An aldehyde-removing and odor-suppressing air purifying agent and its preparation method

Abstract

The present invention discloses an air purifier for removing formaldehyde and suppressing odor and a preparation method, which belongs to the field of air purification technology. The purifier includes peanut shell biochar, diatomaceous earth, composite amino acid, metal oxide, and dispersant. The present invention uses discarded peanut shells to prepare porous biochar materials, the surface structure of which is lamellar and fluffy, and the specific surface area is greatly increased, thereby improving the catalytic effect. The acid treatment from low concentration to high concentration can, on the one hand, effectively acidify the impurities in the raw materials, and the fluffy lamellar structure on the surface is more significant. At the same time, its clear pore structure allows the functional groups on it to be exposed. On the other hand, it can effectively graft acidic organic functional groups on the surface and pore structure, change its surface polarity, and greatly improve the chemical adsorption capacity of biochar for formaldehyde. The biochar finally obtained has greatly improved adsorption and catalytic capacity for organic pollutants such as formaldehyde. The purifier of the present invention does not require regeneration, is safe and environmentally friendly, and has potential market application prospects.

Description

Technical Field

[0001] The invention belongs to the technical field of air purification, and particularly relates to an aldehyde-removing and odor-suppressing air purifier and a preparation method thereof. Background Art

[0002] As people's awareness of health and wellness grows, their requirements for indoor living environments are becoming increasingly stringent. The primary sources of indoor pollution are microorganisms and volatile organic compounds (VOCs). Indoor microbial contamination primarily includes common pathogens such as bacteria, fungi, and molds, with the primary hazards of bacterial and viral transmission and cross-infection. Furthermore, the extensive use of artificial wood panels in interior decoration contributes to indoor air pollution. VOCs such as formaldehyde and benzene are highly toxic and irritating to the eyes, mucous membranes, and respiratory tract. Consequently, indoor air purification has become a focus of recent attention.

[0003] Current indoor air purification methods primarily rely on filtration and adsorption. Filtration primarily removes suspended matter from the air, such as dust and smoke. Volatile organic compounds (VOCs) in the air must be removed through adsorption, but adsorption merely transfers the organic matter to the adsorbent, not eliminating it. As the amount of adsorption increases, adsorption performance decreases, eventually reaching saturation and losing its air purification capacity. Photocatalysis can eliminate air pollutants, particularly effectively degrading volatile organic compounds (VOCs). It is a new air purification method developed in recent years. The reaction occurs at room temperature and pressure, degrading organic matter into water and carbon dioxide without causing secondary pollution.

[0004] For example, CN113181767A discloses a capsule-type sustained-release formaldehyde scavenger and its preparation process, which belongs to the field of formaldehyde removal technology. The capsule comprises a sustained-release carrier core and a thin-coated capsule, which is composed of the following raw materials in proportion by mass: 40-70 parts of an activated carbon substrate, 30-60 parts of a titanium dioxide substrate, 5-10 parts of a molding material, 2-20 parts of a sustained-release material, 1-5 parts of a plasticizer, and 0.5-1.5 parts of an anti-adhesive agent. The capsule is a polytetrafluoroethylene breathable and waterproof thin coating, and the preparation process includes matrix preparation, mixing, granulation, preparation of a sustained-release liquid, and coating. By mixing titanium dioxide oxide in the activated carbon matrix and fusing the activated carbon with the molding material and the sustained-release material, the sustained-release capsule can continuously adsorb and purify formaldehyde under photocatalysis, and the surface film can isolate the external water vapor from wetting, thereby improving the sustained-release efficiency and significantly extending the coating placement time, thereby meeting the continuous purification capacity of formaldehyde.

[0005] For another example, CN111514883A discloses a carbon-based catalyst for decomposing indoor formaldehyde at room temperature and its preparation method. The catalyst uses shaped activated carbon as a carrier, utilizes equal volume impregnation to load the catalytic component, and after high-temperature calcination, obtains a formaldehyde elimination catalyst. The carbon-based catalyst of the present invention can efficiently purify formaldehyde at room temperature. The prepared titanium dioxide-containing catalyst has the performance of eliminating formaldehyde by both photocatalysis and catalytic oxidation, combining the adsorption effect of activated carbon, the oxidation effect of manganese oxide, and the photocatalytic effect of titanium dioxide, thereby improving the purification efficiency of formaldehyde. In addition, the preparation process does not use precious metals, has the characteristics of high efficiency and environmental protection, and uses shaped activated carbon to purify formaldehyde, which is convenient for recycling and no secondary pollution.

[0006] However, current biochar-based air purifiers have poor removal effects on low-concentration pollutants and have not been practically applied or promoted. Summary of the Invention

[0007] The present invention aims to solve the problems existing in the prior art and provides a green and efficient air purifier. The present invention uses biochar prepared from discarded peanut shells as the main adsorption material to effectively remove organic pollutants such as formaldehyde, with good purification effect, safety, greenness and environmental protection.

[0008] In order to achieve the above technical objectives, the technical solution adopted by the present invention is:

[0009] A formaldehyde-removing and odor-suppressing air purifier comprises the following raw materials in parts by weight: 50-100 parts of peanut shell biochar, 10-20 parts of diatomaceous earth, 1-5 parts of composite amino acids, 0.5-1.5 parts of metal oxides, and 0.1-0.5 parts of dispersants.

[0010] Preferably, the composite amino acids include glutamic acid, proline and tryptophan, and the mass ratio of the three is (1-1.5): (1.5-3): (2-9).

