KR102312962B1 - Device and method for treating perfluoro compound by using reaction-separation simultaneous process - Google Patents

Abstract

The present invention relates to an apparatus and method for treating perfluorinated compounds in which a hydrolysis reaction of a perfluorinated compound and a HF removal reaction by an HF adsorbent are performed together in one reactor. A reactor and method for treating perfluoro compounds (PFCs) according to the present invention is a reaction for forming a calcium fluoride (CaF ₂ ) from a hydrolysis reaction of a perfluoro compound and HF formed from the hydrolysis reaction. by the carried out in the reactor, calcium fluoride (CaF ₂₎ through the reaction of forming becomes the forward reaction of the hydrolyzed predominantly by the laws in reusya wrong, as the HF consumption perfluorinated compound of the hydrolysis reaction in the reactor As the efficiency is improved, it is possible to form calcium fluoride useful as a resource.

Description

Device and method for treating perfluoro compound by using reaction-separation simultaneous process

The present invention relates to an apparatus and method for treating perfluorinated compounds through simultaneous reaction and separation processes.

Hazardous waste gases emitted from the semiconductor manufacturing process are emitted in a very diverse way according to each process, and most of them are highly volatile and consist of components that are harmful to the human body or have a high global warming potential, so their removal is required. Among them, perfluorocompound (PFC), a perfluorine compound that is mainly discharged from etching and deposition (CVD) processes of semiconductor processes, is very stable and difficult to remove. PFC compounds are more stable than CFC (chlorofluorocompound) used as a refrigerant, and have a problem of accumulation in the atmosphere when released because they have a large global warming potential and a very long decomposition time. PFCs emitted from semiconductor processes are increasing at a high rate every year. Therefore, since the effect of PFC generation on global warming is increasing, each country is gradually strengthening the regulation on PFC.

Various technologies for removing PFC compounds, particularly carbon-based PFC compounds, are under development, and can be divided into the field of separation and recovery using PSA and separation membrane and the field of decomposition and removal using plasma, combustion and catalyst.

First, the separation and recovery technology is a technology that separates and concentrates only PFC from the exhaust gas of a semiconductor process using a separation membrane or an adsorbent, and was developed by Air Products & Chemicals, Air Liquide, and the like in the United States. In the process _{, SiH 4} , TEOS, acid gas, etc. in the waste gas are removed by a prefilter, compressed with a compressor, passed through a HEPA filter to capture particulates, and passed through a molecular sieve It consists of a complicated process of finally separating and recovering PFC from a PSA unit using an adsorbent and a cooling method after removing moisture. The above technology is very attractive in terms of recycling the discarded PFC, but it is a situation in which the equipment cost and operating cost for separation and recovery cannot be ignored because it must go through several stages of process, and must be compressed and cooled. In addition, since it is contaminated with other impurities even after separation, it has a disadvantage that it can be recycled in a semiconductor process only after a purification process.

The decomposition and removal technology is a technology that decomposes and removes PFC compounds in various ways rather than recovering resources. The decomposition and removal technology can be broadly classified into three types: direct/indirect thermal decomposition, plasma decomposition, and catalytic decomposition. The direct/indirect thermal decomposition method is a technology that decomposes PFC by contacting it with oxygen either by direct heating with a combustion flame at a high temperature of 1000°C or higher or by using an electric heating furnace to decompose. There is an advantage that However, it has disadvantages that thermal NOx is generated due to low efficiency and to operate at a high temperature of 1000°C or higher. Plasma decomposition method is a technique for decomposing by flowing waste gas containing PFC after generating plasma in a high energy state using microwaves, high frequency, etc., and is known to be very effective in decomposing PFCs. However, when the gases are exposed to too high energy of the plasma, not only the PFC to be decomposed but also _{stable gases such as N 2} react with oxygen to produce an excess of NO _x . In addition, the problem is that plasma generation is good in He or Ar atmosphere, but _{it is difficult to generate plasma under N 2} , especially O ₂ environment, so the decomposition efficiency is sharply decreased.

