Process and device for purifying high-purity acetic acid

Abstract

The invention provides a process and a device for purifying high-purity acetic acid. The high-purity acetic acid produced by combining the technological processes of crude distillation, adsorption, rectification and filtration with the equipment disclosed by the invention is high in yield and stable in product quality. Particularly, a modified SAPO-34 adsorbent is adopted in the adsorption process, and micropores, mesopores and macropores cooperate for adsorption, so that organic impurities such as 2-butenal, 2-ethyl-2-butenal, acetaldehyde and the like are efficiently removed.

Description

Technical Field

[0001] The invention belongs to the technical field of electronic-grade chemical preparation, and in particular relates to a purification process and a device for high-purity acetic acid. Background Art

[0002] Electronic grade acetic acid is one of the wet electronic chemicals used in the microelectronics industry. It can be used to clean silicon wafers, effectively remove impurity particles, inorganic residues and carbon deposits on the wafers, and is widely used in the production of photovoltaic solar cells, flat panel displays, integrated circuits and other electronic components.

[0003] During the production, transportation and storage of acetic acid, due to raw materials and equipment reasons, some metal ions, dust particles, unreacted raw materials and intermediate products are inevitably introduced into the product, and these impurities can easily lead to the generation of staggered layers, resulting in PN combined leakage current, breakdown, etc. For integrated circuits with smaller line widths, in addition to very few metal ions and particles that may destroy the entire circuit, organic matter in the solvent, such as aldehydes (strongly reducible), etc., also affect the performance of the circuit. Therefore, with the rapid development of integrated circuits, the requirements for the purity of electronic-grade reagents are getting higher and higher. How to effectively remove metal ions, dust particles and organic impurities is a technical problem that needs to be solved urgently. For acetic acid, since its impurities such as 2-butenal and 2-ethyl-2-butenal easily form azeotropes with water, how to efficiently remove moisture and organic impurities is also a topic that needs to be overcome urgently.

[0004] CN114989005A discloses a method for preparing electronic-grade acetic acid, comprising the following steps: step 1: using ion exchange resin to remove part of the metal ions in the initial industrial-grade acetic acid; step 2: further distilling the acetic acid obtained in step 1; step 3: purifying and filtering the distilled acetic acid again with ion exchange resin to obtain the electronic-grade acetic acid. The process is simple, but the water removal effect cannot meet the needs of high-purity acetic acid, and does not involve the removal of azeotropic organic impurities.

[0005] CN102399140A discloses a method for producing ultrapure electronic-grade acetic acid, which combines membrane filtration, distillation and rectification, conveniently and effectively removes metal ions and solid particles, can prepare ultrapure electronic-grade acetic acid, and is simple to operate, has low energy consumption and high safety. It includes the following steps: a method for producing ultrapure electronic-grade acetic acid, which combines membrane filtration, distillation and rectification. Step 2, filter the fraction collected in step 1 using a 0.05-0.3 μm pore size filter membrane. Step 3, at 125-135°C, perform atmospheric distillation on the filtrate; collect the fraction at 117.5-118.5°C. Step 4, filter the fraction collected in step 3 using a 0.05-0.3 μm pore size filter membrane, collect the filtrate, and obtain the ultrapure electronic-grade acetic acid. It uses a β-cyclodextrin composite membrane for filtration, has low filtration efficiency, is not conducive to industrial production, and does not involve the removal of azeotropic organic impurities.

[0006] In the existing disclosed preparation process, the removal efficiency of impure metals, particles, organic impurities and moisture is low, which cannot meet the production of high-grade electronic-grade acetic acid and the needs of large-scale production. Summary of the invention

[0007] The present invention provides a purification process and device for high-purity acetic acid, aiming to provide a new and efficient method for reducing the content of impurities such as metals, particles, and water in electronic-grade acetic acid and improving the quality of acetic acid.

[0008] The purpose of the present invention is to overcome the deficiencies in the prior art and provide a purification process for high-purity acetic acid. To achieve the above technical objectives, the technical solution adopted by the present invention is: a purification process for high-purity acetic acid, comprising the following steps:

[0009] (1) Crude distillation: Using industrial acetic acid as raw material, the moisture content is controlled to be less than or equal to 3% after crude distillation.

[0010] (2) Adsorption: The temperature of the crude distilled acetic acid was controlled at 40-50°C and adsorbed using a modified SAPO-34 adsorbent.