[0011] Preferably, the mesh size of the diatomaceous earth is 300-500 mesh.

[0012] Preferably, the peanut shell biochar is prepared by activation and modification of waste peanut shells, and the specific preparation method is:

[0013] (1) After washing the discarded peanut shells with deionized water, drying them in an oven at 70-80° C. for 24-48 hours; crushing the dried peanut shells with a crusher, screening them with a 100-120 mesh screen, and storing them;

[0014] (2) Pyrolysis: The peanut shells obtained in step (1) were placed in a tube furnace, nitrogen was first introduced to remove air, the temperature was raised to 200°C at a rate of 5°C / min, the temperature was kept at that temperature for 1 hour, and then the temperature was raised to 600°C for pyrolysis for 2 hours. After the pyrolysis was completed, the tube furnace was naturally cooled to room temperature and the precursor biochar was taken out;

[0015] (3) Surface modification: The precursor biochar obtained in step (2) was placed in a container, and metal salts and sodium oleate solution were added, and finally sulfuric acid solution was added. After mixing evenly, the mixture was placed in a heat-collecting magnetic heating stirrer and stirred at 40°C for 0.5h in a stainless steel reactor. The mixture was placed in a reaction kettle at 320°C for 2h. After the reaction was completed, the mixture was cooled to room temperature, and the solid product was repeatedly washed with distilled water and dried in an oven.

[0016] (4) Acid activation: The solid product obtained in step (3) was sequentially immersed in propionic acid solutions with mass concentrations of 1-2%, 9-10%, and 19-20% at a solid-liquid ratio of 1 g:10 mL for 6 h, and then dried to obtain the final product, peanut shell biochar.

[0017] More preferably, in step (3), the solid-to-liquid ratio of the biochar, metal salt, sodium oleate solution, and sulfuric acid solution is 10 g:2 g:15 mL:15 mL; the metal salt, cobalt chloride, has a concentration of 0.1-0.3 mol / L, and the concentration of the sulfuric acid solution is 3-5 mol / L.

[0018] Preferably, the metal oxides are nano-titanium dioxide and nano-zinc oxide, and the mass ratio of the two is 1:1.

[0019] More preferably, the average particle size of the nano-titanium dioxide and nano-zinc oxide is 5-20 nm.

[0020] Preferably, the dispersant is sodium dodecylbenzenesulfonate or sodium dodecyl sulfate.

[0021] A method for preparing an aldehyde-removing and odor-suppressing air purifier comprises the following steps:

[0022] (1) Preparation of peanut shell biochar;

[0023] (2) Prepare peanut shell biochar, diatomaceous earth, composite amino acid, metal oxide, and dispersant according to weight, mix the raw materials evenly, use a granulator to granulate, the particle size is 0.2-1 mm, and dry at 50-60° C. for 5-15 hours.

[0024] Preferably, in step (2), during granulation, a binder such as starch may be added to assist granulation.

[0025] All raw materials used in the present invention are commercially available.

[0026] Biochar-based materials have long been a popular choice for air purification products due to their environmental friendliness and rich functional groups. However, biochar's inherent poor adsorption and difficulty in recycling often limit its application, particularly its limited ability to adsorb and fix complex pollutants. Furthermore, traditional biochar has limited adsorption efficiency for certain gaseous pollutants, for example, having virtually no effect on microorganisms such as bacteria. Furthermore, its adsorption efficiency for mixed pollutants is lower than for single pollutants, and its cost of use is higher.

[0027] Therefore, the present invention adopts discarded peanut shell to prepare porous biochar material, and after anaerobic pyrolysis prepares biochar precursor, carries out two-step treatment, surface modification and acid activation. Sulfuric acid etching opens the peanut shell biochar pore structure and improves porosity. Subsequently, high-temperature pyrolysis is used to prepare nano-cobalt oxide, which is loaded on the biochar surface to form a surface structure of sheet villi, and the specific surface area is greatly increased, thereby improving the catalytic effect. Secondly, a propionic acid solution with a low concentration to a high concentration is used for activation treatment. In the preparation process of biochar, functional groups such as hydroxyl and lactone groups are filled and blocked by some impurities during the preparation process. Acid treatment from low concentration to high concentration can effectively acidify the impurities in the raw materials on the one hand, and the villi-like sheet structure on the surface is more significant. At the same time, its clear pore structure allows the functional groups on it to be exposed. On the other hand, acidic organic functional groups can be effectively grafted in the surface and pore structure to change its surface polarity, greatly improving the chemical adsorption capacity of biochar to pollutants such as formaldehyde, TVOC, ammonia, and hydrogen sulfide. The biochar finally obtained has a greatly improved adsorption catalytic capacity for various air pollutants.

[0028] The present invention also incorporates a certain amount of diatomaceous earth. Diatomaceous earth has a porous structure and a very large internal surface area, enabling it to absorb tiny particles in the air, such as dust, pollen, formaldehyde, and other harmful gases. The diatomaceous earth's pore structure not only physically absorbs these particles, but also chemically adsorbs harmful gases onto the pore surface. The silanol groups on its surface react with surface active sites to further degrade these harmful gases.

[0029] The invention adds small molecule amino acids and nano metal oxides. The small molecule amino acids can quickly undergo polymerization reaction with formaldehyde, while the nano metal oxides have a lasting catalytic decomposition effect on organic volatiles, further playing a purification role.