The catalytic decomposition method is a technology to decompose difficult-to-decompose PFC at a low temperature of 800° C. or less using a catalyst, and low-temperature decomposition brings many advantages. If the catalytic method is used, the decomposition temperature can be significantly lowered, and the size of the scrubber can be greatly reduced and miniaturized by increasing the reaction activity. In addition, if the decomposition is performed at a low temperature of 800° C. or less, the advantage of reducing operating costs and securing the durability of the system due to continuous operation is easy, and the generation of thermal NO _{x resulting from N 2 present in the exhaust gas is reduced.} It has the advantage that it can be completely suppressed.

On the other hand, there have been attempts to develop a new alternative gas to reduce PFC emissions, but _{an alternative gas that is more efficient than CF 4} and superior in product quality has not been proposed as a gas used for etching silicon substrates during the semiconductor manufacturing process. _{Accordingly, CF 4} is used in most semiconductor manufacturing processes.

In the case of Korea, which is currently the world's No. 1 producer of semiconductor DRAM, it is predicted that the domestic semiconductor industry will be severely hit if the use of PFC is restricted. Therefore, the development of a technology for recovering or decomposing PFC gas generated in the semiconductor manufacturing process is urgently needed in terms of protecting the Korean semiconductor industry.

Therefore, it is necessary to develop an efficient PFC processing process applicable to the semiconductor manufacturing process.

It is an object of the present invention to provide an apparatus and method capable of efficient PFC treatment.

A first aspect of the present invention provides a reactor for treating perfluoro compounds (PFCs), comprising: a first compartment including a catalyst for hydrolysis of perfluoro compounds; and a second compartment comprising an HF adsorbent, wherein HF formed by hydrolysis of the perfluorinated compound is transferable from the first compartment to the second compartment.

A second aspect of the present invention provides a method for treating perfluoro compounds (PFCs) in the reactor of the first aspect, the reactor comprising: a first compartment equipped with a catalyst for hydrolysis of perfluorinated compounds; and a second compartment comprising an HF adsorbent, wherein the first step of hydrolyzing the perfluorinated compound in the first compartment to form HF; and a second step in which the HF formed in the first step is transferred to the second compartment and removed by the HF adsorbent.

A third aspect of the present invention is a method for producing calcium fluoride from perfluoro compounds (PFCs) in the reactor of the first aspect, wherein the reactor is a first compartment; and a second compartment comprising a HF adsorbent, wherein the first step of hydrolyzing the perfluorinated compound in the first compartment to form HF; and a second step in which the HF formed in the first step is transferred to the second compartment to form _{calcium fluoride (CaF 2 ) by the HF adsorbent.}

A fourth aspect of the present invention is a reactor for treating perfluoro compounds (PFCs), including a catalyst for hydrolysis of perfluorinated compounds and a mixture of an HF adsorbent in the reactor, This hydrolysis to form HF and provide a reactor characterized in that the formed HF is removed by the HF adsorbent.

A fifth aspect of the present invention is a method for treating perfluoro compounds (PFCs) in the reactor of the fourth aspect, comprising a catalyst for hydrolysis of perfluorinated compounds and a mixture of an HF adsorbent in the reactor a first step of hydrolyzing the perfluorinated compound by a catalyst for hydrolysis of the perfluorinated compound to form HF in the reactor; and a second step in which HF formed in the first step is removed by an HF adsorbent is provided.

A sixth aspect of the present invention is a method for producing calcium fluoride from perfluoro compounds (PFCs) in the reactor of the fourth aspect, a mixture of a catalyst for hydrolysis of perfluorinated compounds and an HF adsorbent in the reactor A first step of hydrolyzing the perfluorinated compound by a catalyst for hydrolysis of the perfluorinated compound to form HF in a reactor comprising: and a second step in which the HF formed in the first step forms _{calcium fluoride (CaF 2 ) by the HF adsorbent.}

Hereinafter, the present invention will be described in detail.