[0011] (3) Distillation: The adsorbed acetic acid enters a distillation tower to obtain distillation components;

[0012] (4) The fraction is cooled and filtered to obtain high-purity acetic acid.

[0013] The pore structure of the modified adsorbent is as follows: the micropore diameter is 0.2-0.5 nm, the mesopore diameter is 2-30 nm, the macropore diameter is 60-90 nm, and the specific surface area is 500-600 m 2 / g.

[0014] More preferably, the micropore diameter is 0.38-0.5 nm and the pore volume is 0.25-0.28 cm 3 / g, the mesopore diameter is 15-30nm, and the pore volume is 0.07-0.08cm 3 / g, the macropore diameter is 80-90nm, and the pore volume is 0.04-0.06cm 3 / g, with a specific surface area of ​​500-600m 2 / g.

[0015] Optionally, the modified adsorbent is prepared by post-treating the SAPO-34 molecular sieve with a modifier containing a base.

[0016] Optionally, the modifier includes tetramethylammonium hydroxide and a surfactant, and the treatment temperature is 80-100°C.

[0017] The concentration of the alkali is 0.05-0.3 mol / L, and the concentration of the surfactant is 1-3 g / L.

[0018] Optionally, the surfactant is one or both of fatty acid methyl ester sulfonate and fatty alcohol polyether sulfate.

[0019] Optionally, the concentration of the high-purity acetic acid is greater than or equal to 99.00%.

[0020] Optionally, the filter uses an electronic grade filter for filtering.

[0021] Optionally, a cation exchange process is provided after step (2).

[0022] Preparation method of modified adsorbent:

[0023] SAPO-34 molecular sieve is used as raw material, mixed in an aqueous solution of tetramethylammonium hydroxide (0.05-0.3 mol / L) and a surfactant, mixed at 80-100° C. for 2-12 hours, and the treated SAPO-34 is filtered and separated, and then washed and dried before use.

[0024] SAPO-34 molecular sieve is a microporous molecular sieve with a crystal structure similar to chabazite. It is a small-pore zeolite with a pore size between 0.2-0.5nm. After being treated with an aqueous solution of an organic base and a surfactant, a tertiary pore structure can be obtained, including mesopores with a pore size of 2-30nm and macropores with a pore size of 60-90nm.

[0025] Optionally, the distillation conditions are: the number of tower plates is greater than or equal to 45, the top pressure is 0.21-0.3 MPa, the top temperature is 120-128°C, the bottom pressure is 0.29-0.36 MPa, the bottom temperature is 142-147°C, and the reflux ratio is 5-10.

[0026] The present invention adopts a modified adsorbent for adsorption after crude distillation. The adsorbent has excellent adsorption properties not only for water, but also for organic impurities in acetic acid such as acetaldehyde, 2-butenal, 2-ethyl-2-butenal, etc., especially for the adsorption of 2-butenal and 2-ethyl-2-butenal, which can solve the problem that distillation cannot effectively remove some organic impurities.

[0027] Another aspect of the present invention is the use of the modified SAPO-34 molecular sieve prepared by the above method in removing 2-butenal and 2-ethyl-2-butenal from acetic acid solvent.

[0028] The present invention also provides an acetic acid production device, comprising a crude distillation device, a cooling device, a first modified SAPO-34 adsorption column, a second modified SAPO-34 adsorption column, a rectification device, a filter, and a container connected in sequence, wherein the first modified SAPO-34 adsorption column and the second modified SAPO-34 adsorption column are connected in parallel, and the adsorption columns are filled with modified SAPO-34 adsorbents, and the pore structure of the adsorbent is: micropore diameter is 0.2-0.5nm, mesopore diameter is 2-30nm, macropore diameter is 60-90nm, and specific surface area is 500-600m 2 / g.

[0029] Preferably, the filter is an electronic grade filter.

[0030] Preferably, the pore structure of the modified adsorbent is: the micropore diameter is 0.38-0.5 nm, the pore volume is 0.25-0.28 cm 3 / g, the mesopore diameter is 15-30nm, and the pore volume is 0.07-0.08cm 3 / g, the macropore diameter is 80-90nm, and the pore volume is 0.04-0.06cm 3 / g, with a specific surface area of ​​500-550m 2 / g.

[0031] In order to further reduce the cation content, a cation exchange column can be arranged after the adsorption column.

