JP6727384B1 - Dispersion method of hydrogen in liquid solvent - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of continuously dispersing hydrogen in a liquid solvent for a long period of time in a state of exceeding a saturated dissolution amount under standard atmospheric pressure, in which a liquid solvent in which hydrogen is dispersed is a beverage or a liquid. Provided is a liquid solvent that can be a raw material thereof, and a method capable of satisfactorily dispersing a large amount of hydrogen in ultrafine bubbles in the liquid solvent for a long time. A method of dispersing hydrogen 15 in a liquid solvent for a beverage in excess of a saturated dissolution amount under standard atmospheric pressure, wherein a pressure P of a closed space 11 filled with hydrogen 15 is 0.28 MPa. A pressure adjusting means for pressurizing so that ≦P and a gas permeable means 14 formed of a polypropylene porous film for separating a liquid solvent and hydrogen from each other are provided. A method for dispersing hydrogen in a liquid solvent for beverage, wherein hydrogen 15 is dispersed in the liquid solvent in the form of ultrafine bubbles having a particle size of 1000 nm or less independently of the liquid phase. [Selection diagram] Figure 1

Description

The present invention relates to a method capable of continuously dispersing, in a liquid solvent, an amount of hydrogen in excess of a saturated dissolution amount under standard atmospheric pressure for a long time, in particular, a liquid solvent in which hydrogen is dispersed is a beverage liquid. Alternatively, the present invention relates to a liquid solvent that can be a raw material thereof, and hydrogen can be dispersed in the liquid solvent in the form of ultrafine bubbles for a long time.

The types of beverage products in Japan continue to increase year by year in order to respond to changes in lifestyle and diversification of taste for food and drink.
Further, in recent years, so-called functional foods and drinks having a physiologically active function for the body have been particularly attracted due to the increased awareness of food and health. Beverage products are no exception to this rule, and many types of products called “Tokuho beverages” are already on the market.
Furthermore, in addition to the above specified health foods (Tokuho) specified by the Health Promotion Act, etc., and the nutritionally functional foods, a new system that allows the labeling of functionality to foods by providing certain requirements Consideration is underway at the Consumer Affairs Agency.
As described above, it is expected that demand for beverages having a physiologically active function will continue to increase.

By being contained in the beverage at a constant concentration, examples of components that may exert a physiologically active function include catechin, chlorogenic acid, polyphenols such as anthocyanins, and dietary fiber such as indigestible dextrin. In addition to the components that are in a solid or liquid state when isolated, solutes in a gaseous state such as hydrogen, nitrogen, carbon dioxide, oxygen, etc. can be envisioned.

Among the beverages in which these gas solutes are dissolved, a so-called hydrogen water beverage in which the solute is hydrogen has attracted attention in recent years.
Although the specific behavior of hydrogen contained in the hydrogen water and the mechanism of action on the body are unknown, various molecular hydrogen removes active oxygen (oxygen radical) in the body, It is expected to have a health promoting effect.

However, in general, when the solute is a gas, most of them are hardly soluble in water except some gases, and the amount that can be dissolved in a liquid solvent such as water is very small. In the case of hydrogen, the saturated dissolution amount in water is 0.806 mol/L (about 1.6 mg/L (1.6 ppm)) at 20° C. and 0.974 mol (1.9 mg/L (1.9 ppm) at 0° C. ). Therefore, when hydrogen is a solute, it is important to include as much amount as possible in the liquid solvent in order to provide a beverage capable of exerting a physiologically active function.

Since the amount of gas dissolved in the liquid solvent is proportional to the pressure of the gas in contact with the liquid solvent according to Henry's law, it is possible to increase the amount of the gas dissolved by contacting the gas with the liquid solvent at a higher pressure. Is possible. Several methods have already been disclosed as a method of dissolving a gas in excess of the saturated dissolution amount under standard atmospheric pressure by utilizing Henry's law.
For example, in Patent Document 1, as a method of dissolving hydrogen in water, a method of filling hydrogen in a pressure vessel in a high pressure state and spraying water into the pressure vessel in a shower shape to bring hydrogen into contact with water Is disclosed.
Further, in Patent Document 2 and Patent Document 3, water and a hydrogen phase pressurized to about 1.2 to 2.0 atm (about 0.12 MPa to 0.20 MPa) are partitioned by a gas permeable membrane, and A method of dissolving hydrogen in water through a gas permeable membrane is disclosed.
It is possible to dissolve hydrogen in water in excess of the saturated dissolution amount by the method disclosed in Patent Documents 1 to 3 above.

However, the dissolved gas (ie, hydrogen) in the liquid solvent follows Henry's law, and even if the predetermined gas is dissolved to the supersaturated state by pressurization, the pressurized state is released after the container is filled, or the atmospheric pressure is released by opening. When placed below, there was a problem that the amount of dissolution drastically decreased to the saturated amount of dissolution at that pressure depending on the filling pressure or atmospheric pressure.