As used herein, the term “perfluoro compounds (PFCs)” refers to hydrocarbons composed of carbon and fluorine, which collectively refer to perfluorinated (-C _n F _2n+1 ) alkyl compounds in which fluorine is substituted for hydrogen. Concept. Specifically, the perfluorinated compound may be CF ₄ , CHF ₃ , C ₂ F ₆ , C ₃ F ₈ , C ₄ F ₈ , C ₄ F ₁₀ , C ₅ F ₈ , SF ₆ , NF ₃ or a combination thereof. .

In the semiconductor manufacturing process, it is impossible to confirm the process in detail due to internal circumstances, and it is impossible to introduce a new process for reusing etching gas and CVD gas in each process. As shown in FIG. 1, it is realistically possible to process acid gases through an alkali scrubber for various gases discharged from the PFC collection duct, and then to the following formula in the Regenerative Catalytic System (RCS). It is removed through a hydrolysis reaction expressed as

CF ₄ + 2H ₂ O → CO ₂ + 4HF

Acid gases including hydrofluoric acid (HF) are discharged after passing through an acid gas scrubber. However, hydrofluoric acid generated in hydrolysis causes serious corrosion problems in downstream processes including RCS, and in order to solve this problem, a process configuration using expensive materials is essential.

Recently, various studies are being conducted to reuse hydrofluoric acid, and in particular, a calcium fluoride formation reaction expressed by the following formula using hydrofluoric acid as a _{non-CO 2 process, that is, fluorite production research is in progress.}

CaO + 2HF → CaF ₂ + H ₂ O

However, this also requires the use of expensive materials to construct the fluorite manufacturing process. Therefore, it is necessary to develop a new process that can prevent hydrofluoric acid leakage from RCS and maximize RCS efficiency.

The present inventors performed the hydrolysis reaction of the perfluorinated compound and the reaction of forming calcium fluoride (CaF ₂ ) from hydrofluoric acid (HF) formed from the hydrolysis reaction in one reactor, by Le Chatelier's law, As HF is consumed through the reaction to form calcium fluoride (CaF ₂ ) in the reactor, the forward reaction of the hydrolysis becomes dominant, and it has been found that the efficiency of the hydrolysis reaction of the perfluoride compound can be improved. The present invention is based on this.

Accordingly, the reactor for treating perfluoro compounds (PFCs) according to the first aspect of the present invention ( FIGS. 2 and 3 ) includes a first compartment equipped with a catalyst for hydrolysis of perfluoro compounds; and a second compartment equipped with an HF adsorbent, wherein HF formed by hydrolysis of the perfluorinated compound can be transferred from the first compartment to the second compartment.

As HF, a result of the hydrolysis reaction of the perfluorinated compound, is removed by the HF adsorbent in the second compartment, the forward reaction of the hydrolysis reaction of the perfluorinated compound is dominant according to Le Chatelier's law, thereby increasing the efficiency of the hydrolysis reaction can be improved

The reactor for treating perfluoro compounds (PFCs) according to the first aspect of the present invention is a shell-and-tube type reactor, wherein the first compartment is a shell type and the second compartment is a tube type ( FIG. 2 ), or the first The compartment may be in the form of a tube and the second compartment may be in the form of a shell. The shell-and-tube type reactor preferably has a structure that can be modularized.

In addition, in the reactor for treating perfluoro compounds (PFCs) according to the first aspect of the present invention, the first compartment and the second compartment may be alternately stacked ( FIG. 3 ). Through such a layered structure, it is possible to separate the perfluorinated compound hydrolysis catalyst from the reactor, regenerate the catalyst, and then mount it back in the reactor or replace it with a new catalyst, and also easily separate calcium fluoride, a final product, from the reactor It can be retrieved and used.

Although HF can be transferred from the first compartment to the second compartment between the first compartment and the second compartment, it is preferable that a structure for physically separating the catalyst for the hydrolysis reaction of the first compartment and the HF adsorbent of the second compartment is provided. The structure may be a structure in the form of a net that can accommodate a catalyst for a hydrolysis reaction or an HF adsorbent.

