JP2023124395A - Non-circulating deodorizing method of odorous gas and non-circulating deodorizing device - Google Patents

Abstract

To provide a non-circulating deodorization method of a malodorous gas capable of performing a deodorizing treatment by one pass without circulating a malodorous gas containing an odor component made of a volatile organic compound, and a non-circulating deodorization device thereof.SOLUTION: Provided are a non-circulating deodorizing method and a non-circulating deodorizing device 10 for odorous gas containing malodorous components made of volatile organic compounds that generate acetaldehyde and acetic acid in a gas decomposition process, wherein the malodorous gas to be a target to be deodorized is supplied to a malodorous component oxidation and decomposition filter 19 provided with an ozone decomposition catalyst so that a space velocity SV value is 3000/hr to 60000/hr, and an ozone gas is supplied to the malodorous gas supplied to a deodorant component oxidation and decomposition filter 19 such that the ozone concentration to be 5 ppm to 50 ppm, a non-methane hydrocarbon concentration in the malodorous gas in which the malodorous component is decomposed and the deodorization treatment is applied is rendered 10 mg/m3 or less.SELECTED DRAWING: Figure 1

Description

TECHNICAL FIELD The present invention relates to a non-circulating deodorizing method and a non-circulating deodorizing apparatus for malodorous gases containing malodorous components composed of volatile organic compounds that produce acetaldehyde and acetic acid in the gas decomposition process. In addition, a volatile organic compound is also called "VOC." This "VOC" is an abbreviation for Volatile Organic Compounds.

In recent years, pollution of the living environment has adverse effects on health, so odors caused by volatile organic compounds contained in gases emitted from factories and offices are regulated by the Offensive Odor Control Law. While environmental standards for emission standards and odors have been enacted, the establishment of efficient decomposition treatment technology for volatile organic compounds has become an urgent social issue.

Methods for removing odors and harmful components in the air include physical adsorption using activated carbon or zeolite, combustion using precious metal catalysts, chemical adsorption and decomposition using manganese oxide catalysts, adsorption decomposition using photocatalysts, and oxidative decomposition catalysts using ozone. Various techniques are known that work differently.
However, in order to achieve a complete decomposition level that decomposes many of the volatile organic compounds to be deodorized to only CO ₂ +H ₂ O, the odor detection limit concentration is ppb level. It is difficult to further oxidatively decompose and reduce ultra-low-concentration components.

Combustion method is mentioned as a decomposition|disassembly removal method of a volatile organic compound.
In general, exhaust gas has a component concentration of several hundred ppm, and these high-concentration gas components are first pretreated, and the low-concentration of several ppm to several tens of ppb or less, which is the source of odor generated in the final decomposition treatment process. Combustion methods are not efficient due to high combustion costs, as very low concentration gases containing volatile organic compounds are required.

As for the adsorption method, it is difficult to uniformly adsorb all the components of the volatile organic compound, and there is no adsorbent that can uniformly adsorb all of the multiple organic compounds that constitute the volatile organic compound.
In general, in the case of a molecular structure that is easily adsorbed, the smaller the molecular weight, the more difficult it is to adsorb. For example, alcohols have "butanol>propanol>methanol", fatty acids have "butyric acid>propionic acid>acetic acid>formic acid", and structurally "aromatic compounds>fatty acids". The adsorption performance also changes depending on the hydrophobicity and hydrophilicity of the molecule. Furthermore, the adsorption performance varies depending on the fact that a substance with a high concentration preferentially occupies the adsorption site, and also varies depending on chemical adsorption and physical adsorption, and also varies depending on the charge of the adsorbed molecule.
As described above, the adsorption method is useful for extremely low-concentration gases, although it has its own limitations.

On the other hand, there is a photocatalyst as a method for uniformly decomposing low-concentration volatile organic compounds.
When the photocatalyst is irradiated with light with a wavelength of 380 nm or less, a hydroxy radical (also described as _.OH ), which _is a strong oxidizing agent, is generated. have the ability to decompose. However, when a photocatalyst is used to decompose low-concentration organic matter, there is a problem that the organic matter and the photocatalyst cannot effectively come into contact with each other. The contact between low-concentration organic substances and photocatalysts is affected by the diffusion resistance of the surface film and the adsorption characteristics of adsorbents. This is because they are greatly affected by competitive adsorption, ease of adsorption to adsorbents, and differences in decomposing power of photocatalysts. In other words, it is difficult to control the decomposition of gases containing low concentrations of volatile organic compounds using photocatalysts. These shortcomings are major obstacles to efficient and complete oxidation treatment of compounds over a long period of time, making high-level decomposition and deodorization difficult. In addition, photocatalysts are limited in their use because they are affected by the number of photons of light of a specific wavelength. Big restrictions.

As a countermeasure for this, it is conceivable to use a photocatalyst and an adsorbent together.
Specifically, in order to deal with low concentrations, an adsorbent such as activated carbon or zeolite supports a catalyst such as a photocatalyst that oxidizes and decomposes organic matter, and the adsorbent adsorbs low-concentration volatile organic compounds, and then It is a method of decomposing by contacting with a photocatalyst.

A photocatalyst that decomposes adsorbed molecules decomposes most organic substances through sequential reactions with hydroxyl radicals generated by ultraviolet light, thereby decomposing compounds with large molecular weights into small low-molecular-weight compounds, and finally low-molecular-weight compounds. It is widely known that it progresses to completely decomposed CO ₂ and H ₂ O via acetaldehyde (also described as CH ₃ CHO, C ₂ H ₄ O), formaldehyde, and formic acid.

Ozone, which decomposes organic matter, has high reactivity with carbon-carbon unsaturated bonds with high electron density and low reactivity with fatty acid alcohols and carboxylic acids. Therefore, direct oxidation by ozone molecules is a selective reaction and is effective for lowering aromatics having carbon-unsaturated bonds.
However, since organic substances with carbon-carbon unsaturated bonds are eventually decomposed into organic acids and aldehydes, it is difficult to completely decompose and remove organic substances by treatment with ozone alone. The technology for treating organic compounds in the gas has already been put to practical use as a deodorizing technology for refrigerators, etc., and has also been reported as a technology for decomposing volatile organic compounds in gas streams. Although ozone itself has limited ability to decompose volatile organic compounds, it is widely used by increasing its oxidizing power by using an ozone decomposition catalyst such as manganese dioxide (also described as _MnO2 ). .

For example, Patent Literature 1 describes that organic gases contained in the air to be treated are deodorized by using the decomposition action of ozone, the decomposition action of oxygen atoms, and the decomposition action of peroxide radicals. there is In addition, there is disclosure of an embodiment using a hydrophobic zeolite impregnated with a catalyst comprising manganese dioxide or a composite thereof for decomposition.
Patent Document 2 discloses that a hydrophobic deodorizing material in which manganese dioxide is supported on hydrophobic zeolite exhibits high deodorizing performance even against gases in a high-humidity environment. As its effects, high deodorizing capacity can be maintained for a long period of time even in a high-humidity environment. Regarding decomposition, each adsorption capacity of ammonia and acetic acid (CH ₃ COOH, C ₂ H ₄ O ₂ ), In addition, it is disclosed that the hydrophobic deodorant achieved excellent results in each regeneration ability of the deodorant after adsorbing ammonia, acetic acid and acetaldehyde.
Patent Document 3 describes decomposing odorous components with a deodorizing catalyst obtained by mixing powdery manganese dioxide and powdery hydrophobic zeolite. Specifically, the deodorizing catalyst deodorizes odorous components or harmful gas components, and is obtained by mixing powdered manganese oxide and hydrophobic zeolite, respectively. Odorous components and harmful gases adsorbed by the agent smoothly move to the deodorizing catalyst, promoting the oxidation reaction and deodorizing at a relatively low temperature. In particular, manganese oxide and hydrophobic zeolite both have a particle size of 1 mm or less, so the specific surface area per unit volume increases. The efficiency of contact with the adsorbent and the deodorizing catalyst is improved, and the ability to remove odorous components and the like can be further improved.