In addition to the method of dissolving the gas, there is a method of allowing the gas to exist in the solvent as fine bubbles, so-called micro bubbles, as a method of containing the gas in the liquid solvent.
As a specific method, a method of dissolving a large amount of a predetermined gas under high pressure and then rapidly depressurizing the gas in a supersaturated state to re-bubble in a liquid solvent (pressurization/depressurization method), or A method (gas-liquid shearing method) of generating bubbles by generating a vortex (400 to 600 rotations per second), entraining the gas in the vortex, and cutting/crushing the gas with a fan or the like can be mentioned.

Unlike ordinary bubbles, fine bubbles (microbubbles) generated in the liquid solvent by such a method have an extremely slow rising speed toward the liquid surface, and thus float in the liquid solvent for at least several minutes. Can exist in the state, during which the liquid solvent is visually perceived as clouded by the fine bubbles.

However, the size of the microbubbles generated by the above method is relatively large, about several tens of μm, and when the liquid solvent is a beverage, for example, it is dispersed in the container or in the mouth before drinking. Since the gas is released from the solvent, it is difficult to take the gas component into the body. Therefore, compared with the case of drinking a liquid solvent in which gas is dissolved in a supersaturated state, a large amount of gas component cannot be ingested. Incidentally, according to the international standardization ISO/TC281, bubbles having a bubble diameter of 1 to 100 μm are called “micro bubbles”.

In view of the above, the applicant has determined that not only the gas is dissolved in the liquid solvent, but also a method of holding the gas in the liquid solvent by dispersing ultrafine bubbles that are much smaller than the microbubbles is a predetermined gas permeability performance requirement. Through a gas permeable membrane made of non-porous silicone rubber having a certain pressure, by feeding the gas into the liquid solvent at a predetermined pressure, the gas is not only dissolved in the liquid solvent, but rather than microbubbles. Further, it was found that it is possible to allow the gas to exist in a dispersed state in a liquid solvent while maintaining the gas phase state of minute ultrafine bubbles, and filed a patent application (Patent Document 4). In addition, in Patent Document 4, the ultrafine bubbles refer to bubbles having a diameter of 500 nm or less.
By the way, since such ultrafine bubble particles have properties similar to colloidal particles, they are less likely to agglomerate and float up when charged in a liquid solvent and repel each other. Since the effect of buoyancy is also small, it is possible to stably maintain the dispersed state in the liquid solvent while maintaining the state of the ultrafine bubbles.

According to the above-mentioned invention by the present applicant (Patent Document 4), it is possible to introduce a larger amount of hydrogen into water (or a liquid solvent) than the hydrogen-containing liquid obtained by other methods up to now. However, as described above, when hydrogen, which is poorly soluble in water, is a solute, it is possible to provide a beverage capable of exerting a physiologically active function by containing as much amount as possible in the liquid solvent. Therefore, further improvement is required.

Japanese Patent No. 3606466 Japanese Patent No. 4551964 JP, 2013-169153, A JP, 2016-87523, A

The present invention is a method in which hydrogen is continuously dispersed in a liquid solvent for a long period of time in a state in which the saturated dissolution amount under standard atmospheric pressure is exceeded, and in particular, the liquid solvent in which hydrogen is dispersed is a beverage liquid. Alternatively, it is a liquid solvent that can be a raw material thereof, and an object thereof is to provide a method capable of favorably dispersing a large amount of hydrogen in ultrafine bubbles in the liquid solvent for a long time.

That is, the present invention is
[1] A method of dispersing hydrogen in a liquid solvent for beverage in excess of the saturated dissolution amount under standard atmospheric pressure,
Pressure adjusting means for pressurizing so that the pressure P of the closed space filled with hydrogen is 0.28 MPa≦P;
Formed from a gas permeable film made of a polypropylene porous film, comprising a gas permeable means for partitioning the liquid solvent and the hydrogen,
Dispersing the hydrogen in the liquid solvent through the gas permeable film in the form of ultrafine bubbles having a particle size of 1000 nm or less in a state independent of the liquid phase. Dispersion method.
[2] The method for dispersing hydrogen in a liquid solvent for beverage according to [1], wherein the liquid solvent is water.
[3] The method for dispersing hydrogen in a liquid solvent for beverage according to [1] or [2], wherein the gas permeable membrane has a thickness of 10 to 100 µm.
[4] The liquid solvent for beverage according to any one of [1] to [3], wherein the pores formed in the gas permeable membrane have an average pore diameter of 0.01 to 0.06 μm. Dispersion method of hydrogen inside.
[5] The method for dispersing hydrogen in a liquid solvent for beverage according to any one of [1] to [4], wherein the gas permeable membrane has a porosity of 10 to 40%.
[6] One or more hollow fiber membrane modules composed of a bundle of hollow fiber membranes in which a plurality of hollow fiber membranes are bundled are arranged in the closed housing as the gas permeable means, and the inner surface of each hollow fiber membrane is arranged. And a pressure adjusting step of adjusting the pressure P of hydrogen perfused on the outer surface of the hollow fiber membrane in the closed housing. 1] to a method for dispersing hydrogen in the liquid solvent for beverage according to any one of [5].
[7] One or more hollow fiber membrane modules composed of a bundle of hollow fiber membranes, which are a bundle of a plurality of hollow fiber membranes, are arranged in the closed housing as the gas permeation means, and the inner surface of each hollow fiber membrane is arranged. And a liquid feeding step of irrigating and feeding the liquid solvent for a beverage to the outside of the hollow fiber membrane in the closed housing [1]. A method for dispersing hydrogen in the liquid solvent for beverage according to any one of [5].
[8] Any one of [1] to [7], characterized in that the pressure of the liquid solvent that is in contact with the sealed space filled with hydrogen through the gas permeable membrane is higher than the pressure P. Item 1. A method for dispersing hydrogen in a liquid solvent for beverage according to item 1.
[9] A method for producing a hydrogen dispersion for beverages, which comprises dispersing hydrogen in a liquid solvent by the method according to any one of [1] to [8].