In the present invention, the HF adsorbent or the second compartment provided with the HF adsorbent may be replaceable. Accordingly, the HF adsorbent obtained by adsorbing/catalyzing HF from the reactor can be separated and recovered and used as a resource, and a new HF adsorbent can be exchanged into the reactor.

The shell-and-tube type reactor for treating perfluorinated compounds as shown in FIG. 2 includes a tube having an HF adsorbent therein; and a shell having a catalyst for hydrolysis of the perfluorinated compound, wherein HF formed by hydrolysis of the perfluorinated compound introduced into the shell may be transferred to the HF adsorbent inside the tube.

In the present invention, the tube provided with the HF adsorbent may be a separation membrane capable of selectively permeating HF. In addition, the tubular membrane may also transmit _{CO 2 together with HF.}

In addition, the reactor for treating perfluoro compounds (PFCs) according to a fourth aspect of the present invention (FIG. 4) includes a catalyst for hydrolysis of perfluorinated compounds and a mixture of an HF adsorbent in the reactor, It is characterized in that the perfluorinated compound is hydrolyzed inside the reactor to form HF, and the formed HF is removed by the HF adsorbent.

In the reactor according to the present invention, the perfluorinated compound is hydrolyzed through a catalyst for hydrolysis reaction provided inside the reactor.

As a catalyst for the hydrolysis of the perfluorinated compound, a catalyst having a spinel structure and/or an aluminum phosphate catalyst having a composition _{of AB 2} O _{4 may be used.}

A catalyst having a spinel structure can be prepared using a co-precipitation method and an incipient wetness method.

The co-precipitation method is a method of preparing a catalyst having a spinel structure by dissolving two metal salts in the form of nitrate to be co-precipitated in water, adjusting the pH, drying and calcining after co-precipitation. For co-precipitation, Ni, Zn or Ma may be used as metal A, and Al or Cr may be used as metal B.

The initial wet method can be used when metal B constituting the spinel is insoluble, and a desired amount of metal A precursor to be supported is dissolved in water corresponding to the pore volume of metal B oxide, supported, dried and then fired. am. At this time, drying may be performed at 120° C. and calcination may be performed at 700° C. As metal A, Zn, Ni, Pd, Ti, Sn, Co, Zr, Ce, etc. may be used, and as metal B, alumina may be used. Specifically, as the catalyst, aluminum oxide (Al ₂ O ₃ ) having a composition of 80 wt% and nickel oxide (NiO) of 20 wt% may be used.

A phosphate-based catalyst containing aluminum _{is dissolved in water at a desired ratio, Al(NO 3} ) ₃ .9H ₂ O, and NH ₄ H ₂ PO ₄ to be supported, followed by an evaporation method of evaporating water as a solvent ( It is a method of manufacturing using evaporation). In addition, the catalyst produced after the evaporation may be dried at 180° C. and calcined at 800° C.

For the hydrolysis reaction, water may be introduced into the reactor from the outside. Water may be supplied through a source separately provided outside the reactor, and may be heated through a heat exchanger before being introduced into the reactor and supplied in the form of water vapor. Preferably, pure water is used as the water supplied into the reactor, and the supply amount can be adjusted in consideration of the hydrolysis reaction formula.

From the hydrolysis reaction the perfluorinated compound can form HF. In addition, it may be _{accompanied with HF to form CO 2} and/or SO ₃ and the like depending on the type of the perfluorinated compound.

Specifically, when the perfluorinated compound is CF ₄ , as described above, HF may be formed according to the following reaction formula.

CF ₄ + 2H ₂ O → CO ₂ + 4HF

When the perfluorinated compound is CHF ₃ , HF may be formed according to the following reaction scheme.

CHF ₃ + (1/2)O ₂ + H ₂ O → CO ₂ + 3HF

When the perfluorinated compound is C ₂ F ₆ , HF may be formed according to the following reaction scheme.

