JP2004089708A - Gas cleaning method and gas cleaning apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a gas cleaning method and a gas cleaning apparatus at low costs and easy in maintenance, which can decompose and remove chemical substances with high efficiency. <P>SOLUTION: Under the atmosphere, after particulate matters are removed from the gas 8 which contains the particulate matters and the chemical substances, the chemical substances are collected by an adsorbent 3. While the moisture in the gas is collected, the adsorbent 3 which collected the chemical substances is maintained as zero electric potential, and the electric discharge is conducted between the adsorbent and an electrode. By the active species produced on the surface of the adsorbent by the electric discharge, or by the active species produced by the reaction between the irradiated active species and the moisture existing in the atmosphere or on the surface of the adsorbent 3, the chemical substances adsorbed on the adsorbent are decomposed and removed. <P>COPYRIGHT: (C)2004,JPO

Description

The present invention relates to a gas purification method and a gas purification apparatus, and more particularly to a gas purification suitable for purifying an atmosphere containing volatile organic compounds (VOCs: Volatile Organic Compounds) such as formaldehyde and acetaldehyde, and a chemical substance such as ammonia. The present invention relates to a method and a gas purification device.

In recent years, due to the deterioration of the global environment, air pollution in homes and workplaces has become a problem. One of the causes of this air pollution is the occurrence of various odors and allergies caused by chemical substances such as ammonia, hydrogen sulfide, and acetoaldehyde, and in order to realize a healthy and comfortable living and working environment. There is an urgent need to remove these chemicals. Of the substances contained in the atmosphere, particulate matter such as dust usually has a size on the order of μm to mm, and can be removed by various commercially available filters. However, since the chemical substances that cause odors are of the order of nanometers, a special filter such as activated carbon with fine pores is required to remove them with a filter. , The filters used are easily clogged, and maintenance is troublesome. For the removal of chemical substances, it is necessary to develop a new method that replaces the removal method using commercially available filters Met.

The conventional air cleaning device includes, for example, an ion generator 11, an air outlet 12, a pre-filter 13, an activated carbon filter 14, a HEPA filter 15, a blower fan 16, and an air inlet 17. Further, as shown in FIG. 2, the ion generator 11 includes a cylindrical glass tube 21, and an inner electrode 22 and an outer electrode made of a stainless steel mesh which are arranged to face each other with the cylindrical glass tube 21 interposed therebetween. 23, and is provided on the upstream side of the air outlet 17. When an alternating voltage of 15 KHz and 1.1 to 1.4 kV (effective value) is applied between the inner electrode 22 and the outer electrode 23 of the ion generator 11 under the atmosphere, H ⁺ , O ₂ ^−, etc. Positive ions and negative ions are generated. If these positive ions and negative ions are generated at the same time, oxygen and water contained in the atmosphere react with positive ions and negative ions, and hydrogen peroxide and water, which have a sterilizing effect, are removed. Active species such as oxidized radicals are generated. These active species generated by the reaction of positive ions and negative ions with oxygen and water contained in the atmosphere have a strong active action, and when released into space, they decompose and remove chemicals in the air. Thus, an air purifier that can be easily maintained is realized (for example, see Patent Document 1).

JP-A-2002-58731 (page 3, FIG. 1, FIG. 2)

In the conventional air purifier, since an AC voltage is supplied to the ion generator 11, positive and negative charges are alternately applied to the inner electrode 22 of the ion generator 11. Note that the outer electrode 23 is grounded. Thereby, when a positive voltage is applied to the inner electrode 22 of the ion generator 11, the negative ions are attracted to the inner electrode 22 side and disappear by colliding with the inner electrode 22. At this time, the positive ions move toward the outer electrode 23 and collide with the outer electrode 23 and disappear. Conversely, when a negative voltage is applied to the inner electrode 22 of the ion generator 11, positive ions are attracted to the inner electrode 22 side and disappear by colliding with the inner electrode 22, while negative ions are It is drawn to the side 23 and disappears by colliding with the outer electrode 23.

As described above, in the conventional air purifier, positive and negative ions are generated by the application of the AC charge, so that the positive ions and the negative ions generated from the ion generator each become negative in a short time after the generation. Since the electric charge is lost by being attracted to an adjacent electrode having a potential, a positive potential or a zero potential (ground potential), the charge is lost and disappears. Therefore, the generation efficiency of the above-mentioned active species having a disinfecting effect is extremely low. Was. Also, regarding the decomposition of chemical substances by active species, the probability that the active species generated reacts with the chemical substance is low because the active species reacts with the chemical substance by floating in the air, Decomposition of chemical substances takes time, and active species may naturally decompose while floating in the air, so the decomposition efficiency is low and it is difficult to decompose chemical substances at low cost. Had.

The present invention aims to solve such problems, and after removing particulate matter from a gas containing particulate matter and a chemical substance, while collecting the chemical substance contained in the gas with an adsorbent, A discharge is generated between the adsorbent and the electrode while collecting moisture contained in the adsorbent, and the active substance generated by the discharge on the adsorbent surface decomposes and removes the chemical substance adsorbed on the adsorbent. Things.

In the gas purification method according to the present invention, after removing the particulate matter from the gas containing the particulate matter and the chemical substance, the chemical substance contained in the gas is collected by the adsorbent, and the adsorbent is removed under atmospheric pressure. Decomposes the chemical substance adsorbed by the adsorbent, using active species generated by the discharge of water or active species generated by the reaction of moisture existing in the air or on the surface of the adsorbent by the discharge. It is to be removed.

A gas purifying apparatus according to the present invention includes a particulate matter separating means for separating particulate matter from a gas containing particulate matter and a chemical substance, an adsorbent for adsorbing a chemical substance contained in the gas, and an adsorbent. A supply electrode for adjusting the potential, a discharge electrode provided facing the adsorbent, a potential adjusting means for setting the potential of the supply electrode or the discharge electrode to zero potential, and a high-voltage power supply for generating a high voltage. The active species generated by the discharge generated in the space formed by the adsorbent and the discharge electrode, or by the active species generated by the moisture present in the air or on the surface of the adsorbent reacting by the discharge. And decompose and remove the chemical substances collected by the adsorbent.

According to the gas purification method of the present invention, after removing the particulate matter from the gas containing the particulate matter and the chemical substance, the chemical substance contained in the gas is collected by the adsorbent, The chemical substance adsorbed by the adsorbent using an active species generated by discharge in the atmosphere or an active species generated by reacting moisture in the air or on the surface of the adsorbent by the discharge. By decomposing and removing the chemicals, the chemicals are efficiently adsorbed by the adsorbent, and the chemicals are efficiently decomposed by the discharge or radicals generated by the discharge and moisture, and the chemicals are decomposed and removed with high efficiency Thus, a gas purification method that is low-cost and easy to maintain is realized.

Further, according to the gas purifying apparatus according to the present invention, a particulate matter separating means for separating particulate matter from a gas containing particulate matter and a chemical substance, and an adsorbent for adsorbing the chemical substance contained in the gas A supply electrode for adjusting the potential of the adsorbent, an electrode provided facing the adsorbent, a potential adjusting means for setting the potential of the supply electrode or the electrode to zero potential, and a high-voltage power supply for generating a high voltage. The active species generated by the discharge generated in the space formed by the adsorbent and the electrode, or the active species generated by the reaction of moisture existing in the air or on the surface of the adsorbent by the discharge. Is configured to decompose and remove the chemical substances collected by the adsorbent, so that the chemical substances can be efficiently adsorbed to the adsorbent and generated by electric discharge or electric discharge and moisture To detoxifying chemicals adsorbed on the adsorbent by radicals, allow disassembly removal of chemicals at high efficiency, low cost and easy maintenance gas purifying device can be realized.

