The intervention includes supplying oxygen or air to the cathode to promote an oxygen reduction reaction; or
26. The method of claim 25 , wherein the intervention comprises applying an electric current to the EDCS to promote a hydrogen evolution reaction.

the intervention includes extending the stage of operation until a higher voltage threshold is reached, the higher voltage threshold being in the range of about 1.0 to about 2.0 V per cell; or
28. The method of claim 27 , wherein the intervention comprises extending the stage of operation until a predetermined amount of charge has passed, the predetermined amount of charge being in the range of about 80% to about 120% of a nominal electrode capacity.