Preparation method and application of pore channel hydrophobic modified activated carbon

Abstract

The invention relates to a preparation method and application of pore channel hydrophobic modified activated carbon, the preparation method adopts organosilane as a modifier, granular activated carbon is modified into pore channel hydrophobic modified activated carbon by a soaking method, the preparation conditions are green, efficient and mild, and the pore channel hydrophobic modified activated carbon cannot be crosslinked to block pores in the high-temperature modification process; the internal developed pore structure of the pore channel hydrophobic modified activated carbon is subjected to sufficient hydrophobic modification, and the water absorption rate of the granular activated carbon is greatly reduced, so that the adsorption rate of organic pollutants in high-humidity waste gas is remarkably improved; the use efficiency of the granular activated carbon is obviously improved in the working condition of practical application; the porous hydrophobic modified activated carbon prepared by the preparation method is applied to high-humidity organic waste gas treatment.

Description

Technical Field

[0001] The invention relates to the technical field of hydrophobic modification of activated carbon, and in particular to a preparation method and application of pore hydrophobic modified activated carbon. Background Art

[0002] The impact of air pollution and water pollution on the socio-economic and environmental aspects is one of the most important negative impacts of advanced industry. Due to the adverse effects of air pollution on the environment and public health in industrial and non-industrial areas around the world, more advanced waste gas and wastewater treatment technologies are needed to eliminate or reduce the harmful effects of industrial emissions. Industrial air pollutants mainly include particulate matter, sulfur dioxide, nitrogen oxides, hydrogen chloride, hydrogen fluoride, hydrogen bromide, chlorine, other organic pollutants, etc. Among them, the emission of organic pollutants has become a nightmare for environmentalists and chemical engineers because it can cause health diseases such as acute and chronic respiratory effects, neurotoxicity, lung cancer, fatigue, headaches, and depression.

[0003] In this context, activated carbon, as an adsorption material with well-developed pores, is widely used in various aspects of industrial pollution emissions, providing key support for the sustainable development of all walks of life. However, due to the competitive adsorption of water molecules, the adsorption capacity of activated carbon for organic compounds is greatly reduced under high humidity conditions. Not only is the application efficiency in sewage low, but a large amount of water vapor is also inevitable in the exhaust gas containing volatile organic compounds. Hydrophobic modification of activated carbon can be used as an important solution to these problems. At present, the hydrophobic modification method of activated carbon is mainly limited to surface hydrophobic modification, the hydrophobic effect is general, and it is mostly dependent on organic solvents and laboratory equipment, which is difficult to achieve large-scale production. Therefore, the development of a low-cost, environmentally friendly, and efficient method for hydrophobic modification of activated carbon pores using water as a solvent has broad application prospects.

[0004] Therefore, the present invention proposes a preparation method and application of pore hydrophobic modified activated carbon to solve the above problems. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide a preparation method and application of pore hydrophobic modified activated carbon, and to improve the utilization efficiency of granular activated carbon by hydrophobic modification of granular activated carbon.

[0006] In order to solve the above technical problems, the technical solution of the present invention is: a preparation method and application of pore hydrophobic modified activated carbon, the innovation of which is: comprising the following steps:

[0007] Step 1: Take a beaker, weigh deionized water, then add a surfactant, stir magnetically for 10 minutes at room temperature, then add a catalyst, continue stirring for 10 minutes, and finally add an organosilane modifier to the aqueous solution in the beaker, stir under a certain temperature condition to obtain a modified solution;

[0008] Step 2: Weigh the granular activated carbon and immerse it in the modified solution prepared in step 1, take it out and let it stand to dry, and finally react it at high temperature to obtain the pore hydrophobic modified activated carbon.

[0009] Furthermore, in step 1, the organosilane modifier is one of hexamethyldisilazane, hexamethyldisiloxane, dodecyltrichlorosilane, octadecyltrichlorosilane, and dimethyloctadecylchlorosilane.