Hereinafter, the present invention will be described in more detail with reference to the accompanying drawings.
Embodiment 1
FIG. 1 is a configuration explanatory view showing an example of the gas purification device according to the present invention. In such a gas purifying apparatus, first, a gas 8 to be treated containing particulate matter and a chemical substance is guided to the blower 2 and introduced into the discharge space through the filter 7. At this time, the particulate matter contained in the gas to be treated 8 is removed by the filter 7. As the filter 7, a filter suitable for the type, size or concentration of the particulate matter contained in the gas 8 to be treated can be used. For example, a commercially available resin filter, paper filter, HEPA filter, ULPA filter, or Or a combination thereof.

The gas 8 from which particulate matter has been removed passes through the discharge space between the adsorbent 3 whose outer periphery is covered by the supply electrode 4 and the metal electrode (discharge electrode or wire electrode) 1 and passes through the adsorbent 3 When passing through, the chemical substance contained in the gas to be treated 8 is adsorbed by the adsorbent 3. The adsorbent 3 is a conductive and adsorbent material such as graphite or activated carbon, or a non-conductive but highly water-adsorbent adsorbent such as silica gel or zeolite. It is made of a non-conductive adsorbent which is made to have conductivity by adsorbing moisture with a substance, and is provided with pores serving as passages of a gas to be treated. The to-be-processed gas 8 from which the chemical substance has been removed by the adsorbent 3 is discharged to the outside through a discharge port (not shown).

At this time, the potential of the supply electrode 4 is set to zero potential (ground) by the potential adjusting device 5, and a high voltage is applied to the metal electrode 1 by the high voltage power supply 6. As a result, corona discharge occurs between the metal electrode 1 and the adsorbent 3, and plasma is generated near the metal electrode 1. Usually, the gas to be treated 8 is often air, and oxygen and water in the air are present. Therefore, in such a plasma portion, electrons and positive and negative ions such as H ⁺ and O ₂ ⁻ coexist. ing. The metal electrode 1 is provided with a thin line having a diameter of 0.1 to 0.2 mm on a metal frame, and the thin line is attached to the metal frame via a metal spring (not shown). Is designed so that it does not bend under constant tension. Further, the metal electrode 1 does not need to be a metal, and can be replaced with a conductive object.

(4) When a negative high voltage is applied to the metal electrode 1, positive ions are electrically attracted to the metal electrode 1 and disappear by colliding with the metal electrode 1. On the other hand, negative ions and electrons move from the metal electrode 1 toward the adsorbent 3 and can be guided to the adsorbent 3. Further, since the moving direction is the same as the moving direction of the gas caused by the blower 2, negative ions and electrons generated near the metal electrode 1 are efficiently guided to the adsorbent 3 having a relatively positive potential. be able to. Negative ions and electrons have very strong reactivity and have a strong oxidizing effect. Therefore, when guided to the adsorbent 3, they react with the chemical substance adsorbed on the surface of the adsorbent 3 to decompose the chemical substance. When moisture is present in the atmosphere or on the surface of the adsorbent, negative ions react with the moisture to generate new radicals (active species) having high activity such as hydroxyl radicals, which are also strong. Has an oxidizing effect and breaks down chemicals. Conversely, when a positive high voltage is applied to the metal electrode 1, the plasma region expands (when the plasma space moves toward the adsorbent 3) as compared to when a negative high voltage is applied. Therefore, radicals are generated in the vicinity of the surface of the adsorbent 3 by ions or electrons reaching the vicinity of the adsorbent 3, reacting with the chemical substance adsorbed on the surface of the adsorbent 3, and the chemical substance is decomposed. .

Further, similarly to the case where a negative voltage is applied, when moisture is present in the air or on the surface of the adsorbent, the negative ions react with the moisture to form new radicals (active species) having high activity such as hydroxyl radicals. Can be generated, and the adsorbed chemical substance can be decomposed more efficiently. As described above, the chemical substance adsorbed by the adsorbent 3 is rendered harmless by the radicals generated by the discharge generated between the adsorbent 3 and the metal electrode 1, and is released to the outside.

If particulate matter such as dust is present in the atmosphere, the charged particulate matter consumes discharge power and reduces the energy used for radical generation, or the particulate matter is transferred to the adsorbent 3. This causes a problem that the chemical substance adsorbing performance of the adsorbent 3 is reduced. However, in the present apparatus, since particulate matter is removed in advance by the filter 7, the energy used for radical generation is reduced by the particles, and the chemical substance adsorption performance of the adsorbent is reduced by the presence of the particles. There is no.
As described above, in the gas purification method and the gas purification device according to the present invention, under the atmosphere, particulate matter present in the gas to be treated such as the atmosphere or exhaust gas is removed in advance by collection, and the chemical substance is removed. By adsorbing with the adsorbent, the adsorbent is used only for adsorbing the chemical substance without being used for adsorbing the particulate matter, so that the chemical substance is adsorbed efficiently by the adsorbent.

化学 Further, by being adsorbed by the adsorbent, the concentration of the chemical substance is increased as compared with the concentration in the gas to be treated, and the chemical substance is substantially concentrated. Furthermore, by causing a discharge between the adsorbent and the metal electrode while adsorbing the chemical with the adsorbent, radicals are efficiently generated in the vicinity of the adsorbent, and the radicals are efficiently generated in the vicinity of the adsorbent. Will react. At this time, if moisture is present on the surface of the adsorbent, new radicals having high activity such as hydroxyl radicals are generated, and these radicals also decompose the chemical substance adsorbed on the adsorbent. That is, according to the gas purification method and the gas purification apparatus of the present invention, active species (radicals) generated by electric discharge are efficiently guided to the adsorbent to detoxify the chemical substance adsorbed by the adsorbent. A gas purifying method and a gas purifying apparatus which can decompose and remove chemical substances with high efficiency, are low in cost, and are easy to maintain.

In the present embodiment, the case where the operation of adsorbing the chemical substance on the adsorbent 3 and the operation of discharging between the adsorbent 3 and the metal electrode 1 are performed simultaneously and continuously has been described. May be performed continuously, and the discharge operation may be performed intermittently. By doing so, the concentration of the chemical substance by adsorption proceeds, and the chemical substance can be decomposed by discharging in a state of being concentrated at a higher concentration, so that the energy required to decompose the chemical substance is reduced, that is, high efficiency is achieved. Has the effect of decomposing chemical substances. However, since the temperature of the adsorbent 3 rises at the start of discharge, the adsorbed chemical substance may be partially desorbed, and if leakage of such a chemical substance becomes a problem, it may not be applicable. .

In the above configuration, the blower 2 is arranged on the windward side of the metal electrode 1, but the blower 2 may be arranged on the leeward side of the adsorbent 3. With such an arrangement, there is an advantage that the durability of the blower 2 can be improved when the gas 8 to be treated contains a corrosive gas. FIG. 2 is an example in which the blower 2 is arranged on the leeward side of the adsorbent 3 based on the configuration of FIG. Further, since the above process can be performed in the atmosphere, the present apparatus does not necessarily require high airtightness. However, if the gas introduced into the adsorbent 3 contains particulate matter, the adsorbent 3 Is used for the adsorption of particulate matter. In addition to the fact that the adsorption capacity for chemical substances is substantially reduced, if the particulate matter cannot be completely removed by the adsorbent 3, some of the particulate matter The energy released into the space between the adsorbent 3 and the metal electrode 1 to generate radicals and the like is used to charge these particulate matter and is consumed. For this reason, it is preferable that the present device has airtightness to the extent that particulate matter can be prevented from flowing into the space between the filter 7 and the metal electrode 1.