According to the present invention, hydrogen can be continuously dispersed in a beverage liquid or a liquid solvent which can be a raw material thereof for a long period of time in a state where the saturated dissolution amount under standard atmospheric pressure is exceeded.

1 is an embodiment of a method for dispersing hydrogen in a liquid solvent according to the present invention, and is a schematic diagram showing the configuration of one hollow fiber membrane module when the gas permeable membrane module is formed in the form of a hollow fiber membrane module. FIG. It is a graph showing the relationship between the ratio of the flow rate of hydrogen gas to the flow rate of water and the hydrogen concentration in hydrogen water at the time of production in Examples and Comparative Examples, and shows that the hydrogen gas utilization efficiency differs depending on the module used. Showing.

Hereinafter, one embodiment of the present invention will be described mainly by taking the case where the liquid solvent is water as an example, but as long as the requirements of the present invention described above are satisfied, other liquid solvents may be used. It can be appropriately selected.

In the present specification, "dissolution" refers to a state defined as "forming a uniform liquid phase" by mixing a gas, a liquid, or a solid with a liquid solvent (Chemical Dictionary No. 7, P1468; Tokyo, Inc.). Issuing chemistry coterie). In addition, in the present specification, “dispersion” is defined as that a certain substance system is suspended as fine particles in another medium (Chemical Dictionary, 7th edition, P1278; published by Tokyo Kagaku Dojin).

In the present invention, the ultrafine bubbles are those having a size (diameter) of 1000 nm or less, particularly 50 to 500 nm. Since the ultrafine bubbles are formed in such a size (smallness), they cannot be directly visually recognized even in the liquid solvent. This is because the presence of bubbles smaller than the diffraction limit wavelength of visible light (about 380 nm) does not scatter light and the water does not appear turbid. That is, water containing ultrafine bubbles looks transparent. Therefore, even if superfine bubbles are present in the solution, it cannot be distinguished from the state in which hydrogen is simply dissolved in the liquid solvent.
In addition to hydrogen dissolved in a solvent, when hydrogen is dispersed as microscopic bubbles, each microscopic bubble exists as a “gas phase” independently of the liquid phase of the liquid solvent. Therefore, it does not follow Henry's law as described above and can exist in the liquid solvent for a long time. It is considered that this is because the buoyancy becomes almost negligible because the volume of the ultrafine bubbles is extremely small, and rather, because of the minuteness, the Brownian motion causes random movement in the solvent. Further, as described above, since the particles of the ultrafine bubbles have a property similar to that of colloidal particles, the particles are charged in a liquid solvent and repel each other, which makes it difficult for the particles to aggregate and float up. The dispersion state can be stably maintained in the liquid solvent while maintaining the above.
When the liquid solvent is a beverage material, the above-mentioned ultrafine bubbles are less likely to be released in the mouth even during drinking, and the bubbles are not aggregated in the esophagus or stomach after drinking and are not easily released to the outside.
Therefore, it becomes possible to take in a large amount of the gas component (hydrogen) in the body, as compared with the case of only dissolving it in a liquid solvent, and as a result, it is possible to provide a beverage in which hydrogen easily exerts its physiologically active function. Become.

(Liquid solvent)
In the embodiment of the present invention, the type of liquid solvent is not particularly limited, but when the hydrogen dispersion is used as a beverage or a raw material thereof, the liquid solvent is water, fruit juice, vegetable juice, coffee extract, tea extract. , Liquids suitable for drinking such as milk are preferable, and water is most preferable.
Further, when the liquid solvent is water, if it is suitable for drinking, hard water, regardless of the type of soft water, considering that it is suitable for drinking, and considering addition to coffee extract or fruit juice, The hardness (calculated value of calcium concentration (mg/L)×2.5+magnesium concentration (mg/L)×4.5) is preferably less than 120.

(Deaeration process)
In the present embodiment, since hydrogen is not only dissolved in the liquid solvent but also exists in the state of extremely fine bubbles, the degassing treatment of the liquid solvent in advance is not always essential. However, from the viewpoint of not containing a gas component other than hydrogen, it is preferable to use degassed water in advance as the liquid solvent. As the degassing treatment, conventionally known methods can be selected. For example, there is a method of performing heat distillation under vacuum or reduced pressure.

