TWI554468B - Methods and devices of producing ozone - Google Patents

Description

Ozone manufacturing method and device

The present disclosure relates to an ozone manufacturing method, and more particularly to an ozone manufacturing method using an ultraviolet light source.

Ozone is a highly effective bactericidal substance that has strong oxidizing power and can decompose substances harmful to human health in the environment. The use of ozone to purify air or water has been widely used in areas such as diet, medicine, agriculture, and laundry. At present, the manner in which ozone generating devices produce ozone is mainly classified into a high pressure discharge method (CD) and an ultraviolet (UV) chemical method.

The principle of the high-voltage discharge method is similar to the discharge phenomenon in nature, which is to pass air between two electrode plates, and then apply an electric field to move electrons between the two electrode plates, and the electrons driven by the electric field provide energy to free air oxygen. Molecules produce ozone. However, the ozone generating apparatus of the high pressure discharge method may generate nitrogen oxides (e.g., NOx, etc.) which are toxic and have been confirmed to be carcinogenic substances by research, in addition to ozone.

The UV chemistry method uses ultraviolet light to illuminate the air. Ultraviolet light with a wavelength of less than 242 nm can liberate the oxygen molecules of the air to form ozone. UV-based ozone generating devices mainly use low-pressure mercury lamps or excimer ultraviolet lamps (Excimer UV, EUV, also known as Dielectric barrier discharge (DBD)) as an ultraviolet light source.

The proportion of ultraviolet light (e.g., wavelength 185 nm) capable of efficiently generating ozone in the emission spectrum of a low-pressure mercury lamp is usually only about 7 to 15% of the total spectral energy. Therefore, the ozone generating device of the low-pressure mercury lamp is inefficient in producing ozone.

The lamp tube of the EUV lamp is filled with an inert gas. When an electric field is applied to the EUV lamp, an inert gas (for example, Xe) in the lamp tube radiates ultraviolet light, and oxygen molecules in the air are excited by ultraviolet light to generate ozone. In general, EUV lamps produce higher ozone concentrations than low pressure mercury lamps.

However, the high temperatures generated by the action of EUV lamps can affect the concentration and efficiency of ozone generation. In order to avoid the problem that the high temperature affects the concentration of ozone generation, the existing means for solving the problem include improving the cooling structure of the ozone generating device of the EUV lamp on the one hand, and producing ozone by using high purity oxygen as the reaction gas on the other hand. Although these methods can increase the concentration of ozone generation, the manufacturing cost is greatly increased due to factors such as an excessively complicated structure of the improved device and difficulty in production of high-purity oxygen, and thus such means are not practical.

Therefore, how to solve various problems of the existing ozone manufacturing technology and improve the yield of ozone by the UV chemical method is to develop the purpose of the disclosure.

The present disclosure provides a method for producing ozone, comprising: providing a mixed gas containing carbon dioxide and oxygen; and irradiating the mixed gas with an excimer ultraviolet lamp to generate ozone, wherein the excimer ultraviolet lamp is filled with a selected one selected from the group consisting of At least one gas of the group consisting of helium, argon, neon, xenon, fluorine and bromine.

The present disclosure further provides an ozone manufacturing apparatus comprising a gas supply unit, a reaction chamber, and an excimer ultraviolet light, the gas supply unit providing a mixed gas containing oxygen and carbon dioxide, the reaction chamber communicating with the gas supply unit, the excimer An ultraviolet lamp is disposed in the reaction chamber and filled with at least one gas selected from the group consisting of ruthenium, rhodium, argon, krypton, xenon, fluorine, and bromine.

Since a mixed gas containing carbon dioxide and oxygen is used as a reaction gas, carbon dioxide irradiated by ultraviolet light can promote an ozone generation reaction, and carbon dioxide can stabilize the generated ozone, so that the apparatus for applying the ozone manufacturing method of the present disclosure can greatly reduce the reaction. The production cost of gas can effectively improve the yield of ozone produced by ultraviolet light source.

1,1'‧‧‧Ozone manufacturing equipment

10,10’‧‧‧ gas supply unit

11‧‧‧Reaction room

12‧‧‧Excimer UV Lamp

100‧‧‧Ozone concentration detector

101‧‧‧Oxygen source

102‧‧‧Carbon dioxide source

103‧‧‧ pipeline

1A is a schematic view of an apparatus for applying the ozone manufacturing method of the present disclosure; and FIG. 1B is a schematic view of another apparatus for applying the ozone manufacturing method of the present disclosure.

The embodiments of the present disclosure are described below by way of specific embodiments, and those skilled in the art can understand the other advantages and functions of the disclosure by the contents disclosed in the specification. The present invention may be embodied or applied in various other specific embodiments. The details of the present invention can be variously modified and changed without departing from the spirit and scope of the invention.

Unless otherwise stated in the text, the specification and the scope of the appended patent application The singular forms "a" and "the" are used in the plural.

