WO2013179684A1

WO2013179684A1 - Apparatus for producing hydrogen gas and method for producing hydrogen gas

Info

Publication number: WO2013179684A1
Application number: PCT/JP2013/051653
Authority: WO
Inventors: 忠政長谷川
Original assignee: Hasegawa Tadamasa
Priority date: 2012-06-01
Filing date: 2013-01-25
Publication date: 2013-12-05

Abstract

The invention provides a novel apparatus and method for producing hydrogen gas by using water as a raw material. The apparatus (1) for producing hydrogen gas is provided with a reaction tank (11) for storing water (W) for decomposition, a hydrogen gas collection unit (12) for separating and collecting the hydrogen gas from the mixed gas (Vp) of oxygen gas and hydrogen gas generated in the reaction tank (11), and a bubble generator (13) for generating micro-bubbles (MB) 50 μm or less in diameter in the water (W) stored in the reaction tank (11). The apparatus (1) for producing hydrogen gas generates hydrogen gas based on a phenomenon whereby water molecules are decomposed by a physicochemical reaction caused by a free radical field, local high temperature, or the like generated during collapse of micro-bubbles (MB) in the water in the reaction tank (11).

Description

Hydrogen gas production apparatus and hydrogen gas production method

The present invention relates to a hydrogen gas production apparatus and a hydrogen gas production method for producing hydrogen gas by water decomposition.

Conventional hydrogen gas production methods include an electrolysis method, a polymer separation membrane method, and a thermal decomposition method, all of which have poor hydrogen gas production efficiency with respect to production costs. Consuming fossil fuels and generating carbon dioxide. Among these, the hydrogen gas production apparatus by electrolysis of water can produce hydrogen gas appropriately by controlling the current for electrolysis, so a full-scale storage cylinder is unnecessary, and a high-temperature combustion flame used for welding, etc. It is conveniently used as a hydrogen gas source for generating hydrogen. For example, in order to reduce the size of the apparatus and improve the production efficiency of hydrogen gas, a hydrogen gas production apparatus is known in which a mixed gas of hydrogen gas and oxygen gas is produced by electrolysis under low-frequency vibration stirring conditions. (For example, refer to Patent Document 1). In this device, hydrogen and oxygen generated in the vicinity of the electrode are carried to the electrolyte surface by vibrating and stirring the electrolyte before forming bubbles, so that the hydrogen and oxygen generated in the solution adhere to the electrode surface. In other words, high current density electrolysis can be realized without increasing the electrical resistance.

By the way, in recent years, various phenomena have been elucidated and applied development has been performed on bubbles called micro-bubbles of several tens of μm or less in water. For such microbubbles, microbubbles with a particle size of 50 μm or less are generated in water and then naturally suspended in water to reduce the particle size, thereby stabilizing microbubbles with a particle size of 3 μm or less. There is known a method for producing water that is present in (see, for example, Patent Document 2). In this method, the particle size is reduced at a certain depth of water having a predetermined electric conductivity and normal hexane extraction concentration. However, a high-concentration ion shell is harmonized on the entire gas-liquid interface of bubbles. When formed, the particle size is stable at 3 μm or less. In addition, a microbubble crushing method has been proposed in which microbubbles having a diameter of 50 μm or less floating in a solution are crushed to generate free radicals (see, for example, Patent Document 3). In this method, the microbubbles are crushed by self-compression due to the surface tension of the gas-liquid interface, and when the microbubbles disappear, the charge energy charged at the gas-liquid interface of the microbubbles is released and freed by the energy. Radicals are generated.

International Publication No. 03/048424 Pamphlet JP 2008-93611 A Japanese Patent No. 4378543

However, in the electrolysis-type hydrogen gas production apparatus as shown in Patent Document 1 described above, although the production efficiency of hydrogen gas is improved as compared with the conventional one, further efficiency improvement is desired. In addition, in the technology related to microbubbles as shown in Non-Patent Document 1 and Patent Documents 2 and 3 described above, the purpose is to efficiently dissolve a useful gas in a liquid phase and to generate a functional liquid. There is no technical idea about hydrogen gas production using the next generated gas. In addition, in hydrogen gas production, in addition to improvements in safety and production efficiency, a new basic hydrogen gas production apparatus and method are desired.

The present invention solves the above-described problems, and an object of the present invention is to provide a new basic hydrogen gas production apparatus and hydrogen gas production method using water as a raw material with a simple configuration.