[0010] Furthermore, when the organosilane modifier is hexamethyldisilazane, the mass ratio of deionized water, hexamethyldisilazane and surfactant is 200:12:1, and magnetic stirring is performed at a temperature of 40° C. to 100° C. for 2 to 24 hours to obtain a modified solution.

[0011] Furthermore, when the organosilane modifier is hexamethyldisiloxane, the mass ratio of deionized water, hexamethyldisiloxane and surfactant is 200:12:1, and magnetic stirring is performed at a temperature of 60° C. to 150° C. for 2 to 24 hours to obtain a modified solution.

[0012] Furthermore, when the organosilane modifier is dodecyltrichlorosilane or octadecyltrichlorosilane, the mass ratio of deionized water, organosilane modifier and surfactant is 400:48:1, and magnetic stirring is performed at room temperature to 50° C. for 0.5 to 4 hours to obtain a modified solution.

[0013] Furthermore, when the organosilane modifier is dimethyloctadecylchlorosilane, the mass ratio of deionized water, dimethyloctadecylchlorosilane and surfactant is 400:48:1, and magnetic stirring is performed at room temperature to 50° C. for 2 to 8 hours to obtain a modified solution.

[0014] Furthermore, the catalyst is ammonia water, and the surfactant is sodium dodecylbenzene sulfonate.

[0015] Furthermore, in step 2, the mass ratio of the granular activated carbon to the modified solution is 1:2, the soaking time is 2 hours, and the standing and drying time is 30 minutes.

[0016] Furthermore, in step 2, the process of high temperature reaction is: putting the dried granular activated carbon into a drying oven and baking it at a temperature of 180° C. to 250° C. for 4 to 6 hours.

[0017] The pore hydrophobic modified activated carbon prepared by the above preparation method is applied to the treatment of high-humidity organic waste gas.

[0018] The advantages of the present invention are:

[0019] (1) The present invention uses organosilane as a modifier and adopts an immersion method to modify granular activated carbon into a pore hydrophobic modified activated carbon. The preparation conditions are green, efficient, and mild, and the pores will not be cross-linked and blocked during the high-temperature modification process, thereby obtaining granular activated carbon with hydrophobicity. The well-developed pore structure inside the pore hydrophobic modified activated carbon is fully hydrophobically modified, which greatly reduces the water absorption rate of the granular activated carbon, thereby significantly improving the adsorption rate of organic pollutants in high-humidity exhaust gas, and significantly improving the utilization efficiency of the granular activated carbon in actual application conditions.

[0020] (2) The present invention uses deionized water as a solvent, thereby avoiding the pollution of air, water and soil caused by the large-scale use of organic solvents, which harms the ecological environment.

[0021] (3) The present invention uses deionized water as the solvent, and adding a small amount of surfactant can make the modified solution more uniform.

[0022] (4) In the present invention, adding ammonia water during the preparation of the modified solution can effectively shorten the reaction time of the modified solution, improve the reaction activity, and reduce heat consumption. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0024] Figure 1 Schematic diagram of the static water contact angle of the pore hydrophobic modified activated carbon of the present invention.

[0025] Figure 2 It is a schematic diagram of the static water contact angle of the pore hydrophobic modified activated carbon after polishing of the present invention. DETAILED DESCRIPTION

[0026] In order to further explain the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the specific implementation mode, structure, characteristics and effects of the present invention are described in detail below in combination with the accompanying drawings and preferred embodiments.

[0027] Example 1

[0028] The present embodiment provides a method for preparing a pore hydrophobic modified activated carbon, comprising the following steps:

[0029] Step 1, heating the granular activated carbon at 100°C for 4 hours for standby use;

[0030] Step 2: Take a 200 mL beaker, weigh 80 g of deionized water, then add 0.4 g of sodium dodecylbenzene sulfonate, and stir magnetically for 10 min at room temperature; then add 6 mL of ammonia water, and continue stirring for 10 min; finally, add 4.8 g of hexamethyldisilazane to the aqueous solution in the beaker, and stir magnetically for 24 h at a temperature of 40 ° C to obtain a modified solution;

[0031] Step 3, weigh 40g of granular activated carbon and soak it in 80g of the modified solution prepared in step 2, soak it for 2h, take it out, let it stand and dry for 30min, and finally put it into a drying oven and bake it at 250°C for 6h to obtain dried pore hydrophobic modified activated carbon;

[0032] Step 4: Cool the dried pore hydrophobic modified activated carbon, and finally package it to obtain a finished pore hydrophobic modified activated carbon.