JP 2008-272736 A JP-A-8-243383 JP-A-2005-237997

When odorous gases contain malodorous components composed of volatile organic compounds such as lower fatty acids, aldehydes, sulfur compounds, etc., the performance of removing these at substantially the same time is required. In that case, it is required to improve the overall deodorizing performance of adsorption and decomposition by faster adsorption, decomposition rate, and larger adsorption capacity. That is, it is required to deodorize in one pass without circulating the malodorous gas.
However, in the above-mentioned prior art, it was not possible to sufficiently deodorize in one pass without circulating the odorous gas containing malodorous components.
In the method of decomposing volatile organic compounds using photocatalysts, many experimental results have been reported on the decomposition of simple substances, and it is not particularly difficult. Effective decomposition and reduction were difficult.

(Case 1)
For example, according to experimental results at a sewage treatment plant, a mixed gas consisting of VOCs such as benzene, acetone, and toluene, aldehydes, and lower fatty acids with a total concentration of 2 to 8 ppm was decomposed using a photocatalyst and zeolite. A specific increase in acetaldehyde did not lead to decomposition and deodorization.

(Case 2)
At an intermediate treatment facility for recycling plastic waste, a mixed gas of benzene, toluene, xylene, ethylbenzene, formaldehyde, acetaldehyde, phenol, acetone, and naphthalene, with a total chemical concentration of about 0.2 ppm, is generated. However, even in this intermediate treatment facility, acetaldehyde increased from 21 ppb to 138 ppb, as in the photocatalyst treatment of foul-smelling components at the sewage treatment plant.

(Case 3)
The target volatile organic compounds are lower fatty acids such as acetic acid, propionic acid, isobutyric acid, butyric acid, isovaleric acid, valeric acid, isocaproic acid, caproic acid, and aldehydes such as formaldehyde, acetaldehyde, propionaldehyde, isobutyraldehyde, n -Deodorization of sewage treatment facilities consisting of 22 major components: butyraldehyde, isobutyraldehyde, n-valeraldehyde, sulfur compounds hydrogen sulfide, carbonyl sulfide, methyl mercaptan, carbon disulfide, ethyl mercaptan, dimethyl sulfide, dimethyl disulfide However, the increase of acetaldehyde was remarkable at first, and no effective decomposition method was found.

The present invention has been made in view of such circumstances, and a non-circulating deodorizing method for malodorous gas that can deodorize in one pass without circulating the malodorous gas containing malodorous components composed of volatile organic compounds. An object of the present invention is to provide such a non-circulating deodorizing device.

The present inventors have made intensive studies on a method for decomposing and removing odorous gases containing volatile organic compounds consisting of mixtures of lower fatty acids, aldehydes, and sulfur compounds. As a result, volatile organic compounds consisting of multiple components in the gas can be oxidatively decomposed with high efficiency, and acetic acid and acetaldehyde are decomposed with ".OH" and other components are adsorbed, realizing amazing deodorization. I found what I can do.

First of all, the present inventors found that among the measures against the odor generated at the sewage treatment plant containing VOCs and lower fatty acids according to the above-mentioned Case 1, the combination of hydrophobic zeolite that adsorbs acetaldehyde and a photocatalyst in particular was used to remove acetaldehyde, which was difficult. It has been found that it can be effectively reduced, and that the decomposition and deodorization efficiency of the mixed gas is improved dramatically.

Lower fatty acids and simple aldehydes are finally completely decomposed by a photocatalyst, but in the previous stage, as shown in FIG. Through low-molecular-weight organic substances such as formaldehyde, complete decomposition of only CO ₂ and H ₂ O is reached. However, the acetic acid in the middle is a persistent substance and is not easily decomposed, and if the decomposition by "OH" is not sufficient, it becomes rate-limiting. end up

Therefore, it is necessary to adopt an adsorbent such as zeolite that can efficiently adsorb acetaldehyde and a decomposition speed that minimizes the generation of intermediate products in order to promote decomposition in one pass. As a generation mechanism that replaces the generation of radicals, we have come up with a configuration using ozone (also described as _O3 ) and an ozone decomposition catalyst such as _MnO2 .
It is known that ozone is decomposed on the ozone decomposition catalyst by the ozone decomposition catalyst and ozone to generate active oxygen (also described as O*), and furthermore, ".OH" is generated by H ₂ O in the air. there is

The photocatalyst reaction proceeds with the number of photons proportional to the illuminance and UV light, but the matching with the number of TiO ₂ , which is the corresponding number of reaction sites, and physical adsorption conditions due to contact with the target gas must be considered.
On the other hand, in the case of ozone and a composite oxide such as MnO ₂ /hydrophobic zeolite in which an ozone decomposition catalyst is supported on an adsorbent, the generation of ".OH" is caused by chemical adsorption of ozone and the ozone decomposition catalyst, It is carried out by physical adsorption to the adsorbent, the influence of the film resistance on the surface of the catalyst is reduced, and the process of generating active oxygen in the ozone decomposition catalyst and developing the Mn active site is cyclic, and "OH" is generated. The frequency is proportional to the ozone concentration, and the ozone decomposition catalyst is placed in every corner of the adsorbent. be.

Also, as a deodorizing catalyst containing an ozone decomposition catalyst and an adsorbent, a deodorizing catalyst in which manganese dioxide and copper oxide are supported on hydrophobic zeolite is shown to exhibit high deodorizing properties. A deodorizing catalyst containing active manganese dioxide and high-silica zeolite as active ingredients adsorbs sulfur-based malodorous gases and has oxidative decomposition properties. Furthermore, it is shown that a deodorizing catalyst obtained by mixing powdery manganese oxide and powdery hydrophobic zeolite adsorbs and decomposes odors.
Here, when we investigated the components that reacted with ozone by manganese dioxide, and the components that were reduced by adsorption to hydrophobic zeolite and mere manganese dioxide, we found that most of the components other than acetic acid and aldehydes, including sulfur compounds, were adsorbed. was
That is, it was shown that odor reduction is possible if acetaldehyde and acetic acid, which cannot be adsorbed, can be decomposed in the decomposition and adsorption treatment of multiple components.

In other words, low-concentration gas of 10 ppm or less, which consists of multiple components such as lower fatty acids, aldehydes, and sulfur, is oxidatively decomposed into CO ₂ and H ₂ O by “OH” into acetaldehyde generated during the decomposition process. components converge. Acetaldehyde is generally converted to acetic acid when oxidatively decomposed. If acetic acid does not decompose and stagnate, acetaldehyde is released without being decomposed.
After all, the decomposition of acetaldehyde and the decomposition of acetic acid are rate-limiting for the process to complete decomposition.

This intermediate product, acetaldehyde, has a small molecular weight and is generally difficult to catch by catalytic adsorption, and cannot be brought into efficient contact with ".OH". For these reasons, it is necessary to catch acetaldehyde preferentially and quickly and bring it into contact with ".OH" generated from the catalyst in order to quickly oxidize and decompose it.

Decomposition progresses from volatile organic compounds with large molecular weights to low molecular weight compounds, and in the process of progressing to complete decomposition, it is necessary to decompose low molecular weight acetaldehyde or not to decompose acetic acid formed by oxidation of acetaldehyde, formic acid, formaldehyde , CO ₂ , and H ₂ O. For this reason, the carrier is provided with the function of a molecular sieve that selectively adsorbs acetaldehyde, and ".OH" generated by a photocatalyst or ozone and an ozone decomposition catalyst is brought into effective contact with the adsorbed acetaldehyde to decompose it. , to improve the decomposition of acetaldehyde, which was rate-limiting in the entire decomposition process.
This further advances the decomposition process to total complete decomposition.