In order to achieve the above object, a hydrogen gas production apparatus of the present invention is a hydrogen gas production apparatus for producing hydrogen gas by decomposing water, a reaction tank for storing water for decomposition, and hydrogen generated in the reaction tank. A hydrogen gas collecting part that separates and collects hydrogen gas from a mixed gas of gas and oxygen gas, and a bubble generating part that generates microbubbles having a diameter of 50 μm or less in water stored in the reaction tank, Hydrogen gas collection unit collects hydrogen gas generated by decomposition of water molecules due to physicochemical reaction caused by free radical field and local high temperature generated when microbubbles in water in the reaction tank collapse It is characterized by doing.

In this hydrogen gas production apparatus, the reaction tank may have an electrode for electrolyzing water stored in the reaction tank.

In this hydrogen gas production apparatus, the reaction tank may have an ultrasonic wave generation unit that emits ultrasonic waves to water stored in the reaction tank.

In this hydrogen gas production device, the bubble generation unit generates a gas-liquid mixed fluid by mixing the pipe for taking in water in the reaction tank, the pipe for taking in air in the atmosphere, and the water and air taken in by both pipes. And a gas-liquid mixed fluid may be injected from the mixer into the reaction vessel to generate microbubbles.

In this hydrogen gas production apparatus, the bubble generation unit mixes piping for taking in water in the reaction tank, piping for taking in oxygen gas separated by the hydrogen gas collecting unit, and water and oxygen gas taken in by both pipings. And a mixer that generates a gas-liquid mixed fluid, and may have a gas-liquid circulation configuration in which the gas-liquid mixed fluid is injected from the mixer into the reaction tank to generate microbubbles.

The hydrogen gas production method of the present invention is generated by a bubble generation step of generating fine bubbles having a diameter of 50 μm or less in water and a bubble generation step in the hydrogen gas production method of producing hydrogen gas by decomposing water. From a crushing process that crushes microbubbles and decomposes water molecules by a physicochemical reaction caused by a free radical field and local high temperature generated during the crushing, and a mixed gas of hydrogen gas and oxygen gas generated by the crushing process A collection step of separating and collecting hydrogen gas.

The hydrogen gas production method may further include an electrolysis process for generating hydrogen gas by electrolyzing water, and the collection process may collect the hydrogen gas generated by the electrolysis process.

According to the hydrogen gas production apparatus and the hydrogen gas production method of the present invention, it is possible to provide a new apparatus and method for producing hydrogen gas by physicochemical reaction based on the collapse of microbubbles using water as a raw material.

The block diagram including the partial cross section of the hydrogen gas manufacturing apparatus which concerns on one Embodiment of this invention. The perspective view of the apparatus. The conceptual diagram explaining the characteristic of a bubble. The flowchart of the hydrogen gas manufacturing method which concerns on one Embodiment of this invention. The block diagram containing the partial cross section of the hydrogen gas manufacturing apparatus which concerns on other embodiment. The flowchart of the hydrogen gas manufacturing method which concerns on other embodiment. Furthermore, the block diagram containing the partial cross section of the hydrogen gas manufacturing apparatus which concerns on other embodiment. Furthermore, the block diagram containing the partial cross section of the hydrogen gas manufacturing apparatus which concerns on other embodiment.

Hereinafter, a hydrogen gas production apparatus and a hydrogen gas production method according to an embodiment of the present invention will be described with reference to the drawings. 1 and 2 show a hydrogen gas production apparatus 1 according to an embodiment. The hydrogen gas production apparatus 1 includes a reaction tank 11 that stores water W for decomposition, and a hydrogen gas collection unit that separates and collects hydrogen gas from a mixed gas Vp of hydrogen gas and oxygen gas generated in the reaction tank 11. 12 and a bubble generation unit 13 that generates microbubbles MB having a diameter of 50 μm or less in the water W stored in the reaction tank 11.

The reaction tank 11 is a box-shaped airtight container, and the water surface upper space of the stored water W is filled with water vapor evaporated from the water surface and a mixed gas Vp of hydrogen gas and oxygen gas generated by the decomposition of the water W. To do. The hydrogen gas collection unit 12 is disposed in the upper part of the reaction tank 11. The casing of the hydrogen gas collection unit 12 is provided with a gas intake port communicating with the upper space of the reaction tank 11, and further, a hydrogen gas pipe 12a for sending out hydrogen gas, and a discharge pipe for discharging water vapor and oxygen gas 12b is connected. In addition, a hydrogen gas separation membrane and a hydrogen gas permeable porous material that selectively permeate hydrogen gas are provided inside the housing of the hydrogen gas collection unit 12.

