Preparation method of aldehyde-removing antibacterial activated carbon material

Abstract

The application relates to the technical field of air purification, and discloses a preparation method of aldehyde-removing and antibacterial activated carbon material, which comprises the following steps: raw material preparation, acidification treatment, carbonization treatment, silver loading treatment, activation treatment, washing and drying treatment, and product processing. The carbonization treatment is carried out in a three-stage heating mode after the acidification treatment, which is beneficial to optimizing the pore distribution, forming more abundant micropores, mesopores and macropores. The activation treatment is carried out after the silver loading, which is helpful to increasing the porosity and specific surface area of the activated carbon, improving the adsorption performance, the physical and chemical properties and the adsorption capacity of the activated carbon, avoiding easy saturation, and facilitating the reduction of the loaded silver. The adsorption-catalysis combination mode significantly improves the aldehyde-removing and antibacterial effect of the activated carbon and prolongs the service life. The activated material is washed, dried and processed into products, so that the products can be practically applied in real scenes such as indoor environments according to different requirements.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of air purification technology, in particular to a preparation method of an aldehyde-removing and antibacterial activated carbon material. BACKGROUND

[0002] Formaldehyde, also known as antiseptic aldehyde, is an organic compound with the chemical formula CH2O. Formaldehyde has a strong irritating effect on the mucous membranes of the eyes, nose, and throat. The most common symptoms are eye irritation and headache. Severe cases can cause allergic dermatitis and asthma. Long-term exposure to low doses of formaldehyde can cause chronic respiratory diseases, and even lead to nasopharyngeal cancer, colon cancer, brain cancer, and other malignant tumors. In addition, formaldehyde can also cause chromosomal abnormalities in newborns, leukemia, and intelligence decline in adolescents. The main sources of formaldehyde include building materials (such as plywood, large core board, medium density fiberboard, and particle board), furniture, man-made board, various adhesives and coatings (such as coatings using formaldehyde as a preservative), synthetic textiles (such as chemical fiber carpets and curtains), and smoking.

[0003] With the improvement of modern building airtightness and the widespread use of home decoration materials, indoor air pollution problems are becoming increasingly serious, with formaldehyde pollution being the most serious. Therefore, the public is particularly concerned about the cleaning and elimination of indoor formaldehyde. In addition, indoor bacterial growth is also an important factor affecting air quality. Activated carbon, as an excellent adsorbent, is widely used in the field of indoor air purification due to its developed pore structure, large specific surface area, and strong adsorption performance.

[0004] The activated carbon processed by the existing process has good initial effect in removing formaldehyde, but has problems such as easy saturation and limited adsorption capacity, which leads to inefficient formaldehyde purification. At the same time, the quality and adsorption effect of activated carbon also significantly affect its antibacterial performance. Therefore, it is of great significance to develop an activated carbon material that can efficiently remove formaldehyde and effectively resist bacteria. SUMMARY

[0005] (I) Technical problems to be solved

[0006] In view of the deficiencies of the prior art, the present application provides a preparation method of an aldehyde-removing and antibacterial activated carbon material to solve the technical problems of easy saturation, limited adsorption capacity, and poor adsorption effect of the above-mentioned activated carbon in removing formaldehyde and effectively resisting bacteria.

[0007] (II) Technical solutions

[0008] To achieve the above-mentioned purpose, the present application provides the following technical solutions: a preparation method of an aldehyde-removing and antibacterial activated carbon material, comprising the following steps:

[0009] (1) Raw material preparation: The raw material is pulverized by a crusher, screened by a screening machine, and then washed with water to remove surface impurities. After filtration, the material is dried in a drying oven at 80-100°C for 12-24h to obtain the dried raw material.

[0010] (2) Acidification treatment: Take phosphoric acid with a mass fraction of 65%-90%, mix the dried raw material obtained in step (1) with the phosphoric acid, and uniformly stir with an electric mixer. Stir / soak at 40-70°C for 3-10h, and then dry at 80-100°C for 12-24h after filtration.

[0011] (3) Carbonization treatment: The material obtained in step (2) is put into a carbonization furnace for staged carbonization treatment, with a heating rate of 10-15°C / min.

[0012] First stage: The temperature of the carbonization furnace is 400-500°C, and the heat treatment time is 0.5-1h.

[0013] Second stage: The temperature of the carbonization furnace is 500-600°C, and the heat treatment time is 1-2h.

[0014] Third stage: The temperature of the carbonization furnace is 600-700°C, and the heat treatment time is 0.5-1h.

