Electrochemical reaction device and electrochemical reaction method

Patent metadata

Field	Value
Publication number	US-2023243042-A1
Application number	US-202217903186-A
Country	US
Kind code	A1
Filing date	Sep 6, 2022
Priority date	Jan 28, 2022
Publication date	Aug 3, 2023
Grant date	—

Abstract

An electrochemical reaction device of an embodiment includes: an electrochemical reaction cell 1 that includes: a first electrode having a first flow path, a second electrode having a second flow path, and a separating membrane sandwiched between the first electrode and the second electrode; a liquid tank that contains a liquid to be treated supplied to the second flow path of the second electrode; a first pipe that connects an inlet of the second flow path and the liquid tank; a second pipe that connects an outlet of the second flow path and the liquid tank; and a backflow suppression mechanism that is provided in the second pipe to prevent backflow of the liquid to be treated flowing in the second pipe or reduce a backflow speed.

First claim

What is claimed is:

1 . An electrochemical reaction device, comprising:
an electrochemical reaction cell that includes a first electrode having a first flow path, a second electrode having a second flow path, and a separating membrane sandwiched between the first electrode and the second electrode; a liquid tank to contain a liquid to be treated supplied to the second flow path of the second electrode; a first pipe that connects an inlet of the second flow path and the liquid tank to supply the liquid to be treated to the second flow path; a second pipe that connects an outlet of the second flow path and the liquid tank to return the liquid to be treated to the liquid tank; and a backflow suppression mechanism that is provided in the second pipe to prevent backflow of the liquid to be treated flowing in the second pipe or reduce a backflow speed.

2 . The device according to claim 1 , wherein
the liquid tank includes a liquid level sensor, and the second pipe is connected at a position lower than a liquid level in the liquid tank, which is set by the liquid level sensor.

3 . The device according to claim 1 , wherein
the backflow suppression mechanism includes a check valve.

4 . The device according to claim 3 , wherein
the check valve includes a swing check valve, a lift check valve, a wafer check valve, or a ball check valve.

5 . The device according to claim 1 , wherein
the backflow suppression mechanism includes a backflow suppression pipe having a shape capable of forming a gas accumulation portion.

6 . The electrochemical reaction device according to claim 5 , wherein
the backflow suppression mechanism includes a gas supply unit to supply gas to the gas accumulation portion of the backflow suppression pipe.

7 . The device according to claim 1 , wherein
the liquid tank includes a liquid level sensor, and the second pipe is connected at a position higher than a liquid level in the liquid tank, which is set by the liquid level sensor.

8 . The device according to claim 1 , further comprising:
a gas-liquid separation tank that is connected to an outlet of the first flow path, wherein the gas-liquid separation tank is disposed so that an internal liquid level is higher than the liquid level in the liquid tank, which is set by the liquid level sensor provided in the liquid tank.

9 . The device according to claim 1 , further comprising:
a gas-liquid separation tank that is connected to an outlet of the first flow path, and a valve provided in a gas discharge pipe of the gas-liquid separation tank, wherein the valve is controlled so that an internal pressure of the gas-liquid separation tank is higher than an internal pressure of the liquid tank.

10 . The device according to claim 1 , further comprising:
a pure-water production unit that is connected to the liquid tank and supplies pure water to the liquid tank, and an ultrapure-water production unit that is provided in the first pipe and supplies ultrapure water to the second flow path of the second electrode, wherein the electrochemical reaction cell is constituted to electrolyze the ultrapure water.

11 . An electrochemical reaction device, comprising:
an electrochemical reaction cell that includes a first electrode having a first flow path, a second electrode having a second flow path, and a separating membrane sandwiched between the first electrode and the second electrode; a liquid to be treated supply system that includes a pure-water production unit to produce pure water and an ultrapure-water production unit to produce ultrapure water by treating the pure water supplied from the pure-water production unit, and supplies the ultrapure water to the electrochemical reaction cell as a liquid to be treated; and a liquid tank that accommodates the liquid to be treated supplied to the electrochemical reaction cell and treated, wherein the liquid to be treated supply system includes a pure-water backflow suppression mechanism that suppresses backflow of the liquid to be treated containing the pure water from the liquid tank into the electrochemical reaction cell.

12 . The device according to claim 11 , wherein
the liquid tank has an overflow structure with two tanks separated by an overflow wall into a low water level tank portion and a high water level tank portion, a pipe that supplies the pure water from the pure-water production unit to the ultrapure-water production unit is connected to the low water level tank portion of the liquid tank, and the pure water is supplied to the ultrapure-water production unit through the low water level tank portion of the liquid tank, and a pipe that returns the liquid to be treated from the electrochemical reaction cell to the liquid tank is connected to the high water level tank portion of the liquid tank.

13 . The electrochemical reaction device according to claim 11 , wherein
a supply pipe that supplies the pure water from the pure-water production unit to the ultrapure-water production unit is directly connected to the ultrapure-water production unit, and a pipe that returns the liquid to be treated from the electrochemical reaction cell to the liquid tank is connected to the liquid tank, and a pipe that supplies the liquid to be treated from the liquid tank to the electrochemical reaction cell is connected to the supply pipe at an upstream side than the ultrapure-water production unit through a check valve.

14 . The device according to claim 11 , wherein
a pipe that supplies the liquid to be treated from the liquid tank to the electrochemical reaction cell is connected to the ultrapure-water production unit through a pump and an injector, and a water supply port that discharges the pure water from the pure-water production unit is connected to the injector.

15 . An electrochemical reaction method, comprising:
preparing a liquid to be treated by treating a treatment liquid concentrate; supplying the liquid to be treated to a second flow path of an electrochemical reaction cell, which includes: a first electrode having a first flow path; a second electrode having the second flow path; and a separating membrane sandwiched between the first electrode and the second electrode, to cause the liquid to be treated to undergo an electrochemical reaction at the electrochemical reaction cell; and stopping the electrochemical reaction of the liquid to be treated and suppressing backflow of the liquid to be treated containing the treatment liquid concentrate into the second flow path.

16 . The method according to claim 15 , wherein
the treatment liquid concentrate is once contained in a liquid tank and then treated to prepare the liquid to be treated, and the liquid to be treated that is treated in the electrochemical reaction cell is returned to the liquid tank through a pipe provided with a check valve.

17 . The method according to claim 15 , wherein
the treatment liquid concentrate is once contained in a liquid tank and then treated to prepare the liquid to be treated, and the liquid to be treated that is treated in the electrochemical reaction cell is returned to the liquid tank through a backflow suppression pipe having a shape capable of forming a gas accumulation portion.

18 . The method according to claim 15 , wherein
the treatment liquid concentrate is once contained in a low water level tank portion of a liquid tank that has an overflow structure with two tanks separated by an overflow wall into the low water level tank portion and a high water level tank portion and then t

Assignees

• Toshiba Kk
• Toshiba Energy Systems & Solutions Corp

Inventors

• Yoshinaga Norihiro
• Sekiguchi Shinichi
• Syoji Naoki
• Kitagawa Ryota
• Nakamori Yoji
• Sato Hideaki
• Sugano Yoshitsune
• Tanoue Tetsuharu

Classifications

• C25B1/04 Primary

  by electrolysis of water · CPC title

• C25B9/19

  with diaphragms · CPC title

• C25B13/02

  characterised by shape or form · CPC title

• C25B15/02

  Process control or regulation · CPC title

• C25B15/085

  Removing impurities · CPC title