(Deionization treatment)
The deionization treatment of water means removing cations and anions other than hydrogen ions and hydroxide ions contained in water. The water obtained by the deionization treatment is generally called pure water, and in particular, the theoretical ionic product of water (hydrogen ion concentration×hydroxide ion concentration=1.0×10 ⁻¹⁴ ), conductivity 5. A substance having a value close to 5×10 ⁻⁸ S/cm is also called ultrapure water.
In the present embodiment, in order to stably hold the ultrafine bubbles dispersed in the liquid solvent, it is preferable that a predetermined amount of cations be present in the liquid solvent. No treatment is required, but the use of deionized water is not restricted.

(hydrogen)
In the present invention, hydrogen is dissolved in the above-mentioned liquid solvent and dispersed as ultrafine bubbles, but the grade of hydrogen used (JIS standard grade) or quality standard is not particularly limited.

(Gas permeable membrane)
The gas permeable membrane used in this embodiment is made of porous polypropylene. In order to maintain the strength against pressure, it is preferable that the film thickness is formed to about 10 μm to 100 μm, but since hydrogen is dispersed at a higher concentration, it is possible to withstand the applied hydrogen pressure and liquid solvent pressure. Therefore, in this embodiment, the thickness is preferably 20 to 60 μm. More preferably, the thickness of the hollow fiber membrane is 20 to 50 μm, and further preferably 30 to 50 μm.
The porosity of the gas permeable membrane is preferably 10-40%. A more preferable porosity is 15 to 30%. Here, the porosity is calculated from the volume of the gas permeable membrane made of porous polypropylene and its measured mass, and the density of the porous polypropylene that is the material of the gas permeable membrane. Volume x polypropylene density-mass of gas permeable membrane)/(volume of gas permeable membrane x polypropylene density).
On the other hand, the average pore diameter of the pores is preferably within the range of 0.01 to 0.06 μm. Here, the average pore diameter means the median value of the pore diameter in the present application. A more preferable average pore diameter is in the range of 0.02 to 0.04 μm. The overall distribution of pore diameters is preferably in the range of 0.005 to 0.08 μm. Incidentally, the pore diameter can be measured using an image analysis method based on a scanning electron microscope image at a magnification of 500 to 2000 times.
By using a porous membrane having such a porosity and a pore diameter and adjusting the hydrogen pressure described later, it becomes possible to form extremely fine bubbles satisfactorily.

In the present embodiment, the gas permeable membrane refers to a material such as hydrogen, oxygen, nitrogen, carbon dioxide, etc. that is present as a gas under normal temperature and normal pressure but is permeable to liquid. The gas permeability of the gas permeable membrane can be calculated by the following formula.
Gas permeability = Gas permeation amount (volume) / (pressure difference x permeation area x time)
Incidentally, the gas permeability test can be measured by the differential pressure method of JIS K7126-1.

(Hollow fiber membrane)
The method for dispersing hydrogen in a liquid solvent according to the present embodiment, a gas permeable membrane for partitioning the liquid solvent and hydrogen is arranged, while applying a predetermined pressure from the hydrogen side, hydrogen on the liquid solvent side through the gas permeable membrane. it is intended to deliver the very fine bubbles. Therefore, as long as the above-mentioned configuration and hydrogen pressure requirements are satisfied, the form of the gas permeable membrane is not particularly limited, but the contact area of hydrogen to be permeated is increased, and the device configuration is simple and From the viewpoint of improving the permeation efficiency and obtaining an efficient hydrogen introduction method, it is preferable to use a gas permeable membrane having a hollow fiber membrane shape.
The hollow fiber membrane is a form of utilization of a gas permeable membrane, and refers to a membrane body formed in a thin straw-shaped thin tube. Generally, the diameter (inner diameter) per individual hollow fiber membrane is about several mm to 100 μm, but in the present embodiment, it is formed to be 500 to 100 μm in order to efficiently flow the liquid solvent. Is preferably 300 to 100 μm, and more preferably 300 to 100 μm.