[0030] In summary, the beneficial effects of the present invention are:

[0031] The present invention uses peanut shells to prepare highly active biochar, supplemented with diatomaceous earth, small molecule amino acids, metal oxides and other ingredients, which can effectively inhibit bacteria and remove odors, especially for organic pollutants such as formaldehyde. It has a high efficiency in removing organic pollutants, has a long service life, does not require regeneration, is safe and environmentally friendly, and has potential market application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 This is a cross-sectional electron microscope image of peanut shell raw material;

[0033] Figure 2 These are the enlarged surface images of the peanut shell biochar obtained in Example 5 of the present invention and Comparative Examples 2-4, where (A) is Example 5, (B) is Comparative Example 2, (C) is Comparative Example 3, and (D) is Comparative Example 4. DETAILED DESCRIPTION

[0034] The technical solution of the present invention will be further described below with reference to specific embodiments, but is not limited thereto.

[0035] Example 1

[0036] A formaldehyde-removing and odor-suppressing air purifier comprises the following raw materials in parts by weight: 50 parts of peanut shell biochar, 10 parts of diatomaceous earth, 1 part of composite amino acid, 0.5 parts of metal oxide, and 0.1 parts of dispersant.

[0037] The complex amino acids include glutamic acid, proline and tryptophan, with the mass ratio of the three being 1:1.5:2.

[0038] The mesh size of diatomaceous earth is 300-500 mesh.

[0039] Peanut shell biochar is prepared from discarded peanut shells through activation and modification. The specific preparation method is as follows:

[0040] (1) After washing the discarded peanut shells with deionized water, drying them in an oven at 70°C for 24 hours; crushing the dried peanut shells with a crusher, screening them with a 100-120 mesh screen and storing them;

[0041] (2) Pyrolysis: The peanut shells obtained in step (1) were placed in a tube furnace, nitrogen was first introduced to remove air, the temperature was raised to 200°C at a rate of 5°C / min, the temperature was kept at that temperature for 1 hour, and then the temperature was raised to 600°C for pyrolysis for 2 hours. After the pyrolysis was completed, the tube furnace was naturally cooled to room temperature and the precursor biochar was taken out;

[0042] (3) Surface modification: The precursor biochar obtained in step (2) was placed in a container, cobalt chloride and sodium oleate solution were added, and finally sulfuric acid solution was added, wherein the solid-liquid ratio of biochar, metal salt, sodium oleate solution and sulfuric acid solution was 10 g:2 g:15 mL:15 mL; after being mixed evenly, the mixture was placed in a heat-collecting magnetic heating stirrer and stirred at 40 ° C for 0.5 h in a stainless steel reactor, and then placed in a reaction kettle at 320 ° C for 2 h. After the reaction was completed, the mixture was cooled to room temperature, and the solid product was repeatedly washed with distilled water and dried in an oven;

[0043] (4) Acid activation: The solid product obtained in step (3) was sequentially immersed in propionic acid solutions with mass concentrations of 1-2%, 9-10%, and 19-20% at a solid-liquid ratio of 1 g:10 mL for 6 h, and then dried to obtain the final product, peanut shell biochar.

[0044] Step (3) The solid-liquid ratio of biochar, metal salt, sodium oleate solution and sulfuric acid solution is 10g:2g:15mL:15mL; the metal salt is cobalt chloride; the concentration of the sodium oleate solution is 0.1mol / L, and the concentration of the sulfuric acid solution is 3mol / L

[0045] A method for preparing an aldehyde-removing and odor-suppressing air purifier comprises the following steps:

[0046] (1) Preparation of peanut shell biochar;

[0047] (2) Prepare peanut shell biochar, diatomaceous earth, composite amino acid, metal oxide, and sodium dodecylbenzene sulfonate dispersant according to weight, mix the raw materials evenly, use a granulator to add starch to granulate, the particle size is 0.2-1 mm, and dry at 50°C for 5 hours.

[0048] The metal oxides are nano-titanium dioxide and nano-zinc oxide, with an average particle size of 5-20 nm and a mass ratio of 1:1;

[0049] The dispersant is sodium dodecylbenzenesulfonate.

[0050] Example 2

[0051] A formaldehyde-removing and odor-suppressing air purifier comprises the following raw materials in parts by weight: 65 parts of peanut shell biochar, 13 parts of diatomaceous earth, 2 parts of composite amino acids, 0.8 parts of metal oxides, and 0.2 parts of dispersants.

[0052] Complex amino acids include glutamic acid, proline and tryptophan, with a mass ratio of 1.5:2:5.

[0053] The mesh size of diatomaceous earth is 300-500 mesh.

[0054] Peanut shell biochar is prepared from discarded peanut shells through activation and modification. The specific preparation method is as follows:

[0055] (1) After washing the discarded peanut shells with deionized water, drying them in an oven at 75°C for 24 hours; crushing the dried peanut shells with a crusher, screening them with a 100-120 mesh screen, and storing them;

[0056] (2) Pyrolysis: The peanut shells obtained in step (1) were placed in a tube furnace, nitrogen was first introduced to remove air, the temperature was raised to 200°C at a rate of 5°C / min, the temperature was kept at that temperature for 1 hour, and then the temperature was raised to 600°C for pyrolysis for 2 hours. After the pyrolysis was completed, the tube furnace was naturally cooled to room temperature and the precursor biochar was taken out;

[0057] (3) Surface modification: The precursor biochar obtained in step (2) was placed in a container, cobalt chloride and sodium oleate solution were added, and finally sulfuric acid solution was added, wherein the solid-liquid ratio of biochar, metal salt, sodium oleate solution and sulfuric acid solution was 10 g:2 g:15 mL:15 mL; after being mixed evenly, the mixture was placed in a heat-collecting magnetic heating stirrer and stirred at 40 ° C for 0.5 h in a stainless steel reactor, and then placed in a reaction kettle at 320 ° C for 2 h. After the reaction was completed, the mixture was cooled to room temperature, and the solid product was repeatedly washed with distilled water and dried in an oven;

[0058] (4) Acid activation: The solid product obtained in step (3) was sequentially immersed in propionic acid solutions with mass concentrations of 1-2%, 9-10%, and 19-20% at a solid-liquid ratio of 1 g:10 mL for 6 h, and then dried to obtain the final product, peanut shell biochar.

