Preparation method of high-strength coal-based columnar activated carbon

Abstract

The present invention relates to a preparation method of high-strength coal-based columnar activated carbon, belonging to the technical field of activated carbon preparation. A preparation method of high-strength coal-based columnar activated carbon comprises the following steps: placing activated carbon, zirconium poly-chloride and deionized water in a stirrer, stirring and mixing them, then precipitating and standing, filtering, washing with deionized water, drying in an oven, soaking in a mixed solution, mixing evenly and then performing ultrasonic treatment, mixing evenly in an ethanol solution, adding protocatechuic aldehyde, stirring at a constant temperature and then performing ultrasonic treatment, performing rotary evaporation treatment, washing with ethanol, and drying in an oven to obtain the product. The present invention uses coal-based activated carbon and zirconium poly-chloride as inorganic adsorbents, and introduces organic polymers for compounding, so that the compounding system has the characteristics of both inorganic and organic polymer adsorbents, having both the effect of neutralizing charges and the strong net trapping effect of macromolecules.

Description

Technical Field

[0001] The present invention belongs to the technical field of activated carbon preparation, and relates to a preparation method of high-strength coal-based columnar activated carbon. Background Art

[0002] As an efficient adsorbent, activated carbon has been widely used in the field of drinking water treatment. Due to its excellent adsorption performance and purification effect, the application prospect of activated carbon in drinking water treatment is very broad, and its usage is also increasing year by year. China has rich coal resources and huge coal reserves, which enables us to use coal resources to produce activated carbon on a large scale. By preparing activated carbon from coal, the stable supply of production can be ensured to meet the market demand. Therefore, coal-based activated carbon has become a major type of activated carbon in the field of water treatment.

[0003] However, although coal-based activated carbon has certain advantages in water treatment, its adsorption capacity is relatively limited, and a longer contact time is required in actual applications to achieve the ideal purification effect. To overcome these limitations, researchers and engineers have been committed to the preparation and research of modified activated carbon. Through modification techniques, the adsorption performance of activated carbon can be significantly improved, the contact time can be shortened, and thus the water treatment efficiency and water quality can be improved. The modification methods include physical modification, chemical modification, biological modification and other methods, which can effectively increase the specific surface area of activated carbon, adjust the pore structure, and introduce new functional groups, so that it can play a greater role in water treatment. Summary of the Invention

[0004] The purpose of the present invention is to provide a preparation method of high-strength coal-based columnar activated carbon. The present invention uses coal-based activated carbon and zirconium poly chloride as inorganic adsorbents, and introduces organic polymers for compounding, so that the compounding system has the characteristics of both inorganic and organic polymer adsorbents, having both the effect of neutralizing charges and the strong net trapping effect of macromolecules.

[0005] The purpose of the present invention can be achieved by the following technical solutions:

[0006] A preparation method of high-strength coal-based columnar activated carbon includes the following steps:

[0007] Step S1: Put activated carbon, zirconium poly chloride and deionized water into a stirrer, stir and mix them, then precipitate and stand still. After filtration, wash with deionized water, and place in an oven for drying to obtain prefabricated activated carbon;

[0008] Step S2: Immerse the prefabricated activated carbon in the mixed solution, mix well and then perform ultrasonic treatment to obtain a prefabricated solution;

[0009] Step S3: Place the pre-prepared solution in an ethanol solution, mix well, add protocatechuic aldehyde, stir at a constant temperature, perform ultrasonic treatment, carry out rotary evaporation, wash with ethanol, and then place in an oven for drying to obtain the product.

[0010] As a preferred technical solution of the present invention, the activated carbon is coal-based activated carbon, which is made from Taixi washed clean coal as raw material. After being crushed to 80 μm, an appropriate amount of coal tar (50%) is added, and it is kneaded into columnar particles in a kneading device, and then obtained after carbonization at a temperature of 600 °C for 1 h.

[0011] As a preferred technical solution of the present invention, in step S1, the stirring and mixing is carried out at a rotation speed of 600 - 800 r / min for 10 - 12 h; the drying is carried out at a temperature of 60 - 70 °C for 3 - 4 h.

[0012] As a preferred technical solution of the present invention, in step S1, the mass ratio of the activated carbon, zirconium poly chloride, and deionized water is 4 - 5: 1.0 - 1.3: 40 - 50.

[0013] As a preferred technical solution of the present invention, in step S2, the ultrasonic treatment is carried out at a frequency of 800 - 1000 W for 10 - 15 min.

[0014] As a preferred technical solution of the present invention, in step S2, the mixed solution is composed of chitosan, fulvic acid, and deionized water mixed in a mass ratio of 3.6 - 4.0: 1.2 - 1.4: 180 - 200.