(Hollow fiber membrane module)
A bundle of a large number of the above hollow fiber membranes is called a hollow fiber membrane module. The hollow fiber membrane module is hermetically stored in a housing container made of a synthetic resin such as vinyl chloride, stainless steel, or a metal such as aluminum. One or more hollow fiber membrane modules can be housed in the housing container. As one hollow fiber membrane module, it is preferable to use a bundle of 4000 to 250,000 hollow fiber membranes described above, but it can be appropriately adjusted according to the flow rate of liquid or hydrogen. The hollow fiber membrane module (hollow fiber membrane bundle) may have one housing (bundle) in one housing, or may have a plurality of modules (bundle) in one housing.
Also, the length of the hollow fiber membrane in each module can be adjusted according to the application, but if it is too long, the pressure for flowing the liquid solvent will be high, so fixing the both ends in the form of a hollow fiber membrane bundle. It is preferable to form the so-called effective length excluding the part to 100 to 1000 mm. More preferably, it is 120 to 900 mm. Even more preferably, it is 200 to 800 mm.
On the other hand, the total contact area of the hollow fiber membrane with the gas phase and the liquid phase (effective membrane area) can be appropriately changed according to the size of the module (the amount of flow in the gas phase and the liquid phase). A large device can have a large effective film area, and a small device can have a small effective film area depending on the size of the device. However, in order to efficiently introduce hydrogen into the liquid phase, it is preferable to consider the ratio between the effective film area and the liquid phase flow rate. Specifically, the value obtained by dividing the liquid phase flow rate by the effective film area (liquid phase flow rate/effective film area: unit is L/min·m ² ) is preferably 0.5 to 5. With such a range, hydrogen can be satisfactorily and efficiently introduced into the liquid phase. More preferably, the value of flow rate of liquid phase/effective membrane area is 0.6 to 3. Regardless of a large-sized apparatus or a small-sized apparatus, if the flow rate is set so that the value of the flow rate of the liquid phase/the value of the effective membrane area falls within the above range, the hydrogen gas can be introduced more efficiently.
With the hollow fiber membrane module having the above-described configuration, it is possible to efficiently introduce ultrafine bubble-like hydrogen into the liquid solvent. In the present embodiment, the contact area is calculated by taking into consideration the difference between the inside and outside of the hollow fiber membrane and showing the converted value in the middle portion of the thickness, that is, the average value of the outer surface area and the inner surface area.

(How to pass hydrogen and liquid solvent)
When hydrogen is contained in the liquid solvent through the hollow fiber membrane in the form of ultrafine bubbles,
(1) It is also possible to circulate a liquid solvent on the inner surface of the hollow fiber membrane, and to perfuse hydrogen inside the sealed housing container at a predetermined pressure outside the hollow fiber membrane, or conversely to the above. ,
(2) It is also possible to select a mode in which hydrogen is perfused on the inner surface of the hollow fiber membrane at a predetermined pressure, and the liquid solvent is perfused inside the sealed housing container outside the hollow fiber membrane.
Incidentally, in order to facilitate the pressure adjustment of hydrogen, it is preferable that the liquid solvent is perfused inside the hollow fiber membrane. On the other hand, in the case where the flow rate of the liquid solvent is set to be large, on the contrary, it is preferable that the liquid solvent is perfused outside the hollow fiber membrane.

(Flow rate of hydrogen gas)
Flow rate of hydrogen at the time of pumping hydrogen into the module unit area of hollow fiber membrane ^{(m 2) per} be adjusted to be 0.01L / min · m 2 ~0.5L / min · m 2 Is preferred. More ^preferably, the 0.03L / min · m 2 ~0.1L / min · m 2.

(Pressurization of hydrogen gas)
In order to efficiently and as much hydrogen as possible be fed into the liquid solvent in the form of ultrafine bubbles through a gas permeable membrane such as a hollow fiber membrane, the pressure on the hydrogen side is adjusted to a predetermined pressure or higher. It is necessary. The pressure on the hydrogen side is 0.28 MPa or more. The pressure is preferably 0.30 MPa or more, more preferably 0.35 MPa or more, and most preferably 0.40 MPa or more. The upper limit of the hydrogen pressure is preferably 0.9 MPa from the viewpoint of the strength of equipment such as the hollow fiber membrane module and cost performance. A more preferable upper limit of hydrogen pressure is 0.75 MPa. By adjusting the hydrogen pressure within such a range, it becomes possible for hydrogen to be maintained in a gas phase state in the liquid solvent, that is, to be fed in the form of extremely fine bubbles.

(Pressurization of liquid solvent)
As a result of earnest research, the present inventors not only pressurize only the gas side, that is, the hydrogen side to introduce hydrogen into the liquid solvent, but also apply pressure to the solvent liquid side in addition to pressurizing the hydrogen side. In addition, it has been found that when hydrogen and a solvent liquid are put into a sealed container via a gas permeable membrane, a larger amount of hydrogen in the form of ultrafine bubbles is taken into the liquid solvent. In particular, it has been found that the effect becomes more remarkable by making the pressure on the liquid solvent side higher than the pressure on the hydrogen side. That is, in the hydrogen dispersion method, it is preferable that the pressure P on the hydrogen side is smaller than the pressure Q on the liquid solvent side. Incidentally, the difference between the pressure Q and the pressure P (pressure Q-pressure P) is preferably 0.03 to 0.12 MPa. More preferably, the difference between the pressure Q and the pressure P is 0.04 to 0.1 MPa. Under such a pressure condition, ultrafine bubble-like hydrogen can be introduced into the liquid solvent even better. According to the study by the present inventors, when the pressure difference is within the above range, hydrogen gas can be introduced into the liquid phase better.

Hereinafter, the embodiment of the present invention will be described in more detail by taking as an example the case where the liquid solvent is water and hydrogen is dispersed in the liquid solvent to give a drink.

