KR101235015B1 - Volatile organic compound treatment system using honeycomb adsorptive element and ozone, and voc treatment method using it - Google Patents

Abstract

PURPOSE: A system and a method for VOC(Volatile Organic Compound) treatment are provided to enhance VOC treatment efficiency and to ensure simple maintenance. CONSTITUTION: A VOC treatment system comprises a reaction unit(301), a post-treatment unit(302), a inlet part(305), a blower(303), and an outlet part(307). The reaction unit contains a honey comb adsorptive element in which metal-doped mesopore silica adsorbent is supported for decomposing VOC. The post-treatment unit decomposes VOC degradation product and unreacted ozone. The blower is mounted between the inlet part and the reaction part. [Reference numerals] (301) Honey comb adsorptive element; (302) Residual ozone removing absorber(catalyst); (303) Blower; (308) Ozone generator; (AA) VOC containing gas; (BB) Decomposing residual ozone with oxygen; (CC) Decomposing residual ozone with oxygen; (DD) Air; (EE) Metal doped mesoporous silica or fumed silica absorber; (FF) Reaction; (GG) Oxidation decomposing

Description

Volatile Organic Compound (BIO) treatment system using honeycomb adsorption element and ozone and VOC treatment method using same {VOLATILE ORGANIC COMPOUND TREATMENT SYSTEM

The present invention relates to a honeycomb adsorption device and a volatile organic compound (VOC) treatment system using ozone and a method using the same, and more particularly, a reaction unit equipped with a honeycomb porous adsorption device containing waste gas and ozone including VOC. The present invention relates to a VOC treatment system capable of oxidatively decomposing and removing VOC even at room temperature by passing through the same, and a VOC treatment method using the same.

Volatile Organic Compound (VOC) is a generic term for hydrocarbon compounds with a vapor pressure of 10 ^-2 kPa or more. Heterogeneous hydrocarbons (aldehydes, ketones, etc.) are included, and most of them are not only harmful to the human body but also cause various problems such as air pollution, water pollution, odor, and environmental hormones. Causes

Therefore, the research on the technology for treating such VOC is active, and as the VOC treatment technology currently being studied, it can be largely divided into oxidation method, direct combustion method and adsorption method using a catalyst.

Direct combustion, which directly thermally oxidizes VOCs, typically uses a thermal oxidizer with a processing efficiency of 97% and uses auxiliary fuel to maintain a relatively high average of 750 ° C. Such a direct combustion method is very uneconomical when the load fluctuations are severe or the concentration is low and the flow rate is low, and the system is relatively large, so that the installation area is high, making it difficult to expand the equipment. In addition, when the hardly decomposable VOC material is present in the exhaust gas, the combustion reaction temperature is increased, so that the annual operating cost is relatively high, and secondary air pollutants such as NOx / Dioxin are generated according to the reaction conditions.

Catalytic combustion, which burns VOCs using a catalyst, has been developed to enable VOC removal at relatively low temperatures in order to avoid problems such as the complexity of the incineration by simple heating and the use of auxiliary fuels for maintaining high temperatures. However, these expensive precious metal catalysts are susceptible to sulfur, heavy metals, phosphates, and halogen compounds in the combustion gases, causing rapid deactivation of the catalyst and losing the original catalytic activity. This has a disadvantage of difficulty.

On the other hand, as a technique for removing the recent VOC, Korean Patent No. 0684924, ozone generator; A power supply unit supplying power to the ozone generator; A mixer for mixing ozone generated from the ozone generator and a processing gas; A blower for forcibly blowing ozone mixed with the treatment gas in the mixer; Plasma air purifying sterilization deodorizer comprising a; plasma arc generator comprising an arc reactor body and a pair of electrode plates coated with a photocatalyst and a honeycomb photocatalyst layer installed in the body corresponding to a predetermined height from an upper portion of the electrode plate; Is disclosed. The plasma air purifying sterilization deodorizer is treated with VOC using ozone as in the present invention, but the residual harmful gas which is not decomposed by ozone should be treated by passing through a plasma arc generator. There is a problem that the handling is not easy because it must be operated at a high temperature, the operating cost is consumed a lot.

Accordingly, the present inventors have completed the present invention as a result of intensive studies on techniques for improving VOC processing efficiency while solving problems of conventional techniques for VOC removal.

Registered Korean Patent No. 0684924 (Plasma Air Purification Sterilization Deodorizer, 2007.02.13, Registered) Japanese Patent Application Publication No. 2010-172804 (Temperature Swing VOC Concentration for Removing Water by Adsorbent, Recovering Cold Heat, Low Temperature Liquefied VOC Recovery Method, 2010.08.12.)

An object of the present invention is to provide a VOC treatment system that can efficiently treat VOCs by adsorbing and decomposing VOCs at room temperature using a honeycomb adsorption element and ozone.