[0015] As a preferred technical solution of the present invention, in step S2, the mass ratio of the pre-prepared activated carbon and the mixed solution is 18 - 20: 100 - 110.

[0016] As a preferred technical solution of the present invention, in step S3, the constant temperature stirring is carried out at a temperature of 25 - 28 °C for 14 - 16 h; the number of times of washing with ethanol is three; the drying is carried out at a temperature of 50 - 60 °C until constant weight.

[0017] As a preferred technical solution of the present invention, in step S3, the ultrasonic treatment is carried out at a frequency of 600 - 700 W for 10 - 12 min.

[0018] As a preferred technical solution of the present invention, in step S3, the mass ratio of the pre-prepared solution, the ethanol solution, and protocatechuic aldehyde is 13 - 16: 50 - 60: 1.6 - 1.8; the concentration of the ethanol solution is 90 wt%.

[0019] Advantages of the present invention:

[0020] The present invention uses coal-based activated carbon and zirconium poly-chloride as inorganic adsorbents, and introduces organic polymers for compounding, so that the compounding system has the characteristics of both inorganic and organic polymer adsorbents, having both the function of neutralizing charges and the strong network capture effect of macromolecules.

[0021] Specifically, the weak acid property of fulvic acid in the present invention promotes the dissociation of amino groups in chitosan. Low temperature enables the reaction between amino groups and aldehyde groups to proceed slowly, which is beneficial to the formation of micropores and mesopores. Ultrasonic treatment can reduce the interaction between fulvic acid and chitosan, expose more amino groups, and promote the grafting amount of protocatechuic aldehyde. The present invention uses coal-based activated carbon and zirconium poly-chloride as inorganic adsorbents. Zirconium poly-chloride enhances the strength and water resistance stability of activated carbon. By compounding fulvic acid and chitosan, a macromolecular organic network is formed. The dihydroxy groups of protocatechuic aldehyde further promote stability, and compounding with inorganic adsorbents enables the compounding system to have the characteristics of both inorganic and organic polymer adsorbents, having both the function of neutralizing charges and the strong network capture effect of macromolecules. Detailed implementation mode

[0022] To further elaborate on the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the following combines examples to elaborate in detail on the specific implementation mode, structure, characteristics and their effects according to the present invention.

[0023] Example 1

[0024] A preparation method of high-strength coal-based columnar activated carbon includes the following steps:

[0025] Step S1: Place activated carbon, zirconium poly-chloride and deionized water in a stirrer, stir and mix them, then precipitate and stand still. After filtration, wash with deionized water, and place in an oven for drying to obtain prefabricated activated carbon.

[0026] Step S2: Immerse the prefabricated activated carbon in a mixed solution, mix well and then perform ultrasonic treatment to obtain a prefabricated solution.

[0027] Step S3: Place the prefabricated solution in an ethanol solution, mix well, add protocatechuic aldehyde, stir at a constant temperature and then perform ultrasonic treatment. After rotary evaporation treatment, wash with ethanol, and place in an oven for drying to obtain the product.

[0028] In step S1, the stirring and mixing is carried out at a speed of 600 r / min for 10 h; the drying is carried out at a temperature of 60 °C for 3 h; the mass ratio of activated carbon, zirconium poly-chloride and deionized water is 4:1.0:40.

[0029] In step S2, the ultrasonic treatment is ultrasonic treatment at 800 W for 10 min; the mixed solution is prepared by mixing chitosan, fulvic acid and deionized water in a mass ratio of 3.6:1.2:180; the mass ratio of the prefabricated activated carbon to the mixed solution is 18:100.

[0030] In step S3, the constant-temperature stirring is stirring at 25 °C for 14 h; the ultrasonic treatment is ultrasonic treatment at 600 W for 10 min; the number of times of ethanol washing is three; the drying is drying to constant weight at 50 °C; the mass ratio of the prefabricated solution, the ethanol solution and protocatechuic aldehyde is 13:50:1.6; the concentration of the ethanol solution is 90 wt%.

[0031] Example 2

[0032] A preparation method of high-strength coal-based columnar activated carbon comprises the following steps:

[0033] Step S1: Put activated carbon, zirconium poly chloride and deionized water into a stirrer, stir and mix them, precipitate and stand, filter, wash with deionized water, and place them in an oven for drying to obtain prefabricated activated carbon;

[0034] Step S2: Immerse the prefabricated activated carbon in the mixed solution, mix well and then perform ultrasonic treatment to obtain a prefabricated solution;

[0035] Step S3: Put the prefabricated solution into an ethanol solution, mix well, add protocatechuic aldehyde, stir at a constant temperature, then perform ultrasonic treatment, perform rotary evaporation treatment, wash with ethanol, and place in an oven for drying to obtain the product.