[0059] In step (3), the solid-liquid ratio of the biochar, the metal salt, the sodium oleate solution, and the sulfuric acid solution is 10 g:2 g:15 mL:15 mL; the metal salt is cobalt chloride; the concentration of the sodium oleate solution is 0.2 mol / L, and the concentration of the sulfuric acid solution is 4 mol / L.

[0060] A method for preparing an aldehyde-removing and odor-suppressing air purifier comprises the following steps:

[0061] (1) Preparation of peanut shell biochar;

[0062] (2) Prepare peanut shell biochar, diatomaceous earth, composite amino acid, metal oxide, and sodium lauryl sulfate dispersant according to weight, mix the raw materials evenly, use a granulator to add starch to granulate, the particle size is 0.2-1 mm, and dry at 55°C for 10 hours.

[0063] The metal oxides are nano-titanium dioxide and nano-zinc oxide, with an average particle size of 12nm and a mass ratio of 1:1;

[0064] Preferably, the dispersant is sodium lauryl sulfate.

[0065] Example 3

[0066] A formaldehyde-removing and odor-suppressing air purifier comprises the following raw materials in parts by weight: 80 parts of peanut shell biochar, 15 parts of diatomaceous earth, 3 parts of composite amino acids, 1 part of metal oxide, and 0.3 part of a dispersant.

[0067] Complex amino acids include glutamic acid, proline and tryptophan, with a mass ratio of 1.5:2:5.

[0068] The mesh size of diatomaceous earth is 300-500 mesh.

[0069] Peanut shell biochar is prepared from discarded peanut shells through activation and modification. The specific preparation method is as follows:

[0070] (1) After washing the discarded peanut shells with deionized water, they were dried in an oven at 75°C for 36 hours; the dried peanut shells were crushed by a crusher, sieved with a 110-mesh sieve, and stored;

[0071] (2) Pyrolysis: The peanut shells obtained in step (1) were placed in a tube furnace, nitrogen was first introduced to remove air, the temperature was raised to 200°C at a rate of 5°C / min, the temperature was kept at that temperature for 1 hour, and then the temperature was raised to 600°C for pyrolysis for 2 hours. After the pyrolysis was completed, the tube furnace was naturally cooled to room temperature and the precursor biochar was taken out;

[0072] (3) Surface modification: The precursor biochar obtained in step (2) was placed in a container, cobalt chloride and sodium oleate solution were added, and finally sulfuric acid solution was added, wherein the solid-liquid ratio of biochar, metal salt, sodium oleate solution and sulfuric acid solution was 10 g:2 g:15 mL:15 mL; after being mixed evenly, the mixture was placed in a heat-collecting magnetic heating stirrer and stirred at 40 ° C for 0.5 h in a stainless steel reactor, and then placed in a reaction kettle at 320 ° C for 2 h. After the reaction was completed, the mixture was cooled to room temperature, and the solid product was repeatedly washed with distilled water and dried in an oven;

[0073] (4) Acid activation: The solid product obtained in step (3) was sequentially immersed in propionic acid solutions with mass concentrations of 1-2%, 9-10%, and 19-20% at a solid-liquid ratio of 1 g:10 mL for 6 h, and then dried to obtain the final product, peanut shell biochar.

[0074] A method for preparing an aldehyde-removing and odor-suppressing air purifier comprises the following steps:

[0075] (1) Preparation of peanut shell biochar;

[0076] (2) Prepare peanut shell biochar, diatomaceous earth, composite amino acid, metal oxide, and sodium lauryl sulfate dispersant according to weight, mix the raw materials evenly, use a granulator to add starch to granulate, the particle size is 0.2-1 mm, and dry at 55°C for 10 hours.

[0077] The metal oxides are nano-titanium dioxide and nano-zinc oxide, with an average particle size of 5-20 nm and a mass ratio of 1:1;

[0078] The dispersant is sodium dodecylbenzenesulfonate.

[0079] Example 4

[0080] A formaldehyde-removing and odor-suppressing air purifier comprises the following raw materials in parts by weight: 90 parts of peanut shell biochar, 18 parts of diatomaceous earth, 4 parts of composite amino acids, 1.2 parts of metal oxides, and 0.4 parts of a dispersant.

[0081] Complex amino acids include glutamic acid, proline and tryptophan, with a mass ratio of 1.5:2:4.

[0082] The mesh size of diatomaceous earth is 300-500 mesh.