Note that the adsorbent 3 preferably has a honeycomb structure in consideration of the pressure loss of the gas flow at the time of chemical substance concentration and the mobility of ions when the surface is treated with ions. In order to adjust the potential of the adsorbent 3, the adsorbent 3 needs to be electrically connected to the supply electrode 4. FIG. 3 shows an example of the configuration of the adsorbent 3 integrated with the supply electrode 4, and shows a configuration in which the outer periphery of the adsorbent 3 is clamped by the supply electrode (metal frame) 4. . The metal frame may be any conductive material, and is not particularly limited.

構成 In addition, as the configuration of the adsorbent 3 and the supply electrode 4, instead of a configuration in which the periphery of the adsorbent is surrounded by a metal frame, a material in which the adsorbent is formed on the surface of a metal honeycomb can be used. FIG. 4 is a cross-sectional view showing an example in which the adsorbent 3 and the supply electrode 4 are integrally formed. The surface of a corrosion-resistant material such as stainless steel or platinum is coated with a conductive material such as activated carbon or graphite. Adsorbent material having, or non-conductive, such as silica gel or zeolite, but highly water-absorbent adsorbent, that is, to adsorb moisture together with the substance to be treated, to have conductivity 3 shows a non-conductive adsorption material.

Such an integrated body is obtained by, for example, immersing a metal honeycomb in a slurry-like solution in which activated carbon is dissolved, drying and firing at an appropriate temperature. In the case of such an integrated body, external charges are directly supplied to the metallic honeycomb.
In addition, the configuration of the adsorbent 3 and the supply electrode 4 may be such that a gas-permeable conductor is disposed in the gas passage on the leeward side of the adsorbent 3 so as to be in close contact with the adsorbent 3. it can.

As such a conductor having air permeability, for example, a metal product having conductivity such as a metal mesh or a punched metal, a metal fiber such as fibrous stainless steel, or a conductive fiber such as carbon paper can be used. . In such a configuration, it is important that the adsorbent 3 and the supply electrode 4 be in close contact with each other so as not to cause a discharge between the adsorbent 3 and the supply electrode 4. Accordingly, it is possible to prevent discharge from occurring on the leeward side of the adsorbent 3.

Further, in the above embodiment, a conductive adsorbent such as graphite or activated carbon, or a non-conductive adsorbent such as silica gel or zeolite adsorbs moisture together with the substance to be treated, thereby increasing the conductivity. The case where the non-conductive adsorbent is used is described. However, manganese dioxide (MnO ₂ ), titanium dioxide (TiO ₂ ), zinc oxide (ZnO), platinum (Pt), copper By supporting a substance having a catalytic action such as (Cu), the effect of decomposing and removing chemical substances can be further enhanced.
In the above embodiment, the case where the potential of the supply electrode 4 is set to zero potential (ground) by the potential adjusting device 5 and a high voltage is applied to the metal electrode 1 by the high voltage power supply 6 has been described. 6, a high voltage may be applied to the metal electrode 1 and a potential adjusting device 5 may apply a positive voltage or a negative voltage to the supply electrode 4. When a positive voltage is applied to the supply electrode 4, the adsorbent 3 is charged to a positive polarity, and a negatively charged chemical substance in a gas, for example, a nitrogen oxide is selectively and efficiently used. Can be adsorbed. When a negative voltage is applied to the supply electrode 4, the adsorbent 3 is negatively charged, and a positively charged chemical substance in the gas, such as a volatile organic compound or ammonia, is selected. Adsorption can be targeted and efficiently. As described above, by applying a voltage to the supply electrode 4 by the potential adjusting device 5, an effect of selectively and efficiently removing certain substances can be obtained. However, electric power is consumed to charge the adsorbent 3, which causes a problem that power consumption increases. In addition, it is necessary to take measures such as not to place an object serving as a counter electrode on the lee side of the adsorbent 3 to which the voltage is applied. Further, in order to ensure electrical safety, it is necessary to take a voltage protection measure for preventing a person or an object from touching the adsorbent 3 to which a voltage is applied.
Furthermore, a high voltage may be applied to the supply electrode 4 by the high voltage power supply 6 and the potential of the metal electrode 1 may be set to zero potential by the potential adjusting device 5. FIG. 5 shows an example in which a high voltage is applied to the supply electrode 4 by the high voltage power supply 6 and the potential of the metal electrode 1 is set to zero potential by the potential adjusting device 5 based on the configuration of FIG. Even in this case, discharge can be caused near the surface of the adsorbent, and the adsorbed chemical substance can be decomposed. However, when a discharge occurs on the leeward side of the adsorbent 3, ozone or nitrogen oxide as a discharge product comes to be contained in the clean gas, which causes a problem that the clean gas is contaminated. Therefore, it is necessary to take measures such as not placing an object serving as a counter electrode on the leeward side of the adsorbent 3 to which the high voltage is applied. In addition, in order to ensure electrical safety, it is necessary to take high voltage protection measures to prevent a person or an object from touching the adsorbent 3 or the supply electrode 4 to which a high voltage is applied.

Next, the relationship between the concentration of a chemical substance and the decomposition efficiency when a chemical substance is decomposed by electric discharge will be described. FIG. 6 is a diagram showing a time change of an acetic acid decomposition amount (μmol) when acetic acid, which is a representative of a hardly decomposable organic chemical substance, is irradiated with negative ions generated by electric discharge. A TOC meter (Total Organic Carbon: Shimadzu Corporation) that measures the time change of acetic acid decomposed by spraying negative ions on an aqueous solution having two non-concentrated concentrations and measures the amount of organic carbon contained in the aqueous solution. (TOC 5000). In the figure, the vertical axis represents acetic acid decomposition amount (μmol), and the horizontal axis represents decomposition time (hr).

In the drawing, the solid line 101 indicates the case where the acetic acid concentration is 5 mg / L (liter) (concentration), and the dotted line 102 indicates the case where the acetic acid concentration is 1 mg / L (non-concentrated). In addition, as other experimental conditions, the amount of the acetic acid solution is 300 mL, the negative ion concentration is 10 ⁶ ions / cm ³ , the flow rate of the gas containing ions is 200 L / min, and the distance between the ion generator and the liquid surface is 2 cm. .

(4) When the acetic acid concentration indicated by 101 in the figure is high, the amount of acetic acid decomposition increases with time, indicating that acetic acid is efficiently decomposed by negative ion irradiation. On the other hand, when the acetic acid concentration indicated by 102 in the figure is low, the amount of acetic acid decomposition hardly increases even after a certain period of time, indicating that the decomposition of acetic acid by negative ion irradiation has not progressed. . As described above, it can be seen that in the decomposition of the chemical substance using the radical generated by the discharge, the higher the concentration of the chemical substance, the more efficient the decomposition. In other words, it can be seen that the irradiation after the chemical substance is concentrated can use the radical generated by the discharge more efficiently.