[0033] In this embodiment, the catalyst ammonia water is added during the preparation process of the modified solution, which can effectively shorten the solution preparation time, improve the reaction activity and reduce energy consumption.

[0034] The pore hydrophobic modified activated carbon obtained in this example has an average static water contact angle of 130° (see Figure 1 ), indicating that the surface of the pore-hydrophobic modified activated carbon has good hydrophobicity; the static water contact angle of the surface of the pore-hydrophobic modified activated carbon after polishing with 60-mesh sandpaper is 117° on average

[0035] (See Figure 2 ), indicating that the pore hydrophobic modified activated carbon has good hydrophobicity inside.

[0036] The pore hydrophobic modified activated carbon prepared by the above preparation method is applied to the treatment of high-humidity organic waste gas.

[0037] Example 2

[0038] The present embodiment provides a method for preparing a porous hydrophobic granular activated carbon, comprising the following steps:

[0039] Step 1, heating the granular activated carbon at 100°C for 4 hours for standby use;

[0040] Step 2: Take a 200 mL beaker, weigh 80 g of deionized water, then add 0.4 g of sodium dodecylbenzene sulfonate, and stir magnetically for 10 min at room temperature; then add 6 mL of ammonia water, and continue stirring for 10 min; finally, add 4.8 g of hexamethyldisilazane to the aqueous solution in the beaker, and stir magnetically for 2 h at a temperature of 100 ° C to obtain a modified solution;

[0041] Step 3, weigh 40g of granular activated carbon and soak it in 80g of the modified solution prepared in step 2, soak it for 2h, take it out, let it stand and dry for 30min, and finally put it into a drying oven and bake it at 250°C for 6h to obtain dried pore hydrophobic modified activated carbon;

[0042] Step 4: Cool the dried pore hydrophobic modified activated carbon, and finally package it to obtain a finished pore hydrophobic modified activated carbon.

[0043] Example 3

[0044] The present embodiment provides a method for preparing a porous hydrophobic granular activated carbon, comprising the following steps:

[0045] Step 1, heating the granular activated carbon at 100°C for 4 hours for standby use;

[0046] Step 2: Take a 200 mL beaker, weigh 80 g of deionized water, then add 0.4 g of sodium dodecylbenzene sulfonate, and stir magnetically for 10 min at room temperature; then add 6 mL of ammonia water, and continue stirring for 10 min; finally, add 4.8 g of hexamethyldisiloxane to the aqueous solution in the beaker, and stir magnetically for 24 h at a temperature of 60 ° C to obtain a modified solution;

[0047] Step 3, weigh 40g of granular activated carbon and soak it in 80g of the modified solution prepared in step 2, soak it for 2h, take it out, let it stand and dry for 30min, and finally put it into a drying oven and bake it at 220℃ for 6h to obtain dried pore hydrophobic modified activated carbon;

[0048] Step 4: Cool the dried pore hydrophobic modified activated carbon, and finally package it to obtain a finished pore hydrophobic modified activated carbon.

[0049] Example 4

[0050] The present embodiment provides a method for preparing a porous hydrophobic granular activated carbon, comprising the following steps:

[0051] Step 1, heating the granular activated carbon at 100°C for 4 hours for standby use;

[0052] Step 2: Take a 200 mL beaker, weigh 80 g of deionized water, then add 0.4 g of sodium dodecylbenzene sulfonate, and stir magnetically for 10 min at room temperature; then add 6 mL of ammonia water, and continue stirring for 10 min; finally, add 4.8 g of hexamethyldisiloxane to the aqueous solution in the beaker, and stir magnetically for 2 h at a temperature of 150 ° C to obtain a modified solution;

[0053] Step 3, weigh 40g of granular activated carbon and soak it in 80g of the modified solution prepared in step 2, soak it for 2h, take it out, let it stand and dry for 30min, and finally put it into a drying oven and bake it at 220℃ for 6h to obtain dried pore hydrophobic modified activated carbon;

[0054] Step 4: Cool the dried pore hydrophobic modified activated carbon, and finally package it to obtain a finished pore hydrophobic modified activated carbon.