In other words, for volatile organic compounds consisting of multiple components composed of lower fatty acids, aldehydes, and sulfur compounds, the generated "OH" decomposes acetic acid, which is difficult to decompose. Autooxidation progresses from fatty acids to lower aldehydes. This acetic acid is persistent and generally decomposed only by ".OH". Therefore, the present invention uses an ozone decomposition catalyst to decompose ozone to generate high-concentration ".OH".
Lower fatty acids are highly compatible with ozone and are decomposed. Specifically, in a state where ozone is abundant, lower fatty acids are decomposed into n-1 lower aldehydes by autoxidation, and then oxidized to n-1 lower fatty acids in order. In the process of decomposition, lower fatty acids and aldehydes converge to acetaldehyde. ".OH" further decomposes acetaldehyde, and through low-molecular-weight organic substances such as acetic acid, formic acid and formaldehyde, the decomposition progresses to CO ₂ and H ₂ O (see FIG. 4).
From the above, regarding the decomposition of odorous gases containing multiple types of volatile organic compounds, it is possible to reduce the odor concentration astonishingly by efficiently decomposing acetaldehyde, which was not possible with photocatalysts.
The present invention was made based on the above findings, and the gist thereof is as follows.

A non-circulating deodorizing method for malodorous gas according to a first invention that meets the above object is a non-circulating deodorizing method for malodorous gas containing malodorous components consisting of volatile organic compounds that produce acetaldehyde and acetic acid in the process of decomposing the gas. and
An odorous gas to be deodorized is supplied toward an odor component oxidation decomposition filter equipped with an ozone decomposition catalyst so that the space velocity SV value is 3000/hr to 60000/hr,
supplying ozone gas so that the ozone concentration is 5 ppm to 50 ppm with respect to the malodorous gas supplied toward the malodorous component oxidation decomposition filter,
The concentration of non-methane hydrocarbons in the odorous gas deodorized by decomposing the malodorous components is reduced to 10 mg/m ³ or less.

A non-circulating deodorizing method for malodorous gas according to a second invention that meets the above object is a non-circulating deodorizing method for malodorous gas containing malodorous components consisting of volatile organic compounds that produce acetaldehyde and acetic acid in the process of decomposing the gas. and
an untreated gas introducing step of introducing an odorous gas to be deodorized from an inlet;
a particulate component removing step of removing particulate components from the odorous gas introduced in the untreated gas introducing step;
an adsorption removal step of adsorbing and removing part of the malodorous components from the odorous gas treated in the particulate component removal step;
a malodorous component concentration homogenization step in which the malodorous component concentration of the malodorous gas is brought closer to uniformity by adsorption or desorption of the malodorous components remaining in the malodorous gas treated in the adsorption removal step;
Ozone gas is treated in the malodorous component concentration equalization step and supplied to the malodorous component oxidative decomposition filter equipped with an ozone decomposition catalyst so that the space velocity SV value is 3000/hr to 60000/hr. an ozone gas supply step of supplying so that the ozone concentration is 5 ppm to 50 ppm;
Active oxygen is generated from ozone gas by the ozone decomposition catalyst supported on the malodorous component oxidative decomposition filter, and the active oxygen oxidatively decomposes the malodorous components remaining in the malodorous gas treated in the malodorous component concentration equalization step. and a malodorous component oxidative decomposition step of oxidatively decomposing acetaldehyde and acetic acid generated in the oxidative decomposition process;
a treated gas discharging step of discharging the malodorous gas treated in the malodorous component oxidative decomposition step from an outlet;
The malodorous gas introduced in the untreated gas introduction step is sequentially subjected to the particle component removal step to the malodorous component oxidative decomposition step, and the malodorous components are decomposed and deodorized. After the non-methane hydrocarbon concentration is reduced to 10 mg/m ³ or less, the treated gas is discharged from the discharge port in the treated gas discharge step.

In the non-circulating deodorizing methods for odorous gases according to the first and second inventions, the odorous gases to be deodorized are, for example, food and chemical factory production lines, wastewater treatment facilities, sewage treatment plants, and sewage relay pumping stations. For example, lower fatty acids acetic acid, propionic acid, isobutyric acid, butyric acid, isovaleric acid, valeric acid, isocaproic acid, caproic acid, aldehydes formaldehyde, acetaldehyde, propionaldehyde, isobutyraldehyde , n-butyraldehyde, isobutyraldehyde, n-valeraldehyde, sulfur compounds hydrogen sulfide, carbonyl sulfide, methyl mercaptan, carbon disulfide, ethyl mercaptan, dimethyl sulfide, dimethyl disulfide Among the 22 volatile organic compounds is a mixed gas containing malodorous components consisting of any two or more of .
In the non-circulating deodorizing method for odorous gases according to the first and second inventions, the ozone decomposition catalyst is a deodorizing catalyst composition or a deodorizing catalyst containing the composition, and has a deodorizing effect on the above-mentioned odorous gases. It demonstrates.
The above is the same for the third and fourth inventions described later.

In the non-circulating odor gas deodorizing methods according to the first and second inventions, the space velocity SV value can be calculated by the following formula. Note that "SV" is an abbreviation for Space Velocity.
Space velocity SV value = Q/V (1/hr)
Here, Q represents the flow rate (m ³ /hr) of the malodorous gas supplied to the malodorous component oxidative decomposition filter per unit time, and V represents the volume (m ³ ) of the malodorous component oxidative decomposition filter through which the malodorous gas passes. there is
That is, the space velocity SV value is the speed at which malodorous gas passes through the malodorous component oxidation decomposition filter, and the space velocity SV value can define the contact time between the malodorous component oxidation decomposition filter and the odorous gas.
The above is the same for the third and fourth inventions described later.

In the non-circulating deodorizing methods for odorous gas according to the first and second inventions, the concentration of non-methane hydrocarbons (also referred to as NMHC) in the deodorized odorous gas is 10 mg/m ³ or less. The non-methane hydrocarbons are hydrocarbons (also described as HC) excluding methane (also described as CH ₄ ), which has a very slow photochemical reaction rate, that is, "non-methane hydrocarbons containing high to low molecular weights". = means "VOC" - "persistent methane". A non-methane hydrocarbon concentration of 10 mg/m ³ corresponds to 15 ppmC.
Here, the concentration of non-methane hydrocarbons in the odorous gas was used as the criterion for deodorizing the odorous gas because the odorous gas contains various odorous components as described above. This is to grasp
In addition, when the non-methane hydrocarbon concentration of 10 mg/m ³ or less is expressed in terms of odor concentration, it is considered to correspond to, for example, about 1000 or less. The odor concentration is the value of the dilution ratio required to dilute the odor until it becomes odorless, and the odor concentration of 1000 means that the odor becomes odorless only when diluted 1000 times with odorless clean air. .
The above is the same for the third and fourth inventions described later.

In the non-circulating method for deodorizing odorous gas according to the first and second inventions, the humidity of the odorous gas supplied to the malodorous component oxidation decomposition filter is measured in advance, and the measured humidity is more than 80%. On this condition, it is preferable to heat the malodorous gas supplied to the malodorous component oxidative decomposition filter so as to lower the humidity to 80% or less.

In the non-circulating method for deodorizing malodorous gases according to the first and second inventions, it is preferable that the malodorous component oxidation decomposition filter has an adsorbent carrying the ozone decomposition catalyst.
Here, the adsorbent contains zeolite, and the zeolite preferably contains 20% by mass or more of hydrophobic zeolite.

In the non-circulating deodorizing method for odorous gas according to the first and second inventions, it is preferable to set the supply flow rate of odorous gas to 100 m ³ /min to 1000 m ³ /min.

In the non-circulating deodorizing method for odorous gas according to the first and second inventions, the ozone concentration of the odorous gas mixed with the ozone gas after the deodorizing treatment is further measured, and the measured ozone concentration is a predetermined concentration. It is preferable to control so as to reduce the amount of ozone gas supplied to the malodorous gas on condition that it is higher than.

A non-circulating deodorizing apparatus for malodorous gas according to a third aspect of the present invention that meets the above object is a non-circulating deodorizing apparatus for malodorous gas containing malodorous components consisting of volatile organic compounds that produce acetaldehyde and acetic acid in the process of decomposing the gas. and
a malodorous component oxidation decomposition filter equipped with an ozone decomposition catalyst;
an odorous gas supply unit that supplies an odorous gas to be deodorized toward the malodorous component oxidation decomposition filter so that the space velocity SV value is 3000/hr to 60000/hr;
an ozone gas supply means for supplying ozone gas to the odorous gas supplied toward the malodorous component oxidation decomposition filter so that the ozone concentration is 5 ppm to 50 ppm;
The malodorous gas is passed through the malodorous component oxidation decomposition filter to decompose the malodorous component and deodorize the malodorous gas so that the concentration of non-methane hydrocarbons in the odorous gas is reduced to 10 mg/m ³ or less.

