IP Library Granted Patent US 12,434,964
Granted Patent B2
US 12,434,964 · App. 17/682,046 · Granted Oct 7, 2025

Hydrogen production apparatus

Inventors: Hiromasa Takahashi (Tokyo, JP); Shin Yabuuchi (Tokyo, JP); Naoto Fukatani (Tokyo, JP); Futoshi Furuta (Tokyo, JP); Jun Hayakawa (Tokyo, JP)
Assignee: HITACHI, LTD.
C01B3/08B01J19/127B01J35/39C01B3/042C01B3/50C25B1/04C25B1/55C25B9/23C25B15/083C01B2203/0277C01B2203/04
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Quick Facts
Patent No.
US 12,434,964
App. No.
17/682,046
Granted
Oct 7, 2025
Kind
B2
Abstract

A hydrogen production apparatus including a photocatalyst and generating hydrogen from water includes a wavelength separation unit separating sunlight by wavelength, an infrared light conversion unit converting infrared light separated by the wavelength separation unit to visible light, and an ultraviolet light conversion unit converting ultraviolet light separated by the wavelength separation unit to visible light.

Claims (55)

1. A hydrogen production apparatus including a photocatalyst and generating hydrogen from water, the hydrogen production apparatus comprising:

a wavelength separation unit separating sunlight by wavelength;

an infrared light conversion unit converting infrared light separated by the wavelength separation unit to visible light, wherein the visible light is incident upon the photocatalyst; and

an ultraviolet light conversion unit converting ultraviolet light separated by the wavelength separation unit to visible light, wherein the visible light is incident upon the photocatalyst,

wherein visible light separated from sunlight by the wavelength separation unit is incident upon the photocatalyst.

2. The hydrogen production apparatus according to claim 1 , wherein the wavelength separation unit transmits infrared light out of the sunlight and reflects visible light and ultraviolet light.

3. The hydrogen production apparatus according to claim 2 , wherein the ultraviolet light conversion unit reflects the visible light, converts the ultraviolet light to visible light by wavelength, and emits the visible light out of the visible light and the ultraviolet light reflected by the wavelength separation unit.

4. The hydrogen production apparatus according to claim 2 , wherein the ultraviolet light conversion unit separates wavelength of the visible light and the ultraviolet light reflected by the wavelength separation unit and emits the visible light and the ultraviolet light.

5. The hydrogen production apparatus according to claim 1 , wherein the wavelength separation unit separates wavelength of the sunlight to infrared light, visible light, and ultraviolet light.

6. A hydrogen production apparatus, comprising:

a photocatalyst generating a hydrogen gas from water by irradiating light;

a pipe allowing water to flow through the inside;

a wavelength separation unit separating sunlight by wavelength;

a first optical system condensing on and irradiating to the photocatalyst visible light obtained by separating sunlight by wavelength using the wavelength separation unit;

a second optical system converting ultraviolet light obtained by separating sunlight by wavelength using the wavelength separation unit to visible light and condensing on and irradiating the visible light to the photocatalyst; and

a third optical system converting infrared light obtained by separating sunlight by wavelength using the wavelength separation unit to visible light and condensing on and irradiating the visible light to the photocatalyst.

7. The hydrogen production apparatus according to claim 6 , further comprising:

a first pipe allowing water to flow in the inside; and

a second pipe allowing water to flow in the inside,

wherein an auxiliary catalyst for hydrogen gas is formed in a part of the photocatalyst,

an auxiliary catalyst for oxygen gas is formed in another part of the photocatalyst,

the photocatalyst on a side of forming the auxiliary catalyst for hydrogen gas is disposed inside the first pipe, and

the photocatalyst on a side of forming the auxiliary catalyst for oxygen gas is disposed inside the second pipe.

8. The hydrogen production apparatus according to claim 6 , wherein the photocatalyst is disposed inside the pipe.

9. The hydrogen production apparatus according to claim 8 ,

wherein an auxiliary catalyst for hydrogen gas is formed in a part of the photocatalyst disposed inside the pipe, and

an auxiliary catalyst for oxygen gas is formed in another part of the photocatalyst.

10. The hydrogen production apparatus according to claim 8 ,

wherein an auxiliary catalyst for hydrogen gas is formed in a part of the photocatalyst disposed inside the pipe,

an opposite electrode is disposed at a position inside the pipe and apart from the photocatalyst, and

the photocatalyst and the opposite electrode are separated from each other inside the pipe by an ion-exchanging membrane.

11. A hydrogen production apparatus, comprising:

a photocatalyst generating a hydrogen gas in water by irradiating visible light;

a light irradiation unit irradiating visible light originating from a sun and visible light generated from light other than the visible light of the sunlight to the photocatalyst; and

a water/gas separation mechanism unit separating a hydrogen gas from the water, the hydrogen gas being generated by the photocatalyst, the visible light included in the sunlight and the generated visible light being irradiated to the photocatalyst from the light irradiation unit,

wherein the light irradiation unit includes:

a first optical system condensing on and irradiating to the photocatalyst visible light obtained by separating the sunlight by wavelength using a wavelength separation unit;

a second optical system converting ultraviolet light to visible light using an ultraviolet light conversion unit and condensing on and irradiating the visible light to the photocatalyst, the ultraviolet light being obtained by separating the sunlight by wavelength using the wavelength separation unit; and

a third optical system converting infrared light to visible light using an infrared light conversion unit and condensing on and irradiating the visible light to the photocatalyst, the infrared light being obtained by separating the sunlight by wavelength using the wavelength separation unit.

12. The hydrogen production apparatus according to claim 11 , further comprising:

a first pipe allowing water to flow in the inside; and

a second pipe allowing water to flow in the inside,

wherein an auxiliary catalyst for hydrogen gas is formed in a part of the photocatalyst,

an auxiliary catalyst for oxygen gas is formed in another part of the photocatalyst,

the photocatalyst on a side of forming the auxiliary catalyst for hydrogen gas is disposed inside the first pipe, and

the photocatalyst on a side of forming the auxiliary catalyst for oxygen gas is disposed inside the second pipe.

13. The hydrogen production apparatus according to claim 11 , further comprising a pipe allowing water to flow through the inside,

wherein the photocatalyst is disposed inside the pipe,

an auxiliary catalyst for hydrogen gas is formed in a part of the photocatalyst disposed inside the pipe, and

an auxiliary catalyst for oxygen gas is formed in another part of the photocatalyst.

14. The hydrogen production apparatus according to claim 11 , further comprising a pipe allowing water to flow through the inside,

wherein the photocatalyst is disposed inside the pipe,

an auxiliary catalyst for hydrogen gas is formed in a part of the photocatalyst disposed inside the pipe,

an opposite electrode is disposed at a position inside the pipe and apart from the photocatalyst, and

the photocatalyst and the opposite electrode are separated from each other by an ion-exchanging membrane in the inside of the pipe.

Assignments (1)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Mar 2, 2022
From: TAKAHASHI, HIROMASA; YABUUCHI, SHIN; FUKATANI, NAOTO; FURUTA, FUTOSHI; HAYAKAWA, JUN
To: HITACHI, LTD.
Reel/Frame 059144/0972 →
Priority Claims (1)
JP 2021-161361 · Sep 30, 2021 · national
Continuity (1)
Related Publication 20230094287A1 · Mar 30, 2023
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