[0055] Example 5

[0056] The present embodiment provides a method for preparing a porous hydrophobic granular activated carbon, comprising the following steps:

[0057] Step 1, heating the granular activated carbon at 100°C for 4 hours for standby use;

[0058] Step 2: Take a 200 mL beaker, weigh 80 g of deionized water, then add 0.2 g of sodium dodecylbenzene sulfonate, and stir magnetically for 10 min at room temperature; then add 6 mL of ammonia water, and continue stirring for 10 min; finally, add 9.6 g of dodecyltrichlorosilane to the aqueous solution in the beaker, and stir magnetically for 4 h at room temperature to obtain a modified solution;

[0059] Step 3, weigh 40g of granular activated carbon and soak it in 80g of the modified solution prepared in step 2, soak it for 2h, take it out, let it stand and dry for 30min, and finally put it into a drying oven and bake it at 180°C for 5h to obtain dried pore hydrophobic modified activated carbon;

[0060] Step 4: Cool the dried pore hydrophobic modified activated carbon, and finally package it to obtain a finished pore hydrophobic modified activated carbon.

[0061] Example 6

[0062] The present embodiment provides a method for preparing a porous hydrophobic granular activated carbon, comprising the following steps:

[0063] Step 1, heating the granular activated carbon at 100°C for 4 hours for standby use;

[0064] Step 2: Take a 200 mL beaker, weigh 80 g of deionized water, then add 0.2 g of sodium dodecylbenzene sulfonate, and stir magnetically for 10 min at room temperature; then add 6 mL of ammonia water and continue stirring for 10 min; finally, add 9.6 g of dodecyltrichlorosilane to the aqueous solution in the beaker, and stir magnetically for 30 min at a temperature of 50 ° C to obtain a modified solution;

[0065] Step 3, weigh 40g of granular activated carbon and soak it in 80g of the modified solution prepared in step 2, soak it for 2h, take it out, let it stand and dry for 30min, and finally put it into a drying oven and bake it at 180°C for 5h to obtain dried pore hydrophobic modified activated carbon;

[0066] Step 4: Cool the dried pore hydrophobic modified activated carbon, and finally package it to obtain a finished pore hydrophobic modified activated carbon.

[0067] Example 7

[0068] The present embodiment provides a method for preparing a porous hydrophobic granular activated carbon, comprising the following steps:

[0069] Step 1, heating the granular activated carbon at 100°C for 4 hours for standby use;

[0070] Step 2: Take a 200 mL beaker, weigh 80 g of deionized water, then add 0.2 g of sodium dodecylbenzene sulfonate, and stir magnetically for 10 min at room temperature; then add 6 mL of ammonia water, and continue stirring for 10 min; finally, add 9.6 g of octadecyltrichlorosilane to the aqueous solution in the beaker, and stir magnetically for 4 h at room temperature to obtain a modified solution;

[0071] Step 3, weigh 40g of granular activated carbon and soak it in 80g of the modified solution prepared in step 2, soak it for 2h, take it out, let it stand and dry for 30min, and finally put it into a drying oven and bake it at 180°C for 5h to obtain dried pore hydrophobic modified activated carbon;

[0072] Step 4: Cool the dried pore hydrophobic modified activated carbon, and finally package it to obtain a finished pore hydrophobic modified activated carbon.