[0032] Compared with the prior art, the present invention has the following advantages and beneficial effects.

[0033] (1) The process flow and equipment used in the present invention have high yield and stable product quality, are convenient for industrial production, and are highly practical. The number of distillation steps is reduced, energy consumption is reduced, and the separation process is simple, without causing additional environmental pollution.

[0034] (2) The present invention uses a specific modified adsorbent for adsorption. The crystal structure of SAPO-34 molecular sieve is similar to that of chabazite, which is a small-pore zeolite. After modification, it has a multiple pore structure, a large specific surface area, and good water adsorption. The multi-mesoporous structure cooperates with each other to effectively remove organic impurities in acetic acid and avoid the problem that organic-water azeotropes cannot be separated by distillation. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 It is a purification device for high-purity acetic acid, wherein: 1 - a crude distillation device; 2 - a condensation device; 3 - a first modified SAPO-34 adsorption column; 4 - a second modified SAPO-34 adsorption column; 5 - a rectification device; 6 - a filter; and 7 - a container. DETAILED DESCRIPTION

[0036] The following embodiments are merely examples covered by the present invention and do not constitute any limitation to the scope of implementation.

[0037] Example 1

[0038] A purification process for high-purity acetic acid, which uses Figure 1 This is achieved by the device shown.

[0039] Specifically, industrial-grade acetic acid with a concentration of 70% is distilled using a crude distillation device 1, and a fraction of 118-119°C is collected, and the moisture content is controlled to be less than 1%. The fraction is cooled to 50°C by a cooling device and supplied to an adsorption column filled with a modified SAPO-34 adsorbent, wherein a first modified SAPO-34 adsorption column 3 and a second modified SAPO-34 adsorption column 4 are connected in parallel, and a control valve flows to two adsorption columns or one of the adsorption columns. The adsorbed acetic acid liquid enters a distillation device 5, and the distillation conditions are: 60 plates, a tower top pressure of 0.21MPa, a tower top temperature of 120°C, a tower bottom pressure of 0.29MPa, a tower bottom temperature of 142 degrees Celsius, and a reflux ratio of 4. After the acetic acid flows out from the top of the tower, it is filtered through an electronic grade filter 6 to obtain high-purity acetic acid.

[0040] The first modified SAPO-34 adsorption column 3 and the second modified SAPO-34 adsorption column 4 can be used simultaneously or separately. When the adsorption column is dehydrated and regenerated, only one adsorption column can be used to improve production efficiency.

[0041] The first modified SAPO-34 adsorption column 3 and the second modified SAPO-34 adsorption column 4 are both filled with an organic base-modified adsorbent, and the specific preparation method is as follows:

[0042] The SAPO-34 adsorbent was mixed in an aqueous solution of tetramethylammonium hydroxide (0.15 mol / L) and a surfactant, sodium fatty acid methyl ester sulfonate (1 g / L), at 85°C for 6 hours. The treated SAPO-34 was separated by filtration and then washed and dried before use.

[0043] The specific surface area of ​​the modified adsorbent is 531.79m 2 / g, containing micropores of 0.38-0.5nm and a pore volume of 0.28g / cm 3 , mesopores with pore diameters of 15-20 nm and pore volumes of 0.08 g / cm 3 , macropores with a pore size of 80-90 nm and a pore volume of 0.04 g / cm 3 .

[0044] For pore volume calculation, the conventional mercury porosimetry method in the art was used to evaluate the volume of macropores, and the nitrogen physical adsorption method was used to test the volume of micropores and mesopores.

[0045] Example 2

[0046] A purification process for high-purity acetic acid, which uses Figure 1 This is achieved by the device shown.

[0047] Specifically, industrial-grade acetic acid with a concentration of 70% is distilled using a crude distillation device 1, and a fraction of 118-119°C is collected, and the moisture content is controlled to be less than 1%. The fraction is cooled to 45°C by a cooling device and supplied to an adsorption column filled with a modified SAPO-34 adsorbent, wherein a first modified SAPO-34 adsorption column 3 and a second modified SAPO-34 adsorption column 4 are connected in parallel, and a control valve flows to two adsorption columns or one of the adsorption columns. The adsorbed acetic acid liquid enters a distillation device 5, and the distillation conditions are: 65 plates, a tower top pressure of 0.21MPa, a tower top temperature of 120°C, a tower bottom pressure of 0.29MPa, a tower bottom temperature of 142 degrees Celsius, and a reflux ratio of 5. After the acetic acid flows out from the top of the tower, it is filtered through an electronic grade filter to obtain high-purity acetic acid.