C ₂ F ₆ + 3H ₂ O + (1/2)O ₂ → 2CO ₂ + 6HF

When the perfluorinated compound is SF ₆ , HF may be formed according to the following reaction scheme.

SF ₆ + 3H ₂ O → SO ₃ + 6HF

In the present invention, the reactor internal temperature may be preferably 600 to 750 ℃, more preferably 600 to 700 ℃, most preferably 650 ℃.

In the conventional reactor for treating perfluorinated compounds, the reaction temperature during the hydrolysis reaction of the perfluorinated compound is a temperature at which most of the perfluorinated compounds can be hydrolyzed, that is, a temperature that can represent a decomposition rate of approximately 100%, and a temperature of 750 ° C. in need. _{However, in the present invention, by performing the hydrolysis reaction of the perfluoride compound and the reaction of forming calcium fluoride (CaF 2} ) from hydrofluoric acid (HF) in one reactor, the efficiency of the hydrolysis reaction is improved, so that even at a level of 600 ° C. It may represent a decomposition rate of % or more, and at a level of 650° C., it may represent a decomposition rate of 95% or more ( FIG. 5 ). Therefore, the present invention can lower the internal temperature of the reactor and exhibit an energy saving effect due to the reduction in the amount of heat.

In the present invention, the HF adsorbent may be a catalyst or reactant capable of forming water (H ₂ O) or carbon dioxide (CO _{2 ) together with calcium fluoride (CaF 2 ) from HF.}

In the present invention, the HF adsorbent is a calcium salt capable of generating calcium fluoride by adsorbing HF, and may be calcium oxide (CaO), calcium carbonate (CaCO ₃ ), or a combination thereof, but is not limited thereto. The HF adsorbent may be in the form of powder or pellets, and the pellet form is preferable in consideration of ease of handling. The pellets may be formed in a cylindrical shape or a spherical shape, but is not limited thereto. Specifically, in the present invention, spherical pellets of calcium oxide (CaO) were used.

When the HF adsorbent is calcium oxide (CaO), calcium fluoride may be formed by the following reaction.

CaO + 2HF → CaF ₂ + H ₂ O

When the HF adsorbent is calcium carbonate (CaCO ₃ ), calcium fluoride may be formed by the following reaction.

CaCO ₃ + 2HF → CaF ₂ + H ₂ O + CO ₂

In the present invention, the material of the reactor may be preferably stainless steel or inconel material in consideration of the high temperature of the hydrolysis reaction.

According to a second aspect of the present invention, the method of treating perfluoro compounds (PFCs) in the reactor of the first aspect comprises:

a first step of hydrolyzing the perfluorinated compound in the first compartment to form HF; and

and a second step in which the HF formed in the first step is transferred to a second compartment and removed by the HF adsorbent.

According to the third aspect of the present invention, the method for producing calcium fluoride from perfluoro compounds (PFCs) in the reactor of the first aspect is

a first step of hydrolyzing the perfluorinated compound in the first compartment to form HF; and

and a second step in which the HF formed in the first step is transferred to the second compartment to form _{calcium fluoride (CaF 2 ) by the HF adsorbent.}

According to the fifth aspect of the present invention, the method of treating perfluoro compounds (PFCs) in the reactor of the fourth aspect is

a first step of hydrolyzing the perfluorinated compound by the catalyst for hydrolysis of the perfluorinated compound to form HF in a reactor having a mixture of a catalyst for hydrolysis of the perfluorinated compound and an HF adsorbent inside the reactor; and a second step in which the HF formed in the first step is removed by an HF adsorbent.

A sixth aspect of the present invention is a method for producing calcium fluoride from perfluoro compounds (PFCs) in the reactor of the second aspect

a first step of hydrolyzing the perfluorinated compound by the catalyst for hydrolysis of the perfluorinated compound to form HF in a reactor having a mixture of a catalyst for hydrolysis of the perfluorinated compound and an HF adsorbent inside the reactor; And HF formed in the first step is characterized in that the second step is performed to form _{calcium fluoride (CaF 2 ) by the HF adsorbent.}

The first step is a step in which the perfluorinated compound is hydrolyzed by a catalyst for hydrolysis of the perfluorinated compound provided in the reactor to form HF.

