Preparation method of formaldehyde-removing antibacterial activated carbon material

Abstract

The invention relates to the technical field of air purification, and discloses a preparation method of an aldehyde-removing 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 finished product processing. The method has the advantages that three-section heating is adopted for carbonization treatment after heating acidification treatment, pore distribution is optimized, and richer micropores, mesopores and macropores are formed. Activating treatment is carried out after silver loading, so that the porosity and the specific surface area of the activated carbon are increased, the adsorption performance of the activated carbon is improved, the physical and chemical characteristics of the activated carbon are improved, the adsorption capacity is improved, and easy saturation is avoided. The formaldehyde-removing and antibacterial effects of the activated carbon are remarkably improved and the service life of the activated carbon is prolonged in an adsorption-catalysis combined manner, and the activated material is washed, dried and processed into a finished product, so that the activated material can be practically applied according to different requirements in real scenes such as indoor scenes and the like.

Description

Technical Field

[0001] The invention relates to the technical field of air purification, and in particular to a method for preparing a formaldehyde-removing and antibacterial activated carbon material. Background Art

[0002] Formaldehyde, also known as formic 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 headaches. 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 malignant tumors such as nasopharyngeal cancer, colon cancer, and brain cancer. In addition, formaldehyde may also cause chromosomal abnormalities and leukemia in newborns, as well as decreased intelligence in adolescents. The main sources of formaldehyde include building materials (such as plywood, core board, medium-density fiberboard, particle board, etc.), furniture, artificial boards, various adhesive coatings (such as coatings with formaldehyde as a preservative), synthetic textiles (such as chemical fiber carpets, curtains, etc.) and smoking.

[0003] With the improvement of airtightness of modern buildings and the widespread use of home decoration materials, indoor air pollution has become increasingly prominent, among which formaldehyde pollution is the most serious, so 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. As an excellent adsorption material, activated carbon is widely used in the field of indoor air purification because of its developed pore structure, large specific surface area, strong adsorption performance and other characteristics.

[0004] The activated carbon produced by the existing process has a good initial effect in removing formaldehyde, but it has problems such as easy saturation and limited adsorption capacity, which makes it impossible to purify formaldehyde efficiently. At the same time, the quality and adsorption effect of activated carbon also significantly affect its antibacterial properties. Therefore, it is of great significance to develop an activated carbon material that can both efficiently remove formaldehyde and effectively resist bacteria. Summary of the invention

[0005] 1. Technical issues to be solved

[0006] In view of the shortcomings of the prior art, the present invention provides a method for preparing formaldehyde-removing and antibacterial activated carbon materials to solve the technical problems of the above-mentioned activated carbon in effectively removing formaldehyde and preventing bacteria, such as easy saturation, limited adsorption capacity, and poor adsorption effect.

[0007] (II) Technical solution

[0008] To achieve the above-mentioned purpose, the present invention provides the following technical solution: a method for preparing an aldehyde-removing and antibacterial activated carbon material, comprising the following steps:

[0009] (1) Raw material preparation: The raw material is crushed by a crusher, and then screened by a screening machine. The screened raw material is washed with water to remove surface impurities, filtered, and placed in a drying oven at 80-100° C. for 12-24 hours to obtain a dry raw material.

[0010] (2) Acidification treatment: Take 65% to 90% by mass phosphoric acid, mix the dry raw material obtained in step (1) with the phosphoric acid, and stir them evenly with an electric stirrer, then 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.

[0011] (3) Carbonization treatment: the material obtained in step (2) is put into a carbonization furnace for staged carbonization treatment at a heating rate of 10 to 15°C / min;

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

[0013] The second stage: the temperature of the carbonization furnace is 500-600℃, and the heat treatment time is 1-2h;

[0014] The 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: the material obtained in step (3) is mixed evenly with a silver nitrate solution, stirred / standing for 0.5 to 3 hours, filtered and then dried at 80 to 100° C. for 12 to 24 hours.

[0016] (5) Activation treatment: The material obtained in step (4) is placed in an activation furnace, activated at 700-800° C. in a carbon dioxide atmosphere for 0.5-2 h, and then cooled to room temperature, wherein the heating rate is 10-15° C. / min.

[0017] (6) Washing and drying: The material obtained in step (5) is repeatedly washed with water until the pH value is 5 to 7, and then dried at 80 to 100° C. for 12 to 24 hours after the water is drained.

[0018] (7) Finished product processing: The dried material obtained in step (6) is passed through a screening machine to screen activated carbon of different mesh sizes and packaged.

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

[0020] Preferably, in step (2), the dry raw material and phosphoric acid are mixed at a solid-liquid ratio of 1:10 to 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-to-liquid ratio of the material obtained in step (3) and the silver nitrate solution is 1:5 to 50.