In addition, another object of the present invention is to provide a VOC treatment method that can efficiently treat VOCs by adsorbing and decomposing VOCs at room temperature using a honeycomb adsorption element and ozone.

In order to achieve the above object, the present invention is a system for treating volatile organic compounds (VOC) using a honeycomb adsorption element and ozone,

A reaction part that decomposes VOC by reacting with ozone after introducing VOC and ozone, and is equipped with a metal-doped mesoporous silica adsorbent or a honeycomb adsorption element carrying a fumed silica adsorbent. part;

A post-treatment unit for decomposing the residual ozone after introducing the decomposition product of the VOC and the unreacted residual ozone discharged from the reaction unit;

An inlet unit for introducing VOC and ozone into the reaction unit;

A blower installed between the inlet part and the reaction part to introduce VOC and ozone into the reaction part; And

It includes an outlet for flowing out the decomposition products and oxygen of the VOC from the post-treatment unit.

Further, according to another aspect of the present invention, in the VOC treatment system, the metal is doped Mesoporous silica adsorbent is mesoporous silica (Ti-HMS or Al-HMS) doped with titanium or aluminum.

According to another aspect of the present invention, there is provided a method for treating a volatile organic compound (VOC) using a honeycomb adsorption element and ozone.

Introducing VOC and ozone into a reaction part including a honeycomb adsorption element carrying a metal-doped mesoporous silica adsorbent or a fumed silica adsorbent;

Adsorbing VOC to the adsorbent supported on the honeycomb adsorption element in the reaction unit, and decomposing VOC by reacting radicals generated by decomposing ozone by the adsorbent with VOC;

Decomposing the decomposed product and unreacted residual ozone generated by decomposing the VOC into a post-treatment unit, and then decomposing the residual ozone to generate oxygen; And

It is configured to include; the step of flowing out the decomposition products and oxygen of the VOC.

According to another aspect of the present invention, in the above VOC treatment method, the metal-doped mesoporous silica adsorbent is aluminum or titanium ions-doped mesoporous silica.

The honeycomb adsorption element and the VOC treatment system and the VOC treatment method using ozone according to the present invention have a high VOC treatment efficiency because the adsorption and decomposition of the VOC is simultaneously performed at room temperature.

In addition, the VOC treatment system according to the present invention can be compact in the whole system, easy to maintain the system, low operating costs, and can be applied to the treatment of VOC gas according to various sources.

1 is a view for explaining the manufacturing process of the metal-doped mesoporous silica adsorbent used in the present invention.
2 is a block diagram showing a VOC treatment system using ozone and honeycomb adsorption elements according to the present invention.
3 is a block diagram showing a VOC treatment system using ozone and honeycomb adsorption elements according to another embodiment of the present invention.
4 (a) and 4 (b) are test data showing the treatment efficiency when styrene and m-xylene are used as the VOC, respectively, and a honeycomb adsorption element carrying a metal-doped mesoporous silica adsorbent on a honeycomb carrier. Is a test data comparing the effect of using a honeycomb carrier with no adsorbent.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

First, the adsorbent used in the VOC treatment system according to the present invention is a metal-doped mesoporous silica adsorbent, and an adsorbent in which mesoporous silica having a wormhole structure is doped with Al or Ti, for example, Al-HMS. Or Ti-HMS, or fumed silica adsorbent is preferably used. This is due to the addition of highly reactive hydroxy radicals (OH ·), superoxide radical anions (O ₂ ⁻ ·), ozone radicals when metals doped with mesoporous silica or fumed silica adsorbents decompose ozone. anion (O ₃ ^- ·) to produce radicals, such as because the advantage of increasing the VOC removal efficiency.

In general, mesoporous silica refers to a material having mesopores prepared using micelles by supermolecular self-assembly of a surfactant. Meanwhile, according to the IUPAC definition, mesoporous silica refers to silica having a pore size of 2 to 50 nm, and an adsorbent or a fumed silica adsorbent doped Al or Ti to a mesoporous silica having a wormhole structure used in the present invention. Both are mesoporous silica according to the IUPAC definition.

Looking at the manufacturing process of Al-HMS in the metal-doped mesoporous silica adsorbent as follows.

As in step S201 and S202, dodecylamine was added to HCl and stirred for 20 minutes to 1 hour, and then, steps S203 and S204 were entered to dilute the water glass in water, and a little water was added thereto. Stir at 16-24 hours. Then, as step S205 and step S206, after putting a solution in which aluminum isopropoxide is mixed with isopropyl alcohol, the mixture is stirred for 16 to 32 hours.

Thereafter, steps S207 and S208 are entered, and the silica precipitate is filtered and dried at room temperature. Then, Al-mesoporous silica is prepared through a S209 step of calcination at 400 ° C. to 800 ° C., preferably 550 ° C. to 650 ° C. for 2 to 6 hours, more preferably 3 to 5 hours. .