A non-circulating deodorizing apparatus for malodorous gas according to a fourth aspect of the present invention that meets the above object is a non-circulating deodorizing apparatus for malodorous gas containing malodorous components consisting of volatile organic compounds that produce acetaldehyde and acetic acid in the process of decomposing the gas. and
an inlet section provided with an introduction port for an odorous gas to be deodorized;
a particulate component removal filter disposed on the downstream side of the inlet for removing particulate components in the odorous gas;
an adsorption removal filter arranged downstream of the particulate component removal filter for adsorbing and removing part of the malodorous components from the malodorous gas;
a malodorous component concentration equalization filter disposed downstream of the adsorption removal filter, which adsorbs or desorbs the malodorous components remaining in the malodorous gas to bring the malodorous component concentration of the malodorous gas closer to uniformity;
Active oxygen is generated from ozone gas by an ozone decomposition catalyst that is disposed downstream of the filter for equalizing the concentration of malodorous components, and the active oxygen remains in the odorous gas processed by the filter for equalizing the concentration of malodorous components a malodorous component oxidative decomposition filter that oxidatively decomposes the malodorous components and oxidatively decomposes acetaldehyde and acetic acid generated in the oxidative decomposition process;
The malodorous gas treated by the malodorous component concentration equalizing filter is supplied to the introduction port so that the malodorous component oxidative decomposition filter has a space velocity SV value of 3000/hr to 60000/hr. an odor gas supply unit for
With respect to the malodorous gas supplied toward the malodorous component oxidative decomposition filter, ozone gas is supplied between the malodorous component concentration equalizing filter and the malodorous component oxidative decomposition filter so that the ozone concentration is 5 ppm to 50 ppm. a supply means;
a processed gas discharge part provided downstream of the malodorous component oxidative decomposition filter for discharging odorous gas resulting from oxidative decomposition of the malodorous component from an outlet,
The malodorous gas is passed from the inlet portion to the treated gas discharge portion, and the non-methane hydrocarbon concentration in the malodorous gas decomposed and deodorized is reduced to 10 mg/m ³ or less.

In the non-circulating deodorizing device for malodorous gas according to the fourth invention,
an inlet connection region comprising the inlet section, the particulate component removal filter, the adsorption removal filter, the malodorous component concentration equalization filter, and the odorous gas supply section;
an odorous gas processing area comprising the malodorous component oxidation decomposition filter and the ozone gas supply means;
and an outlet connection region comprising the process gas discharge part,
Each unit is configured to be separable and connectable to each other,
It is preferable that a plurality of the malodorous gas treatment regions are connected in series according to the concentration of malodorous components of the odorous gas to be deodorized.

In the non-circulating malodorous gas deodorizing apparatus according to the third and fourth inventions, it is preferable that the malodorous component oxidation decomposition filter has an adsorbent carrying the ozone decomposition catalyst.

In the non-circulating malodorous gas deodorizing apparatus according to the third and fourth inventions,
an ozone concentration sensor provided downstream of the malodorous component oxidation decomposition filter for measuring the ozone concentration of odorous gas mixed with ozone gas;
a processing gas concentration control unit for controlling the ozone gas supply means to reduce the amount of ozone gas supplied to the malodorous gas on condition that the ozone concentration measured by the ozone concentration sensor is higher than a predetermined concentration. It is preferable to have

In the non-circulating malodorous gas deodorizing apparatus according to the third and fourth inventions,
an odorous gas humidity sensor for measuring the humidity of the odorous gas supplied toward the malodorous component oxidation decomposition filter;
a heat exchanger arranged upstream of the odorous gas humidity sensor and capable of varying and maintaining a temperature within a range of 30° C. to 40° C.;
It is preferable to further include a humidity control section that variably controls the temperature of the heat exchanger so as to reduce the humidity of the odorous gas to 80% or less on condition that the humidity of the odorous gas is higher than 80%.

The non-circulating deodorizing method for malodorous gas and the non-circulating deodorizing apparatus for the same according to the present invention, for example, in the process of deodorizing the malodorous gas generated in a drainage facility or the like, converts the malodorous gas into a malodorous component oxidizer equipped with an ozone decomposition catalyst. It is supplied to the decomposition filter so that the space velocity SV value is 3000/hr to 60000/hr, and ozone gas is supplied to the malodorous component oxidation decomposition filter with an ozone concentration of 5 ppm to 5 ppm. By supplying 50 ppm, it is possible to ensure the contact time necessary for decomposing high-concentration ozone in the malodorous component oxidation decomposition filter. As a result, the ozone is sufficiently decomposed by the ozone decomposition catalyst to generate a sufficient amount of active oxygen such as ".OH", and the sufficient amount of active oxygen sufficiently decomposes the malodorous components of the volatile organic compounds. At the same time, it is possible to effectively decompose acetaldehyde and acetic acid, which are difficult to decompose completely, and eventually decompose most of the malodorous components.
As a result, the odorous gas, which has been difficult to make almost odorless in the past, is deodorized in one pass without circulation, and the concentration of non-methane hydrocarbons in the odorous gas is reduced to 10 mg/m ³ or less, making it almost odorless. That is, it becomes possible to decompose to a complete decomposition level of only CO ₂ +H ₂ O, and to complete the removal of malodorous components.

In addition, when the malodorous component oxidation decomposition filter is made by supporting an ozone decomposition catalyst such as manganese dioxide on an adsorbent such as a hydrophobic zeolite, the malodorous component is adsorbed by the adsorbent, and the adsorption action causes the mixed gas to be decomposed. A flow occurs in a direction different from the direction of flow. As a result, the speed of the gas passing through the malodorous component oxidation decomposition filter is slowed down, so that the time required for decomposition by active oxygen can be further secured, and the malodorous component decomposition efficiency can be further improved.

Furthermore, the ozone concentration of the odorous gas mixed with the ozone gas after the deodorizing treatment is measured, and on the condition that the measured ozone concentration is higher than a predetermined concentration, the amount of ozone gas supplied to the odorous gas is reduced. In the case of controlling, it is possible to clear the regulation of the ozone concentration in the odorous gas after the deodorization treatment based on the influence on the human body.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an explanatory diagram of a non-circulating malodorous gas deodorizing device according to an embodiment of the present invention; It is explanatory drawing of the non-circulation type deodorizing apparatus of the malodorous gas which concerns on a modification. 4 is a graph showing the effects of ozone concentration and space velocity SV value on the concentration of non-methane hydrocarbons in odorous gas. FIG. 4 is an explanatory diagram schematically showing the state of decomposition of malodorous components contained in malodorous gas.

Next, specific embodiments of the present invention will be described with reference to the attached drawings for better understanding of the present invention.
The non-circulating deodorizing apparatus 10 for deodorizing malodorous gas according to one embodiment of the present invention shown in FIG. It is a device that can deodorize in one pass without circulation. Note that volatile organic compounds are generally a generic term for organic compounds that are volatile and become gaseous in the atmosphere. Refers to containing.
A detailed description will be given below.

The non-circulating deodorizing apparatus 10 for odorous gas has a casing 11 through which the odorous gas to be deodorized is continuously passed without being circulated.
The casing 11 is made of ozone-resistant material such as SUS304 or SUS316 and has a cylindrical shape with a circular cross section. An inlet portion 13 having an odor gas inlet 12 at a diameter-reduced portion is provided at a diameter-reduced portion at the downstream end portion of the casing 11. The malodorous component is oxidized and decomposed to deodorize the gas. A processing gas discharge part 15 for discharging gas from the discharge port 14 is provided respectively.
The configuration of the casing is not particularly limited as long as the odorous gas flows in one direction inside the casing. , the overall shape viewed from the side may be, for example, curved, or may be bent in multiple zigzags.

