Water treatment system using alkaline water electrolysis device and alkaline fuel cell

Patent metadata

Field	Value
Publication number	US-10622659-B2
Application number	US-201615580200-A
Country	US
Kind code	B2
Filing date	Jun 16, 2016
Priority date	Jun 17, 2015
Publication date	Apr 14, 2020
Grant date	Apr 14, 2020

Abstract

Provided is a water treatment system using an alkaline water electrolytic device and an alkaline fuel cell in which for continuing an electrolytic treatment, a hydrogen gas and an oxygen gas required in an alkaline water electrolytic device and an alkaline fuel cell, an amount of water corresponding to raw water lost through the electrolytic treatment, and an electrolytic solution are efficiently circulated and used in a water treatment system to considerably reduce electric power consumption. The water treatment system is a water treatment system using an alkaline water electrolytic device and an alkaline fuel cell in which an alkaline water electrolytic device and an alkaline fuel cell are connected to each other, the volume of raw water is reduced, an oxygen gas and a hydrogen gas that are generated from the alkaline water electrolytic device are fed to the alkaline fuel cell, the oxygen gas and hydrogen gas are used to generate electric power by the alkaline fuel cell, electric energy and water are collected, and the collected electric energy is fed to the alkaline water electrolytic device as an electric power source thereof.

First claim

The invention claimed is:

1. A water treatment system using an alkaline water electrolytic device and an alkaline fuel cell, configured to have following features,
(1) the alkaline water electrolytic device and the alkaline fuel cell are connected to each other,
(2) an electrolytic solution obtained by mixing raw water, which is water to be treated by the alkaline water electrolytic device, and an alkaline aqueous solution so as to form a mixture and adjusting the mixture to have a desired alkali concentration, an amount of water corresponding to an amount of the raw water lost through an electrolytic treatment are fed to the alkaline water electrolytic device, and the electrolytic treatment is performed continuously while an alkali concentration is maintained at the initial desired concentration, and the electrolytic solution is circulated, a volume of the raw water is reduced, an oxygen gas is generated from an anode chamber of the alkaline water electrolytic device, and a hydrogen gas is generated from a cathode chamber of the alkaline water electrolytic device,
(3) the electrolytic solution formed of the alkaline aqueous solution adjusted to have the desired alkali concentration, the oxygen gas and the hydrogen gas generated by the alkaline water electrolytic device are fed to the alkaline fuel cell, at least part of the oxygen gas and the hydrogen gas is used to generate electric power by the alkaline fuel cell, and electric energy and water are collected, and
(4) the collected electric energy is fed to the alkaline water electrolytic device as an electric power source thereof, part or all of the collected water is fed to a circulation line of the electrolytic solution in the alkaline water electrolytic device, and the electrolytic treatment is continued,
whereby most or part of electric power energy required in each of the alkaline water electrolytic device and the alkaline fuel cell, the hydrogen gas and the oxygen gas serving as raw materials for generating the electric power energy, and the amount of the water corresponding to the raw water lost through the electrolytic treatment is recycled in the water treatment system.

2. The water treatment system using an alkaline water electrolytic device and an alkaline fuel cell according to claim 1 ,
wherein 2nd, 3rd, . . . and nth alkaline water electrolytic devices and 2nd, 3rd, . . . and nth alkaline fuel cells are connected to the alkaline water electrolytic device and the alkaline fuel cell in a cascade mode,
an electrolytic solution electrolytically treated and concentrated by the alkaline water electrolytic device is sequentially fed to the 2nd, 3rd, . . . and nth alkaline water electrolytic devices,
an electrolytic treatment is performed in the same manner as in the electrolytic treatment using the alkaline water electrolytic device,
an oxygen gas and a hydrogen gas generated are fed to at least one of the alkaline fuel cell and the 2nd, 3rd, . . . and nth alkaline fuel cells, at least part of the oxygen gas and hydrogen gas is used to generate electric power by the at least one of the alkaline fuel cell and the 2nd, 3rd, . . . and nth alkaline fuel cells, electric energy is collected, and water is generated,
the collected electric energy is fed to at least one of the alkaline water electrolytic device and the 2nd, 3rd, . . . and nth alkaline water electrolytic devices, and the electrolytic treatment is continued,
water generated in the electric power generation by the at least one of the alkaline fuel cell and the 2nd, 3rd, . . . and nth alkaline fuel cells is discarded or fed to a circulation line of the electrolytic solution in at least one of the alkaline water electrolytic device and the 2nd, 3rd, . . . and nth alkaline water electrolytic devices, and the volume of the raw water subjected to volume reduction by the alkaline water electrolytic device is further reduced by the 2nd, 3rd, . . . and nth alkaline water electrolytic devices.

