KR20200062590A - Chemical filter - Google Patents

Abstract

The present invention provides a method of manufacturing a chemical filter including an adsorption filter medium for removing organic compound gas, wherein the adsorption filter medium is a structure formed by laminating a first adsorbent layer supported on a support and a second adsorbent layer supported on the support, an average boiling point of the organic compound adsorbed in the first adsorbent layer is greater than an average boiling point of the organic compound adsorbed in the second adsorbent layer, and the first adsorbent layer is located at a front end of the gas inflow. According to the invention, the chemical filter is provided such that the adsorption capacity of total volatile organic compounds is improved by simultaneously removing volatile organic compounds in mid/low molecular weight range.

Description

Chemical filter {CHEMICAL FILTER}

The present invention relates to a chemical filter. More specifically, the present invention relates to a chemical filter for adsorbing and removing organic compounds generated in a semiconductor device manufacturing process.

In general, a semiconductor device includes a fab process for forming an electrical circuit on a silicon wafer used as a semiconductor substrate, and an electrical die sorting (EDS) process for inspecting electrical properties of semiconductor devices formed in the fab process, Each of the semiconductor devices is manufactured through a package assembly process for sealing and individualizing each of the epoxy devices.

The fab process comprises using a deposition process to form a film on a wafer, a chemical mechanical polishing process to planarize the film, a photolithography process to form a photoresist pattern on the film, and the photoresist pattern. An etching process for forming a film in a pattern having electrical characteristics, an ion implantation process for implanting ions into a predetermined area of the wafer, a cleaning process for removing impurities on the wafer, and drying for drying the cleaned wafer And a inspection process for inspecting defects in the film or pattern.

The manufacturing process of the semiconductor device as described above is performed in a clean space such as a clean room.

In particular, the degree of contamination of the clean room for semiconductor manufacturing is an important factor directly related to the semiconductor manufacturing yield. Moreover, recent semiconductor devices are becoming highly integrated, and the diameter of wafers for manufacturing the semiconductor devices is getting larger. Therefore, even a minute contaminant in the clean room may cause defects in the semiconductor device, so the cleanliness index in the clean room is more strictly managed. The contaminants in the clean room include particulate contaminants such as fine dust and chemical contaminants such as harmful gases, especially volatile organic compounds (VOCs).

Chemical contaminants generated in the clean room for manufacturing semiconductor devices are controlled by chemical filters. The chemical filter generally removes the harmful gas by collecting harmful gas by using impregnated activated carbon or zeolite as a filter medium.

However, the conventional chemical filter is configured to remove only one organic compound or the same type of organic compound, and thus there is a limit to control various types of organic compounds in the clean room. Alternatively, as disclosed in Patent Literature 2 and the like, each filter medium may be configured by mixing with each other, but it is difficult to ensure satisfactory removal efficiency for all of these various organic compounds.

In particular, since organic compounds having good adsorption efficiency are different for each adsorption material, there is a problem that the adsorption capacity for total volatile organic compounds (tVOCs) is low, so these organic compounds can be removed at the same time to improve the adsorption capacity of total volatile organic compounds. The development of a filter medium is desired.

Korean Patent Publication No. 1999-027844 Japanese Patent Publication No. 2001-300218

One aspect of the present invention is to provide a chemical filter capable of improving adsorption capacity of a total volatile organic compound by simultaneously removing volatile organic compounds in a medium/low molecular region by compensating for different adsorption performance by adsorption material.

However, the problems to be solved by the present invention are not limited to the problems mentioned above, and other problems not mentioned will be clearly understood by those skilled in the art from the following description.

In order to achieve the above object, an aspect of the present invention, in the chemical filter comprising an adsorption filter medium for removing the organic compound gas, the adsorption filter medium is a first adsorbent layer supported on the support and the agent supported on the support 2 The structure in which the adsorbent layer is stacked, the average boiling point of the organic compound adsorbed on the first adsorbent layer is greater than the average boiling point of the organic compound adsorbed on the second adsorbent layer, and the first adsorbent layer is located at the front end of the gas inlet. , Provides a method for manufacturing a chemical filter.