Inside the casing 11 , a particulate component removal filter 16 is arranged on the downstream side of the inlet section 13 .
The particulate component removal filter 16 removes particulate components in the odorous gas, and pre-filters such as HEPA filters, semi-HEPA filters, and particle filters can be used. HEPA is an abbreviation for High Efficiency Particulate Air Filter.
As a result, particles in the odorous gas supplied from the inlet 12 into the casing 11 can be removed. The particles to be removed are, for example, inorganic or organic particles having a size of .mu.m or larger. In addition, the specifications of the particulate component removal filter 16 can be appropriately selected, for example, depending on the particle size distribution of the particles, the gas humidity at the inlet, the oil component condition, etc. The particulate component removal filter 16 is a consumable, for example, It is preferable to replace it regularly every 6 to 24 months.

Inside the casing 11, an adsorption removal filter 17 is arranged downstream of the particulate component removal filter 16 to adsorb and remove part of the malodorous components from the odor gas. A malodorous component concentration equalizing filter 18 is arranged to bring the malodorous component concentration of the malodorous gas closer to uniformity by adsorbing or desorbing the malodorous components remaining in the gas. In FIG. 1, the particulate component removal filter 16 and the adsorption removal filter 17 are arranged in close contact with each other, but they may be arranged with a gap therebetween.
The adsorption removal filter 17 and the foul odor component concentration equalization filter 18 can be appropriately selected according to the components of the volatile organic compounds contained in the odor gas, such as activated carbon filters, zeolite filters, hydrophilic filters, and hydrophobic filters. As a consumable item, it is preferable to replace it periodically, for example, every 12 to 60 months.

Inside the casing 11 , a malodorous component oxidative decomposition filter 19 is arranged downstream of the malodorous component concentration equalizing filter 18 . On the downstream side of the malodorous component oxidative decomposition filter 19, a concentration equalizing filter 20 having the same structure as the malodorous component concentration equalizing filter 18 is closely arranged.
The malodorous component oxidative decomposition filter 19 is a catalyst filter in which an ozone decomposition catalyst is supported on a zeolite honeycomb structure, which is an example of an adsorbent, and promotes an oxidative decomposition reaction of ozone gas, which is an oxidant. A zeolite adsorbent supporting an ozone decomposition catalyst can be adhered to or impregnated with a zeolite honeycomb structure, which is an example of a support.
For example, manganese dioxide can be used as the ozone decomposition catalyst. Specifically, porous particles having a large specific surface area, which are called active manganese dioxide, are preferred. That is, the honeycomb structure (adsorbent) supporting the ozone decomposition catalyst becomes a manganese dioxide-zeolite composite oxide.

The honeycomb structure may have any cell shape, and may be, for example, polygonal such as triangular, quadrangular, pentagonal, or hexagonal, or corrugated (wavy).
When the ozone decomposition catalyst is supported on this honeycomb structure, the cell density of the honeycomb structure and the amount of the ozone decomposition catalyst supported can be appropriately selected. can be maximized.
The honeycomb structure as the support can also be constructed by laminating aggregates made of inorganic fibers such as alumina fibers and silica fibers in a honeycomb shape, and this honeycomb structure is preferable because of its low pressure loss. Also, a porous ceramic can be used as the support instead of the honeycomb structure. In this case, it is preferable to adhere or impregnate a support made of a honeycomb structure or a porous ceramic with a zeolite adsorbent carrying an ozone decomposition catalyst.

The above zeolite preferably contains a hydrophobic zeolite.
Hydrophobic zeolites are generally called high-silica zeolites, and due to factors such as a decrease in the ratio of metal cations present in the molecular sieve crystal lattice, the hydrophobic zeolites have a weaker affinity for polar substances such as water, and are nonpolar. It makes the substance more strongly adsorbed. Due to these adsorption properties, it is possible to preferentially adsorb VOCs and odor components that are smaller than moisture in the atmosphere.
As this high silica zeolite, it is preferable to use the trade name "HiSiv-3000" manufactured by Union Showa Co., Ltd. This "HiSiv-3000" is _a high-silica zeolite that is hydrophobic and organophilic and has the ability to preferentially adsorb acetaldehyde. It is preferable to contain 20% by mass or more of high silica zeolite with respect to parts, and the upper limit may be 100% by mass.

In particular, the hydrophobic zeolite used in the present invention is one obtained by removing aluminum in the skeleton by acid treatment, hydrothermal treatment, or the like, and by replacing aluminum in the skeleton with silicon by silicon tetrachloride steam treatment, etc. This refers to zeolite with suppressed water vapor adsorption.
As a result, the volatile organic compound can be efficiently adsorbed in the pores even in the coexistence of water vapor.
In the present invention, zeolites having various structures such as the above-mentioned "HiSiv-3000" can be used as the hydrophobic zeolite. It is desirable to select what is possible as appropriate.

The malodorous component oxidation decomposition filter 19 can be manufactured, for example, by carrying MnO ₂ as an ozone decomposition catalyst on hydrophobic zeolite as an adsorbent, drying it, and then baking it at a temperature of 180° C. for 10 minutes. The resulting hydrophobic zeolite-MnO ₂ composite catalyst shows no decrease in activity not only at high temperatures but also at low temperatures near room temperature, and can remove volatile organic compounds in odorous gases by oxidative decomposition in the presence of ozone. Therefore, it is extremely effective as a processing method.
The malodorous component oxidative decomposition filter 19 can appropriately select specifications such as a MnO ₂ filter, a photocatalyst filter, a hydrophobic catalyst filter, a filter for sulfur-based substances, etc., depending on the type of volatile organic compounds contained in the odorous gas. As a consumable item, it is preferable to replace it periodically, for example, every 12 to 60 months.
As a result, active oxygen is generated from the ozone gas by the supported ozone decomposition catalyst, and this active oxygen oxidatively decomposes the malodorous components remaining in the malodorous gas treated by the malodorous component concentration equalizing filter 18. Acetaldehyde and acetic acid generated in the oxidative decomposition process can be oxidatively decomposed.

An odor gas supply pipe (not shown) for supplying odor gas to the introduction port 12 is connected to the odor gas introduction port 12 of the casing 11, and an odor gas supply unit such as a compressor is attached to the odor gas supply pipe. It is The odorous gas supply pipe is connected to the odorous gas outlet of facilities that generate odorous gas, such as production lines of food and chemical plants, wastewater treatment facilities, sewage treatment plants, sewage relay pumping stations, etc. The discharged odorous gas is continuously supplied to the odorous gas inlet 12 of the casing 11 . The supply of the odorous gas to the introduction port 12 may be intermittent depending on the operating conditions of the equipment.
The malodorous gas supply unit can adjust the flow rate of the malodorous gas supplied into the casing 11, and the malodorous gas processed by the malodorous component concentration equalizing filter 18 is directed to the malodorous component oxidative decomposition filter 19 and discharged into the space. This is for supplying the malodorous gas to the inlet 12 so that the velocity SV value is 3000/hr to 60000/hr. Here, the supply flow rate of the odorous gas is preferably 100 m ³ /min to 1000 m ³ /min.

The casing 11 is attached with an ozone gas supply means, which is an example of an ozone gas supply means.
The ozone gas supply means includes an ozone generator that generates high-concentration ozone gas, an ozone gas supply pipe that is connected to the ozone generator and sends the generated ozone to the casing 11, and is connected to the front end of the ozone gas supply pipe. and has two or more injection nozzles 22 for injecting ozone gas toward a reaction space 21 formed between the malodorous component concentration equalizing filter 18 and the malodorous component oxidative decomposition filter 19 . A spray nozzle for spraying ozone gas can be used instead of the spray nozzle 22 .
Various methods such as a discharge method, a light emitting method, and a water decomposition method can be applied to the method of generating ozone by the ozone generator. In addition, the inside of the ozone gas supply pipe is subjected to anti-ozone treatment. The plurality of injection nozzles 22 are attached and fixed at the same pitch or different pitches over the circumferential direction of the casing 11 .

