JPH044241B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Field of Industrial Application) The present invention relates to a method for generating excited oxygen through a chemical reaction.

(Prior Art) Excited oxygen has long been of interest to biochemists due to its high activity, and has been applied to various organic chemical reactions. Furthermore, in recent years, with the development of laser technology, it has attracted attention as a driving source for iodine lasers.

Excited oxygen, that is, oxygen molecules in the singlet excited state [O ₂ ( ¹ △), O ₂ ( ¹ Σ), these energy levels are metastable, and the spontaneous emission lifetime is 45 minutes for the former and 7 to 7 minutes for the latter. Very long at 12 seconds. ] (hereinafter also simply referred to as excited oxygen) can be generated by ● Direct photoexcitation ● Photodecomposition of ozone (O ₃ ) ● Discharge (direct current, high frequency, microwave) ● Chemical reaction. Among these, the method of generating excited oxygen through chemical reactions is attracting attention because it is possible to increase the proportion of O ₂ ( ¹ △) in the total oxygen (excitation efficiency) to 20% or more.

Although the method using photodecomposition of ozone can achieve an excitation efficiency of 90% or more, there are problems with the generation efficiency and amount of ozone (O ₃ ), and it has not become a practical method of generation.

There are several methods for generating excited oxygen through chemical reactions, but the most efficient chemical reaction is the decomposition reaction of hydrogen peroxide (H ₂ O ₂ ).

Oxygen generated by the reaction between hydrogen peroxide (H ₂ O ₂ ) and hypochlorite ion (HOCl ^- ) is approximately
100% is in the excited states of O ₂ ( ¹ Σ) and O ₂ ( ¹ △). This excited oxygen generation method is currently the most commonly adopted method, and in practice, in order to increase the reaction rate (maximum at pH = 10), peroxidation is made alkaline with sodium hydroxide (NaOH). Aqueous hydrogen solution and chlorine gas are reacted. This can be expressed stoichiometrically as follows.

H ₂ O ₂ + Cl ₂ + 2NaOH → O ₂ ( ¹ △, ¹ Σ, ³ Σ) + 2 NaCl + 2H ₂ O As for the method of generating excited oxygen through the above chemical reaction, glass powder is added to the bottom of the alkaline hydrogen peroxide aqueous solution (reaction solution). A thin reaction solution is created by placing a compressed body plate (bubbler) and blowing chlorine gas through the bubbler method (see Figure 2), and by flowing an aqueous alkaline hydrogen peroxide solution along the walls of numerous thin tubes (more than 400). The mainstream method is the wet column method (see Fig. 3), in which a layer is formed and chlorine gas is passed through the layer to cause a contact reaction between the two on the surface of the liquid layer.

The two conventional methods described above are practical methods that show overwhelmingly higher yields than methods that attempt to obtain excited oxygen through a method other than a chemical reaction, but they also have drawbacks.

In principle, the bubbler method uses a method in which the reaction solution is stored in an excited oxygen generator, so that the solution after reaction cannot be separated from the solution that has not reacted.

That is, it is not possible to efficiently supply the reaction solution, take out the waste solution, and continuously regenerate it.
Not suitable for long-term operation. Furthermore, because the layer of reaction solution stored in the excited oxygen generator is thick, when the excited oxygen generated deep in the reaction solution moves toward the surface of the reaction solution, a deactivation reaction occurs in the liquid phase. , the production efficiency of excited oxygen decreases. Generally, the deactivation rate of excited oxygen is about one order of magnitude higher in the liquid phase than in the gas phase, so this deactivation process results in a large loss.

In addition, in the wet column method, the reaction solution phase formed on the surface of many small tubes is thin, so although the deactivation reaction in the liquid phase is suppressed, the contact area between the chlorine gas and the reaction solution is smaller than that of the excited oxygen generator. Since it is relatively small compared to the space it occupies, it is inevitable that the device will become larger.

Furthermore, since the gas phase/liquid phase reaction between the reaction solution and chlorine gas is a surface reaction, it is necessary to make the column as thin as possible in order to increase the reaction efficiency, which complicates the structure of the apparatus.