[0036] In step S1, the stirring and mixing is stirring at a speed of 700 r / min for 11 h; the drying is drying at 65 °C for 3.5 h; the mass ratio of the activated carbon, zirconium poly chloride and deionized water is 4.5:1.2:45.

[0037] In step S2, the ultrasonic treatment is ultrasonic treatment at 900 W for 12 min; the mixed solution is prepared by mixing chitosan, fulvic acid and deionized water in a mass ratio of 3.8:1.3:190; the mass ratio of the prefabricated activated carbon to the mixed solution is 19:105.

[0038] In step S3, the constant-temperature stirring is stirring at 26 °C for 15 h; the ultrasonic treatment is ultrasonic treatment at 650 W for 11 min; the number of times of ethanol washing is three; the drying is drying to constant weight at 55 °C; the mass ratio of the prefabricated solution, the ethanol solution and protocatechuic aldehyde is 14:55:1.7; the concentration of the ethanol solution is 90 wt%.

[0039] Example 3

[0040] A preparation method of high-strength coal-based columnar activated carbon comprises the following steps:

[0041] Step S1: Place activated carbon, zirconium poly chloride, and deionized water in a stirrer, stir and mix them, let them precipitate and stand still, filter, wash with deionized water, and place them in an oven for drying to obtain prefabricated activated carbon.

[0042] Step S2: Immerse the prefabricated activated carbon in a mixed solution, mix well, and then perform ultrasonic treatment to obtain a prefabricated liquid.

[0043] Step S3: Place the prefabricated liquid in an ethanol solution, mix well, add protocatechuic aldehyde, stir at a constant temperature, then perform ultrasonic treatment, carry out rotary evaporation treatment, wash with ethanol, and place them in an oven for drying to obtain the product.

[0044] In step S1, the stirring and mixing is carried out at a speed of 800 r / min for 12 h; the drying is carried out at a temperature of 70 °C for 4 h; the mass ratio of the activated carbon, zirconium poly chloride, and deionized water is 5:1.3:50.

[0045] In step S2, the ultrasonic treatment is carried out at a frequency of 1000 W for 15 min; the mixed solution is composed of chitosan, fulvic acid, and deionized water mixed according to a mass ratio of 4.0:1.4:200; the mass ratio of the prefabricated activated carbon and the mixed solution is 20:110.

[0046] In step S3, the constant-temperature stirring is carried out at a temperature of 28 °C for 16 h; the ultrasonic treatment is carried out at a frequency of 700 W for 12 min; the number of times of washing with ethanol is three; the drying is carried out at a temperature of 60 °C until constant weight; the mass ratio of the prefabricated liquid, the ethanol solution, and protocatechuic aldehyde is 16:60:1.8; the concentration of the ethanol solution is 90 wt%.

[0047] Comparative Example 1

[0048] Compared with Example 3, the difference in Comparative Example 1 is that zirconium poly chloride is replaced by activated carbon, and the other components, preparation steps, and parameters are the same.

[0049] Comparative Example 2

[0050] Compared with Example 3, the difference in Comparative Example 2 is that chitosan is replaced by fulvic acid, and the other components, preparation steps, and parameters are the same.

[0051] Comparative Example 3

[0052] Compared with Example 3, the difference in Comparative Example 3 is that fulvic acid is replaced by chitosan, and the other components, preparation steps, and parameters are the same.

[0053] Comparative Example 4

[0054] Compared with Example 3, the difference in Comparative Example 4 is that protocatechuic aldehyde is not used, and the other components, preparation steps and parameters are the same.

[0055] Comparative Example 5

[0056] Compared with Example 3, the difference in Comparative Example 5 lies in step S3;

[0057] In step S3, the constant-temperature stirring is carried out at 40 °C for 16 h; the ultrasonic treatment is carried out at a frequency of 700 W for 12 min; the number of times of ethanol washing is three; the drying is carried out at 60 °C until constant weight; the mass ratio of the prefabricated solution, ethanol solution and protocatechuic aldehyde is 16:60:1.8; the concentration of the ethanol solution is 90 wt%;

[0058] The other components, preparation steps and parameters are the same.

[0059] Comparative Example 6

[0060] Compared with Example 3, the difference in Comparative Example 6 lies in step S3. In step S3, ultrasonic treatment is not carried out, and the other components, preparation steps and parameters are the same.

[0061] The activated carbons prepared in Examples 1-3 and Comparative Examples 1-6 were respectively subjected to the following performance tests.