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

[0024] (III) Beneficial effects

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

[0026] (1) First, at least one of sawdust, fruit shell, coconut shell, etc. is used as a raw material, and a dry raw material is obtained through processes such as crushing, screening, water washing, and drying; then, phosphoric acid is used for acidification treatment to react with the carbonaceous components in the raw material shell to form abundant surface functional groups (such as hydroxyl, carboxyl, etc.), thereby improving the adsorption performance of subsequent activated carbon. The process is carried out under heating conditions, which is more conducive to the depth of the reaction.

[0027] (2) Carrying out carbonization treatment, on the one hand, removes impurities and moisture to improve the purity of activated carbon; on the other hand, causes structural changes and promotes the formation of pores. In the present invention, 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 larger specific surface area, and can greatly improve its adsorption of formaldehyde and bacteria, thereby greatly improving the adsorption capacity of formaldehyde and avoiding easy saturation during use.

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

[0029] (4) Activation treatment after silver loading helps to increase the porosity and specific surface area of ​​activated carbon, improve its adsorption performance and improve its physical and chemical properties. In addition, the process in the present invention is also conducive to the reduction of the silver loaded, because at a high temperature of 700-800°C, carbon dioxide is used as a medium for physical activation, which reacts with carbon atoms on the surface of activated carbon to generate carbon monoxide. This reaction can further promote the formation of pore structure. At the same time, this degree of high temperature can also promote the decomposition of silver nitrate to convert its high-valent silver into elemental silver, accompanied by the formation of nitrogen, oxygen or nitrogen dioxide. The reaction occurs in the atmosphere of mobile phase carbon dioxide gas, so it can prevent elemental silver from being oxidized to a certain extent. It is known that efficient elemental silver can be used as a catalytic active center to activate the surrounding molecular oxygen to form active oxygen. It can not only catalyze the oxidation of formaldehyde into harmless substances such as water and carbon dioxide, but also destroy the proliferation ability of microbial cells, inhibit or kill bacteria, and significantly improve the formaldehyde removal and antibacterial effect of activated carbon and extend its service life through the combination of adsorption and catalysis. Therefore, the activation process and temperature control in the present invention are crucial and have a significant impact on the structural properties of the activated carbon material itself.

[0030] (5) Finally, the activated materials are washed, dried and processed into finished products so that they can be applied indoors or in other real-life scenarios according to different needs. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a schematic diagram of the preparation process of the present invention. DETAILED DESCRIPTION

[0032] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0033] The present invention provides a technical solution, a method for preparing an aldehyde-removing and antibacterial activated carbon material, comprising the following steps:

[0034] (1) Raw material preparation: The raw material is crushed by a crusher, and then screened by a screening machine. The screened raw material is washed with water to remove surface impurities, filtered, and placed in a drying oven at 80-100° C. for 12-24 hours to obtain a dry raw material.

[0035] (2) Acidification treatment: Take 65% to 90% by mass phosphoric acid, mix the dry raw material obtained in step (1) with the phosphoric acid, and stir them evenly with an electric stirrer, then 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.

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

[0037] The first stage: the temperature of the carbonization furnace is 400-500°C, and the heat treatment time is 0.5-1h;

[0038] The second stage: the temperature of the carbonization furnace is 500-600℃, and the heat treatment time is 1-2h;

[0039] The third stage: the temperature of the carbonization furnace is 600-700°C, and the heat treatment time is 0.5-1h.

[0040] (4) Silver loading treatment: the material obtained in step (3) is mixed evenly with a silver nitrate solution, stirred / standing for 0.5 to 3 hours, filtered and then dried at 80 to 100° C. for 12 to 24 hours.

[0041] (5) Activation treatment: The material obtained in step (4) is placed in an activation furnace, activated at 700-800° C. in a carbon dioxide atmosphere for 0.5-2 h, and then cooled to room temperature, wherein the heating rate is 10-15° C. / min.

[0042] (6) Washing and drying: The material obtained in step (5) is repeatedly washed with water until the pH value is 5 to 7, and then dried at 80 to 100° C. for 12 to 24 hours after the water is drained.

[0043] (7) Finished product processing: The dried material obtained in step (6) is passed through a screening machine to screen activated carbon of different mesh sizes and packaged.

[0044] In step (1), the raw material is at least one of sawdust, fruit shell, coconut shell, etc., in step (2), the dry raw material is mixed with phosphoric acid at a solid-to-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-to-liquid ratio of the material obtained in step (3) and the silver nitrate solution is 1:5 to 50, in step (5), the flow rate of the carbon dioxide gas is 5 to 20 m / s. 3 / h.