According to the present invention, it is possible to provide a chemical filter capable of improving the adsorption capacity of the total volatile organic compounds by simultaneously removing the volatile organic compounds in the medium/low molecular region.

1 is a block diagram of a chemical filter according to an embodiment of the present invention.
Figure 2 is a graph showing the adsorption capacity (a) of the total organic compound by adsorption material, the adsorption capacity (b) of the medium boiling point compound toluene, and the isopropyl alcohol (IPA) of the low boiling point compound.
Fig. 3 shows the removal efficiency over time of the individual organic compounds and the removal efficiency over time of the total volatile organic compounds in the case of using activated carbon (a) as the absorption filter medium and (b) using a structure in which activated carbon and modified zeolite are stacked. It is a graph showing.
Figure 4 is a graph showing the removal efficiency compared to the adsorption capacity of toluene and isopropyl alcohol (IPA) of activated carbon (a) and modified zeolite (b), respectively.
Figure 5 is a graph showing the removal efficiency over time while varying the flow rate and inlet concentration for the mixed gas of toluene and IPA using the chemical filter of the present invention.

The terms "consisting of" or "comprising" in this specification are not to be construed as including all of the various components, or various steps described in the specification, including some of the components or some steps It may or may not be construed as further comprising additional components or steps.

Further, terms including ordinal numbers such as first and second used in the present specification may be used to describe various components, but the components should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from other components. For example, the first component may be referred to as a second component without departing from the scope of the present invention, and similarly, the second component may be referred to as a first component.

Hereinafter, with reference to the accompanying drawings, the chemical filter of the present invention will be described in detail so that those skilled in the art to which the present invention pertains can easily practice it.

Volatile Organic Compounds (VOCs) refer to organic substances having a sufficiently high vapor pressure, which is a degree of volatilization from the normal state to the atmosphere, and can be defined as follows. Aliphatic carbon groups or chain carbon groups having a vapor pressure higher than 2 mmHg (0.27 kPa) at a temperature of 25° C. are collectively referred to as volatile organic compounds. In this case, the volatile organic compounds may further include elements such as oxygen and nitrogen. However, substances such as carbon dioxide, carbon monoxide, carbonic acid, metal carbide, and carbonates, although containing carbon, are not classified as volatile organic compounds.

When these volatile organic compounds are released into the atmosphere, they generate ozone, which is the main cause of photochemical smog, through photochemical reactions by nitrogen oxides (NO _x ) and other chemicals and sunlight, and have severe odor and harmful effects on the environment and organisms. There are features. In particular, it is known to cause serious damage to the human body such as mutation, carcinogenesis, and respiratory diseases. In each country, regulations on volatile organic compounds are being legislated, and the importance and necessity of developing volatile organic compound removal technologies are increasing as concerns about the seriousness of volatile organic compound emissions increase.

The present invention aims to remove the volatile organic compounds, but is aimed primarily at the removal of volatile organic compounds occurring in semiconductor manufacturing processes or precision electronic manufacturing processes.

The volatile organic compounds inside the clean room of a semiconductor manufacturing plant have the largest portion of low-molecular substances, followed by heavy-molecular substances, and the smallest portion of them are high-molecular substances. Here,'low molecular substance' means that the molecular weight is less than about 80,'medium molecule substance' means that the molecular weight is about 80 or more and less than 130, and'polymer substance' means that the molecular weight is about 130 or more, but this is a relative concept. The above figures are not absolute.

