Method and apparatus for producing hydrogen gas

Abstract

Provided is a method for producing a hydrogen gas, which enables the production of a hydrogen gas with high energy efficiency. This method for producing a hydrogen gas includes: placing water between electrodes; and allowing pulsed discharge to occur between the electrodes to decompose water molecules, thereby generating the hydrogen gas. In the method, the frequency for the pulsed discharge is 190-196 kHz or a double vibration frequency thereof.

Description

Hydrogen gas production method and production device

[0001] The present invention relates to a method and apparatus for producing hydrogen gas, and more particularly to a method and apparatus for producing hydrogen gas that uses high-frequency standing waves to produce hydrogen gas from water with high energy efficiency.

[0002] Hydrogen gas produces only water when burned and does not emit carbon dioxide, making it a promising energy source for realizing a decarbonized society. The most common method for industrially producing hydrogen gas is through the electrolysis of water. However, the electricity used for electrolysis is still mainly derived from fossil fuels, and the environmental impact of the hydrogen gas production process is a significant issue.

[0003] Patent Document 1 (JP 2007-314384 A) discloses a method for producing hydrogen gas, characterized by irradiating water with only infrared rays having a wavelength of 2.8 μm or more and 3.2 μm or less. This invention describes that, without the need for thermal or electrical energy, it is possible to produce hydrogen gas, which will be used in large quantities as fuel for future fuel cells, simply by irradiating water with far-infrared rays contained in sunlight, and that it is also possible to efficiently utilize sunlight.

[0004] Japanese Patent Application Laid-Open No. 2007-314384

[0005] However, splitting water molecules using sunlight has limitations, such as an unstable supply of sunlight and the need to increase the size of the equipment to ensure a sufficient light-receiving area.Furthermore, only specific wavelengths contained in sunlight are involved in the splitting of water molecules, which results in low energy efficiency.

[0006] The present invention was completed in consideration of the above-mentioned problems, and has an object in one embodiment to provide a hydrogen gas production method that can produce hydrogen gas with high energy efficiency. In another embodiment, the present invention has an object to provide a hydrogen gas production device that is suitable for such a hydrogen gas production method and can be miniaturized.

[0007] As a result of extensive research, the inventors have discovered that applying a standing wave in a specific high frequency range to water molecules dissociates the bonds of the OH groups in the water molecules, thereby efficiently generating hydrogen gas. The present invention has been completed based on the above findings, and is exemplified below.

[0008] [1] A method for producing hydrogen gas, comprising disposing water between electrodes and generating hydrogen gas by subjecting the electrodes to pulse discharge to decomposition of water molecules, wherein the frequency of the pulse discharge is 190 to 196 kHz or a harmonic frequency thereof. [2] The method for producing hydrogen gas according to [1], wherein the electrodes consist of a discharge electrode and a ground electrode, the discharge electrode being disposed in insulating oil above the water surface, and the ground electrode being disposed underwater. [3] The method for producing hydrogen gas according to [1] or [2], further comprising applying a magnetic field to the water. [4] An apparatus for producing hydrogen gas, comprising a resonant transformer and a hydrogen generation apparatus, wherein the hydrogen generation apparatus has a water-containing portion separated between electrodes, the resonant transformer being configured to perform pulse discharge between the electrodes, and the frequency of the pulse discharge being 190 to 196 kHz or a harmonic frequency thereof. [5] The apparatus for producing hydrogen gas according to [4], wherein the electrodes consist of a discharge electrode and a ground electrode. [6] The hydrogen gas production device according to [4] or [5], further comprising a magnetic field application means arranged to surround the water storage portion.

[0009] According to one embodiment of the present invention, it is possible to provide a hydrogen gas production method that can produce hydrogen gas with high energy efficiency. According to another embodiment of the present invention, it is possible to provide a hydrogen gas production device that is suitable for such a hydrogen gas production method and that can be miniaturized.

[0010] Fig. 1 is a flow diagram of a method for producing hydrogen gas in one embodiment of the present invention. Fig. 2 is a schematic front view of a hydrogen generation device in one embodiment of the present invention. Fig. 3 is a schematic top view of a hydrogen generation device in one embodiment of the present invention. Fig. 4 is a graph of effective frequencies in vibrating water molecules in one embodiment of the present invention. Fig. 5 is a graph showing the correlation between frequency in vibrating water molecules and decomposition of water molecules in an example of the present invention.

[0011] Next, an embodiment of the present invention will be described with reference to the drawings. It should be understood that the present invention is not limited to the following embodiment, and that appropriate design changes and improvements may be made based on the ordinary knowledge of those skilled in the art without departing from the spirit of the present invention.

[0012] 1 shows the flow of a method for producing hydrogen gas in one embodiment of the present invention. A high-voltage, high-frequency pulse discharge generated by a resonant transformer 1 is transmitted to an electrode 4 of a hydrogen generator 3 via a conductor 2. This excites water 6 molecules placed between the electrode 4 and a ground 8, causing dissociation of the OH covalent bond, thereby generating hydrogen gas. The ground 8 is installed to stabilize the direction of the discharge. Instead of the ground 8 being an earth electrode, an electrode connected to the resonant transformer 1 by a separate conductor may be used.

[0013] It is important that the frequency of the pulse discharge be 190 to 196 kHz or a harmonic frequency thereof. In other words, each substance has its own specific energy level and absorption spectrum, and when the applied vibration (energy) is large, the substance transitions to an excited state. In order to dissociate the OH covalent bond of water molecules with small energy, it is necessary to create conditions for a standing wave in the vibration of the water molecules, thereby creating an excited state.