The types of the perfluorinated compound and catalyst and the conditions for the hydrolysis reaction are the same as those described in the reactor.

The second step is a step in which the HF formed in the first step is removed by the HF adsorbent, or the HF formed in the first step is formed by the HF adsorbent to form _{calcium fluoride (CaF 2 ).}

In the second step, the HF adsorbent may form water or carbon dioxide from HF. Specifically, as described above, in the present invention, when the HF adsorbent is calcium oxide (CaO) and/or calcium carbonate (CaCO ₃ ), water or carbon dioxide can be formed with calcium fluoride by the following reactions. have.

CaO + 2HF → CaF ₂ + H ₂ O

CaCO ₃ + 2HF → CaF ₂ + H ₂ O + CO ₂

Calcium fluoride (CaF ₂ ) is also called calcium fluoride, and is called fluorite as a mineral. The pure calcium fluoride is white, and the fluorine escaped from the lattice is purple because of the F-center. Calcium fluoride has a property of transmitting infrared or ultraviolet rays well, so it is widely used for manufacturing optical devices and is a useful resource material used as a solvent and raw material for fluorine compounds.

Therefore, when the method for producing calcium fluoride of the present invention is used, calcium fluoride, a useful resource material, that is, formation, can be produced from perfluoride compounds in exhaust gas from semiconductor processes, etc., and thus there is an advantage in terms of efficient resource reuse.

Preferred embodiments of the present invention will be described in detail with reference to the drawings to the extent that those of ordinary skill in the art to which the present invention pertains can easily carry out the present invention.

Hereinafter, the configuration of a shell-and-tube type reactor for treating perfluoro compounds (PFCs) according to an embodiment of the present invention will be described.

2 is a conceptual diagram schematically showing the structure of a shell-and-tube type reactor for treating perfluorinated compounds according to an embodiment of the present invention.

2, the shell-and-tube type reactor 100 for treating perfluorinated compounds according to an embodiment of the present invention includes an HF adsorbent 101 therein, and a tubular separation membrane 102 for permeating HF; and a shell 104 having a catalyst 103 for the hydrolysis reaction of perfluoro compounds (PFCs), wherein HF formed by hydrolysis of the perfluorinated compound introduced into the shell 104 is a tubular separation membrane (102) has a structure that can be delivered to the inside of the tubular separator.

_{When water (H 2} O) is introduced into the reactor along with a perfluorinated compound such as _{CF 4} , the perfluorinated compound is hydrolyzed inside the shell to form HF, and the HF formed as described above is delivered to the inside of the tube It reacts with calcium oxide (CaO), an HF adsorbent in the tube, to form _{calcium fluoride (CaF 2 ).}

The calcium fluoride formed in the tube of the reactor can be easily separated out of the reactor by separating the tube from the reactor, and the separated calcium fluoride can be usefully used as a resource.

In addition, water and carbon dioxide generated from the hydrolysis reaction and the calcium fluoride formation reaction may be discharged from the reactor. At this time, the water may be circulated back into the reactor to be recycled.

3 is a conceptual diagram schematically showing the structure of a reactor for treating a perfluorinated compound according to another embodiment of the present invention.

Referring to FIG. 3 , the reactor 200 for treating perfluorinated compounds according to an embodiment of the present invention includes a first compartment 204 having a catalyst 203 for hydrolysis of perfluoro compounds (PFCs). ); and a second compartment (202) having an HF adsorbent (201), wherein HF formed by hydrolysis of the perfluorinated compound has a structure in which HF can be transferred from the first compartment (204) to the second compartment (202) . At this time, the first compartment 204 and the second compartment 202 are alternately stacked, so that the perfluorinated compound hydrolysis catalyst is separated from the reactor to regenerate the catalyst and then installed in the reactor again or replaced with a new catalyst. It is possible, and calcium fluoride, which is a final product, can be easily separated and recovered from the reactor and used.