[0083] Peanut shell biochar is prepared from discarded peanut shells through activation and modification. The specific preparation method is as follows:

[0084] (1) After washing the discarded peanut shells with deionized water, drying them in an oven at 80°C for 36 hours; crushing the dried peanut shells with a crusher, screening them with a 100-120 mesh screen, and storing them;

[0085] (2) Pyrolysis: The peanut shells obtained in step (1) were placed in a tube furnace, nitrogen was first introduced to remove air, the temperature was raised to 200°C at a rate of 5°C / min, the temperature was kept at that temperature for 1 hour, and then the temperature was raised to 600°C for pyrolysis for 2 hours. After the pyrolysis was completed, the tube furnace was naturally cooled to room temperature and the precursor biochar was taken out;

[0086] (3) Surface modification: The precursor biochar obtained in step (2) was placed in a container, cobalt chloride and sodium oleate solution were added, and finally sulfuric acid solution was added, wherein the solid-liquid ratio of biochar, metal salt, sodium oleate solution and sulfuric acid solution was 10 g:2 g:15 mL:15 mL; after being mixed evenly, the mixture was placed in a heat-collecting magnetic heating stirrer and stirred at 40 ° C for 0.5 h in a stainless steel reactor, and then placed in a reaction kettle at 320 ° C for 2 h. After the reaction was completed, the mixture was cooled to room temperature, and the solid product was repeatedly washed with distilled water and dried in an oven;

[0087] (4) Acid activation: The solid product obtained in step (3) was sequentially immersed in propionic acid solutions with mass concentrations of 1-2%, 9-10%, and 19-20% at a solid-liquid ratio of 1 g:10 mL for 6 h, and then dried to obtain the final product, peanut shell biochar.

[0088] In step (3), the solid-liquid ratio of the biochar, the metal salt, the sodium oleate solution, and the sulfuric acid solution is 10 g:2 g:15 mL:15 mL; the metal salt is cobalt chloride; the concentration of the sodium oleate solution is 0.3 mol / L, and the concentration of the sulfuric acid solution is 4 mol / L.

[0089] A method for preparing an aldehyde-removing and odor-suppressing air purifier comprises the following steps:

[0090] (1) Preparation of peanut shell biochar;

[0091] (2) Prepare peanut shell biochar, diatomaceous earth, composite amino acid, metal oxide, and sodium lauryl sulfate dispersant according to weight, mix the raw materials evenly, use a granulator to add starch to granulate, the particle size is 0.2-1 mm, and dry at 60°C for 15 hours.

[0092] The metal oxides are nano-titanium dioxide and nano-zinc oxide, with an average particle size of 5-20 nm and a mass ratio of 1:1;

[0093] The dispersant is sodium lauryl sulfate.

[0094] Example 5

[0095] A formaldehyde-removing and odor-suppressing air purifier comprises the following raw materials in parts by weight: 100 parts of peanut shell biochar, 20 parts of diatomaceous earth, 5 parts of composite amino acids, 1.5 parts of metal oxides, and 0.5 parts of a dispersant.

[0096] Complex amino acids include glutamic acid, proline and tryptophan, with a mass ratio of 1.5:3:9.

[0097] The mesh size of diatomaceous earth is 300-500 mesh.

[0098] Peanut shell biochar is prepared from discarded peanut shells through activation and modification. The specific preparation method is as follows:

[0099] (1) After washing the discarded peanut shells with deionized water, drying them in an oven at 80°C for 48 hours; crushing the dried peanut shells with a crusher, screening them with a 120-mesh sieve, and storing them;

[0100] (2) Pyrolysis: The peanut shells obtained in step (1) were placed in a tube furnace, nitrogen was first introduced to remove air, the temperature was raised to 200°C at a rate of 5°C / min, the temperature was kept at that temperature for 1 hour, and then the temperature was raised to 600°C for pyrolysis for 2 hours. After the pyrolysis was completed, the tube furnace was naturally cooled to room temperature and the precursor biochar was taken out;

[0101] (3) Surface modification: The precursor biochar obtained in step (2) was placed in a container, cobalt chloride and sodium oleate solution were added, and finally sulfuric acid solution was added, wherein the solid-liquid ratio of biochar, metal salt, sodium oleate solution and sulfuric acid solution was 10 g:2 g:15 mL:15 mL; after being mixed evenly, the mixture was placed in a heat-collecting magnetic heating stirrer and stirred at 40 ° C for 0.5 h in a stainless steel reactor, and then placed in a reaction kettle at 320 ° C for 2 h. After the reaction was completed, the mixture was cooled to room temperature, and the solid product was repeatedly washed with distilled water and dried in an oven;

[0102] (4) Acid activation: The solid product obtained in step (3) was sequentially immersed in propionic acid solutions with mass concentrations of 1-2%, 9-10%, and 19-20% at a solid-liquid ratio of 1 g:10 mL for 6 h, and then dried to obtain the final product, peanut shell biochar.

[0103] In step (3), the solid-liquid ratio of the biochar, the metal salt, the sodium oleate solution, and the sulfuric acid solution is 10 g:2 g:15 mL:15 mL; the metal salt is cobalt chloride; the concentration of the sodium oleate solution is 0.3 mol / L, and the concentration of the sulfuric acid solution is 5 mol / L.

[0104] A method for preparing an aldehyde-removing and odor-suppressing air purifier comprises the following steps:

[0105] (1) Preparation of peanut shell biochar;

[0106] (2) Prepare peanut shell biochar, diatomaceous earth, composite amino acid, metal oxide, and sodium dodecylbenzene sulfonate dispersant according to weight, mix the raw materials evenly, use a granulator to add starch to granulate, the particle size is 0.2-1 mm, and dry at 60°C for 15 hours.