Therefore, the organic compounds that can be preferentially removed are those that are normally produced by providing semiconductors. Examples of low molecular substances are chloromethane, chloroethane, methyl ethyl ketone (MEK), and acetic acid. acid), isopropyl alcohol; Examples of heavy molecular materials include n-hexane (n-Hexane), chloroform, Benzene, toluene, ethylbenzene, xylene, and propylene glycol monomethyl ether (Propylene glycol) monomethyl ether; PGME), styrene; Examples of polymer materials include propylene glycol monomethyl ether acetate (Propylene Glycol Mnomethyl Ether Acetate; PGMEA), hexamethyldisilazane (HMDS), hexamethyldisiloxane (HMDSO), and ethyl 3-ethoxypropionate (Ethyl 3-Ethoxypropionate), diethylene glycol diethyl ether (Diethylene Glycol Diethyl Ether), and may be a volatile organic compound containing at least one selected from the group consisting of these materials.

Previously, organic compounds were classified by molecular weight, and it is judged that the molecular weight is related to the boiling point of the organic compound. That is, although not necessarily, the low-molecular substance has the lowest boiling point under the same temperature and pressure conditions, and it can be considered that the tendency to exist in the gaseous state is the highest, and the medium-molecular substance has a medium boiling point and the tendency to exist in the gaseous state is medium. It can be seen that the polymer material has the highest boiling point and the lowest tendency to exist in a gaseous state. In this case, when a mixture of these materials is present, the average size of particles distributed at the same temperature and pressure may be different, and the adsorbent capable of efficiently adsorbing and removing each constituent material also varies depending on the average size of the particles. It means you can. Accordingly, in the present invention, an organic compound targeted for adsorption removal is classified by molecular weight or boiling point, and a chemical filter is constructed by combining an adsorbent capable of efficiently adsorbing and removing each organic compound in an appropriate manner. In the present invention,'low boiling point material' means that the boiling point is less than approximately 90°C,'medium boiling point material' means that the boiling point is approximately 90°C or more and less than 140°C, and'high boiling point material' means that the boiling point is approximately 140°C or more. Meaningfully, this is a relative concept and the figures are not absolute. Or, in the present invention,'low molecular weight/low boiling point material' means that the average particle size is less than 6Å, and'medium molecular weight/low boiling point material' means that the average particle size is approximately 6Å or more and less than 8Å, and'polymer/high boiling point materials' 'Means that the average particle size is approximately 8 mm2 or more, but this is a relative concept and the numerical value is not absolute.

To this end, in the present invention, in the chemical filter including an adsorption filter material for removing organic compound gas, the adsorption filter material is a structure in which a first adsorbent layer supported on a support and a second adsorbent layer supported on a support are stacked. The average boiling point of the organic compound adsorbed on the 1 adsorbent layer is greater than the average boiling point of the organic compound adsorbed on the second adsorbent layer, and it is intended to present a chemical filter in which the first adsorbent layer is positioned before the gas inlet.

The adsorption filter media functions to adsorb the target organic compound gas and pass the remaining components including air to filter, and may be viewed as filter media.

The adsorption filter material may be configured by supporting an adsorbent on a support.

The support may include a material selected from metal materials, inorganic fibers, organic fibers, and composite materials thereof, but is not limited thereto. Examples of the metal material include aluminum, copper, and iron, but are not limited thereto, and metals may be used in combination of one type or two or more types. The inorganic fiber may be one or two or more of glass fiber, ceramic fiber, alumina fiber, mullite fiber, silica fiber, and carbon fiber. The organic fiber may be one or two or more of rayon fiber, pulp fiber, cotton fiber, and cotton linter fiber, nylon fiber, acrylic fiber polyester fiber, polyethylene fiber, polypropylene fiber, and aramid fiber. Moreover, the fiber diameter of the said organic fiber is not specifically limited, Preferably it is 5-20 micrometers.

The shape of the support may be a mesh-like support in which a support yarn having a substantially constant cross-section size is woven into a mesh shape or a linear support in which a support having a substantially constant cross-section size is used as it is.