Next, the performance of the adsorbent for adsorbing a chemical substance when a chemical substance is decomposed by causing a discharge between the adsorbent 3 and the metal electrode 1 will be described. FIG. 7 compares the adsorption characteristics of various adsorbents by investigating changes in the formaldehyde concentration of air containing formaldehyde, which is one of the substances that cause sick house syndrome, to be treated. In the figure, the vertical axis represents formaldehyde concentration (ppm) and the horizontal axis represents elapsed time (min). In the figure, reference numerals 103 to 107 denote hydrophobic zeolites (SiO ₂ / Al ₂ O ₃ = 10), activated carbon, hydrophilic zeolites (SiO ₂ / Al ₂ O ₃ = 2), and hydrophobic zeolites supporting a MnO ₂ catalyst, respectively. The graph shows changes in the formaldehyde concentration when hydrophilic zeolites supporting SiO ₂ / Al ₂ O ₃ = 10) and MnO ₂ catalyst (SiO ₂ / Al ₂ O ₃ = 2) are used as adsorbents. In the test, a closed container having a capacity of 72 liters was used, and the formaldehyde-containing air whose formaldehyde concentration was adjusted to 1 ppm was treated with the above-mentioned gas purifying device. It was measured by XP-308-2 manufactured by Denki.

As shown by 103 in the figure, when hydrophobic zeolite was used as the adsorbent, the concentration of formaldehyde hardly decreased even after the treatment time, indicating that hydrophobic zeolite is not suitable as an adsorbent. ing. Further, as shown by 104 to 106 in the figure, when activated carbon, hydrophilic zeolite, and MnO ₂ catalyst-supported hydrophobic zeolite are used as the adsorbent, the formaldehyde concentration changes with almost the same tendency. There was found. That is, the concentration of formaldehyde decreased to about 0.1 ppm over time, indicating that these adsorbents can be used as adsorbents for formaldehyde. On the other hand, as shown by 107 in the figure, when the hydrophilic zeolite carrying the MnO ₂ catalyst was used as the adsorbent, the ultimate concentration of formaldehyde after a certain period of time became 0.06 ppm, and among the adsorbents used in the experiment, Indicates that the adsorption performance is the highest. Thus, when a chemical substance is adsorbed by an adsorbent, it is more effective to use a hydrophilic adsorbent than to use a hydrophobic adsorbent, and the ratio of SiO ₂ / Al ₂ O ₃ is 5 or less. Has been found to be desirable. In addition, the presence or absence of supporting MnO ₂ indicates that the chemical substance can be efficiently adsorbed when the zeolite supporting MnO ₂ is used. That is, it was found that when the hydrophilic zeolite supporting the MnO ₂ catalyst was used, the chemical substance could be effectively concentrated.

Next, the effect of the material of the adsorbent on the decomposition of the chemical substance when a chemical substance is decomposed by causing a discharge between the adsorbent 3 and the metal electrode 1 will be described. FIG. 8 shows a treatment target of air containing formaldehyde, which is one of the substances causing sick house syndrome, and activated carbon, hydrophobic zeolite (SiO ₂ / Al ₂ O ₃ = 10) and hydrophilic zeolite (SiO ₂ ) as adsorbents. / Al ₂ O ₃ = 2), hydrophobic zeolite supporting MnO ₂ catalyst (SiO ₂ / Al ₂ O ₃ = 10), and hydrophilic zeolite supporting MnO ₂ catalyst (SiO ₂ / Al ₂ O ₃ = 2). This is a comparative study of the adsorption characteristics of various adsorbents by investigating changes in the formaldehyde concentration when chemical substances are decomposed. In the figure, the vertical axis represents formaldehyde concentration (ppm) and the horizontal axis represents elapsed time (min). For the test, a closed container having a capacity of 72 liters was used, and formaldehyde-containing air whose formaldehyde concentration was adjusted to 1 ppm was treated by applying a negative high voltage to the metal electrode 1 of the above-mentioned gas purifier, and the formaldehyde concentration was reduced. Was measured with a formaldehyde measuring device (XP-308-2 manufactured by Shin-Cosmos Electric).

The obtained results show exactly the same tendency as in the case of the above-mentioned adsorption characteristics. As shown by 103 in the figure, when the hydrophobic zeolite is used as the adsorbent, the decrease in the concentration of formaldehyde is small, and the hydrophobic zeolite is adsorbed. It turned out to be unsuitable as an agent. Further, as indicated by reference numerals 104 to 106 in the figure, the formaldehyde concentration when activated carbon, hydrophilic zeolite, and MnO ₂ catalyst-supported hydrophobic zeolite were used as the adsorbent were almost the same (decrease). showed that. This indicates that these adsorbents are not suitable as adsorbents used in the present apparatus. On the other hand, as shown by 107 in the figure, when the MnO ₂ catalyst-supported hydrophilic zeolite is used as the adsorbent, the concentration reached after a certain time (about 30 to 40 minutes) is 0.03 ppm, and the decomposition performance is low. It shows that it is the best. As described above, in order to decompose a chemical substance by using a discharge that occurs between the adsorbent and the metal electrode, it is more effective to use a hydrophilic adsorbent in comparison between hydrophilicity and hydrophobicity, Further, in the presence of MnO ₂担時, it is understood that the adsorbent for担時the MnO ₂ can be effectively adsorbed chemicals. That is, it was found that when a MnO ₂ catalyst-supported hydrophilic zeolite was used as the adsorbent, chemical substances could be decomposed most effectively.

Next, in the case where a chemical substance is decomposed by causing a discharge between the adsorbent 3 and the metal electrode 1, the effect of the polarity of the high voltage applied to the metal electrode 1 on the decomposition of the chemical substance will be described. FIG. 9 shows the case where formaldehyde containing one of the substances causing sick house syndrome is treated, formaldehyde when a high voltage of positive and negative polarity is applied using hydrophilic zeolite carrying MnO ₂ catalyst as an adsorbent. The relationship between the difference in the polarity of the applied voltage and the adsorption characteristics was compared and examined by investigating the change in the concentration. In the figure, the vertical axis represents the formaldehyde concentration (ppm), and the horizontal axis represents the processing time (min). In the test, a closed container having a capacity of 72 liters was used, and formaldehyde-containing air whose formaldehyde concentration was adjusted to 1 ppm was passed through a metal electrode in such a manner that the current flowing through the adsorbent 3 of the gas purifier described above was 0.5 mA. 1 was treated by applying a high voltage, and the time change of the formaldehyde concentration was measured by a formaldehyde measuring device (XP-308-2 manufactured by Shin-Cosmos Electric).

The formaldehyde concentration when a negative high voltage is applied as indicated by 109 in the figure and the formaldehyde concentration when a positive high voltage is applied as shown by 110 in the figure are the formaldehyde concentrations of 108 when no discharge was performed. As compared with the graphs, the value of the discharge decreased significantly with the lapse of time, indicating that the decomposition of formaldehyde progressed by the discharge. Comparison of the data of 109 and 110 shows that the formaldehyde concentration is lower when the positive polarity is applied, and that the decomposition performance of formaldehyde is increased by applying the positive voltage. As described above, in order to decompose a chemical substance by using a discharge that occurs between the adsorbent and the line electrode, the polarity of the voltage applied to the metal electrode 1 may be either, but it is better to apply a positive voltage. It has been found that chemical substances can be decomposed more efficiently.