[0014] Referring to Figure 4, a graph of effective frequencies for vibration of water molecules is shown. This graph is a graph of the IR spectrum of the three degrees of freedom of water molecules, with the horizontal axis representing the frequency of the pulse discharge and the vertical axis representing the molar absorption coefficient. Of these, the value for vibration of one degree of freedom is the largest, and its approximate theoretical value is 1737 cm -1 (frequency 52 THz). In order to vibrate and resonate water molecules, this frequency or its lower harmonic is effective. This advances the excitation of the vibrated water molecules, resulting in the severing of covalent bonds. According to the findings of the inventors, 190 to 196 kHz or harmonic frequencies thereof are frequencies that can vibrate water molecules practically and with high energy efficiency. Harmonic frequencies refer to frequencies that are integer multiples of any frequency within this frequency range.

[0015] The resonant transformer 1 is not particularly limited as long as it is capable of pulse discharge under the above conditions, and one example includes a Tesla coil. When the resonant transformer 1 is connected to an external power supply (100 V, for example), an AC current flows through the primary coil, and the resulting oscillating magnetic field generates electromagnetic induction, causing an AC current to flow through the secondary coil. The amount of energy during pulse discharge is not particularly limited, and any resonant circuit that excites discharge oscillation will suffice.

[0016] The electrode 4, which is a discharge electrode, may be placed in the water 6, but from the viewpoint of the stability of the discharge and preventing the generated hydrogen gas from igniting, it is preferable that it be placed in insulating oil 5 on the surface of the water 6. The type of insulating oil 5 is not particularly limited, but silicone oil, for example, can be used.

[0017] Furthermore, when pulse discharge is performed, it is preferable to apply a magnetic field to the water 6 using a magnetic field application means. By applying a magnetic field, the electron spins in the oxygen can be aligned in the same direction, thereby more efficiently vibrating the water molecules. There are no particular limitations on the method for applying the magnetic field, but examples include a method of placing a ring-shaped magnet around the water 6 or a method of placing a conducting coil around the water 6 and passing electricity through it.

[0018] Fig. 2 is a schematic front view of the hydrogen generator 3 according to one embodiment of the present invention, and Fig. 3 is a schematic top view of the hydrogen generator 3 according to one embodiment of the present invention. The hydrogen generator 3 has a water storage portion isolated between the electrode 4, which is a discharge electrode, and the earth 8, which is a ground electrode, and a ring-shaped neodymium (NdFeB) magnet 7 is arranged around the water storage portion.

[0019] When the water storage portion of the hydrogen generator 3 is filled with water 6 and insulating oil 5 is laid on the water surface, the electrode 4 is placed in the insulating oil 5 and the earth 8 is placed in the water 6. This stabilizes the pulse discharge and makes it possible to prevent the generated hydrogen gas from igniting.

[0020] The mixed gas of hydrogen and oxygen produced by the above method and apparatus can be collected using a pipe or the like by utilizing the pressure difference between the inside and outside of the apparatus. If separation of hydrogen and oxygen is required, a polymer membrane can be placed in the collection path.

[0021] Examples of the present invention are given below, but these examples are provided for a better understanding of the present invention and its advantages, and are not intended to limit the invention.

[0022] The hydrogen generator 3 shown in Fig. 2 and Fig. 3 was charged with insulating oil 5 and water 6, and pulse discharge was performed from the electrode 4 using the resonant transformer 1. The volume of the charged water 6 was 120 cc. The energy used for pulse discharge was 100 V and 2 A. Vibration was applied at different frequencies for 10 minutes each, and the volume of the reacted water 6 (i.e., the decrease in the volume of the water 6) was recorded. The results are shown in Fig. 5.

[0023] As shown in Figure 5, the water reaction volume (cc) on the vertical axis is measured in the range of 190 to 196 kHz, with the horizontal axis representing the excitation frequency (kHz), and is maximized around 193 kHz. Therefore, it was confirmed that pulse discharge in the range of 190 to 196 kHz can decompose water molecules and generate hydrogen gas. Furthermore, since water molecules can be excited by a similar principle using any harmonic frequency within the range of 190 to 196 kHz, it is speculated that these harmonic frequencies can also be used.

[0024] According to the present invention, hydrogen gas can be produced with high energy efficiency by intensively applying pulse discharge at a frequency effective for dissociating the OH covalent bond of water molecules. Furthermore, since the device for performing pulse discharge can be made compact, the entire hydrogen gas production device can be made smaller.

[0025] REFERENCE SIGNS LIST 1 Resonant transformer 2 Conductor 3 Hydrogen generator 4 Electrode 5 Insulating oil 6 Water 7 Neodymium magnet 8 Earth

Claims

1. A method for producing hydrogen gas, comprising disposing water between electrodes and subjecting the electrodes to pulse discharge to decompose water molecules and generate hydrogen gas, wherein the frequency of the pulse discharge is 190 to 196 kHz or a harmonic frequency thereof.

2. The method for producing hydrogen gas as described in claim 1, wherein the electrodes consist of a discharge electrode and an earth electrode, the discharge electrode being disposed in insulating oil above the water surface, and the earth electrode being disposed underwater.

3. The method for producing hydrogen gas according to claim 1 or 2, further comprising applying a magnetic field to the water.

4. A hydrogen gas production apparatus comprising: a resonant transformer; and a hydrogen generation device, the hydrogen generation device having a water storage portion isolated between electrodes, the resonant transformer configured to pulse discharge between the electrodes, and the frequency of the pulse discharge is 190 to 196 kHz or a harmonic frequency thereof.

5. The hydrogen gas production apparatus according to claim 4, wherein the electrodes comprise a discharge electrode and an earth electrode.

6. The hydrogen gas production device according to claim 4 or 5, further comprising a magnetic field applying means arranged to surround the water storage portion.

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