The mesh-like support may be manufactured in the form of a triangular mesh, a quadrangular mesh, and a hexagonal mesh (honeycomb or honeycomb) depending on the shape of the pores (nets) that are the structural units. Depending on the method of weaving the mesh-like support, it may be manufactured in a mesh form, a network form, and a screen form, but is not limited thereto.

The linear support consists of a frame of a frame shape having a predetermined size and a support yarn made of filaments or wires or strings on the frame and wound at regular intervals on the frame. The frame is composed of a linear support by fixing the support yarn, and may be made of a material such as melamine resin, which is light in weight and has good strength, even when using the same material as the support yarn. The thickness may be manufactured and used in a range of 1 to 200 mm depending on the size of the chemical filter of the present invention, but is not limited thereto. At this time, the support yarn is preferably made of a lightweight and flexible material such as nylon, polyester, and acrylic.

The manner in which the adsorbent is supported on the support may vary. As an example, it may be prepared by applying an adhesive to the support and attaching an adsorbent thereto. As the adhesive, various adhesives such as urethane, acrylic, vinyl acetate, silicone, and hot melt adhesives can be used, and it is preferable to use a solvent-free adhesive with less risk of secondary contamination. The solvent-free urethane-based adhesive is an adhesive that adheres to an adsorbent and reacts with moisture in the atmosphere to cause curing. However, it requires a certain amount of time to cure, but is often used because it can prevent secondary contamination by solvent volatilization. In addition, the hot-melt adhesive refers to an adhesive that is applied by heating the adhesive and applying it to the surface of the support yarn, and then attaching the adsorbent after cooling. As such a hot melt adhesive, a polymer adhesive such as EVA (Ethylene Vinyl Acetate) having a melting range of 40 to 140°C, polypropylene, or polyethylene can be used.

Alternatively, the adsorbent per unit area is supported on a material that can be used as the support to be in the range of 60 to 120 g/m 2, and then, in a desired form, for example, a honeycomb structure, with one or more adhesives selected from organic adhesives or inorganic adhesives. It can be molded.

Specifically, the organic adhesive may be one or more selected from phenolic resins, epoxy resins, acrylic resins, and copolymers thereof, and the inorganic adhesive may be one or more selected from silica sol and alumina sol.

In the same manner as above, the support supporting the first adsorbent and the support supporting the second adsorbent may be stacked to form an adsorptive filter medium. That is, the method of laminating the support supporting the first adsorbent and the support supporting the second adsorbent may be adhered using an adhesive or the like, or may be laminated in the form of inserting each support. Therefore, the support supporting the first adsorbent and the support supporting the second adsorbent may be in contact with each other or may be arranged at regular intervals.

As described above, since the molecular weight of the compound is related to the boiling point, the average molecular weight of the organic compound adsorbed on the first adsorbent layer may be greater than the average molecular weight of the organic compound adsorbed on the second adsorbent layer. Therefore, the average pore size of the first adsorbent may be larger than the average pore size of the second adsorbent. Specifically, the average pore size of the first adsorbent is 20 mm 2, and the average pore size of the second adsorbent is 5 mm 2. By doing so, the first adsorbent layer selectively adsorbs medium/high molecular weight or organic compounds of medium/high boiling point, and the second adsorbent layer selectively adsorbs low-molecular or low-boiling organic compounds, resulting in total volatile organic compounds (tVOCs). Adsorption capacity can be improved. Materials that can be used as adsorbents include activated carbon, zeolite, activated carbon fiber (ACF), alumina, and silica gel.

For example, the adsorbent of the first adsorbent layer located at the front end of the inflow of gas may be composed of activated carbon, and the adsorbent of the second adsorbent layer may be composed of zeolite.

Activated carbon is a collection of well-developed amorphous carbon made of wood, lignite, anthracite, and coconut shell as a raw material, and fine pores of a molecular size are well formed in the activation process to have a large internal surface area. It is an adsorbent. Activated carbon may have a surface area of 1,000 mm2 or more per gram, and the functional group of the carbon atom present on the surface adsorbs molecules of the adsorbate by applying an attractive force to the surrounding liquid or gas.