Next, the effect of the amount of input electric power on the decomposition of the chemical substance when a chemical substance is decomposed by causing a discharge between the adsorbent 3 and the metal electrode 1 will be described. FIG. 10 shows that the air containing formaldehyde, which is one of the substances causing sick house syndrome, is treated, and a high voltage of positive and negative polarities is applied to the metal electrode by using an adsorbent such as a hydrophilic zeolite carrying a MnO ₂ catalyst. The relationship between the difference in polarity of the applied voltage and the formaldehyde removal rate was compared by examining the applied power and changing the applied power. In the figure, the vertical axis represents the formaldehyde removal rate (%) during the one-minute treatment, and the horizontal axis represents the discharge power (W). For the test, a closed container having a capacity of 72 liters was used, and formaldehyde-containing air whose formaldehyde concentration was adjusted to 1 ppm was treated for 1 minute by applying a high voltage to the metal electrode 1 of the gas purifier described above. Was measured using a formaldehyde meter (XP-308-2 manufactured by Shin-Cosmos Electric).

In the figure, the formaldehyde removal rate indicated by the vertical axis is defined by the following equation (1).
Formaldehyde removal rate (%) = {(concentration before treatment) − (concentration after treatment)} / (concentration before treatment) * 100 (1)
The input power (discharge power) shown on the horizontal axis indicates the power input to the adsorbent per unit area.
Comparing the formaldehyde removal rate when the negative high voltage shown by 112 in the figure is applied and the formaldehyde removal rate when the positive high voltage shown by 111 in the figure is applied, the discharge power is irrespective of the polarity. It was found that the formaldehyde removal rate increased with the increase. Further, as described above, even when the discharge power (W) is the same, the formaldehyde removal rate is lower when the positive polarity is applied, and the decomposition characteristics of formaldehyde are improved by applying the positive voltage. ing. As described above, in order to decompose a chemical substance using a discharge generated between the adsorbent and the metal electrode, the polarity of the voltage applied to the metal electrode 1 may be either, but it is more preferable to apply a positive voltage. It has been found that chemical substances can be decomposed somewhat efficiently. In the case of formaldehyde, when the concentration in the space becomes 0.25 to 0.5 ppm, it is said that 20% or more of the people complain of an abnormality. Removal rates of ~ 85% or more are required.

However, the research results of the inventors of the present application have revealed that increasing the input power amount increases the generation of nitrogen oxides. FIG. 11 is a graph showing the relationship between the residual ratio of formaldehyde, the nitrogen oxide concentration in the container, and the discharge power after the decomposition treatment. In FIG. 11, the left vertical axis represents the formaldehyde residual rate (%) after the decomposition treatment, the right vertical axis represents the nitrogen oxide concentration in the container (ppb), and the horizontal axis represents the discharge power (Wh). In the drawing, reference numeral 113 denotes a relationship between the residual formaldehyde after the decomposition treatment and the discharge power, and reference numeral 114 denotes a relationship between the nitrogen oxide concentration in the container and the discharge power. In the test, a formaldehyde-containing air whose formaldehyde concentration was adjusted to 1 ppm was applied to a metal electrode 1 of the above-mentioned gas purification device using a semi-closed container having a capacity of 1000 liters (ventilation rate: 0.5 times / hour). Was applied for 60 minutes, and the residual ratio of formaldehyde was measured with a formaldehyde measuring device (XP-308-2 manufactured by Shin-Cosmos Electric). The nitrogen oxide concentration in the container was measured using a NOx analyzer (GLN-32, manufactured by DKK).
In the figure, the residual rate after the decomposition process indicated by the left vertical axis is defined by the following equation (2).
Formaldehyde residual ratio (%) = (remaining amount in container after treatment) / (initial injection amount) × 100 --- (2)
In the drawing, the nitrogen oxide concentration in the container indicated by the vertical axis on the right side indicates the ultimate concentration in the container after a long operation. From FIG. 11, it is understood that supplying an excessively large amount of discharge power, for example, an amount of discharge power that can achieve the above-mentioned required formaldehyde removal rate of 85% (remaining rate of 15%) means that nitrogen oxides are generated. In view of this, it is considered a problem. The reference value of nitrogen oxide is 80 ppb, and it is considered that the nitrogen oxide concentration needs to be 80 ppb or less. Therefore, in order to keep the nitrogen oxide concentration regulation while ensuring the formaldehyde decomposition rate, it is considered necessary to set the discharge power to 10 Wh or less. It should be noted that, even at the same discharge power, it is found that the amount of nitrogen oxides generated is smaller when a high voltage with a positive polarity is applied. Is preferably applied.

In the above-described embodiment, the case where the metal electrode 1 is fixed has been described. However, a movable type line electrode having a slide mechanism for changing the distance between the metal electrode 1 and the adsorbent 3 is used. You may do it. FIG. 12 shows an example in which a movable line electrode 11 is provided instead of the metal electrode 1 based on the configuration of FIG. With this configuration, the chemical substance can be decomposed more efficiently.

Further, in the above-described embodiment, the case where the metal electrode 1 is configured by a thin wire (line electrode) is described. However, the metal electrode 1 may be a needle-like electrode having needle-like protrusions or a brush like a brush. A brush-like electrode in which a metal wire is planted may be used. FIG. 13A is a perspective view showing an example in which a needle-like electrode 12 having needle-like protrusions is provided instead of the metal electrode 1 based on the configuration of FIG. 1, and FIG. FIG. 3 is an enlarged side view of a needle electrode 12. FIG. 14A is a perspective view showing an example in which a brush-like electrode 13 is provided instead of the metal electrode 1 based on the configuration of FIG. 1, and FIG. It is the side view to which the part was expanded. When an electrode having such a shape is used, it is possible to arrange the tip portions of the needle-like electrode 12 and the brush-like electrode 13 in the vicinity of the adsorbent 3 or to insert them into the space inside the honeycomb. FIG. 15 is a perspective view illustrating an example in which the tip of the needle electrode 12 is arranged near the adsorbent 3 based on the configuration of FIG. When such a configuration is employed, discharge can be generated inside or on the surface of the adsorbent 3, and the chemical substance adsorbed on the adsorbent 3 can be decomposed more efficiently. However, if the needle electrode 12 is too close, a spark discharge occurs and a large amount of current flows. Therefore, by incorporating an output current control device in the high voltage power supply 6 or making the output voltage waveform of the high voltage power supply 6 pulse-shaped, It is necessary to take measures to prevent a large current from flowing. Further, when discharging in the honeycomb space, it is necessary to determine the insertion position so that the discharge product is not released to the outside.

In addition, in addition to the above configuration, a configuration may be adopted in which a temperature controller 14 is provided to adjust the temperature of the adsorbent 3. FIG. 16 is a perspective view showing a configuration example in which a temperature controller 14 is provided in the configuration shown in FIG. As described above, when the chemical substance to be treated is adsorbed, by lowering the temperature of the adsorbent 3 by the temperature controller 14, it becomes possible to increase the concentration density of the chemical substance on the surface of the adsorbent 3, and furthermore, Chemical substances can be decomposed efficiently. In the case of decomposing, by increasing the temperature, it is possible to increase the efficiency of radical generation on the surface of the adsorbent, and it is possible to decompose chemical substances more efficiently.