As a result, the ozone gas can be uniformly injected to the malodorous gas supplied toward the malodorous component oxidation decomposition filter 19, and the ozone gas can be supplied so that the ozone concentration is 5 ppm to 50 ppm.
Note that the ozone gas supply means may further include an ozone concentration sensor and a processing gas concentration control section. In this case, the ozone concentration sensor is installed downstream of the malodorous component oxidation decomposition filter 19 in the casing 11, e.g. can measure the ozone concentration of Here, on the condition that the ozone concentration measured by the ozone concentration sensor is higher than a predetermined concentration, the ozone gas supply means is controlled by the processing gas concentration control unit so as to reduce the amount of ozone gas supplied to the odorous gas. It can be controlled automatically. For this predetermined concentration set in advance, for example, the regulation value of ozone concentration based on the influence on the human body can be used.

At the inlet 13 of the casing 11, an odorous gas humidity sensor for measuring the humidity of the odorous gas supplied toward the malodorous component oxidation decomposition filter 19, and a heat exchanger 23 arranged upstream of the odorous gas humidity sensor. is installed.
The heat exchanger 23 adjusts the temperature of the odorous gas entering the casing 11 based on the temperature of the odorous gas measured by the odorous gas humidity sensor, thereby adjusting the relative humidity and dew point of the odorous gas. It is a functionally configured device. Specifically, the temperature of the heat exchanger 23 can be varied within a range of 30.degree. C. to 40.degree. C. and can be maintained. Here, when the humidity of the odorous gas is higher than 80%, the humidity control section variably controls the temperature of the heat exchanger 23 so as to lower the humidity of the odorous gas to 80% or less. Here, 80% humidity means 80% RH.
Note that the humidity sensor, heat exchanger 23, and humidity control unit described above can be omitted when the humidity of the odorous gas is stable within a range of 80% or less.

The odorous gas supply unit, the ozone gas supply means, the heat exchanger 23, and the like, which constitute the non-circulating odor gas deodorizing apparatus 10, are controlled based on information from various sensors provided in the odor gas non-circulating deodorizing apparatus 10. is controlled by control means, for example a computer. Here, for example, by using IoT technology, for example, remote control and monitoring functions of the entire non-circulating deodorizing apparatus 10 for malodorous gas can be realized.
With the above configuration, the malodorous gas is passed once from the inlet portion 13 to the treated gas discharge portion 15 and once through the malodorous component oxidation decomposition filter 19, whereby the malodorous components are decomposed and deodorized. The concentration of non-methane hydrocarbons in the odorous gas can be reduced to 10 mg/m ³ or less, but depending on the concentration of malodorous components in the odorous gas, the non-circulating deodorizing device 30 for odorous gas shown in FIG. can also be used. Since the non-circulating odor gas deodorizing device 30 uses the constituent members of the non-circulating odor gas deodorizing device 10 described above, the same members are denoted by the same reference numerals, and detailed description thereof will be omitted.
The malodorous gas non-circulating deodorizing apparatus 30 has an inlet connection area 31, an odor gas treatment area 32, and an outlet connection area 33, each of which is unitized and configured to be separable and connectable to each other. Therefore, the casing 11 described above is composed of divided casings 11a, 11b, and 11c.

The inlet connection area 31 is composed of the inlet section 13 , the particulate component removal filter 16 , the adsorption removal filter 17 , the foul odor component concentration equalization filter 18 , the odor gas supply section, and the heat exchanger 23 . The malodorous gas processing area 32 is composed of the malodorous component oxidation decomposition filter 19, the concentration equalization filter 20, and the ozone gas supply means. The outlet connection area 33 is composed of the process gas discharge section 15 described above.
The malodorous gas non-circulating deodorizer 30 has a plurality of malodorous gas processing regions 32, for example, two or more, depending on the concentration of the malodorous component of the odorous gas to be deodorized. They are connected in series in the direction of odor gas flow. The number of malodorous gas processing regions 32 is not particularly limited because it is appropriately set according to, for example, the concentration of malodorous components in the malodorous gas and the deodorizing ability of the malodorous component oxidation decomposition filter 19, but is, for example, 10. degree.
As a result, the odorous gas is allowed to pass once from the inlet portion 13 to the treated gas discharge portion 15, and the malodorous components are decomposed and the odorous gas is deodorized. It can be ³ or less.

Next, a non-circulating deodorizing method for malodorous gas according to one embodiment of the present invention will be described with reference to the non-circulating deodorizing apparatus 10 for malodorous gas shown in FIG.
The non-circulating deodorizing method for odorous gases can deodorize odorous gases containing malodorous components consisting of volatile organic compounds that produce acetaldehyde and acetic acid in the gas decomposition process in one pass without circulation. The method includes the following untreated gas introduction step, particle component removal step, adsorption removal step, malodorous component concentration equalization step, ozone gas supply step, malodorous component oxidative decomposition step, and treated gas discharge step. there is

(Untreated gas introduction step)
For example, an odorous gas to be deodorized, which is discharged from a production line of a food or chemical factory, a wastewater treatment facility, a sewage treatment plant, a sewage relay pumping station, or the like, is introduced into the casing 11 through the inlet 12 .
This introduction of the odorous gas is carried out so that the odorous gas treated in the foul-smelling component concentration homogenization process described later is directed to the malodorous-component oxidation decomposition filter 19 with a space velocity SV value of 3000/hr to 60000/hr. Adjust by gas supply.

Odor gases include, for example, lower fatty acids such as acetic acid, propionic acid, isobutyric acid, butyric acid, isovaleric acid, valeric acid, isocaproic acid, caproic acid, and aldehydes such as formaldehyde, acetaldehyde, propionaldehyde, isobutyraldehyde, n-butyl any two of the 22 volatile organic compounds of aldehyde, isobutyraldehyde, n-valeraldehyde, sulfur compounds hydrogen sulfide, carbonyl sulfide, methyl mercaptan, carbon disulfide, ethyl mercaptan, dimethyl sulfide, and dimethyl disulfide It contains malodorous ingredients consisting of the above.
The concentration of non-methane hydrocarbons in the odorous gas varies depending on the equipment that discharges the odorous gas, but is generally about 20 mg/m ³ to 50 mg/m ³ .

(Particulate component removal step)
In the untreated gas introduction step, the odorous gas introduced into the casing 11 through the inlet 12 passes through the particulate component removal filter 16 to remove particulate components from the odorous gas. The particles to be removed are, for example, inorganic or organic particles of μm size or larger.

(Adsorption removal step)
The malodorous gas treated in the particulate component removal step passes through the adsorption removal filter 17, and according to the specifications of the adsorption removal filter 17, target volatile organic compounds, which are part of the malodorous components, are adsorbed and removed from the odorous gas. be done.

(Stink component concentration equalization step)
The malodorous gas treated in the adsorption removal step passes through the malodorous component concentration equalizing filter 18, and according to the specifications of the malodorous component concentration equalizing filter 18, the target volatile components, which are the malodorous components remaining in the odorous gas, are removed. Organic compounds are adsorbed or desorbed. As a result, the malodorous component concentration of the malodorous gas that has passed through the malodorous component concentration equalizing filter 18 approaches uniformity and becomes substantially uniform.

(Ozone gas supply process)
Ozone gas is added to the malodorous gas, which is processed in the malodorous component concentration equalization step and supplied toward the malodorous component oxidation decomposition filter 19 so that the spatial velocity SV value is 3000/hr to 60000/hr, and the ozone concentration is 5 ppm. The ozone gas is supplied to the reaction space 21 by means of the ozone gas supply means so that the concentration is 50 ppm.

(Bad Odor Component Oxidative Decomposition Process)
Active oxygen is generated from the ozone gas by the ozone decomposition catalyst carried on (the adsorbent of) the malodorous component oxidation decomposition filter 19, and the malodorous components remaining in the malodorous gas treated in the malodorous component concentration equalization step are removed by the active oxygen. along with oxidative decomposition of acetaldehyde and acetic acid generated in this oxidative decomposition process.