4 is a conceptual diagram schematically showing the structure of a reactor for treating a perfluorinated compound according to another embodiment of the present invention.

Referring to FIG. 4 , the reactor 300 for treating perfluorinated compounds according to an embodiment of the present invention includes a catalyst 303 and an HF adsorbent 301 for hydrolysis of perfluoro compounds (PFCs) in the reactor. ), the perfluorinated compound is hydrolyzed in the reactor to form HF, and the formed HF reacts with the HF adsorbent 301 to be removed. At this time, the HF formed inside the reactor 300 may be removed while forming calcium fluoride by reacting with the HF adsorbent 301 .

The reactor and method for treating perfluoro compounds (PFCs) of the present invention is a reaction for forming calcium fluoride (CaF ₂ ) from the hydrolysis reaction of the perfluoro compound and the HF formed from the hydrolysis reaction as one By carrying out in the reactor, according to Le Chatelier's law, _{as HF is consumed through the reaction to form calcium fluoride (CaF 2} ) in the reactor, the forward reaction of the hydrolysis becomes dominant, so that the hydrolysis reaction efficiency of the perfluorinated compound As this is improved, calcium fluoride useful as a resource can be formed, which has a useful advantage in terms of energy use efficiency and resource recycling of the entire process.

1 is a conceptual diagram schematically illustrating a method of removing various types of gas discharged from a conventional PFC collection duct with an Alkali Scrubber and a Regenerative Catalytic System (RCS).
2 is a conceptual diagram schematically showing the structure of a shell-and-tube type reactor for treating perfluorinated compounds according to an embodiment of the present invention.
3 is a conceptual diagram schematically showing the structure of a reactor for treating a perfluorinated compound according to another embodiment of the present invention.
4 is a conceptual diagram schematically showing the structure of a reactor for treating a perfluorinated compound according to another embodiment of the present invention.
5 is a result of analyzing the operating efficiency of the shell-and-tube type reactor for treating perfluorinated compounds of the present invention.

Hereinafter, a method for removing perfluoro compounds and/or preparing calcium fluoride using the reactor for treating perfluoro compounds (PFCs) of the present invention will be described in more detail through specific examples. However, these examples are for illustrative purposes only, and the scope of the present invention is not limited to these examples.

Example 1: of the present invention overpayment Fabrication of shell-and-tube reactor for compound processing

As shown in FIG. 2 , a shell-and-tube type reactor for treating perfluorinated compounds according to an embodiment of the present invention was manufactured.

Experimental example 1: of the present invention overpayment Investigation of operating efficiency of shell-and-tube reactor for compound treatment

In order to evaluate the operating efficiency of the shell-and-tube type reactor for treating perfluorinated compounds prepared in Example 1, hydrolysis of perfluorinated compounds was performed in the reactor and the conversion of _{CF 4 according to temperature was investigated.}

Specifically, as conditions for the hydrolysis of the perfluorinated compound, CF ₄ injection concentration was 1,000 ppm, water vapor injection concentration was 2,000 ppm, and the remaining gas was nitrogen (N ₂ ).

_{For comparison, as a control, the CF 4} conversion was investigated by performing only the hydrolysis of the perfluorinated compound under the same conditions without putting the HF adsorbent inside the tube of the shell-and-tube type reactor shown in FIG. 2 .

The CF _{4 conversion rate represents the ratio of CF 4} converted by the initial CF ₄ hydrolysis reaction and was calculated by the following formula.

The results are shown in Table 1 and FIG. 5 below.