[0048] The first modified SAPO-34 adsorption column 3 and the second modified SAPO-34 adsorption column 4 are both filled with an organic base-modified adsorbent, and the specific preparation method is as follows:

[0049] The SAPO-34 adsorbent was mixed in an aqueous solution of tetramethylammonium hydroxide (0.3 mol / L) and a surfactant, sodium fatty acid methyl ester sulfonate (2 g / L), at 100°C for 5 hours. The treated SAPO-34 was separated by filtration and then washed and dried before use.

[0050] The specific surface area of ​​the modified adsorbent is 511.68m 2 / g, containing micropores of 0.38-0.5nm and a pore volume of 0.25cm 3 / g, mesopores with pore diameter of 20-30nm and pore volume of 0.07cm 3 / g, macropores with a pore size of 80-90 nm and a pore volume of 0.06 cm 3 / g.

[0051] Example 3

[0052] A purification process for high-purity acetic acid, the device used and Figure 1 The difference is that a cation exchange column is arranged after the adsorption column.

[0053] Specifically, industrial-grade acetic acid with a concentration of 70% is distilled using a crude distillation device 1, and a fraction of 118-119°C is collected, and the moisture content is controlled to be less than 1%. The fraction is cooled to 50°C by a cooling device and supplied to an adsorption column filled with a modified SAPO-34 adsorbent, wherein a first modified SAPO-34 adsorption column 3 and a second modified SAPO-34 adsorption column 4 are connected in parallel, and a control valve flows to two adsorption columns or one of the adsorption columns. The adsorbed acetic acid liquid enters a distillation device 5 after passing through a cation exchange column, and the distillation conditions are: 60 plates, a tower top pressure of 0.21MPa, a tower top temperature of 120°C, a tower bottom pressure of 0.29MPa, a tower bottom temperature of 142 degrees Celsius, and a reflux ratio of 4. After the acetic acid flows out from the top of the tower, it is filtered through an electronic grade filter to obtain high-purity acetic acid.

[0054] The first modified SAPO-34 adsorption column 3 and the second modified SAPO-34 adsorption column 4 can be used simultaneously or separately. When the adsorption column is dehydrated and regenerated, only one adsorption column can be used to improve production efficiency.

[0055] The first modified SAPO-34 adsorption column 3 and the second modified SAPO-34 adsorption column 4 are both filled with an organic base-modified adsorbent, and the specific preparation method is as follows:

[0056] The SAPO-34 adsorbent was mixed in an aqueous solution of tetramethylammonium hydroxide (0.15 mol / L) and a surfactant, sodium fatty acid methyl ester sulfonate (1 g / L), at 85°C for 6 hours. The treated SAPO-34 was separated by filtration and then washed and dried before use.

[0057] The specific surface area of ​​the modified adsorbent is 531.79m 2 / g, containing micropores of 0.38-0.5nm and a pore volume of 0.28g / cm 3 , mesopores with pore diameters of 15-20 nm and pore volumes of 0.08 g / cm 3 , macropores with a pore size of 80-90 nm and a pore volume of 0.04 g / cm3 .

[0058] Comparative Example 1

[0059] A purification process for high-purity acetic acid, which uses Figure 1 This is achieved by the device shown.

[0060] Specifically, industrial-grade acetic acid with a concentration of 70% is distilled using a crude distillation device 1, and a fraction of 118-119°C is collected, and the moisture content is controlled to be less than 1%. The fraction is cooled to 50°C by a cooling device and supplied to an adsorption column filled with SAPO-34 adsorbent, wherein the first SAPO-34 adsorption column 3 and the second SAPO-34 adsorption column 4 are connected in parallel, and the control valve flows to the two adsorption columns or one of the adsorption columns. The adsorbed acetic acid liquid enters the distillation device 5, and the distillation conditions are: 60 plates, 0.21MPa tower top pressure, 120°C tower top temperature, 0.29MPa tower bottom pressure, 142°C tower bottom temperature, and reflux ratio of 4. After the acetic acid flows out from the top of the tower, it is filtered through an electronic grade filter to obtain high-purity acetic acid.

[0061] The first SAPO-34 adsorption column 3 and the second SAPO-34 adsorption column 4 can be used simultaneously or separately. When the adsorption column is dehydrated and regenerated, only one adsorption column can be used to improve production efficiency.