A pump 14 for circulating the water W inside the reaction tank 11 is provided on the side of the reaction tank 11. The pump 14 is connected to the side wall of the reaction tank 11 by a water intake pipe 14 a, and is connected to the side wall of the reaction tank 11 through a water supply pipe 14 b and the bubble generating unit 13. The bubble generating unit 13 includes a mixer that generates water-gas mixed fluid by mixing water and gas. The bubble generating unit 13 is connected to a pipe 13a that takes in air in the atmosphere and a pipe 13b that takes in water W in the reaction tank 11 (this is the same as the water supply pipe 14b). The bubble generating unit 13 mixes water and air taken in by both the

pipes

13a and 13b with a mixer, and discharges the generated gas-liquid mixed fluid to the water W of the reaction tank 11, so that the diameter in the water W is reduced. Generates microbubbles MB of 50 μm or less. As the mixer, for example, a commercially available loop flow type bubble generating nozzle (Japanese Patent No. 5002480) can be used.

Next, referring to FIGS. 3 and 4, a hydrogen gas production method for producing hydrogen gas using the above-described hydrogen gas production apparatus 1 will be described. The hydrogen gas production apparatus 1 and the hydrogen gas production method are based on a phenomenon in which water molecules are decomposed by a physicochemical reaction caused by a free radical field or local high temperature generated when the microbubbles MB in the water in the reaction tank 11 are crushed. To generate hydrogen gas.

As shown in FIG. 3, for example, a normal large bubble AB having a diameter of about 1 mm rises to the water surface by buoyancy, dissolves in the air, and disappears. However, the microbubbles MB in water having a diameter of, for example, 50 μm or less, for example, collapse (crush) due to the pressure of the surface tension of water and disappear before rising to the water surface. As described above, the microbubbles MB having a diameter of 50 μm or less in the water W exhibit unique characteristics and behavior that are significantly different from those of the normal bubbles AB. Therefore, the microbubbles MB are also referred to as microbubbles in distinction from the normal large bubbles AB. .

The shape of the microbubbles MB (microbubbles) is formed by the gas-liquid interface between the bubbles and the water surrounding the bubbles, and is surrounded by the water W that is a liquid outside the bubbles. The surface tension of water W acts on the gas-liquid interface. The surface tension acts to reduce the area of the gas-liquid interface, that is, the surface area of the bubbles. The surface tension compresses the gas inside the microbubble MB having a closed gas-liquid interface surrounded by the water W. Here, the atmospheric pressure inside the microbubbles MB is represented by a differential pressure ΔP which is the difference between the atmospheric pressure and the water pressure with reference to the surrounding water pressure. Then, the differential pressure ΔP is expressed by Young Laplace's theoretical formula ΔP = 4σ / D using the surface tension σ and the bubble diameter D. The microbubbles MB are pressurized with a differential pressure ΔP based on the surface tension σ.

According to the above equation, the differential pressure ΔP is, for example, about 0.3 atm for a microbubble MB having a diameter of 10 μm and about 3 atm for a diameter of 1 μm. Since the gas is dissolved in water in proportion to the atmospheric pressure according to Henry's law, the gas inside the bubble pressurized by the differential pressure ΔP is efficiently dissolved in the surrounding water. When the microbubbles MB are reduced, the ratio of the surface area to the internal volume is increased to increase the apparent dissolution rate, and the reduction rate is increased as the microbubbles MB are reduced. When the microbubbles MB fall into such a state, the volume decreases as the gas dissolves, the internal pressure further increases, and the pressure increase further accelerates the gas dissolution rate. The phenomenon occurs. If the above equation is applied as it is when it disappears (D = 0), the differential pressure ΔP becomes infinite. Actually, the differential pressure ΔP does not become infinite, but it is said that a very large pressure field, for example, several thousand atmospheres is generated. Further, when the microbubbles MB are rapidly reduced, the internal pressure rapidly increases, and the temperature inside the bubbles is rapidly increased by the adiabatic compression action accompanying the rapid increase in pressure, and a local high temperature is generated when the microbubbles MB disappear. More specifically, the gas in the microbubbles MB is air in the atmosphere taken in by the bubble generating unit 13. The microbubbles MB take in the heat of the atmosphere and release the heat to the water W when the microbubbles MB disappear. That is, the energy source for high temperature generation is the atmosphere. Further, the bubble generating unit 13 and the mechanism for collapsing the microbubbles MB constitute a heat pump. The temperature of the water W in the reaction tank 11 rises with the operation of the hydrogen gas production apparatus 1.