As described above, the odorous gas introduced in the untreated gas introduction step is sequentially subjected to the steps from the particle component removal step to the malodorous component oxidative decomposition step, and the malodorous components are decomposed to deodorize the odorous gas. Non-methane hydrocarbon concentration can be 10 mg/m ³ or less.
Here, the non-methane hydrocarbon concentration in the deodorized odorous gas is set to 10 mg/m ³ or less because of the global efforts to reduce the non-methane hydrocarbon concentration from the viewpoint of environmental problems. This is because the upper limit of the current strictest standard is 10 mg/m ³ . Therefore, the non-methane hydrocarbon concentration is not particularly limited as long as it is 10 mg/m ³ or less, preferably 7 mg/m ³ or less, more preferably 5 mg/m ³ or less, and the lower limit may be zero, Realistically, it is about 2 mg/m ³ to 3 mg/m ³ .

Here, the space velocity SV value of the odorous gas supplied toward the malodorous component oxidation decomposition filter 19, the ozone concentration when the ozone gas is supplied toward this odorous gas, and the non-methane in the deodorized odorous gas The hydrocarbon concentration relationship is described below with reference to FIG.
FIG. 3 shows that the ozone concentration is adjusted in the range of 25 ppm ± 5 ppm with respect to the concentration of non-methane hydrocarbons in the odor gas of 7 to 9 mg / m ³ , and the space velocity SV value of the odor gas is in the range of 5000 to 35000. It is the result of measuring the concentration of non-methane hydrocarbons in odorous gas when changing at . Here, the non-methane hydrocarbon concentration of 7 to 9 mg/m ³ is the inlet concentration ▪ shown in FIG.
As can be seen from FIG. 3, the concentration of non-methane hydrocarbons in the odorous gas can be reduced to 2.5 mg/m ³ or less by adjusting the ozone concentration and the space velocity SV value of the odorous gas within the respective ranges described above. Do you get it. Here, the non-methane hydrocarbon concentration of 2.5 mg/m ³ is the outlet concentration ♦ shown in FIG. Incidentally, the non-methane hydrocarbon concentration was 80% or more when converted into a reduction rate.

In FIG. 3, the concentration of non-methane hydrocarbons in the odorous gas at the inlet is 7 to 9 mg/m ³ , and the concentration of non-methane hydrocarbons in the odorous gas reaches 10 mg/m ³ or less before decomposition of the malodorous components. However, even when the concentration of non-methane hydrocarbons at the inlet is very low, the reduction effect is 80% or more.
In addition, a test was also conducted on odorous gases with a non-methane hydrocarbon concentration at the inlet of 13 to 19 mg/m ³ . It has also been confirmed that the concentration of non-methane hydrocarbons in odorous gas can be reduced to 7 mg/m ³ or less. At this time, the supply flow rate of the odorous gas was 200 m ³ /min.

The above phenomenon occurs when the ozone concentration is adjusted in the range of 5 to 50 ppm according to the concentration of non-methane hydrocarbons in the odorous gas at the inlet, and the space velocity SV value of the odorous gas is set in the range of 3000 to 60000. also obtained a similar trend.
The odor gas is directed to the malodorous component oxidation decomposition filter 19, and the space velocity SV value is 3000/hr to 60000/hr, preferably 5000/hr to 50000/hr, more preferably 5000/hr to 40000/hr. In addition, by supplying ozone gas to this odorous gas so that the ozone concentration is 5 ppm to 50 ppm, preferably 5 ppm to 40 ppm, more preferably 5 ppm to 35 ppm, the malodorous component oxidation decomposition filter 19 This is because the contact time necessary for decomposing high-concentration ozone could be secured.

(Processing gas discharge process)
The odorous gas treated in the malodorous component oxidative decomposition process, that is, the purified gas with a non-methane hydrocarbon concentration of 10 mg/m ³ or less in the odorous gas is discharged from the outlet 14 to the outside of the casing 11 .
Therefore, it is possible to deodorize in one pass without circulating the malodorous gas containing volatile organic compounds.

When an odorous gas humidity sensor is attached to the inlet portion 13 of the casing 11, the humidity of the odorous gas supplied toward the malodorous component oxidation decomposition filter 19 is measured in advance by the odorous gas humidity sensor. Under the condition that the humidity is over 80%, the heat exchanger 23 heats the malodorous gas supplied toward the malodorous component oxidation decomposition filter 19 and controls the humidity to be lowered to 80% or less.
Further, the supply flow rate of the odor gas is 100 m ³ /min to 1000 m ³ /min, preferably 150 m ³ /min to 700 m ³ /min, more preferably 150 m ³ /min to 500 m ³ /min. This is preferable from the viewpoint of the gas deodorizing capacity and the economy of the equipment scale of the non-circulating deodorizing apparatus 10 for malodorous gas.
When the ozone concentration sensor is installed in the vicinity of the outlet 14 of the malodorous component oxidation decomposition filter 19, the ozone concentration of the odorous gas mixed with the ozone gas after the deodorizing treatment is measured, and the measured ozone concentration reaches a predetermined value. On the condition that the ozone gas is higher than the concentration, control is performed so as to reduce the amount of ozone gas supplied to the odorous gas.

When the non-circulating deodorizing apparatus 30 for malodorous gas shown in FIG. After the homogenization process is performed sequentially, the ozone gas supply process and the malodorous component oxidative decomposition process are repeatedly performed to reduce the concentration of non-methane hydrocarbons in the odorous gas to 10 mg/m ³ or less. Then, the deodorized odorous gas is discharged out of the casing 11 through the discharge port 14 in the process gas discharging process.

The present invention has been described above with reference to the embodiments, but the present invention is not limited to the configurations described in the above embodiments, and the matters described in the claims. It also includes other embodiments and variations that are possible within its scope. For example, a combination of some or all of the above-described embodiments and modifications to form a non-circulating deodorizing method for malodorous gas and a non-circulating deodorizing apparatus thereof is also included in the scope of the present invention. be
In the above embodiment, the non-circulating deodorizing apparatus for malodorous gas is provided with a particulate component removal filter, an adsorption removal filter, and a malodorous component concentration equalization filter. Depending on the situation of the odorous gas, such as when no component is contained, any one or more of the particulate component removal filter, the adsorption removal filter, and the malodorous component concentration equalization filter may not be provided. good.

In the above embodiment, the malodorous component oxidation decomposition filter is composed of a zeolite honeycomb structure supporting an ozone decomposition catalyst. It can also consist of a filled reaction vessel. In this case, by forming a plurality of small through holes in the reaction container, the odorous gas can pass through the reaction container.
In the above embodiment, the ozone gas supply means further includes an ozone concentration sensor and a processing gas concentration control unit. is completely decomposed and converted to molecular oxygen, so it can be omitted.

10: non-circulating deodorizing device for odorous gas, 11, 11a, 11b, 11c: casing, 12: inlet, 13: inlet, 14: outlet, 15: treated gas outlet, 16: particulate component removal filter, 17: adsorption removal filter, 18: malodorous component concentration equalization filter, 19: malodorous component oxidation decomposition filter, 20: concentration equalization filter, 21: reaction space, 22: injection nozzle, 23: heat exchanger, 30: odorous gas 31: inlet connection area, 32: odor gas treatment area, 33: outlet connection area

Claims (13)