[0015] (4) Silver loading treatment: Mix the material obtained in step (3) with silver nitrate solution uniformly, stir / stand for 0.5-3h, and then dry at 80-100°C for 12-24h after filtration.

[0016] (5) Activation treatment: Put the material obtained in step (4) into an activation furnace, activate at 700-800°C in a carbon dioxide gas atmosphere for 0.5-2h, and then cool to room temperature, with a heating rate of 10-15°C / min.

[0017] (6) Washing and drying treatment: The material obtained in step (5) is repeatedly washed with water until the pH is 5-7, and then dried at 80-100°C for 12-24h after controlling the moisture content.

[0018] (7) Product processing: The dried material obtained in step (6) is sieved by a screening machine to obtain activated carbon of different mesh sizes and packaged.

[0019] Preferably, in step (1), the raw material is at least one of wood chips, fruit shells, and coconut shells.

[0020] Preferably, in step (2), the dried raw material is mixed with phosphoric acid at a solid-liquid ratio of 1:10-50.

[0021] Preferably, in step (4), the concentration of the silver nitrate solution is 0.002-0.3 mol / L.

[0022] Preferably, in step (4), the solid-liquid ratio of the material obtained in step (3) and the silver nitrate solution is 1:5-50.

[0023] Preferably, in step (5), the flow rate of the carbon dioxide gas is 5-20 m 3 / h.

[0024] (III) Beneficial effects

[0025] Compared with the prior art, the present application discloses a preparation method of an aldehyde-removing antibacterial activated carbon material, and has the following beneficial technical effects:

[0026] (1) First, at least one of wood chips, fruit shells, coconut shells, etc. is used as raw material, and after processes such as crushing, screening, washing, and drying, dry raw materials are obtained; then, acidification treatment is performed with phosphoric acid, which can cause the carbonaceous components in the raw material shells to react and form rich surface functional groups (such as hydroxyl groups and carboxyl groups), thereby improving the adsorption performance of the subsequent activated carbon. Performing this process under heating conditions is more conducive to the depth of the reaction.

[0027] (2) Carbonization treatment is performed, which removes impurities and moisture and improves the purity of the activated carbon; on the other hand, it causes structural changes and promotes the formation of pores. In the present application, the carbonization process adopts a three-stage heating treatment, which is conducive to optimizing the pore distribution and forming more abundant micropores, mesopores, and macropores, which provides a strong guarantee for the activated carbon to have a large specific surface area, greatly improves its adsorption of formaldehyde and bacteria, and thus greatly improves the adsorption capacity of formaldehyde, avoiding saturation during use.

[0028] (3) Silver loading treatment is performed on the basis of carbonization, because after the previous processes, the activated carbon already has certain pores and surface functional groups, which helps the effective adsorption of silver ions and lays a foundation for subsequent activation and further improvement of the performance of the activated carbon.

[0029] (4) The silver-loaded activated carbon is then subjected to an activation treatment, which helps to increase the porosity and specific surface area of the activated carbon, improve the adsorption performance of the activated carbon, and improve the physical and chemical properties of the activated carbon. In addition, the process helps to reduce the silver loaded in the activated carbon, because at a high temperature of 700-800 DEG C, carbon dioxide is used as a medium for physical activation, and the carbon dioxide reacts with carbon atoms on the surface of the activated carbon to generate carbon monoxide, which further promotes the formation of the pore structure. At the same time, the high temperature promotes the decomposition of silver nitrate to convert the high-valence silver into elemental silver, and nitrogen gas, oxygen gas, or nitrogen dioxide is generated. The reaction occurs in a flowing carbon dioxide gas atmosphere, so the elemental silver is prevented from being oxidized to a certain extent. It is known that the elemental silver with high efficiency can be used as a catalytic active center to activate the surrounding molecular oxygen to form active oxygen. The active oxygen not only catalyzes the decomposition of formaldehyde into harmless substances such as water and carbon dioxide, but also destroys the proliferation ability of microbial cells, inhibits or kills bacteria, significantly improves the aldehyde removal and antibacterial effect of the activated carbon through the combination of adsorption and catalysis, and prolongs the service life of the activated carbon. Therefore, the activation process and the temperature control in the present application are crucial and have a significant influence on the structural properties of the activated carbon material.