Further, in the above-described embodiment, a case is described in which one chemical substance treatment portion including the metal electrode 1, the adsorbent 3, and the supply electrode 4 is provided after the filter 7 and the blower 2. After the above, a configuration in which a plurality of chemical substance processing units are provided may be adopted. That is, a plurality of metal electrodes, an adsorbent, and a supply electrode are provided after the blower 2, and when the adsorption of the chemical substance in the first chemical substance processing section is completed, the operation is switched to the second chemical substance processing section, and first, the chemical substance While a chemical substance is decomposed by electric discharge in the chemical substance processing section where adsorption is completed, the chemical substance is adsorbed in the new chemical substance processing section, so that the chemical substance is sufficiently adsorbed and high concentration It becomes possible to treat the chemical substance concentrated in the air by electric discharge, and it is possible to continuously perform highly efficient gas purification without stopping the blower 2. This switching can be performed by arranging a plurality of chemical substance processing units in parallel and sequentially moving the chemical substance processing units arranged in parallel. In addition, the blower 2 and the plurality of chemical substance processing units are connected by piping. It is also possible to adopt a configuration in which the flow of gas is switched by a connection, a valve or the like, and a chemical substance treatment unit is selected.

Further, in the above-described embodiment, the adsorbent 3 is fixed to the chemical processing section. However, the adsorbent 3 may be provided with a rotating mechanism in which the left and right surfaces are reversed in the chemical processing section. . For example, a rotating shaft penetrating above and below the chamber may be provided, and a mechanism for rotating the adsorbent 3 about the rotating shaft may be provided. By providing such a mechanism and making the left and right surfaces of the adsorbent reversible, the decomposition of the chemical substance by the discharge is performed more efficiently. That is, the adsorbent 3 usually adsorbs a large amount of chemical substances on the left side of the figure, but by turning the left and right sides by the above-described rotating mechanism before discharging, more chemical substances are discharged on the discharge surface. This is preferable because efficient existence of decomposition and removal of chemical substances can be realized.

As described above, according to the gas purification method and the gas purification device of the present invention, the chemical substance is adsorbed by the adsorbent after the particulate matter contained in the gas to be treated is removed, and the discharge between the adsorbent and the electrode is performed. Is caused, the chemical substance is efficiently adsorbed on the adsorbent, and the chemical substance is efficiently decomposed by the radical generated by the discharge or the radical generated by the reaction with the moisture. Further, the chemical substance is substantially concentrated by being adsorbed by the adsorbent, and the decomposition efficiency of the chemical substance by the radical generated by the discharge or the radical generated by the reaction with moisture is improved. As a result, it is possible to provide a gas purification method and a gas purification apparatus that can decompose and remove chemical substances with high efficiency, are low in cost, and are easy to maintain.

Embodiment 2
FIG. 17 is a configuration explanatory view showing another example of the gas purification device according to the present invention. The gas purifying apparatus according to the present embodiment is different from the apparatus described in the first embodiment in the configuration of the discharge unit. That is, in Embodiment 1, radicals are generated by electric discharge, but in the present embodiment, radicals are generated by irradiating ultraviolet rays to the metal frame.

The radical generation mechanism is as follows. That is, when the ultraviolet lamp 21 is turned on and ultraviolet rays are emitted, the emitted ultraviolet rays reach the metal frame 22 and electrons are ejected from the metal frame 22 by the photoelectric effect of the ultraviolet rays. These electrons adhere to oxygen molecules and the like in the atmosphere, generating negative ions (radicals). At this time, if the blower 2 blows air from right to left in the drawing, the generated negative ions are released to the outside of the metal frame 22 and head toward the adsorbent 3, and the reaction mechanism described in Embodiment 1 Thus, the chemical substance adsorbed by the adsorbent 3 is decomposed. In addition, as a material of the metal frame 22, a metal having a low work function as an optoelectronic material, that is, a metal that easily emits electrons is appropriate, and gold, titanium, and the like correspond thereto.

The negative ions disappear when they come into contact with the particulate matter existing in the space or the surface of the metal cylinder. However, the particulate matter has been removed in advance by the filter 7, and the blowing action by the blower 2 and the adsorbent 3 Due to the ion accelerating action of the electric field from the adsorbent 3 formed between the metal frame 22 and the metal frame 22, the opportunity of contact between the negative ions and the metal frame is suppressed. Furthermore, when moisture is present on or near the surface of the adsorbent 3, negative ions react with moisture to generate new radicals (active species) having high activity such as hydroxyl radicals, thereby decomposing chemical substances. Is as described in the first embodiment.

In the above embodiment, the case where radicals are generated using electrons emitted from the ultraviolet lamp 21 and the metal frame 22 has been described. However, radicals are generated using electrons emitted to the space by ultraviolet irradiation and discharge. Even so, a similar chemical substance decomposition effect can be obtained. FIG. 18 is a perspective view showing a configuration example when an ultraviolet lamp 21 is provided in the configuration shown in FIG.

As described above, according to the gas purifying apparatus of the present invention, the first embodiment is performed by generating negative ions (radicals) by the ultraviolet lamp and decomposing the chemical substance by the negative ions or the radicals generated by the negative ions and moisture. In combination with the effects described in the above, a gas purifying apparatus having a simple configuration and easy maintenance is realized.

Embodiment 3
FIG. 19 is a configuration explanatory view showing another example of the gas purification device according to the present invention. The gas purifying apparatus according to the present embodiment is different from the apparatus shown in FIG. 1 in that a dehumidifying device 31 is provided between the filter 7 and the blower 2. That is, in the present embodiment, the gas that has passed through the filter 7 is dried by the dehumidifying device 31, and the dehumidified water is sucked out by the pump 32, passes through the nozzle 33, and is guided to the vicinity of the adsorbent 3. It is a configuration that can be inserted. With such a configuration, it is possible to prevent radicals from being generated by a reaction with moisture near the metal electrode 1, and to efficiently generate radicals near the adsorbent 3.

On the other hand, since water is introduced into the vicinity of the adsorbent 3, ions and electrons generated in the space by the discharge react with the water in the vicinity of the adsorbent 3, and as described above, active species such as hydroxyl radicals. Are generated, and these radicals are subjected to decomposition of the chemical substance. Note that these radicals are active and disappear by reacting with particulate matter present in the air or spontaneously decomposing while floating in the air. Can be efficiently used for the decomposition of chemical substances. In addition, since moisture is adsorbed on the surface of the adsorbent 3, the conductivity of the surface of the adsorbent 3 is improved, and the electric potential of the electric potential adjusting means 5 can be easily adjusted.

Next, the effect of the amount of water in the processing gas on the decomposition of the chemical substance when a chemical substance is decomposed by causing a discharge between the adsorbent 3 and the metal electrode 1 will be described. FIG. 20 shows that air containing formaldehyde, which is one of the substances causing sick house syndrome, is treated with an MnO ₂ catalyst-supporting hydrophilic zeolite or another adsorbent at a temperature of 25 ° C. and a relative humidity of 40% and 80%. 5 is a diagram comparing the decomposition characteristics of chemical substances under an atmosphere of%. FIG. In the figure, the vertical axis represents formaldehyde concentration (ppm) and the horizontal axis represents elapsed time (min). In the test, a closed container having a capacity of 72 liters was used, and formaldehyde-containing air whose formaldehyde concentration was adjusted to 1 ppm was treated by applying a negative high voltage to the metal electrode 1 of the above-mentioned gas purification device, The time change of the concentration was measured by a formaldehyde measuring device (XP-308-2 manufactured by Shin-Cosmos Electric).