(Hydrogen water)
Broadly, it refers to water containing hydrogen, but there is no clear definition. In addition, the Japan Molecular Hydrogen Medical Biology Society, which is an academic research group, describes hydrogen water as follows.
“In an academic paper on the drinking effect of hydrogen water on humans, the effect of drinking 1 L of 0.5 mg/L (0.5 ppm) hydrogen water per day was reported, and At present, in order to exert the drinking effect of hydrogen water on humans, the minimum amount is 0.5 mg/L (0.5 ppm) or more and the total amount is 0. It is suggested that it is necessary to drink more than .5 mg.It should be noted that this suggestion is based on academic papers and does not guarantee the effect/efficacy of hydrogen water. , This statement may change as research progresses."

When hydrogen water is taken into the body by drinking, it is expected that the reducing power of contained hydrogen molecules removes active oxygen and prevents oxidative stress in the body.

(container)
When the hydrogen water is for drinking, the produced hydrogen water may be provided in the form of, for example, a water server, or may be provided in the form of being enclosed in a predetermined container. As the container, a so-called pouch-shaped container using a glass bottle, a metal can, and a metal laminated film, in which hydrogen is hard to escape to the outside and which can be sealed, is suitable. An aluminum can is particularly suitable as the metal, and an aluminum/alumina vapor-deposited film is particularly suitable as the metal laminated film because of excellent barrier properties.

Although hydrogen water can be drunk as it is, hydrogen water produced by the method according to the present invention is used as an additive to be added to beverage raw materials such as tea extract, coffee extract, fruit juice, vegetable juice, milk and fermented milk. Can also be used.
By adding hydrogen water to these beverage ingredients, the effect of suppressing the quality deterioration of each beverage due to oxidation can be expected.

Hereinafter, examples of the present invention will be described by taking the case where the liquid solvent is water as an example.

(Examples 1 to 7 and Comparative Examples 1 to 12)
1. Hydrogen Water Raw Material In this example, hydrogen water was produced under the following conditions and apparatus.
(1) Liquid solvent Ion-exchanged water (deionized water) was used as the liquid solvent in this example.
(2) Hydrogen Hydrogen obtained from Iwatani Corporation was used.

2. Method for producing hydrogen water (hollow fiber membrane module)
In this example, a hollow polypropylene membrane module made of porous polypropylene (“Liqui-Cel” model: MM series G800-0 manufactured by 3M) was used as a gas permeable membrane. Details will be described later.
FIG. 1 is a schematic cross-sectional view showing the structure of a gas permeation device including the hollow fiber membrane module used in this example. One or a plurality of hollow fiber membrane modules can be arranged in the housing depending on the manufacturing scale and the like. In the present embodiment, as shown in FIG. 1, one hollow fiber membrane module (hollow fiber membrane module) is used. The membrane bundle is arranged inside the housing. The structure of the gas permeation device does not necessarily have to be the same as the structure shown in FIG. 1, and if the basic configuration is the same, the size and length of the housing, the gas (hydrogen gas) and the liquid phase solvent (water). The installation position of the entrance and exit, the size, etc. can be changed appropriately.

In FIG. 1, a hollow fiber membrane module 10 having a hollow fiber made of the above-mentioned porous polypropylene (hereinafter referred to as a module) is provided with a housing 11 made of a material such as stainless steel or vinyl chloride, and a central portion in the housing 11. And a hollow fiber membrane bundle 14 made of porous polypropylene. The housing 11 is provided with a hydrogen inlet 12 on one side and a hydrogen outlet 13 on the other side, and is designed so that the inside of the housing 11 can be filled with hydrogen 15 at a predetermined pressure and then perfused. A liquid solvent inlet 16 is formed at one end of the hollow fiber membrane bundle 14, and a liquid solvent outlet 17 is formed at the other end.
Next, the procedure for dispersing hydrogen in water, which is a liquid solvent, is shown below.
The module 10 is arranged in a hydrogen water production line (not shown).
Water consisting of degassed natural water (a device for the degassing process is not shown) which is a liquid solvent is fed from the liquid solvent inlet 16 and flows into the thin tubes of each hollow fiber membrane of the hollow fiber membrane bundle 14. To be done.
On the other hand, the hydrogen 15 filled in the housing 11 passes through the pores of the porous polypropylene, which is the membrane material, from the outer side surface of each hollow fiber membrane of the hollow fiber membrane bundle 14 and then inside the tube of the hollow fiber membrane. It is introduced into the passing liquid solvent (water) in the form of ultrafine bubbles. The liquid solvent (water) in which hydrogen is dispersed thus prepared is sent out of the module 10 through the liquid solvent outlet 17.
The hydrogen 15 filled in the housing 11 is perfused into the housing 11 while maintaining a predetermined pressure for each sample. Further, water that passes through the inside of the hollow polypropylene membrane hollow fiber membrane is set so as to pass through the inside of the module 10 while being maintained at a predetermined pressure.