[0030] (5) Finally, the activated material is subjected to washing, drying, and product processing, so as to be applied in real scenes such as indoor environments according to different needs. BRIEF DESCRIPTION OF DRAWINGS

[0031] Figure 1 The present application provides a preparation process. DETAILED DESCRIPTION

[0032] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0033] The present application provides a technical solution, a preparation method of an aldehyde-removing and antibacterial activated carbon material, which comprises the following steps:

[0034] (1) Raw material preparation: After the raw material is crushed by a crusher, the crushed raw material is subjected to a screening treatment by a screening machine, and then the screened raw material is subjected to a water washing treatment to remove surface impurities. After filtration, the filtered raw material is placed in a drying box and subjected to a drying treatment at 80-100 DEG C for 12-24 hours to obtain dried raw material.

[0035] (2) Acidification treatment: take the phosphoric acid with mass fraction of 65% to 90%, mix the dry raw material obtained in step (1) with the phosphoric acid, and uniformly stir with an electric mixer, then stir / soak at 40 to 70°C for 3 to 10 hours, filter, and dry at 80 to 100°C for 12 to 24 hours.

[0036] (3) Carbonization treatment: put the material obtained in step (2) into a carbonization furnace for phased carbonization treatment, with a heating rate of 10 to 15°C / min;

[0037] First phase: the temperature of the carbonization furnace is 400 to 500°C, and the heat treatment time is 0.5 to 1 hour;

[0038] Second phase: the temperature of the carbonization furnace is 500 to 600°C, and the heat treatment time is 1 to 2 hours;

[0039] Third phase: the temperature of the carbonization furnace is 600 to 700°C, and the heat treatment time is 0.5 to 1 hour.

[0040] (4) Silver loading treatment: uniformly mix the material obtained in step (3) with a silver nitrate solution, stir / stand for 0.5 to 3 hours, filter, and dry at 80 to 100°C for 12 to 24 hours.

[0041] (5) Activation treatment: put the material obtained in step (4) into an activation furnace, activate at 700 to 800°C in a carbon dioxide gas atmosphere for 0.5 to 2 hours, and then cool to room temperature, with a heating rate of 10 to 15°C / min.

[0042] (6) Washing and drying treatment: repeatedly wash the material obtained in step (5) with water until the pH is 5 to 7, control the moisture, and then dry at 80 to 100°C for 12 to 24 hours.

[0043] (7) Product processing: sieve the dried material obtained in step (6) into activated carbons of different mesh sizes through a screening machine, and package.

[0044] In step (1), the raw material is at least one of wood chips, fruit shells, and coconut shells, in step (2), the dry raw material is mixed with the phosphoric acid at a solid-liquid ratio of 1:10 to 50, in step (4), the concentration of the silver nitrate solution is 0.002 to 0.3 mol / L, in step (4), the solid-liquid ratio of the material obtained in step (3) mixed with the silver nitrate solution is 1:5 to 50, and in step (5), the flow rate of the carbon dioxide gas is 5 to 20 m 3 / h.

[0045] Example 1:

[0046] Take sawdust, shell, coconut shell and other raw materials 10 kg, the raw materials are added to 40℃ Bé phosphoric acid solution 1:50 phosphoric acid solution for stirring and soaking 4h, in the soaking of raw materials, by and four silver oxide and silver fluoride mixed treatment, and stirring mixing after drying treatment, and the silver-loaded raw materials into the processing furnace for staged carbonization processing produce three segment condensation benzene ring molecules, thus forming a three-way network carbide on the surface;

[0047] The carbonized raw materials are put into the reaction kettle, heated to 900℃ by water vapor, activated for 0.5h, and the activated raw materials are cooled until the temperature drops to 40℃. The raw materials are washed to remove external impurities, and then dried and cut to increase the adsorption effect of the activated carbon product on formaldehyde.

[0048] Example 2:

[0049] Take sawdust, shell, coconut shell and other raw materials 10 kg, the raw materials are added to 40℃ Bé phosphoric acid solution 1:50 phosphoric acid solution for stirring and soaking 4h, in the soaking of raw materials, by and four silver oxide and silver fluoride mixed treatment, and stirring mixing after drying treatment, and the silver-loaded raw materials into the processing furnace for staged carbonization processing produce three segment condensation benzene ring molecules, thus forming a three-way network carbide on the surface;

[0050] The carbonized raw materials are put into the reaction kettle, heated to 900℃ by water vapor, activated for 0.5h, and the activated raw materials are cooled until the temperature drops to 40℃. The raw materials are washed to remove external impurities, and then dried and cut to increase the adsorption effect of the activated carbon product on formaldehyde.