As the adsorbent of the present invention, activated carbon may also be used as impregnated activated carbons, which are activated carbons that have been added to special activated chemicals such as metal salts to general activated carbons so that they do not fall on the surface of activated carbons to increase chemical adsorption performance. Adsorption of harmful gas by the impregnated activated carbon uses a property in which the surface of the adsorbent and the adsorbent are combined by physical or chemical attraction, which can be used to selectively separate or purify a certain component from the mixed adsorbent. The ability to trap harmful gases in the chemical filter can be achieved by using such impregnated activated carbon.

Activated carbon has a high specific surface area (BET) of 1000 (m 2 /g) or more, which is advantageous for controlling various gases. Since it is non-polar and has an average pore size of 20 mm 2, it can adsorb low/medium/high molecular weight or low/medium/high boiling point organic compounds. However, since the pore size is large, there is little selectivity in adsorbing VOCs, so a small molecule or a part of a low-boiling organic compound may be adsorbed. In addition, there is a disadvantage that side reactions between the adsorbent and the activated carbon may occur, and the adsorption capacity may be reduced by moisture.

“Zeolite” includes natural and synthetic zeolites, as well as other microporous and mesoporous materials having molecular sieves and related properties and/or structures, as defined in the International Zeolite Association Constitution. same. “Zeolite” refers to a group of structured aluminosilicate minerals or any member of this group, including cations such as sodium and calcium or less commonly barium, beryllium, lithium, potassium, magnesium and strontium, which are (Al +Si):O is about 1:2, has an ion-exchangeable open square basic framework, and is characterized by weak binding to water molecules to allow reversible dehydration. “Zeolite” also includes “zeolite-related materials” or “zeotypes” prepared by replacing Si ⁴⁺ or Al ³⁺ with other elements.

In general, zeolite is a structure in which silicon and aluminum are three-dimensionally connected through oxygen atoms, and may include alkali metals such as sodium, potassium, and lithium. At this time, various types of zeolites may be manufactured according to a molar ratio (Si/Al) of silicon and aluminum and a three-dimensional structure. The zeolite of the present invention is zeolite A, zeolite X, zeolite Y, zeolite L, ZSM-5 having a pentasil structure, mordenite, beta-zeolite (β-zeolite), ZSM-8, ZSM-11 and silica It may be in the form of at least one zeolite selected from the group consisting of Light-1 (Silicalite-1).

"ZSM-5" refers to a mobile synthetic zeolite-5. It also includes the acid form of ZSM-5, which can be expressed as "H-ZSM-5". "ZSM-5" is a fully crystalline zeolite, has a uniform and dense structure, and is relatively stable against penetration by acids and bases. ZSM-5 has a specific surface area (BET) of 400 (㎡/g). The average pore size is 5.5 mm×5.1 mm, and is polar. Therefore, it is advantageous to adsorb low molecular weight organic compounds having an average particle size of 5 mm 2.

The zeolite of the present invention may have a mesostructure, and "mesostructure" is known in the art and refers to a structure including mesopores that make the structure of a material into a meso- or nanometer-class. "Mesopores" are known in the art and refer to pores comprising medium size pores of about 2 to about 50 nm.

Therefore, it has the advantage of being capable of selectively adsorbing low-molecular VOCs because it has a uniform and relatively small pore size, but has a disadvantage of high cost and low tVOCs adsorption capacity compared to activated carbon.

When the adsorption filter medium is formed in a structure in which activated carbon is disposed as the first adsorbent layer and zeolite is disposed as the second adsorbent layer, relatively medium/high molecular weight or medium/high boiling point organic compounds are primarily adsorbed to activated carbon. , The remaining low-molecular or low-boiling organic compounds filtered out are adsorbed by zeolite secondary. Therefore, it is possible to simultaneously remove various types of organic compounds. Therefore, in order to control various types of organic compounds, it is not necessary to install and use each chemical filter capable of controlling each organic compound in multiple stages, thereby reducing installation space and reducing installation cost and operating cost.