In the above description of FIG. 1 (the description of the flow of hydrogen and the liquid solvent), the liquid solvent (water) is put into the hollow fiber membrane bundle from the liquid solvent inlet 16 provided at one end of the hollow fiber membrane bundle 14, and the hollow fiber membrane is inserted. The mechanism is such that it passes through the bundle and is discharged from the liquid solvent outlet 17 provided at the other end. In this case, hydrogen enters through the hydrogen inlet 12 provided in the housing 11 and is delivered through the hydrogen outlet 13 .
However, the present invention is not limited to this method, and a mechanism may be used in which hydrogen is passed through the tube of the hollow fiber membrane bundle and liquid solvent (water) is passed through the space outside the hollow fiber membrane bundle 14 inside the housing 11. Is.

(Preparation of Samples of Examples 1 to 7 and Comparative Examples 1 to 12)
In the present example and comparative example, the type of the hollow fiber membrane module having the above configuration, the pressure of hydrogen gas perfused in the housing, and the flow rate at equilibrium, the temperature of water flowing in the hollow fiber membrane, and The flow rate and the water pressure were changed as shown in Table 1, and Example samples (hydrogen water) 1 to 7 and Comparative example samples (hydrogen water) 1 to 12 were prepared.
Regarding hydrogen gas, in Examples 1 to 6 and Comparative Examples 1 to 11, first, the gas chamber side was filled with hydrogen gas, and the system reached a steady state at the gas pressure and water pressure shown in Table 1. The flow rate of hydrogen gas at that time was measured and recorded. In addition, in Example 7 and Comparative Example 12, first, the flow rate of hydrogen gas was set to 7.0 L/min to fill the gas chamber side in the housing with hydrogen gas, and then the gas pressure and water pressure shown in Table 1 were used. When the system reached a steady state, the hydrogen gas supply rate (flow rate) was limited to 0.1 L/min.

(Hollow fiber membrane module)
The hollow fiber membrane modules used in Examples 1 to 7 and Comparative Examples 1 to 12 are the following two types.
A: Hollow fiber membrane module having a gas permeable membrane made of porous polypropylene (“Liqui-Cel” manufactured by 3M, model: MM series G800-0): Here, the volume on the gas phase side (hydrogen gas side) in the housing Was 0.16 liters. The effective membrane area of this hollow fiber membrane module is 0.8 m ² , and the hollow fiber membrane thickness is about 50 μm. The length (effective length) of the hollow fiber membrane was 250 mm.
B: Hollow fiber membrane module having a gas permeable membrane made of non-porous silicone rubber (M60-4400 manufactured by Nagayanagi Industry Co., Ltd.): Here, the capacity on the gas phase side (hydrogen gas side) in the housing is about 0. It was 16 liters. The module also has 4400 hollow fiber membranes. The hollow fiber membrane thickness in this module was 60 μm, and the length (effective length) of the hollow fiber membrane in the module was 140 mm.

(Experimental result)
Regarding the prepared example samples 1 to 7 and comparative example samples 1 to 12, the hydrogen content at the time of production was measured under an environment of 25°C. The results are shown in Table 1. In addition, this hydrogen content measurement was performed using the dissolved hydrogen concentration determination reagent (made by Miz Co., Ltd.).

(Measurement of change over time in hydrogen concentration)
Immediately after the production, 2 liters of each of the samples prepared in Example 4, Comparative Example 4, and Comparative Example 9 was collected in a stainless beaker, and dissolved hydrogen concentration determination reagent (manufactured by Miz Co., Ltd.) was used. The concentration was measured. In addition, this experiment was conducted under the conditions of room temperature of 20 to 22°C.
Also. As Examples 8 and 9, samples were prepared in the same manner as in Example 4 (however, the flow rates of hydrogen gas and water, pressure, temperature, etc. were set as shown in Table 2). For the obtained sample, the hydrogen concentration immediately after the production and after 4 hours was determined in the same manner as above. The results are shown in Table 2.

As can be seen from Table 2, the hydrogen concentration during hydrogen water generation in Examples 4, 8 and 9 is larger than that in Comparative Examples 4 and 9. It is considered that this is because the supply pressure of hydrogen gas in the example is higher than that in the comparative example. It was found that the example in which both the supply pressure of hydrogen gas and the water pressure were increased (Example 4) had better hydrogen retention than the other examples shown in Table 2.
By the way, even if the supply pressure was fixed and the water pressure was increased, no significant change was observed in the hydrogen residual property (comparison between Comparative Example 4 and Comparative Example 9, and comparison between Example 8 and Example 9). ..

(Examples 10 to 15)
The same deionized water and hydrogen as those used in Examples 1 to 9 and Comparative Examples 1 to 12 described above were used as raw materials, and the hollow fiber membrane module shown below was used as an apparatus in a housing having a capacity of about 4 liters. Hydrogen gas was produced by using a large-sized apparatus having a configuration in which 1 unit was installed in the above, and setting the hydrogen gas pressure, hydrogen supply pressure, water temperature, flow rate, and water pressure as shown in Table 3.
In addition, in Examples 10 to 15, contrary to the method of Examples 1 to 9 described above, hydrogen is passed through the narrow tube of the hollow fiber membrane module, and degassed water is stored in the housing. The outside of the bundle was perfused.
By the way, in the large-sized apparatus used in Examples 10 to 15, both the flow rate of hydrogen gas and the flow rate of water were the same as those of the apparatus used in Examples 1 to 9 and Comparative Examples 1 to 12 described above. It was possible to make it larger than the actual flow rate.