[0051] Example 3:

[0052] Take sawdust, shell, coconut shell and other raw materials 10 kg, the raw materials are added to 40℃ Bé phosphoric acid solution 1:50 phosphoric acid solution for stirring and soaking 4h, in the soaking of raw materials, by and four silver oxide and silver fluoride mixed treatment, and stirring mixing after drying treatment, and the silver-loaded raw materials into the processing furnace for staged carbonization processing produce three segment condensation benzene ring molecules, thus forming a three-way network carbide on the surface;

[0053] The carbonized raw materials are put into the reaction kettle, heated to 900℃ by water vapor, activated for 0.5h, and the activated raw materials are cooled until the temperature drops to 40℃. The raw materials are washed to remove external impurities, and then dried and cut to increase the adsorption effect of the activated carbon product on formaldehyde.

[0054] The following is a reference table comparing the performance of Examples 1, 2 and 3 with existing common activated carbon and activated carbon for formaldehyde removal.

[0055]

[0056] It is to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting; it is also possible in the present application that steps can be executed in different sequence, where it is possible and advantageous, than described in this specification without changing the essence of the application. It is also possible in some cases to combine or omit certain steps. Where a range of values is provided, it is understood that every intervening value, to the extent that they are independent of each other, along with sub or

[0057] While the embodiments of the application have been illustrated and described, it will be understood by those skilled in the art that various changes, modifications, substitutions, and alterations can be made therein without departing from the spirit and scope of the application, which is defined by the following claims and their equivalents.

Claims

1. A method for preparing an aldehyde-removing antibacterial activated carbon material, characterized by, Includes the following steps: (1) Raw material preparation: After crushing the raw material with a crusher, it is screened with a screening machine. The screened raw material is then washed with water to remove surface impurities. After filtration, it is placed in a drying oven and dried at 80-100℃ for 12-24 hours to obtain dried raw material. The raw material is at least one of wood chips, fruit shells, and coconut shells. (2) Acidification treatment: Take phosphoric acid with a mass fraction of 65% to 90%, mix the dried raw material obtained in step (1) with phosphoric acid, stir evenly with an electric mixer, stir / immerse at 40 to 70°C for 3 to 10 hours, filter and dry at 80 to 100°C for 12 to 24 hours; (3) Carbonization treatment: The material obtained in step (2) is put into a carbonization furnace for staged carbonization treatment, with a heating rate of 10-15℃ / min; First stage: The temperature of the carbonization furnace is 400-500℃, and the heat treatment time is 0.5-1h; Second stage: The temperature of the carbonization furnace is 500-600℃, and the heat treatment time is 1-2 hours; The third stage: the temperature of the carbonization furnace is 600-700℃, and the heat treatment time is 0.5-1h; (4) Silver loading treatment: Mix the material obtained in step (3) with silver nitrate solution evenly, stir / let stand for 0.5 to 3 hours, filter and dry at 80 to 100°C for 12 to 24 hours; (5) Activation treatment: The material obtained in step (4) is put into an activation furnace and activated at 700-800℃ for 0.5-2h in a carbon dioxide atmosphere, and then cooled to room temperature, wherein the heating rate is 10-15℃ / min; (6) Washing and drying treatment: Wash the material obtained in step (5) repeatedly with water until the pH is 5-7, drain the water and then dry it at 80-100℃ for 12-24 hours; (7) Finished product processing: The dried material obtained in step (6) is sieved and packaged by a sieve machine to obtain activated carbon of different mesh sizes.

2. The method for preparing an aldehyde-removing antibacterial activated carbon material according to claim 1, characterized in that: In step (2), the dried raw material is mixed with phosphoric acid at a solid-liquid ratio of 1:10 to 50.

3. The method of claim 1, wherein the method comprises: (a) mixing the activated carbon with the aldehyde-removing agent; (b) drying the mixture; and (c) heating the mixture to obtain the aldehyde-removing antibacterial activated carbon material. In step (4), the concentration of the silver nitrate solution is 0.002 to 0.3 mol / L.

4. The method for preparing an aldehyde-removing and antibacterial activated carbon material according to claim 1, characterized in that: In step (4), the solid-liquid ratio of the material obtained in step (3) to the silver nitrate solution is 1:5 to 50.

5. The method for preparing an aldehyde-removing and antibacterial activated carbon material according to claim 1, characterized in that: In step (5), the flow rate of the carbon dioxide gas is 5 to 20 m 3 / h.

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