A comparison of the formaldehyde concentration in an atmosphere with a relative humidity of 40% shown by 116 in the figure and the formaldehyde concentration in an atmosphere with a relative humidity of 80% shown by 117 in the figure shows that the formaldehyde concentration after a certain period of time has passed. It is lower in the case of an atmosphere of 80%, indicating that the decomposition performance is increased by increasing the relative humidity. As described above, in order to decompose a chemical substance by using discharge generated between the adsorbent and the metal electrode, it was found that increasing the water concentration in the processing gas can decompose the chemical substance more efficiently.

In the above embodiment, the case where moisture in the taken-in processing gas is removed, humidification is performed using the removed moisture, and radicals are efficiently generated in the vicinity of the adsorbent has been described. Even if the vicinity of the adsorbent 3 is humidified, the same chemical substance decomposition effect can be obtained. FIG. 21 shows an example in which a humidifier 34 is additionally installed in the configuration shown in FIG.

As described above, a dehumidifier is provided between the filter for removing particulate matter and the fan for blowing ions to dehumidify the water and guide the water to the vicinity of the adsorbent, so that the potential of the adsorbent can be easily adjusted, and the discharge can be easily performed. As a result, radicals generated by the reaction of moisture are generated near the chemical substance. That is, according to the gas purifying apparatus of the present invention, the efficiency of decomposition of chemical substances by radicals generated by electric discharge and radicals generated by the reaction of water by electric discharge is improved, as described in Embodiment 1. In addition to the effect, a gas purifying apparatus capable of decomposing chemical substances at lower cost is realized.

Embodiment 4
FIG. 22 is a configuration explanatory view showing another example of the gas purification device according to the present invention. The gas purifying apparatus according to the present embodiment is different from the apparatus shown in FIG. 1 in that a gas composition adjusting device 41 is provided. That is, in this embodiment, the gas composition of the atmosphere comprising between metallic electrodes 1 and the adsorbent 3, so as to be O ₂ rich, can be blown uniformly gas between adsorbent 3 and the metal electrode 1 A gas supply plate 42 is provided, and a gas having a predetermined composition is supplied from a gas composition adjusting device 41. As a result, active species derived from oxygen are generated more efficiently and in a larger amount by the discharge between the metal electrode 1 and the adsorbent 3 than in the normal atmosphere.

The gas composition adjusting device 41 includes, for example, an oxygen permeable membrane type oxygen enrichment device, a PSA type oxygen generator, a cryogenic separation type oxygen generator, and a device obtained by combining an oxygen gas cylinder. But it doesn't matter.
In the above embodiment, the case where the gas supply plate 42 is provided on the windward side of the metal electrode 1 has been described. However, even if the gas insertion tube 43 is separately provided to supply the gas from one place, the self-concentration diffusion of the gas may be performed. By the action, a uniform gas can be supplied to the adsorbent 3. FIG. 23 shows an example in which a gas insertion pipe 43 is additionally provided to the configuration shown in FIG.

As described above, according to the gas purification device of the present invention, the gas composition of the atmosphere constituting the space between the metal electrode and the adsorbent is adjusted by the gas composition adjustment device 41 so that O ₂ is enriched. Active species derived from oxygen are generated more efficiently and in a larger amount by the discharge between the first and the adsorbents 3 than in the normal atmosphere. In addition to the effects shown in the first embodiment, the adsorbents The adsorbed chemicals are more efficiently decomposed and preferred.

Embodiment 5
FIG. 24 is a configuration explanatory view showing another example of the gas purification device according to the present invention. The gas purifying apparatus according to the present embodiment is different from the apparatus shown in FIG. 1 in that an MnO ₂ supporting electrode 51 is provided on the leeward side of the adsorbent 3, and the supply electrode 4 for adjusting the potential of the adsorbent 3 is omitted. Is different. That is, in the present embodiment, the adsorbent 3 is sandwiched between the metal electrode 1 and the MnO ₂ supporting electrode 51, a high voltage is applied to the MnO ₂ supporting electrode 51 by the high voltage power supply 6, and the potential adjusting device 5 controls the metal electrode 1. The potential is set to zero potential. As a result, it is possible to cause a discharge even at a downstream portion of the adsorbent 3, and it is possible to more efficiently decompose the chemical substance adsorbed on the adsorbent 3. In addition, even with such a structure, ozone and nitrogen oxide, which are long-life discharge products generated at the downstream portion of the adsorbent 3, are decomposed by the catalytic action of MnO ₂ supported on the surface of the MnO ₂ supporting electrode 51. And discharge products are not released to the outside. From this, it is possible to decompose the chemical substance adsorbed on the adsorbent 3 more efficiently without discharging the discharge product to the outside.

As the MnO ₂ supporting electrode 51, for example, a metal honeycomb or mesh having a surface resistant to oxidation, such as stainless steel, supporting MnO ₂ can be used. Such an integrated body is obtained by, for example, immersing a metal honeycomb in, for example, a slurry-like solution in which MnO ₂ is dissolved, drying and firing at an appropriate temperature.
In the above embodiment, the case where the MnO ₂ supporting electrode 51 is simply provided downstream of the adsorbent 3 has been described. However, even if the MnO ₂ supporting electrode 51 is heated by a heating device, ozone or nitrogen oxide And other discharge products can be more efficiently decomposed. FIG. 25 shows an example in which a heating device 52 is additionally provided to the configuration shown in FIG.

As described above, according to the gas purifying apparatus of the present invention, the adsorbent 3 is sandwiched between the metal electrode 1 and the MnO ₂ supporting electrode 51, a high voltage is applied to the MnO ₂ supporting electrode 51 by the high-voltage power supply 6, and the potential adjusting device 5 Since the discharge is performed by setting the potential of the metal electrode 1 to zero potential, the discharge can be performed at the downstream side of the adsorbent 3 without discharging the discharge product to the outside. In addition to the effects shown above, the chemical substances adsorbed on the adsorbent are more efficiently decomposed and are suitable.

Embodiment 6
FIG. 26 is a configuration explanatory view showing another example of the gas purification device according to the present invention. The gas purifying apparatus according to the present embodiment is different from the apparatus shown in FIG. 1 in that a concentrating adsorbent 61 is provided on the windward side of the metal electrode 1. That is, the adsorbent 61 for concentration is provided on the upstream side of the metal electrode 1 so that the gas composition of the atmosphere constituting the space between the metal electrode 1 and the adsorbent 3 becomes rich in the chemical substance, and the adsorption and desorption of the chemical substance are repeated. , A gas containing a high concentration of chemicals is supplied. As a result, the probability of collision between the chemical substance and radicals generated by the discharge between the metal electrode 1 and the adsorbent 3 increases, and radicals that disappear without colliding with the chemical substance are eliminated as compared with a case where the chemical substance is not concentrated. It will be greatly reduced. In addition, as a means for releasing the concentrated chemical substance from the adsorbent for concentration 61, for example, a pressure swing method or a temperature swing method can be used.

As described above, according to the gas purification apparatus of the present invention, the adsorbent for concentration 61 is provided on the windward side of the metal electrode 1 so that the gas composition of the atmosphere between the metal electrode and the adsorbent is rich in chemical substances. As a result, the probability of collision between the chemical substance and the radical generated by the discharge between the metal electrode 1 and the adsorbent 3 increases, and radicals that disappear without colliding with the chemical substance are significantly reduced as compared with a case where the chemical substance is not concentrated. Therefore, the chemical substance adsorbed on the adsorbent is more efficiently decomposed, which is preferable, in addition to the effects described in the first embodiment.