[0107] The metal oxides are nano-titanium dioxide and nano-zinc oxide, with an average particle size of 5-20 nm and a mass ratio of 1:1;

[0108] The dispersant is sodium dodecylbenzenesulfonate.

[0109] Comparative Example 1

[0110] A formaldehyde-removing and odor-suppressing air purifier comprises the following raw materials in parts by weight: 100 parts of peanut shell biochar, 20 parts of diatomaceous earth, 5 parts of composite amino acids, 1.5 parts of metal oxides, and 0.5 parts of a dispersant.

[0111] Complex amino acids include glutamic acid, proline and tryptophan, with a mass ratio of 1.5:3:9.

[0112] The mesh size of diatomaceous earth is 300-500 mesh.

[0113] Peanut shell biochar is prepared from discarded peanut shells through activation and modification. The specific preparation method is as follows:

[0114] (1) After washing the discarded peanut shells with deionized water, drying them in an oven at 80°C for 48 hours; crushing the dried peanut shells with a crusher, screening them with a 120-mesh sieve, and storing them;

[0115] (2) Pyrolysis: The peanut shells obtained in step (1) were placed in a tube furnace, nitrogen was first introduced to remove air, the temperature was raised to 200°C at a rate of 5°C / min, the temperature was kept for 1 hour, and then the temperature was raised to 600°C for pyrolysis for 2 hours. After the pyrolysis was completed, the tube furnace was naturally cooled to room temperature and the biochar was taken out.

[0116] A method for preparing an aldehyde-removing and odor-suppressing air purifier comprises the following steps:

[0117] (1) Preparation of peanut shell biochar;

[0118] (2) Prepare peanut shell biochar, diatomaceous earth, composite amino acid, metal oxide, and sodium dodecylbenzene sulfonate dispersant according to weight, mix the raw materials evenly, use a granulator to add starch to granulate, the particle size is 0.2-1 mm, and dry at 60°C for 15 hours.

[0119] The metal oxides are nano-titanium dioxide and nano-zinc oxide, with an average particle size of 5-20 nm and a mass ratio of 1:1;

[0120] The dispersant is sodium dodecylbenzenesulfonate.

[0121] Compared with Example 5, the only difference in this comparative example is that the peanut shell biochar is not subjected to surface modification and acid activation.

[0122] pass Figure 1 It can be seen that the surface of conventional peanut shell biochar presents fine protrusions and the end surface presents a porous structure.

[0123] Comparative Example 2

[0124] Compared with Example 5, the only difference in this comparative example is that the peanut shell biochar is only impregnated with propionic acid with a mass concentration of 1-2% for 18 hours during activation modification.

[0125] Peanut shell biochar is prepared from discarded peanut shells through activation and modification. The specific preparation method is as follows:

[0126] (1) After washing the discarded peanut shells with deionized water, drying them in an oven at 80°C for 48 hours; crushing the dried peanut shells with a crusher, screening them with a 120-mesh sieve, and storing them;

[0127] (2) Pyrolysis: The peanut shells obtained in step (1) were placed in a tube furnace, nitrogen was first introduced to remove air, the temperature was raised to 200°C at a rate of 5°C / min, the temperature was kept at that temperature for 1 hour, and then the temperature was raised to 600°C for pyrolysis for 2 hours. After the pyrolysis was completed, the tube furnace was naturally cooled to room temperature and the precursor biochar was taken out;

[0128] (3) Surface modification: The precursor biochar obtained in step (2) was placed in a container, cobalt chloride and sodium oleate solution were added, and finally sulfuric acid solution was added, wherein the solid-liquid ratio of biochar, metal salt, sodium oleate solution and sulfuric acid solution was 10 g:2 g:15 mL:15 mL; after being mixed evenly, the mixture was placed in a heat-collecting magnetic heating stirrer and stirred at 40 ° C for 0.5 h in a stainless steel reactor, and then placed in a reaction kettle at 320 ° C for 2 h. After the reaction was completed, the mixture was cooled to room temperature, and the solid product was repeatedly washed with distilled water and dried in an oven;

[0129] (4) Acid activation: The solid product obtained in step (3) was immersed in a propionic acid solution with a mass concentration of 1-2% at a solid-liquid ratio of 1 g:10 mL for 18 h. After the immersion was completed, the mixture was dried to obtain the final product, peanut shell biochar.

[0130] Comparative Example 3

[0131] Compared with Example 5, the only difference in this comparative example is that the peanut shell biochar was only impregnated with propionic acid with a mass concentration of 9-10% for 18 hours during activation modification.

[0132] Peanut shell biochar is prepared from discarded peanut shells through activation and modification. The specific preparation method is as follows:

[0133] (1) After washing the discarded peanut shells with deionized water, drying them in an oven at 80°C for 48 hours; crushing the dried peanut shells with a crusher, screening them with a 120-mesh sieve, and storing them;

[0134] (2) Pyrolysis: The peanut shells obtained in step (1) were placed in a tube furnace, nitrogen was first introduced to remove air, the temperature was raised to 200°C at a rate of 5°C / min, the temperature was kept at that temperature for 1 hour, and then the temperature was raised to 600°C for pyrolysis for 2 hours. After the pyrolysis was completed, the tube furnace was naturally cooled to room temperature and the precursor biochar was taken out;

[0135] (3) Surface modification: The precursor biochar obtained in step (2) was placed in a container, cobalt chloride and sodium oleate solution were added, and finally sulfuric acid solution was added, wherein the solid-liquid ratio of biochar, metal salt, sodium oleate solution and sulfuric acid solution was 10 g:2 g:15 mL:15 mL; after being mixed evenly, the mixture was placed in a heat-collecting magnetic heating stirrer and stirred at 40 ° C for 0.5 h in a stainless steel reactor, and then placed in a reaction kettle at 320 ° C for 2 h. After the reaction was completed, the mixture was cooled to room temperature, and the solid product was repeatedly washed with distilled water and dried in an oven;

[0136] (4) Acid activation: The solid product obtained in step (3) was immersed in a propionic acid solution with a mass concentration of 9-10% at a solid-liquid ratio of 1 g:10 mL for 18 h. After the immersion was completed, the mixture was dried to obtain the final product, peanut shell biochar.