[0073] Example 8

[0074] The present embodiment provides a method for preparing a porous hydrophobic granular activated carbon, comprising the following steps:

[0075] Step 1, heating the granular activated carbon at 100°C for 4 hours for standby use;

[0076] Step 2: Take a 200 mL beaker, weigh 80 g of deionized water, then add 0.2 g of sodium dodecylbenzene sulfonate, and stir magnetically for 10 min at room temperature; then add 6 mL of ammonia water, and continue stirring for 10 min; finally, add 9.6 g of octadecyltrichlorosilane to the aqueous solution in the beaker, and stir magnetically for 30 min at a temperature of 50 ° C to obtain a modified solution;

[0077] Step 3, weigh 40g of granular activated carbon and soak it in 80g of the modified solution prepared in step 2, soak it for 2h, take it out, let it stand and dry for 30min, and finally put it into a drying oven and bake it at 180°C for 5h to obtain dried pore hydrophobic modified activated carbon;

[0078] Step 4: Cool the dried pore hydrophobic modified activated carbon, and finally package it to obtain a finished pore hydrophobic modified activated carbon.

[0079] Example 9

[0080] The present embodiment provides a method for preparing a porous hydrophobic granular activated carbon, comprising the following steps:

[0081] Step 1, heating the granular activated carbon at 100°C for 4 hours for standby use;

[0082] Step 2: Take a 200 mL beaker, weigh 80 g of deionized water, then add 0.2 g of sodium dodecylbenzene sulfonate, and stir magnetically for 10 min at room temperature; then add 6 mL of ammonia water, and continue stirring for 10 min; finally, add 9.6 g of dimethyloctadecylchlorosilane to the aqueous solution in the beaker, and stir magnetically for 8 h at room temperature to obtain a modified solution;

[0083] Step 3, weigh 40g of granular activated carbon and soak it in 80g of the modified solution prepared in step 2, soak it for 2h, take it out, let it stand and dry for 30min, and finally put it into a drying oven and bake it at 220℃ for 4h to obtain dried pore hydrophobic modified activated carbon;

[0084] Step 4: Cool the dried pore hydrophobic modified activated carbon, and finally package it to obtain a finished pore hydrophobic modified activated carbon.

[0085] Example 10

[0086] The present embodiment provides a method for preparing a porous hydrophobic granular activated carbon, comprising the following steps:

[0087] Step 1, heating the granular activated carbon at 100°C for 4 hours for standby use;

[0088] Step 2: Take a 200 mL beaker, weigh 80 g of deionized water, then add 0.2 g of sodium dodecylbenzene sulfonate, and stir magnetically for 10 min at room temperature; then add 6 mL of ammonia water, and continue stirring for 10 min; finally, add 9.6 g of dimethyloctadecylchlorosilane to the aqueous solution in the beaker, and stir magnetically for 2 h at a temperature of 50 ° C to obtain a modified solution;

[0089] Step 3, weigh 40g of granular activated carbon and soak it in 80g of the modified solution prepared in step 2, soak it for 2h, take it out, let it stand and dry for 30min, and finally put it into a drying oven and bake it at 220℃ for 4h to obtain dried pore hydrophobic modified activated carbon;

[0090] Step 4: Cool the dried pore hydrophobic modified activated carbon, and finally package it to obtain a finished pore hydrophobic modified activated carbon.

[0091] The preparation method parameters of Examples 1-10 are shown in Table 1.

[0092] Table 1 Preparation method parameters of Examples 1-10

[0093]

[0094] The static water contact angles of the unmodified granular activated carbon and the pore hydrophobic modified activated carbon products obtained in Examples 1-10 were tested respectively, and the test data results are shown in Table 2.

[0095] Table 2 Comparison of static water contact angle results of granular activated carbon and pore hydrophobic modified activated carbon

[0096]

[0097]

[0098] The water vapor adsorption rate and carbon tetrachloride adsorption rate of the unmodified granular activated carbon and the pore hydrophobic modified activated carbon products obtained in Examples 1-10 were tested respectively, and the test data results are shown in Table 3.