FIG. 1 is a configuration explanatory diagram illustrating a configuration of a gas purification device according to the present invention. FIG. 1 is a configuration explanatory diagram illustrating a configuration of a gas purification device according to the present invention. FIG. 2 is a configuration explanatory diagram illustrating a configuration of an adsorbent of the gas purification device according to the present invention. FIG. 2 is a configuration explanatory diagram illustrating a configuration of an adsorbent of the gas purification device according to the present invention. FIG. 1 is a configuration explanatory diagram illustrating a configuration of a gas purification device according to the present invention. It is a figure which shows the time change of the acetic acid decomposition amount at the time of ion irradiation to an acetic acid solution. It is a figure which shows the time change of the formaldehyde density | concentration at the time of adsorbing a formaldehyde containing gas. It is a figure which shows the time change of the formaldehyde density | concentration at the time of performing the discharge processing of the formaldehyde containing gas. It is a figure which shows the time change of the formaldehyde density | concentration at the time of performing the discharge processing of the formaldehyde containing gas. It is a figure which shows the time change of the removal rate of formaldehyde at the time of performing a discharge treatment of the formaldehyde containing gas. It is a figure which shows the relationship between the residual ratio of formaldehyde, the nitrogen oxide concentration in a container, and discharge power at the time of performing a discharge treatment of the formaldehyde containing gas. FIG. 1 is a configuration explanatory diagram illustrating a configuration of a gas purification device according to the present invention. FIG. 1 is a configuration explanatory diagram illustrating a configuration of a gas purification device according to the present invention. FIG. 1 is a configuration explanatory diagram illustrating a configuration of a gas purification device according to the present invention. FIG. 1 is a configuration explanatory diagram illustrating a configuration of a gas purification device according to the present invention. FIG. 1 is a configuration explanatory diagram illustrating a configuration of a gas purification device according to the present invention. FIG. 1 is a configuration explanatory diagram illustrating a configuration of a gas purification device according to the present invention. FIG. 1 is a configuration explanatory diagram illustrating a configuration of a gas purification device according to the present invention. FIG. 1 is a configuration explanatory diagram illustrating a configuration of a gas purification device according to the present invention. It is a figure which shows the time change of the formaldehyde density | concentration at the time of performing the discharge processing of the formaldehyde containing gas. FIG. 1 is a configuration explanatory diagram illustrating a configuration of a gas purification device according to the present invention. FIG. 1 is a configuration explanatory diagram illustrating a configuration of a gas purification device according to the present invention. FIG. 1 is a configuration explanatory diagram illustrating a configuration of a gas purification device according to the present invention. FIG. 1 is a configuration explanatory diagram illustrating a configuration of a gas purification device according to the present invention. FIG. 1 is a configuration explanatory diagram illustrating a configuration of a gas purification device according to the present invention. FIG. 1 is a configuration explanatory diagram illustrating a configuration of a gas purification device according to the present invention.

Explanation of reference numerals

1 metal electrode, 2 blower, 3 adsorbent, 4 supply electrode, 5 potential adjustment device,
6 high-voltage power supply, 7 filter, 8 gas to be treated, 11 mobile discharge electrode,
12 needle electrode, 13 brush electrode, 14 temperature controller,
21 ultraviolet lamp, 22 metal frame, 31 dehumidifier, 32 pump,
33 humidifying nozzle, 34 humidifying device, 41 gas composition adjusting device,
42 gas supply plate, 43 gas insertion tube, 51 MnO ₂ supported electrode,
52 heating device, 61 adsorbent for concentration,
101 Relationship between acetic acid decomposition amount and processing time when acetic acid concentration is high,
102 Relationship between acetic acid decomposition amount and treatment time when acetic acid concentration is low,
103 Relationship between formaldehyde concentration and treatment time when using hydrophobic zeolite,
104 Relationship between formaldehyde concentration and treatment time when activated carbon is used,
105 Relationship between formaldehyde concentration and treatment time when hydrophilic zeolite is used,
Relationship between formaldehyde concentration and treatment time when using 106 MnO ₂ supported hydrophobic zeolite,
Relationship between formaldehyde concentration and treatment time when using 107 MnO ₂ supported hydrophilic zeolite,
108 relationship between formaldehyde concentration and treatment time without discharge,
109 Relationship between formaldehyde concentration and treatment time when negative voltage is applied,
110 relation between formaldehyde concentration and treatment time when positive voltage is applied,
111 Relationship between formaldehyde decomposition removal rate and discharge power when positive voltage is applied,
112 Relationship between formaldehyde decomposition and removal rate and discharge power when negative voltage is applied,
113 relation between formaldehyde residual rate and discharge power,
114 relationship between nitrogen oxide concentration and discharge power,
115 relation between formaldehyde concentration and processing time in case of no discharge,
116 Relationship between formaldehyde concentration and treatment time at 40% relative humidity,
117 Relationship between formaldehyde concentration and treatment time at 80% relative humidity.

Claims (8)

After removing the particulate matter from the gas containing the particulate matter and the chemical substance, the chemical substance contained in the gas is collected by an adsorbent, and the adsorbent is generated by discharge in the atmosphere. Active species, or, using the active species generated by the reaction of the water present in the air or the surface of the adsorbent by the discharge, to decompose and remove the chemical substance adsorbed by the adsorbent Gas purification method. 2. The discharge according to claim 1, wherein the discharging is performed between the adsorbent and the electrode by holding the adsorbent at zero potential and applying a high voltage to an electrode disposed relative to the adsorbent. Gas purification method. Particulate matter separating means for separating the particulate matter from a gas containing particulate matter and a chemical substance,
An adsorbent for adsorbing the chemical substance contained in the gas,
A supply electrode for adjusting the potential of the adsorbent;
A discharge electrode provided facing the adsorbent,
Potential adjusting means for setting the potential of the supply electrode or the discharge electrode to zero potential,
A high-voltage power supply that generates high voltage,
It is generated by an active species generated by a discharge generated in a space formed by the adsorbent and the discharge electrode, or by a reaction of moisture existing in the air or on the surface of the adsorbent by the discharge. A gas purifying apparatus comprising decomposing and removing the chemical substance collected by the adsorbent by active species. Gas purification apparatus according to claim 3 wherein the adsorbent is a hydrophilic zeolite carrying the MnO _2. 4. The apparatus according to claim 3, wherein an ultraviolet ray generator for supplying ultraviolet light to a discharge space formed by the adsorbent and the discharge electrode is provided upstream of a discharge space formed by the adsorbent and the discharge electrode. A gas purifying apparatus as described in the above. The gas purifying apparatus according to claim 3, further comprising humidifying means for supplying moisture to a discharge space formed by the adsorbent and the discharge electrode. 4. The gas purifying apparatus according to claim 3, further comprising a chemical substance concentrating means for increasing a chemical substance concentration in a discharge space formed by the adsorbent and the discharge electrode. Particulate matter separating means for separating the particulate matter from a gas containing particulate matter and a chemical substance,
An adsorbent for adsorbing the chemical substance contained in the gas,
An electrode installed on the windward side of the adsorbent,
An electrode installed on the downwind side of the adsorbent and carrying MnO ₂ ,
A high-voltage power supply that applies a high voltage to the MnO ₂ supported electrode;
By an active species generated by a discharge generated in a space formed by the adsorbent and the electrode, or by an active species generated by a reaction of moisture present in the air or on the surface of the adsorbent by the discharge. And a gas purifier configured to decompose and remove the chemical substance collected by the adsorbent.

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