[0062] Stability test: After the activated carbon was placed in water for 60 days, the strength was tested according to the activated carbon ball method of GB / T 20451-2006;

[0063] Adsorption test: Static adsorption experiments were carried out on methanol, benzene and n-hexane, and the static adsorption results are shown in Table 2;

[0064] Table 1

[0065] Strength (MPa) Example 1 3.3 Example 2 3.5 Example 3 3.6 Comparative Example 1 1.8 Comparative Example 2 2.0 Comparative Example 3 2.4 Comparative Example 4 2.5 Comparative Example 5 2.4 Comparative Example 6 2.6

[0066] As can be seen from the test results in Table 1, compared with Comparative Examples 1-6, the mechanical strength of the activated carbon prepared by the present invention is significantly better than that of the activated carbon prepared in Comparative Examples 1-6.

[0067] Table 2

[0068]

[0069]

[0070] As can be seen from the test results in Table 2, compared with Comparative Examples 1-6, the adsorption capacity of the activated carbon prepared by the present invention in a liquid environment is significantly better than that of the activated carbon prepared in Comparative Examples 1-6.

[0071] In the present invention, the weak acidic property of fulvic acid promotes the dissociation of amino groups in chitosan. Low temperature enables the reaction between amino groups and aldehyde groups to proceed slowly, facilitating the formation of microporous and mesoporous structures. Ultrasonic treatment can reduce the interaction between fulvic acid and chitosan, exposing more amino groups and promoting the grafting amount of protocatechuic aldehyde. The present invention uses coal-based activated carbon and zirconium poly-chloride as inorganic adsorbents. Zirconium poly-chloride enhances the strength and water resistance stability of the activated carbon. By compounding fulvic acid and chitosan, a macromolecular organic network is formed. The dihydroxy groups of protocatechuic aldehyde further promote stability. When compounded with inorganic adsorbents, the compounding system combines the characteristics of inorganic and organic polymer adsorbents, having both the effect of neutralizing charges and the strong network capture effect of macromolecules.

[0072] The above are only the preferred embodiments of the present invention and do not impose any form of limitation on the present invention. Although the present invention has been disclosed as above with preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or equivalent changes within the scope of the technical solution of the present invention by using the disclosed technical content. However, as long as it does not depart from the content of the technical solution of the present invention, any brief modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. A method for preparing high-strength coal-based columnar activated carbon comprises the following steps: Step S1: placing activated carbon, polyzirconium chloride and deionized water in a stirrer, stirring and mixing, allowing the mixture to settle and stand, filtering, washing with deionized water, and drying in an oven to obtain prefabricated activated carbon; the mass ratio of the activated carbon, polyzirconium chloride and deionized water is 4-5:1.0-1.3:40-50; Step S2: soaking the prefabricated activated carbon in a mixed solution, mixing the mixture, and then performing ultrasonic treatment to obtain a prefabricated solution; the mixed solution is prepared by mixing chitosan, fulvic acid, and deionized water in a mass ratio of 3.6-4.0:1.2-1.4:180-200; the mass ratio of the prefabricated activated carbon to the mixed solution is 18-20:100-110; Step S3: after the prefabricated liquid is placed in an ethanol solution and mixed evenly, protocatechuic aldehyde is added and stirred at a constant temperature, followed by ultrasonic treatment, rotary evaporation treatment, washing with ethanol, and drying in an oven to obtain the product; the constant temperature stirring is stirring at 25-28° C. for 14-16 hours.

2. The method for preparing high-strength coal-based columnar activated carbon according to claim 1, characterized in that: In step S1, the stirring and mixing is performed at a rotation speed of 600-800 r / min for 10-12 hours; and the drying is performed at a temperature of 60-70° C. for 3-4 hours.

3. The method for preparing high-strength coal-based columnar activated carbon according to claim 1, characterized in that: In step S2, the ultrasonic treatment is 800-1000W frequency ultrasound for 10-15 min.

4. The method for preparing high-strength coal-based columnar activated carbon according to claim 1, characterized in that: In step S3, the ethanol washing is performed three times; and the drying is performed at a temperature of 50-60° C. to a constant weight.

5. The method for preparing high-strength coal-based columnar activated carbon according to claim 1, characterized in that: In step S3, the ultrasonic treatment is performed at a frequency of 600-700W for 10-12 minutes.

6. The method for preparing high-strength coal-based columnar activated carbon according to claim 1, characterized in that: In step S3, the mass ratio of the prefabricated liquid, the ethanol solution and protocatechuic aldehyde is 13-16:50-60:1.6-1.8; and the concentration of the ethanol solution is 90wt%.

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