Furthermore, the present invention proposes a method of further improving the adsorption efficiency by modifying the zeolite that can be used as the second adsorbent layer. The configuration of such a chemical filter is as shown in FIG. 1.

As a method of modifying the zeolite, there is a method of acid treatment. At this time, the acid (acid) that can be used may include hydrochloric acid (HCl), sulfuric acid (H ₂ SO ₄ ), nitric acid (HNO ₃ ), carbonic acid (H ₂ CO ₃ ), acetic acid (CH ₃ COOH), etc. It is not limited. In the acid treatment method, the zeolite is impregnated with the acid produced at a certain ratio.

As a zeolite used for this purpose, ZSM-5, which can be represented by the following Chemical Formula 1, will be described as an example.

[Formula 1]

ZSM-5 has excellent adsorption capacity to polar VOCs due to the surface characteristics of polarity, and is particularly advantageous for adsorption of low molecular VOCs due to its small pore size. In addition, the highest hydrophobicity among zeolites, and the Si/Al ratio is 25.

When ZSM-5 is acid-treated, Al ³⁺ in the crystal structure can be removed and modified with a more hydrophobic zeolite. This can be represented by the following Reaction Scheme 1, and as a result, hydrophobicity increases, water adsorption decreases, specific surface area increases, and adsorption energy decreases to improve VOCs adsorption performance.

[Scheme 1]

The average specific surface area of the ZSM-5 zeolite modified through acid treatment was 450 (m 2 /g), which was confirmed to be higher than the specific surface area of the ZSM-5 zeolite before modification.

Hereinafter, the present invention will be described in detail through examples. However, the following examples are only examples for explaining the present invention in more detail, and do not limit the scope of the present invention.

[Example]

Chemical filter media were prepared while varying the composition of the adsorbent as follows.

Preparation Example 1: Preparation of chemical filter media using activated carbon as an adsorbent

After spraying and applying a hot melt binder melted at 190°C to a nonwoven fabric made of polypropylene fiber, spraying and attaching 20-40 mesh sized activated carbon to prepare a 61cm*61cm chemical filter media and stacking them to produce a 150mm thick Did.

Preparation Example 2: Preparation of chemical filter media using zeolite (ZSM-5) as an adsorbent

Chemical filter media were produced under the same conditions as Comparative Example 1, except that zeolite (ZSM-5) was used instead of 20-40 mesh-size activated carbon.

Preparation Example 3: Preparation of chemical filter media using modified zeolite (DA-ZSM-5) as an adsorbent

Zeolite (ZSM-5) was treated with nitric acid and modified by dealumination. The Si/Al ratio of the zeolite before modification (ZSM-5) was 25, but the Si/Al ratio of the modified zeolite (DA-ZSM-5) was 30.

Chemical filter media were prepared under the same conditions as Comparative Example 1, except that modified zeolite (DA-ZSM-5) was used instead of 20-40 mesh-size activated carbon.

Preparation Example 4: Preparation of a chemical filter media having an adsorbent layer of a layered structure of activated carbon-zeolite (ZSM-5)

The two layers of the chemical filter media prepared in Preparation Example 1 and the five layers of the chemical filter media produced in Preparation Example 2 were laminated by a hot melt method to make the total thickness 150 mm, and the activated carbon layer was configured to be positioned at the front end of the gas inlet.

Preparation Example 5: Preparation of chemical filter media having an adsorbent layer having a layered structure of activated carbon-modified zeolite (DA-ZSM-5)

The two layers of the chemical filter media prepared in Preparation Example 1 and the five layers of the chemical filter media prepared in Preparation Example 3 were laminated by a hot melt method to have a total thickness of 150 mm, and the activated carbon layer was configured to be positioned at the front end of the gas inlet.