(Problems to be Solved by the Invention) In order to overcome the problems of the conventional excited oxygen method described above, it is necessary to combine chlorine gas and alkali production in order to obtain excited oxygen at a high yield through a gas phase/liquid phase reaction. The hydrogen oxide aqueous solution is brought into contact with high efficiency, and the excited oxygen generated is kept from contacting the liquid phase as much as possible to suppress the deactivation reaction, and the solution after the reaction is continuously taken out and regenerated before and after the reaction. It is necessary to develop an excited oxygen generator with a structure that allows solution separation.

In view of the problems of the conventional method, the present inventors
I considered it carefully. As a result, when an alkaline raw hydrogen peroxide aqueous solution is atomized using a spray nozzle and then reacted with chlorine gas, it becomes a method of generating excited oxygen that has a high reaction rate, a low deactivation rate, and is easy to operate for a long time. They discovered this and completed the present invention.

[Structure of the invention]

(Means for Solving the Problems) To summarize the present invention, when generating excited oxygen by reacting an alkaline hydrogen peroxide aqueous solution with chlorine gas, the alkaline hydrogen peroxide aqueous solution is transferred to an atomizer. After making it into a mist,
The present invention relates to a method for generating excited oxygen characterized by a catalytic reaction with chlorine gas.

Hereinafter, one embodiment of the method for generating excited oxygen according to the present invention will be described in detail with reference to the drawings.

As shown in FIG. 1, the main parts of the excited oxygen generator embodying the method of the present invention include an atomizer 5 for atomizing an alkaline hydrogen peroxide aqueous solution;
It is comprised of a chlorine gas outlet 4 for ejecting chlorine gas that reacts with the atomized reaction solution, and a solution separation device 8 for recovering unreacted solution from the reaction solution after reaction. Although not shown, the generated excited oxygen is taken out from the top of the excited oxygen generator. In addition, water vapor (H ₂ O) (H ₂ O ₂ + Cl ₂ + 2NaOH→O ₂ ( ¹ △, ¹ Σ,
^3Σ )+2NaCl+2H ₂ O) also reacts with the generated excited oxygen to deactivate it, so it is preferable to provide a water vapor trap as close as possible to the excited oxygen generation area.

The atomized alkaline hydrogen peroxide aqueous solution is brought into contact with chlorine gas. As a result, the fog particles of the reaction solution and the gas molecules of the chlorine gas come into contact with each other through collision, and the reaction for producing excited oxygen is promoted.

In FIG. 1, an impingement type spray nozzle is used as the atomizer. When this type of nozzle is used, even a liquid phase having a viscosity comparable to that of an aqueous alkaline hydrogen peroxide solution can be efficiently atomized. The alkaline hydrogen peroxide aqueous solution enters the atomizer through the reaction solution supply port 1, is accompanied by a gas such as argon gas introduced from the carrier gas cylinder 10 and the carrier gas supply port 2, and is ejected from the reaction solution spout as indicated by A in the diagram.
They collide with each other at points and become atomized. On the other hand, chlorine gas is introduced from the chlorine gas cylinder 11 and the chlorine gas supply port 3, is ejected from the third ejection port 4, and reacts with the atomized alkaline hydrogen peroxide aqueous solution. The fog particles after the reaction fall by gravity to the bottom 6 of the excited oxygen generator and are transferred from the solution outlet 7 to the solution separation device 8. In the solution separation device 8, the waste liquid and the unreacted solution are separated, the waste liquid is discarded from the take-out port 9, and the unreacted solution is fed back to the reaction solution supply port 1 for reuse.

In FIG. 1, a collision type spray nozzle (atomizer nozzle) is used as the atomizer 5 for the reaction solution.
(nozzle method), but in the present invention, there is no particular restriction as long as the reaction solution can be atomized. It goes without saying that a sound wave method) can also be used.

In the nozzle system as well, two reaction solution inlets other than those shown may be provided, and the structure may be such that the liquids flowing in from each inlet do not mix with each other until they are blown out from the nozzle. In this case, the H ₂ O ₂ solution and the NaOH solution are introduced separately and mixed at the time of atomization. In the nozzle system, the amount of mist introduced, the pressure of the reaction solution, or the diameter of the mist droplets is controlled by the pressure of the carrier gas.