[0099] Table 3 Comparison of adsorption rate test results of granular activated carbon and pore hydrophobic modified activated carbon

[0100]

[0101] By comparison, it can be found that the water vapor adsorption rate of the pore hydrophobic modified activated carbon is greatly reduced compared with that of the unmodified granular activated carbon, and it has good hydrophobic properties; at the same time, the carbon tetrachloride adsorption rate of the pore hydrophobic modified activated carbon is the same as that of the unmodified granular activated carbon, indicating that there is no cross-linking and pore blocking during the modification process. Therefore, when the pore hydrophobic modified activated carbon is used to treat high-humidity organic waste gas, the adsorption amount of organic pollutants in the high-humidity waste gas is greatly increased due to its own reduced water absorption, thereby improving the utilization efficiency of the activated carbon.

[0102] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Although the present invention has been disclosed as a preferred embodiment as above, it is not used to limit the present invention. Any technical personnel in this field can make some changes or modify the technical contents disclosed above into equivalent embodiments without departing from the scope of the technical solution of the present invention. However, any brief modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A method for preparing pore hydrophobic modified activated carbon, characterized in that: The following steps are involved: Step 1: Take a beaker, weigh deionized water, then add a surfactant, stir magnetically for 10 minutes at room temperature, then add a catalyst, continue stirring for 10 minutes, and finally add an organosilane modifier to the aqueous solution in the beaker, stir under a certain temperature condition to obtain a modified solution; Step 2: Weigh the granular activated carbon and immerse it in the modified solution prepared in step 1, take it out and let it stand to dry, and finally react it at high temperature to obtain the pore hydrophobic modified activated carbon.

2. The method for preparing pore hydrophobic modified activated carbon according to claim 1, characterized in that: In the step 1, the organosilane modifier is one of hexamethyldisilazane, hexamethyldisiloxane, dodecyltrichlorosilane, octadecyltrichlorosilane, and dimethyloctadecylchlorosilane.

3. The method for preparing the pore hydrophobic modified activated carbon according to claim 2, characterized in that: When the organosilane modifier is hexamethyldisilazane, the mass ratio of deionized water, hexamethyldisilazane and surfactant is 200:12:1, and magnetic stirring is performed at a temperature of 40° C. to 100° C. for 2 to 24 hours to obtain a modified solution.

4. The method for preparing pore hydrophobic modified activated carbon according to claim 2, characterized in that: When the organosilane modifier is hexamethyldisiloxane, the mass ratio of deionized water, hexamethyldisiloxane and surfactant is 200:12:1, and magnetic stirring is performed at a temperature of 60° C. to 150° C. for 2 to 24 hours to obtain a modified solution.

5. The method for preparing pore hydrophobic modified activated carbon according to claim 2, characterized in that: When the organosilane modifier is dodecyltrichlorosilane or octadecyltrichlorosilane, the mass ratio of deionized water, the organosilane modifier and the surfactant is 400:48:1, and magnetic stirring is performed at room temperature to 50° C. for 0.5 to 4 hours to obtain a modified solution.

6. The method for preparing pore hydrophobic modified activated carbon according to claim 2, characterized in that: When the organosilane modifier is dimethyloctadecylchlorosilane, the mass ratio of deionized water, dimethyloctadecylchlorosilane and surfactant is 400:48:1, and magnetic stirring is performed at room temperature to 50° C. for 2 to 8 hours to obtain a modified solution.

7. The method for preparing pore-hydrophobic modified activated carbon according to claim 1, characterized in that: The catalyst is ammonia water, and the surfactant is sodium dodecylbenzene sulfonate.

8. The method for preparing pore hydrophobic modified activated carbon according to claim 1, characterized in that: In the step 2, the mass ratio of the granular activated carbon to the modified solution is 1:2, the soaking time is 2 hours, and the standing and drying time is 30 minutes.

9. The method for preparing pore-hydrophobic modified activated carbon according to claim 1, characterized in that: In step 2, the process of high temperature reaction is: putting the dried granular activated carbon into a drying oven and drying it at a temperature of 180° C. to 250° C. for 4 to 6 hours.

10. An application of pore hydrophobic modified activated carbon prepared by the preparation method according to claim 1, characterized in that: The pore hydrophobic modified activated carbon is applied to the treatment of high-humidity organic waste gas.

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