Figure 1A is a schematic view of an apparatus for applying the ozone manufacturing method of the present disclosure. As shown in FIG. 1A, the ozone concentration detector 100 is connected to the ozone manufacturing apparatus 1 for detecting the ozone concentration produced by the ozone manufacturing apparatus 1 for subsequent application.

The ozone producing apparatus 1 includes a gas supply unit 10, a reaction chamber 11, and an excimer ultraviolet lamp 12. The gas supply unit 10 provides a mixed gas containing oxygen and carbon dioxide, and the reaction chamber 11 is connected to the gas supply unit 10, and the excimer ultraviolet lamp 12 is disposed in the reaction chamber 11 and filled with a group selected from the group consisting of ruthenium, rhodium, argon, krypton, xenon, and fluorine. And at least one gas of the group consisting of bromine.

In the present embodiment, the gas supply unit 10 may be filled with a gas cylinder mixed with a specific proportion of carbon dioxide and oxygen, and the gas supply unit 10 may be provided with an adjustment mechanism (for example, a flow valve) for regulating the flow rate of the mixed gas (liters per minute). ).

In other embodiments, as shown in FIG. 1B, the gas supply unit 10' of the ozone manufacturing apparatus 1' may be composed of an oxygen source 101, a carbon dioxide source 102, and a line 103, which respectively connect the oxygen source 101, the carbon dioxide source 102, and Reaction chamber 11. The oxygen source 101 and the carbon dioxide source 102 may be oxygen cylinders and carbon dioxide cylinders, and the purity of the oxygen source 101 and the carbon dioxide source 102 is not particularly limited, for example, 90%, 93%, 95%, and 99%. The oxygen source 101 and the carbon dioxide source 102 are respectively provided with adjustment mechanisms for regulating the flow rate ratio of oxygen to carbon dioxide, and oxygen and carbon dioxide of a specific flow rate ratio form the mixed gas via the line 103, and are then sent to the reaction chamber 11.

In the mixed gas, the volume ratio of carbon dioxide to oxygen may be 1:9 to 3:1, such as 1:9, 1:3, 1:1, 3:2, or 3:1, but not limited to this. Specifically, the volume percentage of oxygen is, for example, 90%, 75%, 50%, 40% or 25%, based on the total volume of pure oxygen and pure carbon dioxide in the mixed gas, and the volume percentage of carbon dioxide is, for example, 10%, 25 %, 50%, 60% or 75%, but not limited to this.

The reaction chamber 11 has a gas passage and a gas inlet and a gas outlet, and the gas inlet and the gas outlet communicate with the gas supply unit 10 and the ozone concentration detector 100, respectively.

The excimer ultraviolet lamp 12 is disposed in the gas passage of the reaction chamber 11. The structure or type of the excimer ultraviolet lamp 12 is not particularly limited, and the dielectric barrier discharge lamp disclosed in Japanese Patent No. 201419372 or Chinese Patent No. 101106058 is incorporated by reference in its entirety.

The excimer ultraviolet lamp 12 is filled with at least one gas selected from the group consisting of ruthenium, osmium, argon, krypton, xenon, fluorine, and bromine, and the ultraviolet light that is excited by the gas in the electric field belongs to vacuum ultraviolet light ( The range of wavelengths of vacuum UV (VUV) (ie 200 to 100 nm).

The ozone production method of the present disclosure includes: supplying a mixed gas containing carbon dioxide and oxygen with a gas supply unit 10; and irradiating the mixed gas with an excimer ultraviolet lamp 12 to generate ozone.

Specifically, after the excimer ultraviolet lamp 12 is disposed in the reaction chamber 11, then the gas supply unit 10 is turned on to transport the mixed gas through the reaction chamber 11, and the flow rate of the mixed gas through the reaction chamber 11 can be adjusted according to actual needs. And adjustment, for example, 3 L / min, 6 L / min, 9 L / min, in other words, the mixed gas can be transported through the reaction chamber 11 at a flow rate of 3 to 9 L / min, but not This is limited. Thereafter, a voltage is applied to the excimer ultraviolet lamp 12, and the gas filled by the excimer ultraviolet lamp 12 is excited by the electric field to radiate ultraviolet light to illuminate the mixed gas flowing through the reaction chamber 11. The wavelength of the ultraviolet light irradiated to the mixed gas is not more than 185 nm, and in the case of helium gas, the main wavelengths of the ultraviolet light radiated by the helium gas are 172 nm, 150 nm, and 147 nm.

According to research, the reaction of UV irradiation of oxygen molecules to generate ozone comprises the following reaction formula: Reaction formula 1: O ₂ + UV → 2O, wherein the wavelength of UV is between 185 and 240 nm.

Reaction formula 2: O + O ₂ + M → O ₃ + M + reaction heat (-106.6 kJ / mole), wherein the reaction formula 2 is an exothermic reaction, M represents a neutral third gas, usually does not participate in the reaction, its main role To absorb the heat of reaction to stabilize the generated ozone.