A non-circulating deodorizing method for malodorous gas containing malodorous components consisting of volatile organic compounds that produce acetaldehyde and acetic acid in the gas decomposition process,
An odorous gas to be deodorized is supplied toward an odor component oxidation decomposition filter equipped with an ozone decomposition catalyst so that the space velocity SV value is 3000/hr to 60000/hr,
supplying ozone gas so that the ozone concentration is 5 ppm to 50 ppm with respect to the malodorous gas supplied toward the malodorous component oxidation decomposition filter,
A non-circulating deodorizing method for malodorous gas, characterized in that the concentration of non-methane hydrocarbons in the malodorous gas decomposed and deodorized is reduced to 10 mg/m ³ or less. A non-circulating deodorizing method for malodorous gas containing malodorous components consisting of volatile organic compounds that produce acetaldehyde and acetic acid in the gas decomposition process,
an untreated gas introducing step of introducing an odorous gas to be deodorized from an inlet;
a particulate component removing step of removing particulate components from the odorous gas introduced in the untreated gas introducing step;
an adsorption removal step of adsorbing and removing part of the malodorous components from the odorous gas treated in the particulate component removal step;
a malodorous component concentration homogenization step in which the malodorous component concentration of the malodorous gas is brought closer to uniformity by adsorption or desorption of the malodorous components remaining in the malodorous gas treated in the adsorption removal step;
Ozone gas is treated in the malodorous component concentration equalization step and supplied to the malodorous component oxidative decomposition filter equipped with an ozone decomposition catalyst so that the space velocity SV value is 3000/hr to 60000/hr. an ozone gas supply step of supplying so that the ozone concentration is 5 ppm to 50 ppm;
Active oxygen is generated from ozone gas by the ozone decomposition catalyst supported on the malodorous component oxidative decomposition filter, and the active oxygen oxidatively decomposes the malodorous components remaining in the malodorous gas treated in the malodorous component concentration equalization step. and a malodorous component oxidative decomposition step of oxidatively decomposing acetaldehyde and acetic acid generated in the oxidative decomposition process;
a treated gas discharging step of discharging the malodorous gas treated in the malodorous component oxidative decomposition step from an outlet;
The malodorous gas introduced in the untreated gas introduction step is sequentially subjected to the particle component removal step to the malodorous component oxidative decomposition step, and the malodorous components are decomposed and deodorized. A non-circulating deodorizing method for malodorous gas, characterized in that after the non-methane hydrocarbon concentration is reduced to 10 mg/m ³ or less, the treated gas is discharged from the discharge port in the treated gas discharge step. 3. The non-circulating deodorizing method for malodorous gases according to claim 1 or 2, wherein the humidity of the malodorous gas supplied to the malodorous component oxidative decomposition filter is measured in advance, and the measured humidity exceeds 80%. A non-circulating deodorizing method for malodorous gas, characterized in that the malodorous gas supplied to the malodorous component oxidation decomposition filter is heated and controlled so that the humidity is lowered to 80% or less. The non-circulating deodorizing method for malodorous gases according to any one of claims 1 to 3, characterized in that the malodorous component oxidation decomposition filter has an adsorbent carrying the ozone decomposition catalyst. A non-circulating deodorizing method for odorous gases. 5. The non-circulating deodorizing method for odorous gases according to claim 4, wherein the adsorbent contains zeolite, and the zeolite contains 20% by mass or more of hydrophobic zeolite. Method. The non-circulating deodorizing method for malodorous gas according to any one of claims 1 to 5, characterized in that the supply flow rate of the malodorous gas is 100 m ³ /min to 1000 m ³ /min. Formula deodorization method. The non-circulating deodorizing method for odorous gases according to any one of claims 1 to 6, further comprising measuring the ozone concentration of the odorous gas mixed with the ozone gas after the deodorizing treatment, and measuring the measured ozone concentration in advance. A non-circulating deodorizing method for malodorous gas, characterized by controlling the amount of ozone gas supplied to the malodorous gas so as to be reduced on condition that the concentration is higher than a predetermined concentration. A non-circulating deodorizing device for deodorizing malodorous gas containing malodorous components composed of volatile organic compounds that produce acetaldehyde and acetic acid in the gas decomposition process,
a malodorous component oxidation decomposition filter equipped with an ozone decomposition catalyst;
an odorous gas supply unit that supplies an odorous gas to be deodorized toward the malodorous component oxidation decomposition filter so that the space velocity SV value is 3000/hr to 60000/hr;
an ozone gas supply means for supplying ozone gas to the odorous gas supplied toward the malodorous component oxidation decomposition filter so that the ozone concentration is 5 ppm to 50 ppm;
The odorous gas is passed through the malodorous component oxidative decomposition filter, and the malodorous component is decomposed to reduce the concentration of non-methane hydrocarbons in the odorous gas to 10 mg/m ³ or less. A non-circulating deodorizer for odorous gases. A non-circulating deodorizing device for deodorizing malodorous gas containing malodorous components composed of volatile organic compounds that produce acetaldehyde and acetic acid in the gas decomposition process,
an inlet section provided with an introduction port for an odorous gas to be deodorized;
a particulate component removal filter disposed on the downstream side of the inlet for removing particulate components in the odorous gas;
an adsorption removal filter arranged downstream of the particulate component removal filter for adsorbing and removing part of the malodorous components from the malodorous gas;
a malodorous component concentration equalization filter disposed downstream of the adsorption removal filter, which adsorbs or desorbs the malodorous components remaining in the malodorous gas to bring the malodorous component concentration of the malodorous gas closer to uniformity;
Active oxygen is generated from ozone gas by an ozone decomposition catalyst that is disposed downstream of the filter for equalizing the concentration of malodorous components, and the active oxygen remains in the odorous gas processed by the filter for equalizing the concentration of malodorous components a malodorous component oxidative decomposition filter that oxidatively decomposes the malodorous components and oxidatively decomposes acetaldehyde and acetic acid generated in the oxidative decomposition process;
The malodorous gas treated by the malodorous component concentration equalizing filter is supplied to the introduction port so that the malodorous component oxidative decomposition filter has a space velocity SV value of 3000/hr to 60000/hr. an odor gas supply unit for
With respect to the malodorous gas supplied toward the malodorous component oxidative decomposition filter, ozone gas is supplied between the malodorous component concentration equalizing filter and the malodorous component oxidative decomposition filter so that the ozone concentration is 5 ppm to 50 ppm. a supply means;
a processed gas discharge part provided downstream of the malodorous component oxidative decomposition filter for discharging odorous gas resulting from oxidative decomposition of the malodorous component from an outlet,
The odorous gas is passed from the inlet portion to the treated gas discharge portion, and the concentration of non-methane hydrocarbons in the odorous gas deodorized by decomposition of the malodorous components is reduced to 10 mg/m ³ or less. A non-circulating malodorous gas deodorizing device characterized by: In the non-circulating deodorizing apparatus for odorous gas according to claim 9,
an inlet connection region comprising the inlet section, the particulate component removal filter, the adsorption removal filter, the malodorous component concentration equalization filter, and the odorous gas supply section;
an odorous gas processing area comprising the malodorous component oxidation decomposition filter and the ozone gas supply means;
and an outlet connection region comprising the process gas discharge part,
Each unit is configured to be separable and connectable to each other,
A non-circulating deodorizing apparatus for malodorous gas, wherein a plurality of said malodorous gas treatment regions are connected in series according to the concentration of malodorous components of said odorous gas to be deodorized. 11. The non-circulating deodorizing apparatus for malodorous gases according to claim 8, wherein said malodorous component oxidation decomposition filter has an adsorbent carrying said ozone decomposition catalyst. A non-circulating deodorizing device for odorous gases. In the non-circulating deodorizing device for malodorous gas according to any one of claims 8 to 11,
an ozone concentration sensor provided downstream of the malodorous component oxidation decomposition filter for measuring the ozone concentration of odorous gas mixed with ozone gas;
a processing gas concentration control unit for controlling the ozone gas supply means to reduce the amount of ozone gas supplied to the malodorous gas on condition that the ozone concentration measured by the ozone concentration sensor is higher than a predetermined concentration. A non-circulating deodorizing device for malodorous gas. In the non-circulating deodorizing device for malodorous gas according to any one of claims 8 to 12,
an odorous gas humidity sensor for measuring the humidity of the odorous gas supplied toward the malodorous component oxidation decomposition filter;
a heat exchanger arranged upstream of the odorous gas humidity sensor and capable of varying and maintaining a temperature within a range of 30° C. to 40° C.;
and a humidity control unit that variably controls the temperature of the heat exchanger so as to lower the humidity of the odorous gas to 80% or less on condition that the humidity of the odorous gas is higher than 80%. Non-circulating gas deodorizer.

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