On the other hand, Ti-HMS is prepared using the same manufacturing process as Al-HMS, but using titanium t-butoxide instead of aluminum isopropoxide.

In the present invention, when a metal-doped mesoporous silica adsorbent is prepared or a commercial fumed silica adsorbent is prepared, the adsorbent is supported on a honeycomb carrier to prepare a honeycomb adsorption element. The honeycomb carrier used in the present invention is not limited in material, but is preferably a ceramic material.

By using the honeycomb adsorption element as described above, the VOC treatment system according to the present invention has a pressure drop of VOC, which is a gas to be treated, by about 20% smaller than that of a fixed tower packed with a conventional granular adsorbent. When using a pellet or granule-type granular adsorbent, a pressure drop occurs due to the flow resistance in proportion to the size of the adsorbent particles, the adsorbent stacking height, and the flow rate of the gas, and the higher the pressure drop, the more gas that can be processed. There is a problem that the installation cost increases due to the reduced amount and the size of the device increases. Therefore, by using the honeycomb adsorption element, it is possible to reduce the pressure drop and increase the amount of gas to be treated, thereby eliminating the problem of increased installation cost. In addition, since the adsorbent supported on the surface of the honeycomb porous adsorption element reacts with the waste gas containing VOC, the reaction rate is fast and the reaction area is increased in the same volume, thereby providing an effective adsorption characteristic.

Figure 2 is a block diagram showing a honeycomb porous adsorption device and ozone VOC treatment system proposed in the present invention. As shown, the VOC treatment system according to the present invention, the honeycomb adsorption element 311 in which the mesoporous silica adsorbent 322 or the fumed silica adsorbent 323 doped with metal as an adsorbent is supported on the honeycomb carrier 321. It includes a reaction unit 301 is mounted.

VOC and ozone are introduced into the honeycomb adsorption element 311 mounted inside the reaction part 301 through the respective inlets, that is, the VOC inlet 304 and the ozone inlet 305, or a mixed gas inlet. Can flow through the portion 306.

That is, when using ozone generated using the ozone generator 308 by the silent discharge method, ozone is introduced through the ozone inlet 305, and the VOC is separately supplied through the VOC inlet 304 separately installed. Inflow methods may be used.

In addition, when ozone is introduced according to the photochemical reaction method, as shown in FIG. 3, ozone may be generated while promoting VOC decomposition while passing VOC through a UV lamp capable of ozone generation (not shown). OH · may be generated, and the VOC gas, ozone, and OH · may be mixed and introduced into the reaction unit 301 through the mixed gas inlet 306.

As described above, the method of introducing ozone into the reaction unit 301 can be selected according to the properties and the concentration of the VOC gas to be treated. For example, when a high concentration of ozone is required, a method of generating ozone may be used according to a silent discharge method suitable for generating a large amount of ozone. Otherwise, a method of generating ozone may be used according to a photochemical reaction method. It is not limited.

At this time, in order to introduce the VOC gas and the ozone gas into the reaction unit 301, a blower 303 is installed adjacent to the reaction unit 301.

The VOC introduced into the reaction part 301 by the blower 303 is adsorbed by the adsorbent supported on the honeycomb porous adsorption element 311 and oxidized and decomposed by radicals generated from ozone gas . That is, the ozone gas is decomposed by the adsorbents 321 and 322 supported on the honeycomb adsorption element, and highly reactive hydroxy radicals (OH ·), superoxide radical anions (O ₂ ⁻ ·), and ozone radical anions (O _3). ^- generating a radical, such as ·), and the VOC is oxidized and decomposed by this radical, and as a decomposition product, the H ₂ O and CO ₂ are generated.

After the decomposition products of these VOCs and the remaining ozone gas which has not reacted in the reaction part flow into the aftertreatment unit 302, the ozone gas is decomposed into oxygen by the activated carbon adsorption method or the MnO ₂ catalyst method in the aftertreatment unit, and then the VOCs. With the decomposition product of the gas is discharged through the outlet 307.

The activated carbon adsorption method means that catalytic decomposition occurs on the surface of activated carbon by direct reaction of activated carbon and ozone, and the reaction formula may be expressed as follows.

[Reaction Scheme 1]

2O ₃ + 2C → 2CO ₂ + O ₂

2O ₃ + C → CO ₂ + 2O ₂

2O ₃ + C → 3O ₂ + C

In addition, the MnO ₂ catalyst method is a method of decomposing ozone by catalysis of MnO ₂ , and in order to solve the problem of weakening the processing efficiency and shortening the life of the catalyst by water contained in the gas to be treated, It can be used at the same time as the heating equipment. In the case of treating residual ozone by this MnO ₂ catalyst method, the post-treatment part is controlled to 10,000L / h of empty SV (Space Velocity, 40 ℃).