[0137] Comparative Example 4

[0138] Compared with Example 5, the only difference in this comparative example is that the peanut shell biochar was only impregnated with propionic acid with a mass concentration of 19-20% for 18 hours during activation modification.

[0139] Peanut shell biochar is prepared from discarded peanut shells through activation and modification. The specific preparation method is as follows:

[0140] (1) After washing the discarded peanut shells with deionized water, drying them in an oven at 80°C for 48 hours; crushing the dried peanut shells with a crusher, screening them with a 120-mesh sieve, and storing them;

[0141] (2) Pyrolysis: The peanut shells obtained in step (1) were placed in a tube furnace, nitrogen was first introduced to remove air, the temperature was raised to 200°C at a rate of 5°C / min, the temperature was kept at that temperature for 1 hour, and then the temperature was raised to 600°C for pyrolysis for 2 hours. After the pyrolysis was completed, the tube furnace was naturally cooled to room temperature and the precursor biochar was taken out;

[0142] (3) Surface modification: The precursor biochar obtained in step (2) was placed in a container, cobalt chloride and sodium oleate solution were added, and finally sulfuric acid solution was added, wherein the solid-liquid ratio of biochar, metal salt, sodium oleate solution and sulfuric acid solution was 10 g:2 g:15 mL:15 mL; after being mixed evenly, the mixture was placed in a heat-collecting magnetic heating stirrer and stirred at 40 ° C for 0.5 h in a stainless steel reactor, and then placed in a reaction kettle at 320 ° C for 2 h. After the reaction was completed, the mixture was cooled to room temperature, and the solid product was repeatedly washed with distilled water and dried in an oven;

[0143] (4) Acid activation: The solid product obtained in step (3) was immersed in a propionic acid solution with a mass concentration of 19-20% at a solid-liquid ratio of 1 g:10 mL for 18 h. After the immersion was completed, the mixture was dried to obtain the final product, peanut shell biochar.

[0144] Performance Testing

[0145] Structural characterization: The micromorphology of the samples was characterized and analyzed using a Hitachi HITACHI SU5000 field emission scanning electron microscope (SEM).

[0146] from Figure 2 The enlarged images of the surfaces of Example 5 and Comparative Examples 2-3 show that after surface treatment, the peanut shell biochar presents a clear porous villi structure on the surface of Example 5 due to the deposition and acidification modification of metal cobalt, while in Comparative Examples 2-3, the single concentration treatment method effectively opens the pore structure on the biochar surface, the modification effect is weakened, and the porous villi structure is not clear enough.

[0147] Purification capacity test:

[0148] Test case 1 is in the simulation test chamber (30m 3), the test chamber temperature is controlled at 23±2℃, and the relative humidity is 50±10%. Formaldehyde and other gases are detected in accordance with QB / T 2761-2006 "Determination of purification effect of indoor air purification products" and GB / T 18883-2022 "Indoor air quality standard". Use a micro syringe to inject formaldehyde into the injection port of the test chamber, and the initial formaldehyde concentration in the test chamber. The formaldehyde removal and odor suppression purifiers of the embodiment and the comparative example are respectively placed in the corresponding test chambers, and the formaldehyde removal and odor suppression purifiers are placed in the corresponding test chambers at a rate of 100g / m 2 The formaldehyde purification efficiency and formaldehyde concentration after 12 hours were measured. Each group was repeated three times, and the results were averaged. A blank control was set up, that is, no air purification product was added. The data are shown in Table 1.

[0149] Determination of formaldehyde: The gas concentration was tested using a GT-2000 multifunctional composite gas analyzer (Shenzhen Kerno Electronic Technology Co., Ltd.).

[0150] Table 1. Formaldehyde purification efficiency

[0151]

[0152]

[0153] Table 1 shows the purification effect of the formaldehyde removal and odor suppression purifier on formaldehyde. After 12 hours of use, the purification effect of the purifier on formaldehyde can meet the relevant standards. In contrast, in Comparative Example 1, which changed the composition of biochar, the adsorption capacity of ordinary peanut shell biochar was limited, and in Comparative Examples 2-4, which changed the treatment method, the modification effect of peanut shell biochar decreased, resulting in a weakening of the ability to adsorb and remove formaldehyde. This shows that the surface and pore structure of the peanut shell biochar obtained after modification and acid activation treatment of peanut shells are effectively improved, and the specific surface area is greatly increased. Figure 2 The surface structure of Example 5 also shows a more distinct and prominent surface pore structure. Furthermore, the gradient concentration treatment effectively grafts acidic organic functional groups onto the biochar surface, altering its surface polarity and significantly enhancing the biochar's chemical adsorption capacity for formaldehyde, enabling the present formaldehyde removal and odor control purifier to more thoroughly adsorb formaldehyde.