Also, the gas-liquid interface of the microbubbles MB is charged. Charging has been confirmed by measuring the zeta potential by electrophoresis. Further, it has been reported that the zeta potential rapidly increases as the microbubbles MB are reduced, and the zeta potential tends to increase in inverse proportion to the radius when the microbubbles MB disappear. When the gas-liquid interface disappears due to the rapid disappearance of the microbubbles MB, the energy stored as electric charge is released into the water.

As described above, when the microbubbles MB rapidly shrink and disappear, a region of high temperature, high pressure, and high energy appears locally in the water. The region becomes, for example, a hot spot that is an active energy field of several thousand degrees and several thousand atmospheres. Such a hot spot exists in a very small range in terms of time and space, but decomposes water molecules in and around the hot spot to generate free radicals such as hydroxyl radicals. Free radicals are highly reactive atoms and molecules with unpaired electron pairs, and have the property of causing atomic dissociation and molecular recombination of water molecules. The free radical field, which combines the energy of the hot spot and the free radical, decomposes water molecules existing in the surroundings by physicochemical reaction under local high temperatures, and also generates hydrogen ions, atomic hydrogen, and free radicals. Generate hydrogen molecules from hydrogen. The generated hydrogen molecules are dissolved in water and, when supersaturated in water, are released into the air as hydrogen gas. Hydrogen gas becomes mixed gas Vp together with water vapor evaporated due to the effect of oxygen gas, free radicals, etc. generated by the decomposition of water, and fills the upper space of the reaction tank 11.

As shown in FIG. 4, the hydrogen gas production method includes a bubble generation step (S1) for generating microbubbles MB having a diameter of 50 μm or less in water W, and microbubbles MB generated by the bubble generation step (S1). A crushing step (S2) in which water molecules are decomposed by a physicochemical reaction caused by a free radical field generated at the time of crushing and a local high temperature, and a hydrogen gas and an oxygen gas generated by the crushing step (S2). A collection step (S3) for separating and collecting hydrogen gas from the mixed gas Vp. The raw material for producing hydrogen gas in this method is water W, and the gas in contact with the water W in the upper space of the reaction tank 11 is the mixed gas Vp and the atmosphere.

In the present invention, as means for producing hydrogen gas, supersaturated high-density microbubbles MB are generated in the reaction tank 11 under atmospheric pressure, and a free radical field is generated by crushing by self-compression of the microbubbles MB. In the free radical field, the physicochemical reaction is promoted, and atomization by decomposition of water molecules around the microbubbles MB and generation of hydrogen gas by recombination are performed. The produced hydrogen gas is collected together with the water vapor generated at the same time, and only the hydrogen gas is separated and collected. Thus, according to the hydrogen gas production apparatus 1 and the hydrogen gas production method of the present invention, a new apparatus and method for producing hydrogen gas by a physicochemical reaction based on the collapse of the microbubbles MB are provided.

5 and 6 show another embodiment of the hydrogen gas production apparatus 1 and the hydrogen gas production method. As shown in FIG. 5, the hydrogen gas production apparatus 1 is a positive / negative pair for electrolyzing the water W stored in the reaction tank 11 in the hydrogen gas production apparatus 1 shown in FIGS. The electrode 15 is further provided. Further, as shown in FIG. 6, this hydrogen gas production method further includes an electrolysis step (S4) for producing hydrogen gas by electrolyzing water in the hydrogen gas production method of FIG. 4 described above. is there. The electrode 15 is connected to a power source 15a and supplied with an electrolysis current. The mixed gas Vp includes hydrogen gas and oxygen gas generated by electrolysis of the water W. The current supplied by the power supply 15a is not limited to a direct current wave, but can be various currents such as a rectangular wave, a pulse wave, and an alternating current thereof. Generation of hydrogen gas is promoted by electrolysis of water W using the electrode 15. In the electrolysis of the water W, it is not necessary to add an electrolyte to the water W to form an electrolyte solution. This is because, as described above, the gas-liquid interface of the microbubbles MB is charged, so that a current flows through the microbubbles MB. An electrolyte may be added to the water W.

FIG. 7 shows still another embodiment of the hydrogen gas production apparatus 1 and the hydrogen gas production method. The hydrogen gas production apparatus 1 includes an ultrasonic wave generation unit 16 that radiates an ultrasonic wave US to the water W stored in the reaction tank 11 in the hydrogen gas production apparatus 1 shown in FIG. 5 described above. The ultrasonic generator 16 is driven by a high frequency power source from a power source 16a. The ultrasonic wave US promotes the collapse and disappearance of the microbubbles MB and the generation of hydrogen gas by the cavitation effect based on the pressure wave with respect to the water W.