[0062] The first SAPO-34 adsorption column 3 and the second SAPO-34 adsorption column 4 are both filled with adsorbent that has not been treated with alkali.

[0063] The specific surface area of ​​the adsorbent is 572.78m 2 / g, containing micropores of 0.38-0.5 nm and a pore volume of 0.34 cm 3 / gComparative Example 2

[0064] A purification process for high-purity acetic acid, which uses Figure 1 This is achieved by the device shown.

[0065] Specifically, industrial-grade acetic acid with a concentration of 70% is distilled using a crude distillation device 1, and a fraction of 118-119°C is collected, and the moisture content is controlled to be less than 1%. The fraction is cooled to 50°C by a cooling device and supplied to an adsorption column filled with a modified SAPO-34 adsorbent, wherein a first modified SAPO-34 adsorption column 3 and a second modified SAPO-34 adsorption column 4 are connected in parallel, and a control valve flows to two adsorption columns or one of the adsorption columns. The adsorbed acetic acid liquid enters a distillation device 5, and the distillation conditions are: 60 plates, a tower top pressure of 0.21MPa, a tower top temperature of 120°C, a tower bottom pressure of 0.29MPa, a tower bottom temperature of 142 degrees Celsius, and a reflux ratio of 4. After the acetic acid flows out from the top of the tower, it is filtered through an electronic grade filter to obtain high-purity acetic acid.

[0066] The first modified SAPO-34 adsorption column 3 and the second modified SAPO-34 adsorption column 4 can be used simultaneously or separately. When the adsorption column is dehydrated and regenerated, only one adsorption column can be used to improve production efficiency.

[0067] The first modified SAPO-34 adsorption column 3 and the second modified SAPO-34 adsorption column 4 are both filled with an organic base-modified adsorbent, and the specific preparation method is as follows:

[0068] The SAPO-34 adsorbent was mixed in a tetramethylammonium hydroxide (0.15 mol / L) aqueous solution at 85° C. for 6 hours. The treated SAPO-34 was separated by filtration and then washed and dried before use.

[0069] The specific surface area of ​​the modified adsorbent is 498.76m 2 / g, containing micropores of 0.38-0.5nm and a pore volume of 0.24g / cm 3 , mesopores with pore diameters of 15-20 nm and pore volumes of 0.02 g / cm 3 , macropores with a pore size of 95-100 nm and a pore volume of 0.07 g / cm 3 .

[0070] Comparative Example 3

[0071] A purification process for high-purity acetic acid, which uses Figure 1 This is achieved by the device shown.

[0072] Specifically, industrial-grade acetic acid with a concentration of 70% is distilled using a crude distillation device 1, and a fraction of 118-119°C is collected, and the moisture content is controlled to be less than 1%. The fraction is cooled to 50°C by a cooling device and supplied to an adsorption column filled with a modified SAPO-34 adsorbent, wherein a first modified SAPO-34 adsorption column 3 and a second modified SAPO-34 adsorption column 4 are connected in parallel, and a control valve flows to two adsorption columns or one of the adsorption columns. The adsorbed acetic acid liquid enters a distillation device 5, and the distillation conditions are: 60 plates, a tower top pressure of 0.21MPa, a tower top temperature of 120°C, a tower bottom pressure of 0.29MPa, a tower bottom temperature of 142 degrees Celsius, and a reflux ratio of 4. After the acetic acid flows out from the top of the tower, it is filtered through an electronic grade filter to obtain high-purity acetic acid.

[0073] The first modified SAPO-34 adsorption column 3 and the second modified SAPO-34 adsorption column 4 can be used simultaneously or separately. When the adsorption column is dehydrated and regenerated, only one adsorption column can be used to improve production efficiency.

[0074] The first modified SAPO-34 adsorption column 3 and the second modified SAPO-34 adsorption column 4 are both filled with an organic base-modified adsorbent, and the specific preparation method is as follows:

[0075] The SAPO-34 adsorbent was mixed in an aqueous solution of tetramethylammonium hydroxide (0.4 mol / L) and a surfactant, sodium fatty acid methyl ester sulfonate (5 g / L), at 85°C for 6 hours. The treated SAPO-34 was separated by filtration and then washed and dried before use.