[0154] Further testing of the purification and deodorization effects of the examples and comparative samples on ammonia and hydrogen sulfide was conducted with reference to the "Determination of Purification Effect of Indoor Air Purification Products" QB / T 2761-2006. The test results are shown in Table 2:

[0155] Table 2 Deodorization effect test on ammonia and hydrogen sulfide

[0156]

[0157]

[0158] From the data in the table, we can see that the purifiers in Examples 1-5 of the present invention have a good purification effect on typical odorous gases, while the effects of the comparative examples are weakened to varying degrees.

[0159] The purification effect of the purifier of the present invention on TVOC pollutants was further tested with reference to the "Method for Determining the Purification Effect of Indoor Air Purification Products" QB / T 2761-2006. The test data are shown in Table 3.

[0160] Table 3. TVOC purification efficiency %

[0161] Use formaldehyde removal and odor control agent for 24h (%) Use formaldehyde removal and odor control agent for 120h (%) Example 1 91.2 85.2 Example 2 90.5 84.1 Example 3 90.6 83.6 Example 4 88.5 81.1 Example 5 87.7 80.9 Comparative Example 1 54.7 47.3 Comparative Example 2 76.2 68.9 Comparative Example 3 77.4 71.5 Comparative Example 4 79.1 74.8

[0162] As shown in Table 3, the total volatile organic compounds (TVOC) purification efficiency of Example 1 of the present invention reached 91.2%. After 120 hours of continuous purification testing and analysis, it can be seen that the formaldehyde removal and odor suppression purifier of the present invention still has a TVOC purification efficiency of over 85%. This shows that the present invention is also highly efficient in purifying indoor volatile organic compounds.

[0163] It should be noted that the above embodiments are only some of the preferred embodiments of the present invention, and not all of them. Obviously, based on the above embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work should fall within the scope of protection of the present invention.

Claims

1. A formaldehyde-removing and odor-suppressing air purifier, characterized in that: The raw materials include the following parts by weight: 50-100 parts of peanut shell biochar, 10-20 parts of diatomaceous earth, 1-5 parts of composite amino acids, 0.5-1.5 parts of metal oxides, and 0.1-0.5 parts of dispersants. The peanut shell biochar is prepared by activation and modification of waste peanut shells. The specific preparation method is as follows: (1) After washing the discarded peanut shells with deionized water, drying them in an oven at 70-80° C. for 24-48 hours; crushing the dried peanut shells with a crusher, screening them with a 100-120 mesh screen, and storing them; (2) Pyrolysis: The peanut shells obtained in step (1) were placed in a tube furnace, nitrogen was first introduced to remove air, the temperature was raised to 200°C at a rate of 5°C / min, the temperature was kept at that temperature for 1 hour, and then the temperature was raised to 600°C for pyrolysis for 2 hours. After the pyrolysis was completed, the tube furnace was naturally cooled to room temperature and the precursor biochar was taken out; (3) Surface modification: The precursor biochar obtained in step (2) was placed in a container, and metal salts and sodium oleate solution were added, and finally sulfuric acid solution was added. After mixing evenly, the mixture was placed in a heat-collecting magnetic heating stirrer and stirred at 40°C for 0.5h. The mixture was placed in a stainless steel reactor and reacted at 320°C for 2h. After the reaction was completed, the mixture was cooled to room temperature, and the solid product was repeatedly washed with distilled water and dried in an oven. (4) Acid activation: The solid product obtained in step (3) was sequentially immersed in propionic acid solutions with mass concentrations of 1-2%, 9-10%, and 19-20% at a solid-liquid ratio of 1 g:10 mL for 6 h, and then dried to obtain the final product, peanut shell biochar; In step (3), the solid-liquid ratio of the biochar, the metal salt, the sodium oleate solution, and the sulfuric acid solution is 10 g:2 g:15 mL:15 mL; the metal salt is cobalt chloride; the concentration of the sodium oleate solution is 0.1-0.3 mol / L, and the concentration of the sulfuric acid solution is 3-5 mol / L.

2. The formaldehyde-removing and odor-suppressing air purifier according to claim 1, characterized in that: The complex amino acids include glutamic acid, proline and tryptophan, and the mass ratio of the three is (1-1.5): (1.5-3): (2-9).

3. The formaldehyde-removing and odor-suppressing air purifier according to claim 1, characterized in that: The mesh size of the diatomaceous earth is 300-500 meshes.

4. The formaldehyde-removing and odor-suppressing air purifier according to claim 1, characterized in that: The metal oxides are nano titanium dioxide and nano zinc oxide, and the mass ratio of the two is 1:

1.

5. The formaldehyde-removing and odor-suppressing air purifier according to claim 4, characterized in that: The average particle size of the nano titanium dioxide and nano zinc oxide is 5-20 nm.

6. The formaldehyde-removing and odor-suppressing air purifier according to claim 1, characterized in that: The dispersant is sodium dodecylbenzenesulfonate or sodium dodecyl sulfate.

7. A method for preparing the formaldehyde-removing and odor-suppressing air purifier according to any one of claims 1 to 6, characterized in that: The method comprises the following preparation steps: (1) Preparation of peanut shell biochar; (2) Prepare peanut shell biochar, diatomaceous earth, composite amino acid, metal oxide, and dispersant by weight, mix the raw materials evenly, use a granulator to granulate the particles to a particle size of 0.2-1 mm, and dry at 50-60°C for 5-15 hours.

Images