Analysis Example 1: Evaluation of adsorption performance of VOCs by adsorbent

The chemical filter media of Preparation Example 1, Preparation Example 2, and Preparation Example 3 using activated carbon, zeolite (ZSM-5), and modified zeolite (DA-ZSM-5) as adsorbents were employed to constitute a chemical filter, and The adsorption capacity of total volatile organic compounds (tVOCs), the adsorption capacity of toluene as a medium boiling point compound, and the adsorption capacity of isopropyl alcohol (IPA) as a low boiling point compound were measured and are shown in Table 1 below.

absorbent Adsorption capacity (mg/cc) tVOCs toluene IPA Activated carbon 94 82 12 ZSM-5 38 7.6 30 DA-ZSM-5 55 30 47

This is shown in Figure 2, the total organic compound adsorption capacity (a) for each adsorbent, the adsorption capacity (b) for the toluene, the medium boiling point compound, and the adsorption capacity (c) for the isopropyl alcohol (IPA), which is the low boiling point, corresponds to this. do.

When looking at the adsorption capacity of tVOCs, it was the highest in activated carbon, and the adsorption capacity for toluene, a medium boiling point VOCs, was also very good in activated carbon. On the other hand, when looking at the adsorption capacity of low boiling point VOCs, IPA, the adsorption performance of activated carbon was lowered due to competitive adsorption, and it was the highest in modified zeolite (DA-ZSM-5) showing uniform micropore and hydrophobic properties.

As described above, it can be seen that different kinds of organic compounds are easily adsorbed for each adsorbent material. Since activated carbon has a high specific surface area and various pore sizes, it is believed that it can adsorb contaminant particles of various sizes. However, in the case of ZSM-5 or DA-ZSM-5, there is a limit that the particle size of contaminants that can be adsorbed is less than the corresponding pore size, as the pore size is nm. Therefore, it is evaluated that the adsorption capacity for the medium boiling point compound is low (it can be inferred that the adsorption capacity for the high boiling point compound will also be low) and the adsorption for the low boiling point compound is high.

Analysis Example 2: VOCs mixed gas performance evaluation

The removal efficiency of the mixed gas of toluene and IPA was observed for each of the chemical filter media using activated carbon as an adsorbent (Production Example 1) and the chemical filter media using Modified Zeolite (DA-ZSM-5) as an adsorbent (Production Example 3). Did. This is shown in Figure 4. When only activated carbon was used, the adsorption performance of toluene was high due to competitive adsorption, but the IPA adsorption performance rapidly decreased. On the other hand, when DA-ZSM-5 was used, the selective adsorption performance for low molecules was excellent due to the uniform micropore characteristics. That is, the IPA adsorption performance was high, but the adsorption performance to toluene was low. Through this, it can be seen that in order to simultaneously remove volatile organic compounds in the medium/low molecular region, a mixed composition of activated carbon and modified zeolite is required.

Analysis Example 3: Performance evaluation of chemical media by adsorbent

Chemical filter media using activated carbon as an adsorbent (Preparation Example 1), chemical filter media having an adsorbent layer of an activated carbon-modified zeolite (DA-ZSM-5) layered structure (Preparation Example 5), respectively, at the time of the individual organic compound. The removal efficiency and the removal efficiency over time of the total volatile organic compounds were observed. This is shown in Figure 3. When only activated carbon was used, the adsorption performance of toluene was high, but the adsorption capacity of total volatile organic compounds (tVOCs) was low due to the low adsorption efficiency of IPA. On the other hand, when a laminated structure of activated carbon and DA-ZSM-5 was used, the overall adsorption capacity was adjusted upward. In particular, the removal efficiency of IPA was increased to increase the adsorption capacity of total volatile organic compounds (tVOCs). Specifically, when only activated carbon was used, the total adsorption capacity was 25,900 ppb*hr (based on 50% breakthrough). When using a laminated structure of activated carbon and DA-ZSM-5, the total adsorption capacity was 134,333 ppb*hr (based on 50% breakthrough). It was found to increase about 5 times.