Temperature (K) Control (No sorption) The present invention (Sorption) Increase (%) 873 65.65 86.05 37.4 923 81.01 96.39 19.0 973 92.77 99.5 7.3 1023 97.93 100 2.1

Referring to Table 1 and FIG. 5, when the hydrolysis reaction of the perfluorinated compound and the HF adsorption reaction are carried out together with the HF adsorbent in the reactor as in the present invention, compared to the case where only the hydrolysis of the perfluorinated compound is carried out, each It can be seen that the conversion rate of _{CF 4} increases with each temperature. _{In particular, it can be seen that there was an increase in the CF 4} conversion rate of about 37.4% at 600 °C, and the increase was decreased when going to a high temperature.

In conclusion, it can be seen that when the hydrolysis reaction of the perfluoride compound and the HF adsorption reaction are carried out together, the _{conversion rate of CF 4 is improved, and the production of calcium fluoride (CaF 2} ) can also be improved due to the improvement of the HF yield.

In addition, it shows a high CF ₄ conversion of 96.39% even at 650 ° C. It can be confirmed that the internal temperature of the reactor is lowered by about 100 ° C compared to the 750 ° C level of the conventional reactor for treating perfluorinated compounds, thereby exhibiting the energy saving effect due to the reduction in calorific value. .

Claims (17)

In the reactor for treating perfluoro compounds (PFCs),
a first compartment equipped with a catalyst for hydrolysis of perfluorinated compounds; and
and a second compartment equipped with an HF adsorbent,
HF formed by hydrolysis of the perfluorinated compound is transferable from the first compartment to the second compartment,
The reactor is a shell-and-tube reactor, wherein the first compartment is provided in the form of a shell, and the second compartment is provided in the form of a tube,
The second compartment includes a tubular separation membrane that selectively permeates the HF generated in the first compartment,
wherein the second compartment is a tube detachable from the reactor.
delete delete According to claim 1, wherein HF between the first compartment and the second compartment is transferable from the first compartment to the second compartment, but a structure that physically separates the catalyst for the hydrolysis reaction of the first compartment and the HF adsorbent of the second compartment A reactor characterized in that it is equipped.
The reactor of claim 1 , wherein the HF adsorbent is capable of forming _{calcium fluoride (CaF 2 ) from HF.}
The reactor of claim 1 , wherein the HF adsorbent is capable of forming water or carbon dioxide from HF.
The reactor of claim 1, wherein the HF adsorbent is calcium oxide (CaO), calcium carbonate (CaCO ₃ ), or a combination thereof.
◈Claim 8 was abandoned when paying the registration fee.◈ The reactor according to claim 1, wherein by removing HF from the HF adsorbent in the second compartment, the efficiency of the hydrolysis reaction of the perfluorinated compound in the first compartment is improved according to Le Chatelier's law.
The reactor of claim 1 , wherein the HF adsorbent or the second compartment with the HF adsorbent is replaceable.
◈Claim 10 was abandoned when paying the registration fee.◈ The reactor according to claim 1, wherein the shell-and-tube type reactor has a structure that can be modularized.
In the method of treating perfluoro compounds (PFCs) in the reactor according to claim 1,
The reactor is
a first compartment equipped with a catalyst for hydrolysis of perfluorinated compounds; and
and a second compartment equipped with an HF adsorbent,
a first step of hydrolyzing the perfluorinated compound in the first compartment to form HF; and
and a second step in which the HF formed in the first step is transferred to a second compartment and removed by the HF adsorbent.
12. The method of claim 11,
A treatment method characterized in that in the second step, HF _{forms calcium fluoride (CaF 2 ) together with the HF adsorbent.}
Process according to claim 11, characterized in that in the second step water or carbon dioxide is formed from HF by means of an HF adsorbent.
In the method for producing calcium fluoride from perfluoro compounds (PFCs) in the reactor according to claim 1,
The reactor is
a first compartment equipped with a catalyst for hydrolysis of perfluorinated compounds; and
and a second compartment equipped with an HF adsorbent,
a first step of hydrolyzing the perfluorinated compound in the first compartment to form HF; and
and a second step in which the HF formed in the first step is transferred to the second compartment to form _{calcium fluoride (CaF 2 ) by the HF adsorbent.} delete delete delete

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