Hollow fiber membrane module C: Hollow fiber membrane module having a gas permeable membrane made of porous polypropylene ("Liqui-Cel" model: G333 manufactured by 3M): The capacity of the housing is about 0.16 liters. The effective membrane area of the hollow fiber membrane module is 20 m ² , and the hollow fiber membrane thickness is about 50 μm. The length (effective length) of the hollow fiber membrane was 730 mm.
The hydrogen concentration in the water immediately after generation obtained in Examples 10 to 15 was measured by the same method as that performed in Examples 1 to 9 and Comparative Examples 1 to 12. The results are shown in Table 3.

In the above Examples and Comparative Examples, the relationship between the ratio of the hydrogen flow rate to the water flow rate (hydrogen flow rate/water flow rate) and the hydrogen concentration (ppm) at the time of production in the examples using the modules A and C was plotted in a graph. Similarly, for the example using the module B, the relationship between the hydrogen flow rate/water flow rate and the hydrogen concentration at the time of production was also plotted in the same graph. The results are shown in Figure 2.
As can be seen from FIG. 2, in the experiment using the modules A and C, it can be seen that hydrogen can be satisfactorily introduced into water even under the condition where the gas flow rate is small. That is, according to the present embodiment, it can be expected that the utilization efficiency of hydrogen gas is improved.

(Discussion)
As described above, when the porous polypropylene hollow fiber membrane disclosed in the present embodiment is used and an appropriate hydrogen pressure condition is selected, hydrogen water having a high hydrogen content can be obtained. In particular, it was confirmed that hydrogen water having a higher hydrogen content can be obtained by the production under the condition that the pressure of the liquid solvent is higher than the pressure of hydrogen. It was also found that hydrogen water having a relatively high residual hydrogen ratio can be obtained by increasing both the gas supply pressure and the liquid phase pressure (water pressure).

According to the present invention, it becomes possible to continuously disperse hydrogen in a liquid solvent over a long period of time in a state where the saturated dissolution amount under standard atmospheric pressure is exceeded. In particular, it is possible to confine high-concentration hydrogen in a beverage liquid or a liquid solvent that can be a raw material thereof, and it can be used for producing good drinking water such as hydrogen water.

10 Hollow Fiber Membrane Module 11 Housing 12 Gas (Hydrogen) Inlet 13 Gas (Hydrogen) Outlet 14 Hollow Fiber Membrane Bundle 15 Gas (Hydrogen)
16 Liquid Solvent Inlet 17 Liquid Solvent Outlet

Claims (8)

A method of dispersing hydrogen in a liquid solvent for beverage in excess of a saturated dissolution amount under standard atmospheric pressure,
Pressure adjusting means for pressurizing so that the pressure P of the closed space filled with hydrogen is 0.28 MPa≦P;
Formed from a gas permeable film made of a polypropylene porous film, comprising a gas permeable means for partitioning the liquid solvent and the hydrogen,
The pressure Q of the liquid solvent in contact with the closed space filled with hydrogen through the gas permeable membrane is made larger than the pressure P,
Dispersing the hydrogen in the liquid solvent through the gas permeable film in the form of ultrafine bubbles having a particle size of 1000 nm or less in a state independent of the liquid phase. Dispersion method. The method for dispersing hydrogen in a liquid solvent for beverage according to claim 1, wherein the liquid solvent is water. The method for dispersing hydrogen in a liquid solvent for beverage according to claim 1 or 2, wherein the gas permeable membrane has a thickness of 10 to 100 µm. The average pore size of the pores formed in the gas permeable membrane is 0.01 to 0.06 μm, and hydrogen is dispersed in the beverage liquid solvent according to any one of claims 1 to 3. Method. The method for dispersing hydrogen in a liquid solvent for beverage according to claim 1, wherein the gas permeable membrane has a porosity of 10 to 40%. As the gas permeation means, one or more hollow fiber membrane modules each consisting of a bundle of hollow fiber membranes in which a plurality of hollow fiber membranes are bundled are arranged in a closed housing, and the beverage is provided on the inner surface of each hollow fiber membrane. A liquid-passing step of passing a liquid solvent for use, and a pressure adjusting step of adjusting a pressure P of hydrogen perfused on the outer surface of the hollow fiber membrane in the closed housing are provided. 5. A method for dispersing hydrogen in the liquid solvent for beverage according to any one of 5 above. As the difference between the pressure Q and the pressure P (pressure Q- pressure P) is 0.03～0.12MPa, claim 1-6, characterized by adjusting the pressure P and the pressure Q The method for dispersing hydrogen in the liquid solvent for beverage according to any one of 1. Method for producing a beverage hydrogen dispersions, characterized in that dispersing hydrogen in a liquid solvent by a method according to any one of claims 1-7.

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