Further, various molecular bonds have a bond energy, and if ultraviolet light of a specific wavelength corresponding to the bond energy is applied, the molecular bond can be destroyed to carry out a chemical reaction. The bond energies of the various molecular bonds related to the present disclosure and the wavelengths corresponding to the respective bond energies are shown in Table 1.

As shown in Table 1, the C=O bond energy of the carbon dioxide molecule is 724.2 kJ/mole, and the wavelength of the ultraviolet light corresponding to the bond energy is 164.7 nm, that is, the ultraviolet light having a wavelength shorter than 164.7 nm (such as the wavelength of the helium gas). and the ultraviolet light is 147nm) 150 nm provide enough energy to destroy the carbon dioxide molecules to form C = O or CO + O C + O _2. The chemical activity of CO is extremely high, and it can react with oxygen molecules to form additional oxygen atoms. This additional oxygen atom can further combine with oxygen molecules to form ozone, thereby increasing the yield of ozone.

In the present disclosure, the reaction mechanism of the mixed gas carbon dioxide to promote ozone generation is believed to include the following reaction formula: Reaction Formula 3: CO ₂ + UV → CO + O

Reaction formula 4: CO ₂ + UV → C + O ₂

Reaction formula 5: C+O → CO

Reaction formula 6: CO + O ₂ → CO ₂ + O

Reaction formula 7: O+O ₂ → O ₃

By the above reaction mechanism, carbon dioxide decomposed by ultraviolet light can effectively promote the formation of ozone. Further, the undecomposed carbon dioxide can absorb the heat of reaction of the reaction formula 2, and has a function of stabilizing the generated ozone, thereby ensuring the ozone yield.

Table 2 shows the results of the production of ozone by mixing gases of different ratios of oxygen and carbon dioxide (Examples 1 to 5) and pure oxygen (Comparative Example).

As shown in Table 2, in comparison with the comparative example using pure oxygen as the reaction gas, according to the method of the present disclosure, the mixed gas of various mixing ratios can effectively increase the yield of ozone. While the method of the present disclosure is applied to a continuous reaction, the EUV power consumption per unit can be converted to an ozone yield of 32 mg/hr-watt (mg/hr-W) or more without any toxic by-products.

In summary, in the ozone manufacturing method disclosed in the present invention, since a mixed gas containing carbon dioxide and oxygen is used as a reaction gas, carbon dioxide irradiated by ultraviolet light can promote an ozone generation reaction, and carbon dioxide can stabilize the generated ozone, so application The apparatus for the ozone manufacturing method of the present disclosure may be The production cost of the reaction gas is greatly reduced, and the yield of ozone produced by the ultraviolet light source can be effectively improved.

The above embodiments are merely illustrative and are not intended to limit the disclosure. Any of the above-described embodiments may be modified and altered by those skilled in the art without departing from the spirit and scope of the disclosure. Therefore, the scope of protection of the present disclosure should be as set forth in the scope of the patent application attached to this application.

1‧‧‧Ozone manufacturing equipment

10‧‧‧ gas supply unit

11‧‧‧Reaction room

12‧‧‧Excimer UV Lamp

100‧‧‧Ozone concentration detector

Claims (8)

An ozone production method comprising: providing a mixed gas comprising carbon dioxide and oxygen, wherein a volume ratio of the carbon dioxide to the oxygen is between 1:9 and 3:1 in the mixed gas; and using an excimer ultraviolet lamp The mixed gas is irradiated to generate ozone, wherein the excimer ultraviolet lamp is filled with at least one gas selected from the group consisting of ruthenium, rhodium, argon, krypton, xenon, fluorine, and bromine. The method for producing ozone according to claim 1, wherein in the mixed gas, the volume ratio of the carbon dioxide to the oxygen is between 1:3 and 3:2. The method for producing ozone according to claim 1, wherein the step of irradiating the mixed gas using the excimer ultraviolet lamp comprises: disposing the excimer ultraviolet lamp in a reaction chamber; and conveying the mixed gas through the Reaction chamber. The method for producing ozone according to claim 3, wherein the flow rate of the mixed gas passing through the reaction chamber is between 3 and 9 liters per minute (L/min). The method for producing ozone according to claim 1, wherein the excimer ultraviolet lamp irradiates the mixed gas with an ultraviolet light having a wavelength of not more than 185 nm. The method for producing ozone according to claim 1, wherein the ozone yield is greater than 32 mg/hr-watt (mg/hr-W). An ozone manufacturing device comprising: a gas supply unit for providing a mixed gas containing oxygen and carbon dioxide, wherein a volume ratio of the carbon dioxide to the oxygen is between 1:9 and 3:1 in the mixed gas; the reaction chamber is connected to the gas supply And an excimer ultraviolet lamp disposed in the reaction chamber and filled with at least one gas selected from the group consisting of ruthenium, rhodium, argon, krypton, xenon, fluorine, and bromine. The ozone manufacturing apparatus according to claim 7, wherein the gas supply unit comprises an oxygen source, a carbon dioxide source, and a pipeline, wherein the pipeline is connected to the oxygen source, the carbon dioxide source, and the reaction chamber, respectively.