On the other hand, a power source for driving the blower or the like is not shown, but the configuration for applying the power to such a blower or the like to drive is known because it is a known configuration.

Example 1 Preparation of Al-HMS

0.561 g of dodecylamine (DDA) is added to 20 mL of 0.5M HCl and stirred. 2.7 g of water glass (3 kinds) is added to the solution diluted in 30 mL of water with slow stirring, followed by stirring at room temperature for 20 hours. Then, in order to dope Al into the mesoporous silica, a solution of 125 mg of aluminum isopropoxide dissolved in 10 mL of isopropyl alcohol was added and stirred at room temperature for 24 hours. After that, the precipitate is washed with distilled water and dried by filtration. Al-HMS is produced by calcination at 600 ° C. for 4 hours to remove the surfactant from the dried material.

Example 2 VOC Treatment System Operation Test Results

In the VOC treatment system according to the present invention, the case where the honeycomb adsorption element in which the Al-HMS adsorbent is loaded is mounted in the reaction part 301 and the case where only the honeycomb carrier is mounted in the reaction part 301 is provided. It tested and the result is shown to FIG. 4 (a) and 4 (b).

That is, FIGS. 4A and 4B show an Al-HMS adsorbent for styrene (FIG. 4 (a)) and m-xylene (FIG. 4 (b)), which are types of VOC gas, respectively. After operating the system of the present invention in which the honeycomb adsorption element is mounted, and the system in which the honeycomb carrier without the adsorbent is loaded, respectively, it is test data confirming the treatment efficiency of VOC gas. At this time, the experimental conditions, when the inlet gas was introduced at a rate of 50ppm concentration, inflow flow rate 700ml / min, and ozone was introduced at a rate of 0.01g / h, the VOC treatment efficiency was expressed by the transmittance as shown in the following formula.

As can be seen from the test data of FIGS. 4 (a) and 4 (b), the honeycomb adsorption element loaded with the Al-HMS adsorbent as in the VOC treatment system according to the present invention shows that the VOC treatment efficiency is much higher. Can be. Similarly, the VOC treatment system using the honeycomb adsorption element loaded with fumed silica adsorbent was used to test the treatment efficiency of VOC gas, and the Al-HMS adsorbent was supported. It was.

As described above, the VOC treatment system and the VOC treatment method using the honeycomb porous adsorption element and ozone according to the present invention have a high VOC treatment efficiency because the adsorption and decomposition of VOC are performed at room temperature at the same time, and the compactness of the entire system In addition, the industrial value is extremely high because the system can be easily maintained, the system is easy to maintain, and the operation cost is low.

301: reaction unit 302: post-treatment unit
303 blower
304: VOC inlet 305: ozone inlet
306: mixed gas inlet 307: outlet
311: honeycomb adsorption element
321: honeycomb carrier
322: Mesoporous silica adsorbent doped with metal
323: fumed silica adsorbent

Claims (6)

A system for treating volatile organic compounds (VOC) using honeycomb adsorption elements and ozone,
A reaction part for decomposing VOC by reacting with ozone, comprising: a reaction part including a honeycomb adsorption element carrying a metal-doped mesoporous silica adsorbent;
A post-treatment unit for decomposing the residual ozone after introducing the decomposition product of the VOC and the unreacted residual ozone discharged from the reaction unit;
An inlet unit for introducing VOC and ozone into the reaction unit;
A blower installed between the inlet part and the reaction part to introduce VOC and ozone into the reaction part; And
It includes an outlet for outflow of the decomposition product and oxygen of the VOC passed through the after-treatment,
The metal-doped mesoporous silica adsorbent is a mesoporous silica adsorbent doped with titanium or a mesoporous silica adsorbent doped with aluminum. delete The method of claim 1,
The inlet is VOC treatment system, characterized in that consisting of the inlet and ozone inlet. The method of claim 1,
The inlet is a VOC treatment system, characterized in that the mixed gas inlet of VOC and ozone. A method of treating volatile organic compounds (VOC) using a honeycomb adsorption element and ozone,
Introducing VOC and ozone into a reaction part including a honeycomb adsorption element carrying a metal-doped mesoporous silica adsorbent;
Adsorbing VOC to the adsorbent supported on the honeycomb adsorption element in the reaction unit, and decomposing VOC by reacting radicals generated by decomposing ozone by the adsorbent with VOC;
Decomposing the decomposed product and unreacted residual ozone generated by decomposing the VOC into a post-treatment unit, and then decomposing the residual ozone to generate oxygen; And
Distilling the decomposition product and oxygen of the VOC;
Including;
The metal-doped mesoporous silica adsorbent is titanium-doped mesoporous silica adsorbent or aluminum-doped mesoporous silica adsorbent.
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