3. The water treatment system using an alkaline water electrolytic device and an alkaline fuel cell according to claim 1 , wherein pure water is used as the raw water.

4. The water treatment system using an alkaline water electrolytic device and an alkaline fuel cell according to claim 1 , wherein raw water containing tritiated water is used as the raw water.

5. The water treatment system using an alkaline water electrolytic device and an alkaline fuel cell according to claim 1 , wherein raw water containing tritiated water containing impurities including chloride ions is used as the raw water.

6. The water treatment system using an alkaline water electrolytic device and an alkaline fuel cell according to claim 2 ,
wherein each of the alkaline water electrolytic device and the 2nd, 3rd, . . . and nth alkaline water electrolytic devices comprises:
an anode;
a cathode; and
a diaphragm, and

each of the anode and the cathode comprises an electrode formed of a Ni or iron base material, or an electrode obtained by subjecting a surface of the base material to Raney nickel coating, Ni-based dispersion plating, or noble metal-based pyrolytic coating.

7. The water treatment system using an alkaline water electrolytic device and an alkaline fuel cell according to claim 2 ,
wherein each of the alkaline fuel cell and the 2nd, 3rd, . . . and nth alkaline fuel cells comprises:
a positive electrode;
a negative electrode; and
an anion exchange membrane, and

each of the positive electrode and the negative electrode is formed of an electrode material with a platinum catalyst or a ruthenium-platinum alloy catalyst carried on a carbon black carrier.

8. The water treatment system using an alkaline water electrolytic device and an alkaline fuel cell according to claim 1 ,
wherein raw water containing tritiated water that contains impurities including chloride ions is used as the raw water,
distilling of the raw water for removing the impurities is performed prior to the electrolytic treatment by the alkaline water electrolytic device, and in the distilling, the raw water containing the impurities including chloride ions, which is supplied as a salt slurry, is distilled, and
the raw water containing tritiated water after the impurities are removed is supplied to the alkaline water electrolytic device.

9. The water treatment system using an alkaline water electrolytic device and an alkaline fuel cell according to claim 8 , wherein in the distilling, the salt slurry is concentrated, and a solid is separated and collected.

10. The water treatment system using an alkaline water electrolytic device and an alkaline fuel cell according to claim 2 ,
wherein the electrolytic solution, which is used for the electrolytic treatment by the alkaline water electrolytic device and the 2nd, 3rd, . . . and nth alkaline water electrolytic devices and used in the alkaline fuel cell and the 2nd, 3rd, . . . and nth alkaline fuel cells, comprises the alkaline aqueous solution in an amount from 5 to 60 mass %.

Assignees

• De Nora Permelec Ltd

Inventors

• Manabe Akiyoshi
• TSUJII Fumiya
• Kato Akihiro

Classifications

• H01M8/10

  Fuel cells with solid electrolytes · CPC title

• H01M8/0606

  with means for production of gaseous reactants · CPC title

• G21F9/06

  Processing (separating different isotopes of the same chemical element B01D59/00) · CPC title

• C25B15/02 Primary

  Process control or regulation · CPC title

• H01M4/926

  on carbon or graphite · CPC title