FIG. 8 shows still another embodiment of the hydrogen gas production apparatus 1 and the hydrogen gas production method. This hydrogen gas production apparatus 1 is obtained by connecting the outlet side of the discharge pipe 12b and the inlet side of the pipe 13a to each other in the hydrogen gas production apparatus 1 shown in FIG. Oxygen gas separated by the hydrogen gas collection unit 12 is taken into the mixer of the bubble generation unit 13 instead of the atmosphere. The bubble generation unit 13 has a gas-liquid circulation type configuration in which the water W, oxygen gas, and water vapor in the reaction tank 11 are circulated. The bubble generating unit 13 mixes the water taken in by the

pipes

14b and 13b and the oxygen gas taken in by the

pipes

12b and 13a with a mixer, and releases the generated gas-liquid mixed fluid to the water W. Microbubbles MB having a diameter of 50 μm or less are generated inside.

It should be noted that the present invention is not limited to the above configuration and can be variously modified. For example, the hydrogen gas production apparatus 1 shown in FIGS. 1 and 8 may include the ultrasonic wave generation unit 16 shown in FIG. Further, as shown in FIG. 5, the hydrogen gas production apparatus 1 of FIG. 8 can further include electrodes 15 that form a positive and negative pair for electrolyzing the water W. Further, in order to promote the collapse and disappearance of the microbubbles MB and promote the generation of hydrogen gas, in addition to the ultrasonic generator 16 or independently of the ultrasonic generator 16, Stimulation means such as a discharge device for stimulating W can be provided. Further, the oxygen gas separated by the hydrogen gas collection unit 12 may be released into the atmosphere or recovered separately and used without returning to the reaction tank 11 via the pipe 12b or the pipe 13a. Good.

This application claims priority based on Japanese Patent Application 2012-138216 dated June 1, 2012. The entire contents of that application are incorporated by reference into this application.

The present invention can be applied to a use for producing hydrogen gas added to fuel in order to improve the combustion efficiency of a conventional internal combustion engine or a use for producing hydrogen gas used for welding.

DESCRIPTION OF SYMBOLS 1 Hydrogen gas production apparatus 11 Reaction tank 12 Hydrogen gas collection part 13 Bubble generation part 15 Electrode 16 Ultrasonic generation part

Claims

In a hydrogen gas production device that produces hydrogen gas by decomposing water,
A reaction tank for storing water for decomposition;
A hydrogen gas collecting section for separating and collecting hydrogen gas from a mixed gas of hydrogen gas and oxygen gas generated in the reaction vessel;
A bubble generating unit that generates microbubbles having a diameter of 50 μm or less in the water stored in the reaction vessel,
Hydrogen gas generated by decomposition of water molecules by a physicochemical reaction caused by free radical fields and local high temperatures generated when the microbubbles in the water in the reaction vessel are crushed is captured by the hydrogen gas collector. A hydrogen gas production apparatus characterized by collecting.
The hydrogen gas production apparatus according to claim 1, wherein the reaction tank has an electrode for electrolyzing water stored in the reaction tank.
The hydrogen gas production apparatus according to claim 1 or 2, wherein the reaction tank has an ultrasonic wave generation unit that emits ultrasonic waves to water stored in the reaction tank.
The bubble generating unit includes a pipe that takes in water in the reaction tank, a pipe that takes in air in the atmosphere, and a mixer that mixes water and air taken in by both the pipes to generate a gas-liquid mixed fluid; The hydrogen gas production apparatus according to any one of claims 1 to 3, wherein a gas-liquid mixed fluid is injected from the mixer into the reaction vessel to generate the microbubbles. .
The bubble generating unit mixes a pipe for taking in water in the reaction vessel, a pipe for taking in oxygen gas separated by the hydrogen gas collecting unit, and water and oxygen gas taken in by both the pipes. And a mixer that generates a liquid mixture fluid, and has a gas-liquid circulation configuration in which the gas-liquid mixture fluid is injected from the mixer into the reaction vessel to generate the microbubbles. The hydrogen gas production apparatus according to any one of claims 1 to 3.
In a hydrogen gas production method for producing hydrogen gas by decomposing water,
A bubble generation process for generating microbubbles having a diameter of 50 μm or less in water;
A crushing step of crushing microbubbles generated by the bubble generation step, and decomposing water molecules by a physicochemical reaction caused by a free radical field and a local high temperature generated during the crushing;
And a collecting step of separating and collecting the hydrogen gas from a mixed gas of hydrogen gas and oxygen gas generated by the crushing step.
An electrolysis process for generating hydrogen gas by electrolyzing water;
The method for producing hydrogen gas according to claim 6, wherein the collecting step collects hydrogen gas generated by the electrolysis step.