Analysis Example 4: Performance evaluation according to the flow rate and incoming concentration of VOCs mixed gas

The removal efficiency over time was measured while varying the flow rate and inlet concentration for the mixed gas of toluene and IPA. This is shown in Figure 5. Figure 5 (a) is a condition of the flow rate 0.08m / s (32CMM), IPA 27ppm, toluene 14ppm, Figure 5 (b) is a flow rate of 0.08m / s (32CMM), IPA 22ppm, toluene 21ppm conditions, Figure 5 (c) is the removal efficiency under the conditions of a flow rate of 0.03 m/s (9 CMM), IPA of 20 ppm, and toluene of 20 ppm.

5(a) and 5(b), it can be seen that when the inlet concentration of the low/medium boiling point VOCs at the same flow rate is similar, the gap between the low/medium boiling point VOCs efficiency decreases. 5(b) and 5(c), when the flow rate is different, the difference in efficiency of the low/medium boiling point VOCs is widened even when the inlet concentration of the low/medium boiling point VOCs is similar, and the tVOCs when the flow rate is decreased by 2.6 times It can be seen that the lifespan of is increased by 2.8 times.

Through this, it is considered that the removal efficiency and removal time of the mixed gas can be controlled by adjusting the flow rate and the inlet concentration of the mixed gas.

In addition, it is expected that the removal efficiency can be maximized by varying the composition ratio of the first adsorbent layer and the second adsorbent layer according to the composition of the target gas.

Claims (8)

In the chemical filter comprising an adsorption filter medium for removing the organic compound gas,
The adsorption filter medium has a structure in which a first adsorbent layer supported on a support and a second adsorbent layer supported on a support are stacked, and an average boiling point of the organic compound adsorbed on the first adsorbent layer is an organic compound adsorbed on the second adsorbent layer. Is greater than the average boiling point of
Chemical filter, characterized in that the first adsorbent layer is located in front of the gas inlet. According to claim 1,
A chemical filter characterized in that the average molecular weight of the organic compound adsorbed on the first adsorbent layer is greater than the average molecular weight of the organic compound adsorbed on the second adsorbent layer. According to claim 1,
The first adsorbent is activated carbon, and the second adsorbent is a zeolite filter. According to claim 3,
The zeolite is zeolite A, zeolite X, zeolite Y, zeolite L, ZSM-5 having a pentasil structure, mordenite, beta-zeolite (β-zeolite), ZSM-8, ZSM-11 and silicalite- Chemical filter comprising at least one member selected from the group consisting of 1 (Silicalite-1). The method of claim 1 or 3,
The second adsorbent is a chemical filter characterized in that the zeolite is acid-treated and zeolite modified through dealumination. According to claim 1,
The support is a chemical filter, characterized in that it comprises a material selected from metal materials, inorganic fibers, organic fibers and composite materials thereof. According to claim 1,
The organic compound is chloromethane, chloroethane, methyl ethyl ketone (MEK), acetic acid, isopropyl alcohol, n-hexane (n-Hexane), Chloroform, Benzene, Toluene, Ethylbenzene, Xylene, Propylene glycol monomethyl ether (PGME), Styrene, Propylene glycol monomethyl Epyl Acetate (Propylene Glycol Mnomethyl Ether Acetate; PGMEA), Hexamethyldisilazane (HMDS), Hexamethyldisiloxane (HMDSO), Ethyl 3-Ethoxypropionate, and Di Chemical filter comprising at least one selected from the group consisting of ethylene glycol diethyl ether (Diethylene Glycol Diethyl Ether). According to claim 1,
The average pore size of the first adsorbent is 20 mm 2, and the average pore size of the second adsorbent is 5 mm 2.

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