[0045] Embodiment 1:

[0046] Weigh 10 kg of raw materials such as sawdust, fruit shells, and coconut shells, add the raw materials to a 40°C Bé phosphoric acid solution at a ratio of 1:50, stir and mix, and soak for 4 hours, take out the soaked raw materials, mix them with tetrasilver tetroxide and silver fluoride, stir and mix, and then dry them, and put the silver-loaded raw materials into a processing furnace for staged carbonization to produce molecules with three-stage condensed benzene rings, thereby forming a three-dimensional network carbide on the surface;

[0047] The carbonized raw materials are put into the reactor, heated to 900°C by water vapor, activated for 0.5h, and the activated raw materials are cooled until the temperature drops to 40°C. The raw materials are cleaned and processed to remove external impurities. After the materials are dried, they are cut to increase the adsorption effect of the activated carbon product on formaldehyde.

[0048] Embodiment 2:

[0049] Weigh 10 kg of raw materials such as sawdust, fruit shells, and coconut shells, add the raw materials to a 40°C Bé phosphoric acid solution at a ratio of 1:60, stir and mix, and soak for 3 hours, take out the soaked raw materials, mix with tetrasilver tetroxide and silver fluoride, stir and mix, and then dry, and put the silver-loaded raw materials into a processing furnace for phased carbonization to produce a three-stage condensed benzene ring molecule, thereby forming a three-dimensional network carbide on the surface;

[0050] The carbonized raw materials are put into the reactor, heated to 900°C by water vapor, activated for 0.5h, and the activated raw materials are cooled until the temperature drops to 40°C. The raw materials are cleaned and processed to remove external impurities. After the materials are dried, they are cut to increase the adsorption effect of the activated carbon product on formaldehyde.

[0051] Embodiment 3:

[0052] Weigh 10 kg of raw materials such as sawdust, fruit shells, and coconut shells, add the raw materials to a 40°C Bé phosphoric acid solution at a ratio of 1:70, stir and mix, and soak for 5 hours, take out the soaked raw materials, mix them with tetrasilver tetroxide and silver fluoride, stir and mix, and then dry them, and put the silver-loaded raw materials into a processing furnace for staged carbonization to produce molecules with three-stage condensed benzene rings, thereby forming a three-dimensional network carbide on the surface;

[0053] The carbonized raw materials are put into the reactor, heated to 900°C by water vapor, activated for 0.5h, and the activated raw materials are cooled until the temperature drops to 40°C. The raw materials are cleaned and processed to remove external impurities. After the materials are dried, they are 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 specifically for formaldehyde removal.

[0055]

[0056] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0057] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for preparing an antibacterial activated carbon material, characterized in that: The following steps are involved: (1) Raw material preparation: The raw material is crushed by a crusher, and then sieved by a sieving machine. The sieved raw material is washed with water to remove surface impurities, filtered, and placed in a drying oven at 80-100° C. for 12-24 hours to obtain a dry raw material; (2) Acidification treatment: Take 65% to 90% phosphoric acid by mass, mix the dried raw material obtained in step (1) with the phosphoric acid, and stir them evenly with an electric stirrer, then 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 at a heating rate of 10 to 15°C / min; The first stage: the temperature of the carbonization furnace is 400-500°C, and the heat treatment time is 0.5-1h; The second stage: the temperature of the carbonization furnace is 500-600℃, and the heat treatment time is 1-2h; 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: the material obtained in step (3) is mixed evenly with a silver nitrate solution, stirred / standing for 0.5 to 3 hours, filtered and then dried at 80 to 100° C. for 12 to 24 hours; (5) Activation treatment: the material obtained in step (4) is placed in an activation furnace, activated at 700-800° C. in a carbon dioxide atmosphere for 0.5-2 h, and then cooled to room temperature, wherein the heating rate is 10-15° C. / min; (6) Washing and drying: The material obtained in step (5) is repeatedly washed with water until the pH value reaches 5 to 7, and then dried at 80 to 100° C. for 12 to 24 hours after the water is drained; (7) Finished product processing: The dried material obtained in step (6) is passed through a screening machine to screen activated carbon of different mesh sizes and packaged.

2. The method for preparing a formaldehyde-removing and antibacterial activated carbon material according to claim 1, characterized in that: In step (1), the raw material is at least one of sawdust, fruit shells, and coconut shells.

3. The method for preparing a formaldehyde-removing and antibacterial activated carbon material according to claim 1, characterized in that: In step (2), the dry raw material and phosphoric acid are mixed at a solid-liquid ratio of 1:10 to 50.

4. The method for preparing a formaldehyde-removing and antibacterial activated carbon material according to claim 1, characterized in that: In step (4), the concentration of the silver nitrate solution is 0.002-0.3 mol / L.

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

6. The method for preparing a formaldehyde-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 / s. 3 / h.

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