On the other hand, in the ultrasonic method, ultrasonic waves from an ultrasonic element installed at the bottom of the excited oxygen generator converge near the liquid surface of the reaction solution, and the energy breaks the intermolecular bonds in the reaction solution. It turns into a mist. Therefore, the depth of the reaction solution has an optimum value, the amount of fog generated is controlled by the power of the element, and the diameter of the fog particles is controlled by the frequency.

The excited oxygen generated as described above is applied to organic chemical reactions, etc., but the excited oxygen generation method of the present invention is particularly applicable to chemically pumped iodine laser (CPIL).
It is useful for

CPIL is a pure chemical laser that performs laser operation by forming an inverted population between transitions of iodine atoms by transferring energy from singlet excited oxygen O ₂ ( ¹ △) generated by a chemical reaction to iodine atoms. . Until now, this CPIL has not been put into practical use because the continuous operation time is too short, but the excited oxygen generation method of the present invention is capable of operating for a long time, that is, it is possible to It can prolong energy transfer,
This will pave the way for the practical application of CPIL.

Hereinafter, the present invention will be explained in more detail with reference to Examples.

(Example) An excited oxygen production experiment was conducted using the excited oxygen generator shown in FIG.

<Reaction conditions> () Aqueous alkaline hydrogen peroxide solution (PH=10 with sodium hydroxide, H ₂ O ₂ concentration 5% by weight)
) was supplied to the atomizer 5 through the reaction solution supply port 1 and ejected at a rate of 500 mmol/min.
Atomized.

In addition, when blowing out, carrier gas cylinder 1
Carrier gas (N ₂ ) from 0 to 20SLM
(Standard Liter per Minute) was introduced into the carrier gas supply port 2 at a rate of (Standard Liter per Minute), so that the above-mentioned alkaline hydrogen peroxide aqueous solution was accompanied.

() On the other hand, chlorine gas is introduced from the chlorine gas cylinder 11 to the chlorine gas supply port 3, and from the spout port 4.
It was ejected at a rate of 500 mmol/min.

() The reaction temperature was -5°C and the reaction pressure was 5 Torr.

<Excited Oxygen Generation Efficiency> According to the method of the present invention, excited oxygen could be generated with an excitation efficiency of 80%. This is the second
This method is far superior to the 50% excitation efficiency of the bubbler method shown in the figure and the wet column method shown in FIG. 3, and has an extremely low deactivation rate.

〔Effect of the invention〕

The method for generating excited oxygen according to the present invention has high reaction efficiency because the reaction between the alkaline hydrogen peroxide aqueous solution and chlorine gas is a fog/gas phase contact reaction, and the generated excited oxygen is deactivated in the liquid phase. can be suppressed. Furthermore, the solution before and after the reaction can be taken out from the excited oxygen generator, and the solution after the reaction can be efficiently and continuously regenerated, thus facilitating long-term operation. moreover,
By controlling the diameter and number density of the mist particles, it is possible to optimize the enhancement of reaction efficiency and suppression of the deactivation rate.

[Brief explanation of drawings]

FIG. 1 shows an excited oxygen generator used in the present invention. FIGS. 2 and 3 show conventional excited oxygen generators, with the one in FIG. 2 showing a bubbler type and the one in FIG. 3 showing a wet column type. 1: Alkaline hydrogen peroxide aqueous solution supply port, 2:
Carrier gas supply port, 3: Chlorine gas supply port, 4:
Chlorine gas outlet, 5: Atomizer (alkaline hydrogen peroxide aqueous solution outlet), 6: Bottom of excited oxygen generator,
7: solution outlet, 8: solution separation device, 9: waste liquid outlet, 10: carrier gas cylinder, 11: chlorine gas cylinder.

Claims (1)

[Claims] 1. When generating excited oxygen by reacting an alkaline hydrogen peroxide aqueous solution with chlorine gas, the alkaline hydrogen peroxide aqueous solution is atomized by an atomizer and then brought into contact with the chlorine gas. A method for generating excited oxygen characterized by the following. 2. The method for generating excited oxygen according to claim 1, wherein the atomizer uses an atomizer nozzle. 3. The method for generating excited oxygen according to claim 1, wherein the atomizer uses an ultrasonic element.