[0076] The specific surface area of ​​the modified adsorbent is 451.45m 2 / g, containing micropores of 0.38-0.5nm and a pore volume of 0.20g / cm 3 , macropores with pore diameters of 100-110 nm and pore volumes of 0.10 g / cm 3 .

[0077] Determination method:

[0078] Method for determining the mass fraction of acetic acid: an automatic titrator is used for the test. The specific method is to accurately weigh 1g of sample and add purified water to a 250ml volumetric flask, transfer 10ml of test solution-70ml of water, and titrate to the endpoint with a standard sodium hydroxide solution on the titrator, and perform a blank test at the same time.

[0079] Determination of metal ion mass fraction: Determination by inductively coupled plasma mass spectrometry (ICP-MS). Weigh 5g of sample to an accuracy of 0.01g, slowly put it into a 50mL volumetric flask containing a small amount of ultrapure water, cool to room temperature, dilute to scale with water, and shake well. Determine the signal intensity of each element in the sample under the same analytical conditions as the standard solution series, and perform a blank test at the same time.

[0080] Particle size determination: The particle size was determined using a laser liquid particle counter.

[0081] The total concentration of organic impurities such as acetaldehyde, 2-butenal and 2-ethyl-2-butenal was quantitatively determined by GC-MS analysis (gas chromatography mass spectrometry).

[0082] See Table 1 for specific test data:

[0083]

[0084]

[0085]

[0086] The above embodiments and test data are only some applications and implementations of the present invention, and cannot limit the protection scope of the present invention. Through the above description, any technician in the relevant technical field can see that the present invention is innovated by adopting novel ideas and means, and has obvious practicality and creativity.

Claims

1. A purification process for high-purity acetic acid, comprising the following steps: (1) Rough distillation: using industrial acetic acid as raw material, the moisture content is controlled to be less than or equal to 3% after rough distillation; (2) Adsorption: The temperature of the crude distilled acetic acid is controlled at 40-50°C, and the modified SAPO-34 adsorbent is used for adsorption filtration; (3) Distillation: The adsorbed acetic acid is distilled to collect the fractions; (4) cooling the fraction and filtering it to obtain high-purity acetic acid; The pore structure of the modified adsorbent is as follows: the micropore diameter is 0.38-0.5 nm, the pore volume is 0.25-0.28 cm 3 / g, mesopore diameter is 15-30nm, pore volume is 0.07-0.08cm 3 / g, the macropore diameter is 80-90nm, and the pore volume is 0.04-0.06cm 3 / g, with a specific surface area of ​​500-600m 2 / g.

2. The process according to claim 1, characterized in that: The modified adsorbent is obtained by treating SAPO-34 molecular sieve with a modifier containing a base.

3. The process according to claim 2, characterized in that: The modifier comprises tetramethylammonium hydroxide and a surfactant, and the treatment temperature is 80-100°C.

4. The process according to claim 3, characterized in that: The surfactant is one or two of fatty acid methyl ester sulfonate and fatty alcohol polyether sulfate.

5. The process according to claim 1, characterized in that: The concentration of the high-purity acetic acid is greater than or equal to 99.00%.

6. The process according to claim 1, characterized in that: The filter adopts an electronic grade filter for filtering.

7. The process according to claim 4, characterized in that: The specific surface area of ​​the modified adsorbent is 500 to 550 m 2 / g.

8. An apparatus for producing high-purity acetic acid using the process of claim 1, comprising a crude distillation device (1), a cooling device (2), a first modified SAPO-34 adsorption column (3), a second modified SAPO-34 adsorption column (4), a rectification device (5), a filter (6), and a container (7) connected in sequence, wherein the first modified SAPO-34 adsorption column (3) and the second modified SAPO-34 adsorption column (4) are connected in parallel, and the adsorption columns are filled with a modified SAPO-34 adsorbent, and the pore structure of the adsorbent is: a micropore diameter of 0.38-0.5 nm, a pore volume of 0.25-0.28 cm 3 / g, the mesopore diameter is 15-30nm, and the pore volume is 0.07-0.08cm 3 / g, the macropore diameter is 80-90nm, and the pore volume is 0.04-0.06cm 3 / g, with a specific surface area of ​​500-600m 2 / g.

9. The device according to claim 8, characterized in that: The filter (6) is an electronic grade filter.

10. The device according to claim 8, characterized in that: The specific surface area of ​​the modified adsorbent is 500-550 m 2 / g.

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